diff options
Diffstat (limited to 'modsign-20120510.patch')
| -rw-r--r-- | modsign-20120510.patch | 8096 |
1 files changed, 8096 insertions, 0 deletions
diff --git a/modsign-20120510.patch b/modsign-20120510.patch new file mode 100644 index 000000000..d9aabf83a --- /dev/null +++ b/modsign-20120510.patch @@ -0,0 +1,8096 @@ +From d093caa39460495390c94556f0680218223168c2 Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Fri, 4 May 2012 15:55:49 +0100 +Subject: [PATCH 01/36] MPILIB: Export some more symbols + +Export some more symbols for use by the DSA key subtype. + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + lib/mpi/mpi-cmp.c | 2 ++ + lib/mpi/mpi-div.c | 1 + + lib/mpi/mpi-inv.c | 1 + + lib/mpi/mpi-mpow.c | 1 + + lib/mpi/mpi-mul.c | 1 + + 5 files changed, 6 insertions(+) + +diff --git a/lib/mpi/mpi-cmp.c b/lib/mpi/mpi-cmp.c +index 914bc42..1871e7b 100644 +--- a/lib/mpi/mpi-cmp.c ++++ b/lib/mpi/mpi-cmp.c +@@ -39,6 +39,7 @@ int mpi_cmp_ui(MPI u, unsigned long v) + else + return -1; + } ++EXPORT_SYMBOL_GPL(mpi_cmp_ui); + + int mpi_cmp(MPI u, MPI v) + { +@@ -66,3 +67,4 @@ int mpi_cmp(MPI u, MPI v) + return 1; + return -1; + } ++EXPORT_SYMBOL_GPL(mpi_cmp); +diff --git a/lib/mpi/mpi-div.c b/lib/mpi/mpi-div.c +index f68cbbb..fed3405 100644 +--- a/lib/mpi/mpi-div.c ++++ b/lib/mpi/mpi-div.c +@@ -59,6 +59,7 @@ nomem: + mpi_free(temp_divisor); + return rc; + } ++EXPORT_SYMBOL_GPL(mpi_fdiv_r); + + /**************** + * Division rounding the quotient towards -infinity. +diff --git a/lib/mpi/mpi-inv.c b/lib/mpi/mpi-inv.c +index 0951f98..bfc5ca1 100644 +--- a/lib/mpi/mpi-inv.c ++++ b/lib/mpi/mpi-inv.c +@@ -185,3 +185,4 @@ cleanup: + mpi_free(v); + return rc; + } ++EXPORT_SYMBOL_GPL(mpi_invm); +diff --git a/lib/mpi/mpi-mpow.c b/lib/mpi/mpi-mpow.c +index 7328d0d..b8b22e5 100644 +--- a/lib/mpi/mpi-mpow.c ++++ b/lib/mpi/mpi-mpow.c +@@ -132,3 +132,4 @@ nomem: + err_out: + return rc; + } ++EXPORT_SYMBOL_GPL(mpi_mulpowm); +diff --git a/lib/mpi/mpi-mul.c b/lib/mpi/mpi-mul.c +index 1f3219e..3d514b9 100644 +--- a/lib/mpi/mpi-mul.c ++++ b/lib/mpi/mpi-mul.c +@@ -192,3 +192,4 @@ int mpi_mulm(MPI w, MPI u, MPI v, MPI m) + return -ENOMEM; + return mpi_fdiv_r(w, w, m); + } ++EXPORT_SYMBOL_GPL(mpi_mulm); +-- +1.7.10.2 + + +From 335abcad2d9fa26198c8e99bae2bb9b3185dce22 Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Fri, 4 May 2012 15:55:50 +0100 +Subject: [PATCH 02/36] KEYS: Move the key config into security/keys/Kconfig + +Move the key config into security/keys/Kconfig as there are going to be a lot +of key-related options. + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + security/Kconfig | 68 +--------------------------------------------- + security/keys/Kconfig | 71 +++++++++++++++++++++++++++++++++++++++++++++++++ + 2 files changed, 72 insertions(+), 67 deletions(-) + create mode 100644 security/keys/Kconfig + +diff --git a/security/Kconfig b/security/Kconfig +index ccc61f8..e9c6ac7 100644 +--- a/security/Kconfig ++++ b/security/Kconfig +@@ -4,73 +4,7 @@ + + menu "Security options" + +-config KEYS +- bool "Enable access key retention support" +- help +- This option provides support for retaining authentication tokens and +- access keys in the kernel. +- +- It also includes provision of methods by which such keys might be +- associated with a process so that network filesystems, encryption +- support and the like can find them. +- +- Furthermore, a special type of key is available that acts as keyring: +- a searchable sequence of keys. Each process is equipped with access +- to five standard keyrings: UID-specific, GID-specific, session, +- process and thread. +- +- If you are unsure as to whether this is required, answer N. +- +-config TRUSTED_KEYS +- tristate "TRUSTED KEYS" +- depends on KEYS && TCG_TPM +- select CRYPTO +- select CRYPTO_HMAC +- select CRYPTO_SHA1 +- help +- This option provides support for creating, sealing, and unsealing +- keys in the kernel. Trusted keys are random number symmetric keys, +- generated and RSA-sealed by the TPM. The TPM only unseals the keys, +- if the boot PCRs and other criteria match. Userspace will only ever +- see encrypted blobs. +- +- If you are unsure as to whether this is required, answer N. +- +-config ENCRYPTED_KEYS +- tristate "ENCRYPTED KEYS" +- depends on KEYS +- select CRYPTO +- select CRYPTO_HMAC +- select CRYPTO_AES +- select CRYPTO_CBC +- select CRYPTO_SHA256 +- select CRYPTO_RNG +- help +- This option provides support for create/encrypting/decrypting keys +- in the kernel. Encrypted keys are kernel generated random numbers, +- which are encrypted/decrypted with a 'master' symmetric key. The +- 'master' key can be either a trusted-key or user-key type. +- Userspace only ever sees/stores encrypted blobs. +- +- If you are unsure as to whether this is required, answer N. +- +-config KEYS_DEBUG_PROC_KEYS +- bool "Enable the /proc/keys file by which keys may be viewed" +- depends on KEYS +- help +- This option turns on support for the /proc/keys file - through which +- can be listed all the keys on the system that are viewable by the +- reading process. +- +- The only keys included in the list are those that grant View +- permission to the reading process whether or not it possesses them. +- Note that LSM security checks are still performed, and may further +- filter out keys that the current process is not authorised to view. +- +- Only key attributes are listed here; key payloads are not included in +- the resulting table. +- +- If you are unsure as to whether this is required, answer N. ++source security/keys/Kconfig + + config SECURITY_DMESG_RESTRICT + bool "Restrict unprivileged access to the kernel syslog" +diff --git a/security/keys/Kconfig b/security/keys/Kconfig +new file mode 100644 +index 0000000..a90d6d3 +--- /dev/null ++++ b/security/keys/Kconfig +@@ -0,0 +1,71 @@ ++# ++# Key management configuration ++# ++ ++config KEYS ++ bool "Enable access key retention support" ++ help ++ This option provides support for retaining authentication tokens and ++ access keys in the kernel. ++ ++ It also includes provision of methods by which such keys might be ++ associated with a process so that network filesystems, encryption ++ support and the like can find them. ++ ++ Furthermore, a special type of key is available that acts as keyring: ++ a searchable sequence of keys. Each process is equipped with access ++ to five standard keyrings: UID-specific, GID-specific, session, ++ process and thread. ++ ++ If you are unsure as to whether this is required, answer N. ++ ++config TRUSTED_KEYS ++ tristate "TRUSTED KEYS" ++ depends on KEYS && TCG_TPM ++ select CRYPTO ++ select CRYPTO_HMAC ++ select CRYPTO_SHA1 ++ help ++ This option provides support for creating, sealing, and unsealing ++ keys in the kernel. Trusted keys are random number symmetric keys, ++ generated and RSA-sealed by the TPM. The TPM only unseals the keys, ++ if the boot PCRs and other criteria match. Userspace will only ever ++ see encrypted blobs. ++ ++ If you are unsure as to whether this is required, answer N. ++ ++config ENCRYPTED_KEYS ++ tristate "ENCRYPTED KEYS" ++ depends on KEYS ++ select CRYPTO ++ select CRYPTO_HMAC ++ select CRYPTO_AES ++ select CRYPTO_CBC ++ select CRYPTO_SHA256 ++ select CRYPTO_RNG ++ help ++ This option provides support for create/encrypting/decrypting keys ++ in the kernel. Encrypted keys are kernel generated random numbers, ++ which are encrypted/decrypted with a 'master' symmetric key. The ++ 'master' key can be either a trusted-key or user-key type. ++ Userspace only ever sees/stores encrypted blobs. ++ ++ If you are unsure as to whether this is required, answer N. ++ ++config KEYS_DEBUG_PROC_KEYS ++ bool "Enable the /proc/keys file by which keys may be viewed" ++ depends on KEYS ++ help ++ This option turns on support for the /proc/keys file - through which ++ can be listed all the keys on the system that are viewable by the ++ reading process. ++ ++ The only keys included in the list are those that grant View ++ permission to the reading process whether or not it possesses them. ++ Note that LSM security checks are still performed, and may further ++ filter out keys that the current process is not authorised to view. ++ ++ Only key attributes are listed here; key payloads are not included in ++ the resulting table. ++ ++ If you are unsure as to whether this is required, answer N. +-- +1.7.10.2 + + +From 6569015cb5801f36324c76dee156a3e880fcf9be Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Fri, 4 May 2012 15:55:50 +0100 +Subject: [PATCH 03/36] KEYS: Announce key type (un)registration + +Announce the (un)registration of a key type in the core key code rather than +in the callers. + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + net/dns_resolver/dns_key.c | 5 ----- + security/keys/key.c | 3 +++ + 2 files changed, 3 insertions(+), 5 deletions(-) + +diff --git a/net/dns_resolver/dns_key.c b/net/dns_resolver/dns_key.c +index c73bba3..14b2c3d 100644 +--- a/net/dns_resolver/dns_key.c ++++ b/net/dns_resolver/dns_key.c +@@ -249,9 +249,6 @@ static int __init init_dns_resolver(void) + struct key *keyring; + int ret; + +- printk(KERN_NOTICE "Registering the %s key type\n", +- key_type_dns_resolver.name); +- + /* create an override credential set with a special thread keyring in + * which DNS requests are cached + * +@@ -301,8 +298,6 @@ static void __exit exit_dns_resolver(void) + key_revoke(dns_resolver_cache->thread_keyring); + unregister_key_type(&key_type_dns_resolver); + put_cred(dns_resolver_cache); +- printk(KERN_NOTICE "Unregistered %s key type\n", +- key_type_dns_resolver.name); + } + + module_init(init_dns_resolver) +diff --git a/security/keys/key.c b/security/keys/key.c +index 06783cf..dc62894 100644 +--- a/security/keys/key.c ++++ b/security/keys/key.c +@@ -980,6 +980,8 @@ int register_key_type(struct key_type *ktype) + + /* store the type */ + list_add(&ktype->link, &key_types_list); ++ ++ pr_notice("Key type %s registered\n", ktype->name); + ret = 0; + + out: +@@ -1002,6 +1004,7 @@ void unregister_key_type(struct key_type *ktype) + list_del_init(&ktype->link); + downgrade_write(&key_types_sem); + key_gc_keytype(ktype); ++ pr_notice("Key type %s unregistered\n", ktype->name); + up_read(&key_types_sem); + } + EXPORT_SYMBOL(unregister_key_type); +-- +1.7.10.2 + + +From 13628af46a92a030fdb7dc33976b46cfcc4b3f31 Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Fri, 4 May 2012 15:55:51 +0100 +Subject: [PATCH 04/36] KEYS: Reorganise keys Makefile + +Reorganise the keys directory Makefile to put all the core bits together and +the type-specific bits after. + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + security/keys/Makefile | 12 +++++++++--- + 1 file changed, 9 insertions(+), 3 deletions(-) + +diff --git a/security/keys/Makefile b/security/keys/Makefile +index a56f1ff..504aaa0 100644 +--- a/security/keys/Makefile ++++ b/security/keys/Makefile +@@ -2,6 +2,9 @@ + # Makefile for key management + # + ++# ++# Core ++# + obj-y := \ + gc.o \ + key.o \ +@@ -12,9 +15,12 @@ obj-y := \ + request_key.o \ + request_key_auth.o \ + user_defined.o +- +-obj-$(CONFIG_TRUSTED_KEYS) += trusted.o +-obj-$(CONFIG_ENCRYPTED_KEYS) += encrypted-keys/ + obj-$(CONFIG_KEYS_COMPAT) += compat.o + obj-$(CONFIG_PROC_FS) += proc.o + obj-$(CONFIG_SYSCTL) += sysctl.o ++ ++# ++# Key types ++# ++obj-$(CONFIG_TRUSTED_KEYS) += trusted.o ++obj-$(CONFIG_ENCRYPTED_KEYS) += encrypted-keys/ +-- +1.7.10.2 + + +From 8c5366bc5c1c9ecaa1104d769f60c7b83ed342a9 Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Fri, 4 May 2012 16:15:09 +0100 +Subject: [PATCH 05/36] KEYS: Create a key type that can be used for general + cryptographic operations + +Create a key type that can be used for general cryptographic operations, such +as encryption, decryption, signature generation and signature verification. + +The key type is "crypto" and can provide access to a variety of cryptographic +algorithms. + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + Documentation/security/keys-crypto.txt | 181 +++++++++++++++++++++++++ + include/keys/crypto-subtype.h | 56 ++++++++ + include/keys/crypto-type.h | 25 ++++ + security/keys/Kconfig | 2 + + security/keys/Makefile | 1 + + security/keys/crypto/Kconfig | 7 + + security/keys/crypto/Makefile | 7 + + security/keys/crypto/crypto_keys.h | 28 ++++ + security/keys/crypto/crypto_type.c | 228 ++++++++++++++++++++++++++++++++ + 9 files changed, 535 insertions(+) + create mode 100644 Documentation/security/keys-crypto.txt + create mode 100644 include/keys/crypto-subtype.h + create mode 100644 include/keys/crypto-type.h + create mode 100644 security/keys/crypto/Kconfig + create mode 100644 security/keys/crypto/Makefile + create mode 100644 security/keys/crypto/crypto_keys.h + create mode 100644 security/keys/crypto/crypto_type.c + +diff --git a/Documentation/security/keys-crypto.txt b/Documentation/security/keys-crypto.txt +new file mode 100644 +index 0000000..97dee80 +--- /dev/null ++++ b/Documentation/security/keys-crypto.txt +@@ -0,0 +1,181 @@ ++ ====================== ++ CRYPTOGRAPHIC KEY TYPE ++ ====================== ++ ++Contents: ++ ++ - Overview. ++ - Key identification. ++ - Accessing crypto keys. ++ - Implementing crypto parsers. ++ - Implementing crypto subtypes. ++ ++ ++======== ++OVERVIEW ++======== ++ ++The "crypto" key type is designed to be a container for cryptographic keys, ++without imposing any particular restrictions on the form of the cryptography or ++the key. ++ ++The crypto key is given a subtype that defines what sort of data is associated ++with the key and provides operations to describe and destroy it. However, no ++requirement is made that the key data actually be loaded into the key. ++ ++The crypto key also has a number of data parsers registered with it. The data ++parsers are responsible for extracing information the blobs of data passed to ++the instantiator function. The first data parser that recognises the blob gets ++to set the subtype of the key and define the operations that can be done on ++that key. ++ ++Completely in-kernel key retention and operation subtypes and parsers can be ++defined, but it would also be possible to provide access to cryptographic ++hardware (such as a TPM) that might be used to both retain the relevant key and ++perform operations using that key. In such a case, the crypto key would then ++merely be an interface to the TPM driver. ++ ++ ++================== ++KEY IDENTIFICATION ++================== ++ ++Because the identity of a key is not necessarily known and may not be easily ++calculated when a crypto key is allocated, it may not be a simple matter to set ++a key description to something that's useful for determining whether this is ++the key you're looking for. Furthermore, it may be necessary to perform a ++partial match upon the key identity. ++ ++To help with this, when a key is loaded, the parser calculates the key ++fingerprint and stores a copy in the key structure. ++ ++The crypto key type's key matching function then performs more checks than just ++the straightforward comparison of the description with the criterion string: ++ ++ (1) If the criterion string is of the form "id:<hexdigits>" then the match ++ function will examine a key's fingerprint to see if the hex digits given ++ after the "id:" match the tail. For instance: ++ ++ keyctl search @s crypto id:5acc2142 ++ ++ will match a key with fingerprint: ++ ++ 1A00 2040 7601 7889 DE11 882C 3823 04AD 5ACC 2142 ++ ++ (2) If the criterion string is of the form "<subtype>:<hexdigits>" then the ++ match will match the ID as in (1), but with the added restriction that ++ only keys of the specified subtype (e.g. dsa or rsa) will be matched. For ++ instance: ++ ++ keyctl search @s crypto dsa:5acc2142 ++ ++Looking in /proc/keys, the last 8 hex digits of the key fingerprint are ++displayed, along with the subtype: ++ ++ 1a39e171 I----- 1 perm 3f010000 0 0 crypto modsign.0: DSA 5acc2142 [] ++ ++ ++===================== ++ACCESSING CRYPTO KEYS ++===================== ++ ++To access crypto keys from within the kernel, the following inclusion is ++required: ++ ++ #include <keys/crypto-type.h> ++ ++This gives access to the key type: ++ ++ struct key_type key_type_crypto; ++ ++ ++=========================== ++IMPLEMENTING CRYPTO PARSERS ++=========================== ++ ++The crypto key type keeps a list of registered data parsers. An example of ++such a parser is one that parses OpenPGP packet formatted data [RFC 4880]. ++ ++During key instantiation each parser in the list is tried until one doesn't ++return -EBADMSG. ++ ++The parser definition structure looks like the following: ++ ++ struct crypto_key_parser { ++ struct module *owner; ++ const char *name; ++ ++ int (*instantiate)(struct key *key, ++ const void *data, size_t datalen); ++ }; ++ ++The owner and name fields should be set to the owning module and the name of ++the parser. ++ ++There are a number of operations defined by the parser. They are all optional, ++but it is expected that at least one will be defined. ++ ++ (1) instantiate(). ++ ++ The arguments are the same as for the instantiate function in the key ++ type. 'key' is the crypto key being instantiated; data and datalen are ++ the instantiation data, presumably containing cryptographic key data, and ++ the length of that data. ++ ++ If the data format is not recognised, -EBADMSG should be returned. If it ++ is recognised, but the key cannot for some reason be set up, some other ++ negative error code should be returned. ++ ++ If the key can be successfully set up, then key->payload should be set to ++ point to the retained data, key->type_data.p[0] should be set to point to ++ the subtype chosen and key->type_data.p[1] should be set to point to a ++ copy of the key's identity string and 0 should be returned. ++ ++ The key's identity string may be partially matched upon. For a public-key ++ algorithm such as RSA and DSA this will likely be a printable hex version ++ of the key's fingerprint. ++ ++Functions are provided to register and unregister parsers: ++ ++ int register_crypto_key_parser(struct crypto_key_parser *parser); ++ void unregister_crypto_key_parser(struct crypto_key_parser *subtype); ++ ++Parsers may not have the same name. The names are only used for displaying in ++debugging messages. ++ ++ ++============================ ++IMPLEMENTING CRYPTO SUBTYPES ++============================ ++ ++The parser selects the appropriate subtype directly and sets it on the key; the ++crypto key then retains a reference on the subtype module (which means the ++parser can be removed thereafter). ++ ++The subtype definition structure looks like the following: ++ ++ struct crypto_key_subtype { ++ struct module *owner; ++ const char *name; ++ ++ void (*describe)(const struct key *key, struct seq_file *m); ++ void (*destroy)(void *payload); ++ }; ++ ++The owner and name fields should be set to the owning module and the name of ++the subtype. ++ ++There are a number of operations defined by the subtype: ++ ++ (1) describe(). ++ ++ Mandatory. This allows the subtype to display something in /proc/keys ++ against the key. For instance the name of the public key algorithm type ++ could be displayed. The key type will display the tail of the key ++ identity string after this. ++ ++ (2) destroy(). ++ ++ Mandatory. This should free the memory associated with the key. The ++ crypto key will look after freeing the fingerprint and releasing the ++ reference on the subtype module. +diff --git a/include/keys/crypto-subtype.h b/include/keys/crypto-subtype.h +new file mode 100644 +index 0000000..fa87555 +--- /dev/null ++++ b/include/keys/crypto-subtype.h +@@ -0,0 +1,56 @@ ++/* Cryptographic key subtype ++ * ++ * Copyright (C) 2011 Red Hat, Inc. All Rights Reserved. ++ * Written by David Howells (dhowells@redhat.com) ++ * ++ * This program is free software; you can redistribute it and/or ++ * modify it under the terms of the GNU General Public Licence ++ * as published by the Free Software Foundation; either version ++ * 2 of the Licence, or (at your option) any later version. ++ * ++ * See Documentation/security/keys-crypto.txt ++ */ ++ ++#ifndef _KEYS_CRYPTO_SUBTYPE_H ++#define _KEYS_CRYPTO_SUBTYPE_H ++ ++#include <linux/seq_file.h> ++#include <keys/crypto-type.h> ++ ++extern struct key_type key_type_crypto; ++ ++/* ++ * Keys of this type declare a subtype that indicates the handlers and ++ * capabilities. ++ */ ++struct crypto_key_subtype { ++ struct module *owner; ++ const char *name; ++ unsigned short name_len; /* length of name */ ++ ++ void (*describe)(const struct key *key, struct seq_file *m); ++ ++ void (*destroy)(void *payload); ++}; ++ ++/* ++ * Data parser. Called during instantiation and signature verification ++ * initiation. ++ */ ++struct crypto_key_parser { ++ struct list_head link; ++ struct module *owner; ++ const char *name; ++ ++ /* Attempt to instantiate a key from the data blob passed to add_key() ++ * or keyctl_instantiate(). ++ * ++ * Return EBADMSG if not recognised. ++ */ ++ int (*instantiate)(struct key *key, const void *data, size_t datalen); ++}; ++ ++extern int register_crypto_key_parser(struct crypto_key_parser *); ++extern void unregister_crypto_key_parser(struct crypto_key_parser *); ++ ++#endif /* _KEYS_CRYPTO_SUBTYPE_H */ +diff --git a/include/keys/crypto-type.h b/include/keys/crypto-type.h +new file mode 100644 +index 0000000..47c00c7 +--- /dev/null ++++ b/include/keys/crypto-type.h +@@ -0,0 +1,25 @@ ++/* Cryptographic key type interface ++ * ++ * Copyright (C) 2011 Red Hat, Inc. All Rights Reserved. ++ * Written by David Howells (dhowells@redhat.com) ++ * ++ * This program is free software; you can redistribute it and/or ++ * modify it under the terms of the GNU General Public Licence ++ * as published by the Free Software Foundation; either version ++ * 2 of the Licence, or (at your option) any later version. ++ * ++ * See Documentation/security/keys-crypto.txt ++ */ ++ ++#ifndef _KEYS_CRYPTO_TYPE_H ++#define _KEYS_CRYPTO_TYPE_H ++ ++#include <linux/key-type.h> ++ ++extern struct key_type key_type_crypto; ++ ++/* ++ * The payload is at the discretion of the subtype. ++ */ ++ ++#endif /* _KEYS_CRYPTO_TYPE_H */ +diff --git a/security/keys/Kconfig b/security/keys/Kconfig +index a90d6d3..992fe52 100644 +--- a/security/keys/Kconfig ++++ b/security/keys/Kconfig +@@ -69,3 +69,5 @@ config KEYS_DEBUG_PROC_KEYS + the resulting table. + + If you are unsure as to whether this is required, answer N. ++ ++source security/keys/crypto/Kconfig +diff --git a/security/keys/Makefile b/security/keys/Makefile +index 504aaa0..67dae73 100644 +--- a/security/keys/Makefile ++++ b/security/keys/Makefile +@@ -24,3 +24,4 @@ obj-$(CONFIG_SYSCTL) += sysctl.o + # + obj-$(CONFIG_TRUSTED_KEYS) += trusted.o + obj-$(CONFIG_ENCRYPTED_KEYS) += encrypted-keys/ ++obj-$(CONFIG_CRYPTO_KEY_TYPE) += crypto/ +diff --git a/security/keys/crypto/Kconfig b/security/keys/crypto/Kconfig +new file mode 100644 +index 0000000..3d15710 +--- /dev/null ++++ b/security/keys/crypto/Kconfig +@@ -0,0 +1,7 @@ ++config CRYPTO_KEY_TYPE ++ tristate "Cryptographic key type" ++ depends on KEYS ++ help ++ This option provides support for a type of key that holds the keys ++ required for cryptographic operations such as encryption, decryption, ++ signature generation and signature verification. +diff --git a/security/keys/crypto/Makefile b/security/keys/crypto/Makefile +new file mode 100644 +index 0000000..36db1d5 +--- /dev/null ++++ b/security/keys/crypto/Makefile +@@ -0,0 +1,7 @@ ++# ++# Makefile for cryptographic keys ++# ++ ++obj-$(CONFIG_CRYPTO_KEY_TYPE) += crypto_keys.o ++ ++crypto_keys-y := crypto_type.o +diff --git a/security/keys/crypto/crypto_keys.h b/security/keys/crypto/crypto_keys.h +new file mode 100644 +index 0000000..a339ce0 +--- /dev/null ++++ b/security/keys/crypto/crypto_keys.h +@@ -0,0 +1,28 @@ ++/* Internal crypto type stuff ++ * ++ * Copyright (C) 2011 Red Hat, Inc. All Rights Reserved. ++ * Written by David Howells (dhowells@redhat.com) ++ * ++ * This program is free software; you can redistribute it and/or ++ * modify it under the terms of the GNU General Public Licence ++ * as published by the Free Software Foundation; either version ++ * 2 of the Licence, or (at your option) any later version. ++ */ ++ ++static inline ++struct crypto_key_subtype *crypto_key_subtype(const struct key *key) ++{ ++ return key->type_data.p[0]; ++} ++ ++static inline char *crypto_key_id(const struct key *key) ++{ ++ return key->type_data.p[1]; ++} ++ ++ ++/* ++ * crypto_type.c ++ */ ++extern struct list_head crypto_key_parsers; ++extern struct rw_semaphore crypto_key_parsers_sem; +diff --git a/security/keys/crypto/crypto_type.c b/security/keys/crypto/crypto_type.c +new file mode 100644 +index 0000000..33d279b +--- /dev/null ++++ b/security/keys/crypto/crypto_type.c +@@ -0,0 +1,228 @@ ++/* Cryptographic key type ++ * ++ * Copyright (C) 2011 Red Hat, Inc. All Rights Reserved. ++ * Written by David Howells (dhowells@redhat.com) ++ * ++ * This program is free software; you can redistribute it and/or ++ * modify it under the terms of the GNU General Public Licence ++ * as published by the Free Software Foundation; either version ++ * 2 of the Licence, or (at your option) any later version. ++ * ++ * See Documentation/security/keys-crypto.txt ++ */ ++#include <keys/crypto-subtype.h> ++#include <linux/seq_file.h> ++#include <linux/module.h> ++#include <linux/slab.h> ++#include "crypto_keys.h" ++ ++MODULE_LICENSE("GPL"); ++ ++LIST_HEAD(crypto_key_parsers); ++DECLARE_RWSEM(crypto_key_parsers_sem); ++ ++/* ++ * Match crypto_keys on (part of) their name ++ * We have some shorthand methods for matching keys. We allow: ++ * ++ * "<desc>" - request a key by description ++ * "id:<id>" - request a key matching the ID ++ * "<subtype>:<id>" - request a key of a subtype ++ */ ++static int crypto_key_match(const struct key *key, const void *description) ++{ ++ const struct crypto_key_subtype *subtype = crypto_key_subtype(key); ++ const char *spec = description; ++ const char *id, *kid; ++ ptrdiff_t speclen; ++ size_t idlen, kidlen; ++ ++ if (!subtype || !spec || !*spec) ++ return 0; ++ ++ /* See if the full key description matches as is */ ++ if (key->description && strcmp(key->description, description) == 0) ++ return 1; ++ ++ /* All tests from here on break the criterion description into a ++ * specifier, a colon and then an identifier. ++ */ ++ id = strchr(spec, ':'); ++ if (!id) ++ return 0; ++ ++ speclen = id - spec; ++ id++; ++ ++ /* Anything after here requires a partial match on the ID string */ ++ kid = crypto_key_id(key); ++ if (!kid) ++ return 0; ++ ++ idlen = strlen(id); ++ kidlen = strlen(kid); ++ if (idlen > kidlen) ++ return 0; ++ ++ kid += kidlen - idlen; ++ if (strcasecmp(id, kid) != 0) ++ return 0; ++ ++ if (speclen == 2 && ++ memcmp(spec, "id", 2) == 0) ++ return 1; ++ ++ if (speclen == subtype->name_len && ++ memcmp(spec, subtype->name, speclen) == 0) ++ return 1; ++ ++ return 0; ++} ++ ++/* ++ * Describe the crypto key ++ */ ++static void crypto_key_describe(const struct key *key, struct seq_file *m) ++{ ++ const struct crypto_key_subtype *subtype = crypto_key_subtype(key); ++ const char *kid = crypto_key_id(key); ++ size_t n; ++ ++ seq_puts(m, key->description); ++ ++ if (subtype) { ++ seq_puts(m, ": "); ++ subtype->describe(key, m); ++ ++ if (kid) { ++ seq_putc(m, ' '); ++ n = strlen(kid); ++ if (n <= 8) ++ seq_puts(m, kid); ++ else ++ seq_puts(m, kid + n - 8); ++ } ++ ++ seq_puts(m, " ["); ++ /* put something here to indicate the key's capabilities */ ++ seq_putc(m, ']'); ++ } ++} ++ ++/* ++ * Instantiate a crypto_key defined key ++ */ ++static int crypto_key_instantiate(struct key *key, ++ const void *data, size_t datalen) ++{ ++ struct crypto_key_parser *parser; ++ int ret; ++ ++ pr_devel("==>%s()\n", __func__); ++ ++ if (datalen == 0) ++ return -EINVAL; ++ ++ down_read(&crypto_key_parsers_sem); ++ ++ ret = -EBADMSG; ++ list_for_each_entry(parser, &crypto_key_parsers, link) { ++ pr_debug("Trying parser '%s'\n", parser->name); ++ ++ ret = parser->instantiate(key, data, datalen); ++ if (ret != -EBADMSG) { ++ pr_debug("Parser recognised the format (ret %d)\n", ++ ret); ++ break; ++ } ++ } ++ ++ up_read(&crypto_key_parsers_sem); ++ pr_devel("<==%s() = %d\n", __func__, ret); ++ return ret; ++} ++ ++/* ++ * dispose of the data dangling from the corpse of a crypto key ++ */ ++static void crypto_key_destroy(struct key *key) ++{ ++ struct crypto_key_subtype *subtype = crypto_key_subtype(key); ++ if (subtype) { ++ subtype->destroy(key->payload.data); ++ module_put(subtype->owner); ++ key->type_data.p[0] = NULL; ++ } ++ kfree(key->type_data.p[1]); ++ key->type_data.p[1] = NULL; ++} ++ ++struct key_type key_type_crypto = { ++ .name = "crypto", ++ .instantiate = crypto_key_instantiate, ++ .match = crypto_key_match, ++ .destroy = crypto_key_destroy, ++ .describe = crypto_key_describe, ++}; ++EXPORT_SYMBOL_GPL(key_type_crypto); ++ ++/** ++ * register_crypto_key_parser - Register a crypto key blob parser ++ * @parser: The parser to register ++ */ ++int register_crypto_key_parser(struct crypto_key_parser *parser) ++{ ++ struct crypto_key_parser *cursor; ++ int ret; ++ ++ down_write(&crypto_key_parsers_sem); ++ ++ list_for_each_entry(cursor, &crypto_key_parsers, link) { ++ if (strcmp(cursor->name, parser->name) == 0) { ++ pr_err("Crypto key parser '%s' already registered\n", ++ parser->name); ++ ret = -EEXIST; ++ goto out; ++ } ++ } ++ ++ list_add_tail(&parser->link, &crypto_key_parsers); ++ ++ pr_notice("Crypto key parser '%s' registered\n", parser->name); ++ ret = 0; ++ ++out: ++ up_write(&crypto_key_parsers_sem); ++ return ret; ++} ++EXPORT_SYMBOL_GPL(register_crypto_key_parser); ++ ++/** ++ * unregister_crypto_key_parser - Unregister a crypto key blob parser ++ * @parser: The parser to unregister ++ */ ++void unregister_crypto_key_parser(struct crypto_key_parser *parser) ++{ ++ down_write(&crypto_key_parsers_sem); ++ list_del(&parser->link); ++ up_write(&crypto_key_parsers_sem); ++ ++ pr_notice("Crypto key parser '%s' unregistered\n", parser->name); ++} ++EXPORT_SYMBOL_GPL(unregister_crypto_key_parser); ++ ++/* ++ * Module stuff ++ */ ++static int __init crypto_key_init(void) ++{ ++ return register_key_type(&key_type_crypto); ++} ++ ++static void __exit crypto_key_cleanup(void) ++{ ++ unregister_key_type(&key_type_crypto); ++} ++ ++module_init(crypto_key_init); ++module_exit(crypto_key_cleanup); +-- +1.7.10.2 + + +From e8d4b12988cd23815f1a5f4654d819f5a0a2194b Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Fri, 4 May 2012 16:15:57 +0100 +Subject: [PATCH 06/36] KEYS: Add signature verification facility + +Add a facility whereby a key subtype may be asked to verify a signature against +the data it is purported to have signed. + +This adds four routines: + + (1) struct crypto_key_verify_context * + verify_sig_begin(struct key *keyring, const void *sig, size_t siglen); + + This sets up a verification context for the given signature using + information in that signature to select a key from the specified keyring + and to request a hash algorithm from the crypto layer. + + (2) int verify_sig_add_data(struct crypto_key_verify_context *ctx, + const void *data, size_t datalen); + + Incrementally supply data to be signed. May be called multiple times. + + (3) int verify_sig_end(struct crypto_key_verify_context *ctx, + const void *sig, size_t siglen); + + Complete the verification process and return the result. -EKEYREJECTED + will indicate that the verification failed and 0 will indicate success. + Other errors are also possible. + + (4) void verify_sig_cancel(struct crypto_key_verify_context *ctx); + + Cancel the verification process. + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + Documentation/security/keys-crypto.txt | 101 +++++++++++++++++++++++++++++ + include/keys/crypto-subtype.h | 21 ++++++ + include/keys/crypto-type.h | 9 +++ + security/keys/crypto/Makefile | 2 +- + security/keys/crypto/crypto_verify.c | 111 ++++++++++++++++++++++++++++++++ + 5 files changed, 243 insertions(+), 1 deletion(-) + create mode 100644 security/keys/crypto/crypto_verify.c + +diff --git a/Documentation/security/keys-crypto.txt b/Documentation/security/keys-crypto.txt +index 97dee80..a964717 100644 +--- a/Documentation/security/keys-crypto.txt ++++ b/Documentation/security/keys-crypto.txt +@@ -7,6 +7,7 @@ Contents: + - Overview. + - Key identification. + - Accessing crypto keys. ++ - Signature verification. + - Implementing crypto parsers. + - Implementing crypto subtypes. + +@@ -89,6 +90,65 @@ This gives access to the key type: + struct key_type key_type_crypto; + + ++SIGNATURE VERIFICATION ++---------------------- ++ ++The four operations that can perform cryptographic signature verification, ++using one of a set of keys to provide the public key: ++ ++ (1) Begin verification procedure. ++ ++ struct crypto_key_verify_context * ++ verify_sig_begin(struct key *keyring, const void *sig, size_t siglen); ++ ++ This function sets up a verification context from the information in the ++ signature and looks for a suitable key in the keyring. The signature blob ++ must be presented again at the end of the procedure. The keys will be ++ checked against parameters in the signature, and if the matching one is ++ not found then -ENOKEY will be returned. ++ ++ The hashing algorithm, if such a thing applies, will be determined from ++ information in the signature and the appropriate crypto module will be ++ used. -ENOPKG will be returned if the hash algorithm is unavailable. ++ ++ The return value is an opaque pointer to be passed to the other functions, ++ or a negative error code. ++ ++ (2) Indicate data to be verified. ++ ++ int verify_sig_add_data(struct crypto_key_verify_context *ctx, ++ const void *data, size_t datalen); ++ ++ This function is used to shovel data to the verification procedure so that ++ it can load it into the hash, pass it to hardware or whatever is ++ appropriate for the algorithm being employed. ++ ++ The data is not canonicalised for the document type specified in the ++ signature. The caller must do that. ++ ++ It will return 0 if successful and a negative error code if not. ++ ++ (3) Complete the verification process. ++ ++ int verify_sig_end(struct crypto_key_verify_context *ctx, ++ const void *sig, size_t siglen); ++ ++ This function performs the actual signature verification step and cleans ++ up the resources allocated at the beginning. The signature must be ++ presented again as some of the data therein may need to be added to the ++ internal hash. ++ ++ It will return -EKEYREJECTED if the signature didn't match, 0 if ++ successful and may return other errors as appropriate. ++ ++ (4) Cancel the verification process. ++ ++ void verify_sig_cancel(struct crypto_key_verify_context *ctx); ++ ++ This function cleans up the resources allocated at the beginning. This is ++ not necessary if verify_sig_end() was called. ++ ++ + =========================== + IMPLEMENTING CRYPTO PARSERS + =========================== +@@ -96,6 +156,7 @@ IMPLEMENTING CRYPTO PARSERS + The crypto key type keeps a list of registered data parsers. An example of + such a parser is one that parses OpenPGP packet formatted data [RFC 4880]. + ++ + During key instantiation each parser in the list is tried until one doesn't + return -EBADMSG. + +@@ -107,6 +168,8 @@ The parser definition structure looks like the following: + + int (*instantiate)(struct key *key, + const void *data, size_t datalen); ++ struct crypto_key_verify_context *(*verify_sig_begin)( ++ struct key *keyring, const u8 *sig, size_t siglen); + }; + + The owner and name fields should be set to the owning module and the name of +@@ -135,6 +198,44 @@ but it is expected that at least one will be defined. + algorithm such as RSA and DSA this will likely be a printable hex version + of the key's fingerprint. + ++ (2) verify_sig_begin(). ++ ++ This is similar in concept to the instantiate() function, except that it ++ is given a signature blob to parse rather than a key data blob. ++ ++ If the data format is not recognised, -EBADMSG should be returned. If it ++ is recognised, but the signature verification process cannot for some ++ reason be set up, some other negative error code should be returned. ++ -ENOKEY should be used to indicate that no matching key is available and ++ -ENOPKG should be returned if the hash algorithm or the verification ++ algorithm are unavailable. ++ ++ If successful, the parser should allocate a verification context and embed ++ the following struct in it: ++ ++ struct crypto_key_verify_context { ++ struct key *key; ++ int (*add_data)(struct crypto_key_verify_context *ctx, ++ const void *data, size_t datalen); ++ int (*end)(struct crypto_key_verify_context *ctx, ++ const u8 *sig, size_t siglen); ++ void (*cancel)(struct crypto_key_verify_context *ctx); ++ }; ++ ++ and return a pointer to this to the caller, who will then pass it to the ++ verification operation wrappers described in the "Signature Verification" ++ section. The three operation pointers here correspond exactly to those ++ wrappers and are all mandatory. container_of() should be used to retrieve ++ the actual context. ++ ++ Note that the crypto key type retains a reference on the parser module for ++ the lifetime of this context, though the operation pointers need not point ++ into this module. ++ ++ The parser should also record a pointer to the key selected and take a ++ reference on that key with key_get(). ++ ++ + Functions are provided to register and unregister parsers: + + int register_crypto_key_parser(struct crypto_key_parser *parser); +diff --git a/include/keys/crypto-subtype.h b/include/keys/crypto-subtype.h +index fa87555..f2b927a 100644 +--- a/include/keys/crypto-subtype.h ++++ b/include/keys/crypto-subtype.h +@@ -20,6 +20,20 @@ + extern struct key_type key_type_crypto; + + /* ++ * Context base for signature verification methods. Allocated by the subtype ++ * and presumably embedded in something appropriate. ++ */ ++struct crypto_key_verify_context { ++ struct key *key; ++ struct crypto_key_parser *parser; ++ int (*add_data)(struct crypto_key_verify_context *ctx, ++ const void *data, size_t datalen); ++ int (*end)(struct crypto_key_verify_context *ctx, ++ const u8 *sig, size_t siglen); ++ void (*cancel)(struct crypto_key_verify_context *ctx); ++}; ++ ++/* + * Keys of this type declare a subtype that indicates the handlers and + * capabilities. + */ +@@ -48,6 +62,13 @@ struct crypto_key_parser { + * Return EBADMSG if not recognised. + */ + int (*instantiate)(struct key *key, const void *data, size_t datalen); ++ ++ /* Attempt to recognise a signature blob and find a matching key. ++ * ++ * Return EBADMSG if not recognised. ++ */ ++ struct crypto_key_verify_context *(*verify_sig_begin)( ++ struct key *keyring, const u8 *sig, size_t siglen); + }; + + extern int register_crypto_key_parser(struct crypto_key_parser *); +diff --git a/include/keys/crypto-type.h b/include/keys/crypto-type.h +index 47c00c7..6b93366 100644 +--- a/include/keys/crypto-type.h ++++ b/include/keys/crypto-type.h +@@ -18,6 +18,15 @@ + + extern struct key_type key_type_crypto; + ++struct crypto_key_verify_context; ++extern struct crypto_key_verify_context *verify_sig_begin( ++ struct key *key, const void *sig, size_t siglen); ++extern int verify_sig_add_data(struct crypto_key_verify_context *ctx, ++ const void *data, size_t datalen); ++extern int verify_sig_end(struct crypto_key_verify_context *ctx, ++ const void *sig, size_t siglen); ++extern void verify_sig_cancel(struct crypto_key_verify_context *ctx); ++ + /* + * The payload is at the discretion of the subtype. + */ +diff --git a/security/keys/crypto/Makefile b/security/keys/crypto/Makefile +index 36db1d5..67001bc 100644 +--- a/security/keys/crypto/Makefile ++++ b/security/keys/crypto/Makefile +@@ -4,4 +4,4 @@ + + obj-$(CONFIG_CRYPTO_KEY_TYPE) += crypto_keys.o + +-crypto_keys-y := crypto_type.o ++crypto_keys-y := crypto_type.o crypto_verify.o +diff --git a/security/keys/crypto/crypto_verify.c b/security/keys/crypto/crypto_verify.c +new file mode 100644 +index 0000000..65f734c +--- /dev/null ++++ b/security/keys/crypto/crypto_verify.c +@@ -0,0 +1,111 @@ ++/* Signature verification with a crypto key ++ * ++ * Copyright (C) 2011 Red Hat, Inc. All Rights Reserved. ++ * Written by David Howells (dhowells@redhat.com) ++ * ++ * This program is free software; you can redistribute it and/or ++ * modify it under the terms of the GNU General Public Licence ++ * as published by the Free Software Foundation; either version ++ * 2 of the Licence, or (at your option) any later version. ++ * ++ * See Documentation/security/keys-crypto.txt ++ */ ++ ++#include <keys/crypto-subtype.h> ++#include <linux/module.h> ++#include "crypto_keys.h" ++ ++/** ++ * verify_sig_begin - Initiate the use of a crypto key to verify a signature ++ * @keyring: The public keys to verify against ++ * @sig: The signature data ++ * @siglen: The signature length ++ * ++ * Returns a context or an error. ++ */ ++struct crypto_key_verify_context *verify_sig_begin( ++ struct key *keyring, const void *sig, size_t siglen) ++{ ++ struct crypto_key_verify_context *ret; ++ struct crypto_key_parser *parser; ++ ++ pr_devel("==>%s()\n", __func__); ++ ++ if (siglen == 0 || !sig) ++ return ERR_PTR(-EINVAL); ++ ++ down_read(&crypto_key_parsers_sem); ++ ++ ret = ERR_PTR(-EBADMSG); ++ list_for_each_entry(parser, &crypto_key_parsers, link) { ++ if (parser->verify_sig_begin) { ++ if (!try_module_get(parser->owner)) ++ continue; ++ ++ pr_debug("Trying parser '%s'\n", parser->name); ++ ++ ret = parser->verify_sig_begin(keyring, sig, siglen); ++ if (IS_ERR(ret)) ++ module_put(parser->owner); ++ else ++ ret->parser = parser; ++ if (ret != ERR_PTR(-EBADMSG)) { ++ pr_debug("Parser recognised the format" ++ " (ret %ld)\n", ++ PTR_ERR(ret)); ++ break; ++ } ++ } ++ } ++ ++ up_read(&crypto_key_parsers_sem); ++ pr_devel("<==%s() = %p\n", __func__, ret); ++ return ret; ++} ++EXPORT_SYMBOL_GPL(verify_sig_begin); ++ ++/** ++ * verify_sig_add_data - Incrementally provide data to be verified ++ * @ctx: The context from verify_sig_begin() ++ * @data: Data ++ * @datalen: The amount of @data ++ * ++ * This may be called multiple times. ++ */ ++int verify_sig_add_data(struct crypto_key_verify_context *ctx, ++ const void *data, size_t datalen) ++{ ++ return ctx->add_data(ctx, data, datalen); ++} ++EXPORT_SYMBOL_GPL(verify_sig_add_data); ++ ++/** ++ * verify_sig_end - Finalise signature verification and return result ++ * @ctx: The context from verify_sig_begin() ++ * @sig: The signature data ++ * @siglen: The signature length ++ */ ++int verify_sig_end(struct crypto_key_verify_context *ctx, ++ const void *sig, size_t siglen) ++{ ++ struct crypto_key_parser *parser = ctx->parser; ++ int ret; ++ ++ ret = ctx->end(ctx, sig, siglen); ++ module_put(parser->owner); ++ return ret; ++} ++EXPORT_SYMBOL_GPL(verify_sig_end); ++ ++/** ++ * verify_sig_end - Cancel signature verification ++ * @ctx: The context from verify_sig_begin() ++ */ ++void verify_sig_cancel(struct crypto_key_verify_context *ctx) ++{ ++ struct crypto_key_parser *parser = ctx->parser; ++ ++ ctx->cancel(ctx); ++ module_put(parser->owner); ++} ++EXPORT_SYMBOL_GPL(verify_sig_cancel); +-- +1.7.10.2 + + +From db170ec4f4df7d8f188134c9c9a3e2736ec0dbff Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Fri, 4 May 2012 16:16:46 +0100 +Subject: [PATCH 07/36] KEYS: Asymmetric public-key algorithm crypto key + subtype + +Add a subtype for supporting asymmetric public-key encryption algorithms such +as DSA (FIPS-186) and RSA (PKCS#1 / RFC1337). + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + security/keys/crypto/Kconfig | 10 ++++ + security/keys/crypto/Makefile | 3 +- + security/keys/crypto/public_key.c | 55 +++++++++++++++++++ + security/keys/crypto/public_key.h | 106 +++++++++++++++++++++++++++++++++++++ + 4 files changed, 173 insertions(+), 1 deletion(-) + create mode 100644 security/keys/crypto/public_key.c + create mode 100644 security/keys/crypto/public_key.h + +diff --git a/security/keys/crypto/Kconfig b/security/keys/crypto/Kconfig +index 3d15710..5f2b8ac 100644 +--- a/security/keys/crypto/Kconfig ++++ b/security/keys/crypto/Kconfig +@@ -5,3 +5,13 @@ config CRYPTO_KEY_TYPE + This option provides support for a type of key that holds the keys + required for cryptographic operations such as encryption, decryption, + signature generation and signature verification. ++ ++config CRYPTO_KEY_PUBLIC_KEY_SUBTYPE ++ tristate "Asymmetric public-key crypto algorithm subtype" ++ depends on CRYPTO_KEY_TYPE ++ select MPILIB ++ help ++ This option provides support for asymmetric public key type handling. ++ If signature generation and/or verification are to be used, ++ appropriate hash algorithms (such as SHA-1) must be available. ++ ENOPKG will be reported if the requisite algorithm is unavailable. +diff --git a/security/keys/crypto/Makefile b/security/keys/crypto/Makefile +index 67001bc..6384306 100644 +--- a/security/keys/crypto/Makefile ++++ b/security/keys/crypto/Makefile +@@ -3,5 +3,6 @@ + # + + obj-$(CONFIG_CRYPTO_KEY_TYPE) += crypto_keys.o +- + crypto_keys-y := crypto_type.o crypto_verify.o ++ ++obj-$(CONFIG_CRYPTO_KEY_PUBLIC_KEY_SUBTYPE) += public_key.o +diff --git a/security/keys/crypto/public_key.c b/security/keys/crypto/public_key.c +new file mode 100644 +index 0000000..c00ddac +--- /dev/null ++++ b/security/keys/crypto/public_key.c +@@ -0,0 +1,55 @@ ++/* Asymmetric public key crypto subtype ++ * ++ * Copyright (C) 2011 Red Hat, Inc. All Rights Reserved. ++ * Written by David Howells (dhowells@redhat.com) ++ * ++ * This program is free software; you can redistribute it and/or ++ * modify it under the terms of the GNU General Public Licence ++ * as published by the Free Software Foundation; either version ++ * 2 of the Licence, or (at your option) any later version. ++ */ ++ ++#define pr_fmt(fmt) "PKEY: "fmt ++#include <linux/module.h> ++#include <linux/kernel.h> ++#include "public_key.h" ++ ++MODULE_LICENSE("GPL"); ++ ++/* ++ * Provide a part of a description of the key for /proc/keys. ++ */ ++static void public_key_describe(const struct key *crypto_key, ++ struct seq_file *m) ++{ ++ struct public_key *key = crypto_key->payload.data; ++ ++ if (key) ++ seq_puts(m, key->algo->name); ++} ++ ++/* ++ * Destroy a public key algorithm key ++ */ ++static void public_key_destroy(void *payload) ++{ ++ struct public_key *key = payload; ++ int i; ++ ++ if (key) { ++ for (i = 0; i < ARRAY_SIZE(key->mpi); i++) ++ mpi_free(key->mpi[i]); ++ kfree(key); ++ } ++} ++ ++/* ++ * Public key algorithm crypto key subtype ++ */ ++struct crypto_key_subtype public_key_crypto_key_subtype = { ++ .owner = THIS_MODULE, ++ .name = "public_key", ++ .describe = public_key_describe, ++ .destroy = public_key_destroy, ++}; ++EXPORT_SYMBOL_GPL(public_key_crypto_key_subtype); +diff --git a/security/keys/crypto/public_key.h b/security/keys/crypto/public_key.h +new file mode 100644 +index 0000000..81ed603 +--- /dev/null ++++ b/security/keys/crypto/public_key.h +@@ -0,0 +1,106 @@ ++/* Asymmetric public-key algorithm definitions ++ * ++ * Copyright (C) 2011 Red Hat, Inc. All Rights Reserved. ++ * Written by David Howells (dhowells@redhat.com) ++ * ++ * This program is free software; you can redistribute it and/or ++ * modify it under the terms of the GNU General Public Licence ++ * as published by the Free Software Foundation; either version ++ * 2 of the Licence, or (at your option) any later version. ++ */ ++ ++#ifndef _LINUX_PUBLIC_KEY_H ++#define _LINUX_PUBLIC_KEY_H ++ ++#include <linux/mpi.h> ++#include <crypto/hash.h> ++#include <keys/crypto-subtype.h> ++ ++struct public_key; ++struct public_key_signature; ++ ++enum pkey_hash_algo { ++ PKEY_HASH_MD5, ++ PKEY_HASH_SHA1, ++ PKEY_HASH_RIPE_MD_160, ++ PKEY_HASH_SHA256, ++ PKEY_HASH_SHA384, ++ PKEY_HASH_SHA512, ++ PKEY_HASH_SHA224, ++ PKEY_HASH__LAST ++}; ++ ++/* ++ * Public key type definition ++ */ ++struct public_key_algorithm { ++ const char *name; ++ u8 n_pub_mpi; /* Number of MPIs in public key */ ++ u8 n_sec_mpi; /* Number of MPIs in secret key */ ++ u8 n_sig_mpi; /* Number of MPIs in a signature */ ++ int (*verify)(const struct public_key *key, ++ const struct public_key_signature *sig); ++}; ++ ++/* ++ * Asymmetric public key data ++ */ ++struct public_key { ++ const struct public_key_algorithm *algo; ++ u8 capabilities; ++#define PKEY_CAN_ENCRYPT 0x01 ++#define PKEY_CAN_DECRYPT 0x02 ++#define PKEY_CAN_ENCDEC (PKEY_CAN_ENCRYPT | PKEY_CAN_DECRYPT) ++#define PKEY_CAN_SIGN 0x04 ++#define PKEY_CAN_VERIFY 0x08 ++#define PKEY_CAN_SIGVER (PKEY_CAN_SIGN | PKEY_CAN_VERIFY) ++ union { ++ MPI mpi[5]; ++ struct { ++ MPI p; /* DSA prime */ ++ MPI q; /* DSA group order */ ++ MPI g; /* DSA group generator */ ++ MPI y; /* DSA public-key value = g^x mod p */ ++ MPI x; /* DSA secret exponent (if present) */ ++ } dsa; ++ struct { ++ MPI n; /* RSA public modulus */ ++ MPI e; /* RSA public encryption exponent */ ++ MPI d; /* RSA secret encryption exponent (if present) */ ++ MPI p; /* RSA secret prime (if present) */ ++ MPI q; /* RSA secret prime (if present) */ ++ } rsa; ++ }; ++ ++ u8 key_id[8]; /* ID of this key pair */ ++ u8 key_id_size; /* Number of bytes in key_id */ ++}; ++ ++/* ++ * Asymmetric public key algorithm signature data ++ */ ++struct public_key_signature { ++ struct crypto_key_verify_context base; ++ u8 *digest; ++ enum pkey_hash_algo pkey_hash_algo : 8; ++ u8 signed_hash_msw[2]; ++ u8 digest_size; /* Number of bytes in digest */ ++ union { ++ MPI mpi[2]; ++ struct { ++ MPI s; /* m^d mod n */ ++ } rsa; ++ struct { ++ MPI r; ++ MPI s; ++ } dsa; ++ }; ++ struct shash_desc hash; /* This must go last! */ ++}; ++ ++extern struct crypto_key_verify_context *pgp_pkey_verify_sig_begin( ++ struct key *crypto_key, const u8 *sigdata, size_t siglen); ++ ++extern struct crypto_key_subtype public_key_crypto_key_subtype; ++ ++#endif /* _LINUX_PUBLIC_KEY_H */ +-- +1.7.10.2 + + +From 07f1001d10c926d28b92f0a32dbb57131a0f0942 Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Fri, 4 May 2012 16:30:18 +0100 +Subject: [PATCH 08/36] KEYS: RSA signature verification algorithm + +Implement the RSA algorithm (PKCS#1 / RFC3447). At this time, only signature +verification is supported. This uses the asymmetric public key subtype to hold +its key data. + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + security/keys/crypto/Kconfig | 7 + + security/keys/crypto/Makefile | 1 + + security/keys/crypto/crypto_rsa.c | 282 +++++++++++++++++++++++++++++++++++++ + security/keys/crypto/public_key.h | 2 + + 4 files changed, 292 insertions(+) + create mode 100644 security/keys/crypto/crypto_rsa.c + +diff --git a/security/keys/crypto/Kconfig b/security/keys/crypto/Kconfig +index 5f2b8ac..4e3777e 100644 +--- a/security/keys/crypto/Kconfig ++++ b/security/keys/crypto/Kconfig +@@ -15,3 +15,10 @@ config CRYPTO_KEY_PUBLIC_KEY_SUBTYPE + If signature generation and/or verification are to be used, + appropriate hash algorithms (such as SHA-1) must be available. + ENOPKG will be reported if the requisite algorithm is unavailable. ++ ++config CRYPTO_KEY_PKEY_ALGO_RSA ++ tristate "RSA public-key algorithm" ++ depends on CRYPTO_KEY_PUBLIC_KEY_SUBTYPE ++ select MPILIB_EXTRA ++ help ++ This option enables support for the RSA algorithm (PKCS#1, RFC3447). +diff --git a/security/keys/crypto/Makefile b/security/keys/crypto/Makefile +index 6384306..b6b1a5a 100644 +--- a/security/keys/crypto/Makefile ++++ b/security/keys/crypto/Makefile +@@ -6,3 +6,4 @@ obj-$(CONFIG_CRYPTO_KEY_TYPE) += crypto_keys.o + crypto_keys-y := crypto_type.o crypto_verify.o + + obj-$(CONFIG_CRYPTO_KEY_PUBLIC_KEY_SUBTYPE) += public_key.o ++obj-$(CONFIG_CRYPTO_KEY_PKEY_ALGO_RSA) += crypto_rsa.o +diff --git a/security/keys/crypto/crypto_rsa.c b/security/keys/crypto/crypto_rsa.c +new file mode 100644 +index 0000000..beb5181 +--- /dev/null ++++ b/security/keys/crypto/crypto_rsa.c +@@ -0,0 +1,282 @@ ++/* RSA asymmetric public-key algorithm [RFC3447] ++ * ++ * Copyright (C) 2011 Red Hat, Inc. All Rights Reserved. ++ * Written by David Howells (dhowells@redhat.com) ++ * ++ * This program is free software; you can redistribute it and/or ++ * modify it under the terms of the GNU General Public Licence ++ * as published by the Free Software Foundation; either version ++ * 2 of the Licence, or (at your option) any later version. ++ */ ++ ++#define pr_fmt(fmt) "RSA: "fmt ++#include <linux/module.h> ++#include <linux/kernel.h> ++#include "public_key.h" ++ ++MODULE_LICENSE("GPL"); ++ ++#define kenter(FMT, ...) \ ++ pr_devel("==> %s("FMT")\n", __func__, ##__VA_ARGS__) ++#define kleave(FMT, ...) \ ++ pr_devel("<== %s()"FMT"\n", __func__, ##__VA_ARGS__) ++ ++/* ++ * Hash algorithm OIDs plus ASN.1 DER wrappings [RFC4880 sec 5.2.2]. ++ */ ++static const u8 RSA_digest_info_MD5[] = { ++ 0x30, 0x20, 0x30, 0x0C, 0x06, 0x08, ++ 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x02, 0x05, /* OID */ ++ 0x05, 0x00, 0x04, 0x10 ++}; ++ ++static const u8 RSA_digest_info_SHA1[] = { ++ 0x30, 0x21, 0x30, 0x09, 0x06, 0x05, ++ 0x2B, 0x0E, 0x03, 0x02, 0x1A, ++ 0x05, 0x00, 0x04, 0x14 ++}; ++ ++static const u8 RSA_digest_info_RIPE_MD_160[] = { ++ 0x30, 0x21, 0x30, 0x09, 0x06, 0x05, ++ 0x2B, 0x24, 0x03, 0x02, 0x01, ++ 0x05, 0x00, 0x04, 0x14 ++}; ++ ++static const u8 RSA_digest_info_SHA224[] = { ++ 0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09, ++ 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04, ++ 0x05, 0x00, 0x04, 0x1C ++}; ++ ++static const u8 RSA_digest_info_SHA256[] = { ++ 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, ++ 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, ++ 0x05, 0x00, 0x04, 0x20 ++}; ++ ++static const u8 RSA_digest_info_SHA384[] = { ++ 0x30, 0x41, 0x30, 0x0d, 0x06, 0x09, ++ 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02, ++ 0x05, 0x00, 0x04, 0x30 ++}; ++ ++static const u8 RSA_digest_info_SHA512[] = { ++ 0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, ++ 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, ++ 0x05, 0x00, 0x04, 0x40 ++}; ++ ++static const struct { ++ const u8 const *data; ++ size_t size; ++} RSA_ASN1_templates[PKEY_HASH__LAST] = { ++#define _(X) { RSA_digest_info_##X, sizeof(RSA_digest_info_##X) } ++ [PKEY_HASH_MD5] = _(MD5), ++ [PKEY_HASH_SHA1] = _(SHA1), ++ [PKEY_HASH_RIPE_MD_160] = _(RIPE_MD_160), ++ [PKEY_HASH_SHA256] = _(SHA256), ++ [PKEY_HASH_SHA384] = _(SHA384), ++ [PKEY_HASH_SHA512] = _(SHA512), ++ [PKEY_HASH_SHA224] = _(SHA224), ++#undef _ ++}; ++ ++/* ++ * RSAVP1() function [RFC3447 sec 5.2.2] ++ */ ++static int RSAVP1(const struct public_key *key, MPI s, MPI *_m) ++{ ++ MPI m; ++ int ret; ++ ++ /* (1) Validate 0 <= s < n */ ++ if (mpi_cmp_ui(s, 0) < 0) { ++ kleave(" = -EBADMSG [s < 0]"); ++ return -EBADMSG; ++ } ++ if (mpi_cmp(s, key->rsa.n) >= 0) { ++ kleave(" = -EBADMSG [s >= n]"); ++ return -EBADMSG; ++ } ++ ++ m = mpi_alloc(0); ++ if (!m) ++ return -ENOMEM; ++ ++ /* (2) m = s^e mod n */ ++ ret = mpi_powm(m, s, key->rsa.e, key->rsa.n); ++ if (ret < 0) { ++ mpi_free(m); ++ return ret; ++ } ++ ++ *_m = m; ++ return 0; ++} ++ ++/* ++ * Integer to Octet String conversion [RFC3447 sec 4.1] ++ */ ++static int RSA_I2OSP(MPI x, size_t xLen, u8 **_X) ++{ ++ unsigned X_size, x_size; ++ int X_sign; ++ u8 *X; ++ ++ /* Make sure the string is the right length. The number should begin ++ * with { 0x00, 0x01, ... } so we have to account for 15 leading zero ++ * bits not being reported by MPI. ++ */ ++ x_size = mpi_get_nbits(x); ++ pr_devel("size(x)=%u xLen*8=%zu\n", x_size, xLen * 8); ++ if (x_size != xLen * 8 - 15) ++ return -ERANGE; ++ ++ X = mpi_get_buffer(x, &X_size, &X_sign); ++ if (!X) ++ return -ENOMEM; ++ if (X_sign < 0) { ++ kfree(X); ++ return -EBADMSG; ++ } ++ if (X_size != xLen - 1) { ++ kfree(X); ++ return -EBADMSG; ++ } ++ ++ *_X = X; ++ return 0; ++} ++ ++/* ++ * Perform the RSA signature verification. ++ * @H: Value of hash of data and metadata ++ * @EM: The computed signature value ++ * @k: The size of EM (EM[0] is an invalid location but should hold 0x00) ++ * @hash_size: The size of H ++ * @asn1_template: The DigestInfo ASN.1 template ++ * @asn1_size: Size of asm1_template[] ++ */ ++static int RSA_verify(const u8 *H, const u8 *EM, size_t k, size_t hash_size, ++ const u8 *asn1_template, size_t asn1_size) ++{ ++ unsigned PS_end, T_offset, i; ++ ++ kenter(",,%zu,%zu,%zu", k, hash_size, asn1_size); ++ ++ if (k < 2 + 1 + asn1_size + hash_size) ++ return -EBADMSG; ++ ++ /* Decode the EMSA-PKCS1-v1_5 */ ++ if (EM[1] != 0x01) { ++ kleave(" = -EBADMSG [EM[1] == %02u]", EM[1]); ++ return -EBADMSG; ++ } ++ ++ T_offset = k - (asn1_size + hash_size); ++ PS_end = T_offset - 1; ++ if (EM[PS_end] != 0x00) { ++ kleave(" = -EBADMSG [EM[T-1] == %02u]", EM[PS_end]); ++ return -EBADMSG; ++ } ++ ++ for (i = 2; i < PS_end; i++) { ++ if (EM[i] != 0xff) { ++ kleave(" = -EBADMSG [EM[PS%x] == %02u]", i - 2, EM[i]); ++ return -EBADMSG; ++ } ++ } ++ ++ if (memcmp(asn1_template, EM + T_offset, asn1_size) != 0) { ++ kleave(" = -EBADMSG [EM[T] ASN.1 mismatch]"); ++ return -EBADMSG; ++ } ++ ++ if (memcmp(H, EM + T_offset + asn1_size, hash_size) != 0) { ++ kleave(" = -EKEYREJECTED [EM[T] hash mismatch]"); ++ return -EKEYREJECTED; ++ } ++ ++ kleave(" = 0"); ++ return 0; ++} ++ ++/* ++ * Perform the verification step [RFC3447 sec 8.2.2]. ++ */ ++static int RSA_verify_signature(const struct public_key *key, ++ const struct public_key_signature *sig) ++{ ++ size_t tsize; ++ int ret; ++ ++ /* Variables as per RFC3447 sec 8.2.2 */ ++ const u8 *H = sig->digest; ++ u8 *EM = NULL; ++ MPI m = NULL; ++ size_t k; ++ ++ kenter(""); ++ ++ /* (1) Check the signature size against the public key modulus size */ ++ k = (mpi_get_nbits(key->rsa.n) + 7) / 8; ++ ++ tsize = (mpi_get_nbits(sig->rsa.s) + 7) / 8; ++ pr_devel("step 1: k=%zu size(S)=%zu\n", k, tsize); ++ if (tsize != k) { ++ ret = -EBADMSG; ++ goto error; ++ } ++ ++ /* (2b) Apply the RSAVP1 verification primitive to the public key */ ++ ret = RSAVP1(key, sig->rsa.s, &m); ++ if (ret < 0) ++ goto error; ++ ++ /* (2c) Convert the message representative (m) to an encoded message ++ * (EM) of length k octets. ++ * ++ * NOTE! The leading zero byte is suppressed by MPI, so we pass a ++ * pointer to the _preceding_ byte to RSA_verify()! ++ */ ++ ret = RSA_I2OSP(m, k, &EM); ++ if (ret < 0) ++ goto error; ++ ++#if 0 ++ { ++ int i; ++ printk("H: "); ++ for (i = 0; i < sig->digest_size; i++) ++ printk("%02x", H[i]); ++ printk("\n"); ++ } ++ ++ { ++ int i; ++ printk("EM: 00"); ++ for (i = 0; i < k - 1; i++) ++ printk("%02x", EM[i]); ++ printk("\n"); ++ } ++#endif ++ ++ ret = RSA_verify(H, EM - 1, k, sig->digest_size, ++ RSA_ASN1_templates[sig->pkey_hash_algo].data, ++ RSA_ASN1_templates[sig->pkey_hash_algo].size); ++ ++error: ++ kfree(EM); ++ mpi_free(m); ++ kleave(" = %d", ret); ++ return ret; ++} ++ ++const struct public_key_algorithm RSA_public_key_algorithm = { ++ .name = "RSA", ++ .n_pub_mpi = 2, ++ .n_sec_mpi = 3, ++ .n_sig_mpi = 1, ++ .verify = RSA_verify_signature, ++}; ++EXPORT_SYMBOL_GPL(RSA_public_key_algorithm); +diff --git a/security/keys/crypto/public_key.h b/security/keys/crypto/public_key.h +index 81ed603..7913615 100644 +--- a/security/keys/crypto/public_key.h ++++ b/security/keys/crypto/public_key.h +@@ -42,6 +42,8 @@ struct public_key_algorithm { + const struct public_key_signature *sig); + }; + ++extern const struct public_key_algorithm RSA_public_key_algorithm; ++ + /* + * Asymmetric public key data + */ +-- +1.7.10.2 + + +From a1ac402f327ab537a629c4d365b3f5461eaecb82 Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Fri, 4 May 2012 16:30:20 +0100 +Subject: [PATCH 09/36] Fix signature verification for shorter signatures + +gpg can produce a signature file where length of signature is less than the +modulus size because the amount of space an MPI takes up is kept as low as +possible by discarding leading zeros. This regularly happens for several +modules during the build. + +Fix it by relaxing check in RSA verification code. + +Thanks to Tomas Mraz and Miloslav Trmac for help. + +Signed-off-by: Milan Broz <mbroz@redhat.com> +Signed-off-by: David Howells <dhowells@redhat.com> +--- + security/keys/crypto/crypto_rsa.c | 14 +++++++++++--- + 1 file changed, 11 insertions(+), 3 deletions(-) + +diff --git a/security/keys/crypto/crypto_rsa.c b/security/keys/crypto/crypto_rsa.c +index beb5181..cc5cd95 100644 +--- a/security/keys/crypto/crypto_rsa.c ++++ b/security/keys/crypto/crypto_rsa.c +@@ -219,15 +219,23 @@ static int RSA_verify_signature(const struct public_key *key, + kenter(""); + + /* (1) Check the signature size against the public key modulus size */ +- k = (mpi_get_nbits(key->rsa.n) + 7) / 8; ++ k = mpi_get_nbits(key->rsa.n); ++ tsize = mpi_get_nbits(sig->rsa.s); + +- tsize = (mpi_get_nbits(sig->rsa.s) + 7) / 8; ++ /* According to RFC 4880 sec 3.2, length of MPI is computed starting ++ * from most significant bit. So the RFC 3447 sec 8.2.2 size check ++ * must be relaxed to conform with shorter signatures - so we fail here ++ * only if signature length is longer than modulus size. ++ */ + pr_devel("step 1: k=%zu size(S)=%zu\n", k, tsize); +- if (tsize != k) { ++ if (k < tsize) { + ret = -EBADMSG; + goto error; + } + ++ /* Round up and convert to octets */ ++ k = (k + 7) / 8; ++ + /* (2b) Apply the RSAVP1 verification primitive to the public key */ + ret = RSAVP1(key, sig->rsa.s, &m); + if (ret < 0) +-- +1.7.10.2 + + +From d682ea629a2494aab705468d1479058a03fd7879 Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Fri, 4 May 2012 16:30:23 +0100 +Subject: [PATCH 10/36] PGPLIB: PGP definitions (RFC 4880) + +Provide some useful PGP definitions from RFC 4880. These describe details of +public key crypto as used by crypto keys for things like signature +verification. + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + include/linux/pgp.h | 206 +++++++++++++++++++++++++++++++++++++++++++++++++++ + 1 file changed, 206 insertions(+) + create mode 100644 include/linux/pgp.h + +diff --git a/include/linux/pgp.h b/include/linux/pgp.h +new file mode 100644 +index 0000000..1359f64 +--- /dev/null ++++ b/include/linux/pgp.h +@@ -0,0 +1,206 @@ ++/* PGP definitions (RFC 4880) ++ * ++ * Copyright (C) 2011 Red Hat, Inc. All Rights Reserved. ++ * Written by David Howells (dhowells@redhat.com) ++ * ++ * This program is free software; you can redistribute it and/or ++ * modify it under the terms of the GNU General Public Licence ++ * as published by the Free Software Foundation; either version ++ * 2 of the Licence, or (at your option) any later version. ++ */ ++ ++#ifndef _LINUX_PGP_H ++#define _LINUX_PGP_H ++ ++#include <linux/types.h> ++ ++struct pgp_key_ID { ++ u8 id[8]; ++}; ++ ++struct pgp_time { ++ u8 time[4]; ++}; ++ ++/* ++ * PGP public-key algorithm identifiers [RFC4880: 9.1] ++ */ ++enum pgp_pubkey_algo { ++ PGP_PUBKEY_RSA_ENC_OR_SIG = 1, ++ PGP_PUBKEY_RSA_ENC_ONLY = 2, ++ PGP_PUBKEY_RSA_SIG_ONLY = 3, ++ PGP_PUBKEY_ELGAMAL = 16, ++ PGP_PUBKEY_DSA = 17, ++ PGP_PUBKEY__LAST ++}; ++ ++/* ++ * PGP symmetric-key algorithm identifiers [RFC4880: 9.2] ++ */ ++enum pgp_symkey_algo { ++ PGP_SYMKEY_PLAINTEXT = 0, ++ PGP_SYMKEY_IDEA = 1, ++ PGP_SYMKEY_3DES = 2, ++ PGP_SYMKEY_CAST5 = 3, ++ PGP_SYMKEY_BLOWFISH = 4, ++ PGP_SYMKEY_AES_128KEY = 7, ++ PGP_SYMKEY_AES_192KEY = 8, ++ PGP_SYMKEY_AES_256KEY = 9, ++ PGP_SYMKEY_TWOFISH_256KEY = 10, ++}; ++ ++/* ++ * PGP compression algorithm identifiers [RFC4880: 9.3] ++ */ ++enum pgp_compr_algo { ++ PGP_COMPR_UNCOMPRESSED = 0, ++ PGP_COMPR_ZIP = 1, ++ PGP_COMPR_ZLIB = 2, ++ PGP_COMPR_BZIP2 = 3, ++}; ++ ++/* ++ * PGP hash algorithm identifiers [RFC4880: 9.4] ++ */ ++enum pgp_hash_algo { ++ PGP_HASH_MD5 = 1, ++ PGP_HASH_SHA1 = 2, ++ PGP_HASH_RIPE_MD_160 = 3, ++ PGP_HASH_SHA256 = 8, ++ PGP_HASH_SHA384 = 9, ++ PGP_HASH_SHA512 = 10, ++ PGP_HASH_SHA224 = 11, ++ PGP_HASH__LAST ++}; ++ ++extern const char *const pgp_hash_algorithms[PGP_HASH__LAST]; ++ ++/* ++ * PGP packet type tags [RFC4880: 4.3]. ++ */ ++enum pgp_packet_tag { ++ PGP_PKT_RESERVED = 0, ++ PGP_PKT_PUBKEY_ENC_SESSION_KEY = 1, ++ PGP_PKT_SIGNATURE = 2, ++ PGP_PKT_SYMKEY_ENC_SESSION_KEY = 3, ++ PGP_PKT_ONEPASS_SIGNATURE = 4, ++ PGP_PKT_SECRET_KEY = 5, ++ PGP_PKT_PUBLIC_KEY = 6, ++ PGP_PKT_SECRET_SUBKEY = 7, ++ PGP_PKT_COMPRESSED_DATA = 8, ++ PGP_PKT_SYM_ENC_DATA = 9, ++ PGP_PKT_MARKER = 10, ++ PGP_PKT_LITERAL_DATA = 11, ++ PGP_PKT_TRUST = 12, ++ PGP_PKT_USER_ID = 13, ++ PGP_PKT_PUBLIC_SUBKEY = 14, ++ PGP_PKT_USER_ATTRIBUTE = 17, ++ PGP_PKT_SYM_ENC_AND_INTEG_DATA = 18, ++ PGP_PKT_MODIFY_DETECT_CODE = 19, ++ PGP_PKT_PRIVATE_0 = 60, ++ PGP_PKT_PRIVATE_3 = 63, ++ PGP_PKT__HIGHEST = 63 ++}; ++ ++/* ++ * Signature (tag 2) packet [RFC4880: 5.2]. ++ */ ++enum pgp_signature_version { ++ PGP_SIG_VERSION_3 = 3, ++ PGP_SIG_VERSION_4 = 4, ++}; ++ ++enum pgp_signature_type { ++ PGP_SIG_BINARY_DOCUMENT_SIG = 0x00, ++ PGP_SIG_CANONICAL_TEXT_DOCUMENT_SIG = 0x01, ++ PGP_SIG_STANDALONE_SIG = 0x02, ++ PGP_SIG_GENERAL_CERT_OF_UID_PUBKEY = 0x10, ++ PGP_SIG_PERSONAL_CERT_OF_UID_PUBKEY = 0x11, ++ PGP_SIG_CASUAL_CERT_OF_UID_PUBKEY = 0x12, ++ PGP_SIG_POSTITIVE_CERT_OF_UID_PUBKEY = 0x13, ++ PGP_SIG_SUBKEY_BINDING_SIG = 0x18, ++ PGP_SIG_PRIMARY_KEY_BINDING_SIG = 0x19, ++ PGP_SIG_DIRECTLY_ON_KEY = 0x1F, ++ PGP_SIG_KEY_REVOCATION_SIG = 0x20, ++ PGP_SIG_SUBKEY_REVOCATION_SIG = 0x28, ++ PGP_SIG_CERT_REVOCATION_SIG = 0x30, ++ PGP_SIG_TIMESTAMP_SIG = 0x40, ++ PGP_SIG_THIRD_PARTY_CONFIRM_SIG = 0x50, ++}; ++ ++struct pgp_signature_v3_packet { ++ enum pgp_signature_version version : 8; /* == PGP_SIG_VERSION_3 */ ++ u8 length_of_hashed; /* == 5 */ ++ struct { ++ enum pgp_signature_type signature_type : 8; ++ struct pgp_time creation_time; ++ } hashed; ++ struct pgp_key_ID issuer; ++ enum pgp_pubkey_algo pubkey_algo : 8; ++ enum pgp_hash_algo hash_algo : 8; ++} __packed; ++ ++struct pgp_signature_v4_packet { ++ enum pgp_signature_version version : 8; /* == PGP_SIG_VERSION_4 */ ++ enum pgp_signature_type signature_type : 8; ++ enum pgp_pubkey_algo pubkey_algo : 8; ++ enum pgp_hash_algo hash_algo : 8; ++} __packed; ++ ++/* ++ * V4 signature subpacket types [RFC4880: 5.2.3.1]. ++ */ ++enum pgp_sig_subpkt_type { ++ PGP_SIG_CREATION_TIME = 2, ++ PGP_SIG_EXPIRATION_TIME = 3, ++ PGP_SIG_EXPORTABLE_CERT = 4, ++ PGP_SIG_TRUST_SIG = 5, ++ PGP_SIG_REGEXP = 6, ++ PGP_SIG_REVOCABLE = 7, ++ PGP_SIG_KEY_EXPIRATION_TIME = 9, ++ PGP_SIG_PREF_SYM_ALGO = 11, ++ PGP_SIG_REVOCATION_KEY = 12, ++ PGP_SIG_ISSUER = 16, ++ PGP_SIG_NOTATION_DATA = 20, ++ PGP_SIG_PREF_HASH_ALGO = 21, ++ PGP_SIG_PREF_COMPR_ALGO = 22, ++ PGP_SIG_KEY_SERVER_PREFS = 23, ++ PGP_SIG_PREF_KEY_SERVER = 24, ++ PGP_SIG_PRIMARY_USER_ID = 25, ++ PGP_SIG_POLICY_URI = 26, ++ PGP_SIG_KEY_FLAGS = 27, ++ PGP_SIG_SIGNERS_USER_ID = 28, ++ PGP_SIG_REASON_FOR_REVOCATION = 29, ++ PGP_SIG_FEATURES = 30, ++ PGP_SIG_TARGET = 31, ++ PGP_SIG_EMBEDDED_SIG = 32, ++ PGP_SIG__LAST ++}; ++ ++#define PGP_SIG_SUBPKT_TYPE_CRITICAL_MASK 0x80 ++ ++/* ++ * Key (tag 5, 6, 7 and 14) packet ++ */ ++enum pgp_key_version { ++ PGP_KEY_VERSION_2 = 2, ++ PGP_KEY_VERSION_3 = 3, ++ PGP_KEY_VERSION_4 = 4, ++}; ++ ++struct pgp_key_v3_packet { ++ enum pgp_key_version version : 8; ++ struct pgp_time creation_time; ++ u8 expiry[2]; /* 0 or time in days till expiry */ ++ enum pgp_pubkey_algo pubkey_algo : 8; ++ u8 key_material[0]; ++} __packed; ++ ++struct pgp_key_v4_packet { ++ enum pgp_key_version version : 8; ++ struct pgp_time creation_time; ++ enum pgp_pubkey_algo pubkey_algo : 8; ++ u8 key_material[0]; ++} __packed; ++ ++#endif /* _LINUX_PGP_H */ +-- +1.7.10.2 + + +From 651d6e549374b13b2d0473db17df90ab66abf855 Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Fri, 4 May 2012 16:33:28 +0100 +Subject: [PATCH 11/36] PGPLIB: Basic packet parser + +Provide a simple parser that extracts the packets from a PGP packet blob and +passes the desirous ones to the given processor function: + + struct pgp_parse_context { + u64 types_of_interest; + int (*process_packet)(struct pgp_parse_context *context, + enum pgp_packet_tag type, + u8 headerlen, + const u8 *data, + size_t datalen); + }; + + int pgp_parse_packets(const u8 *data, size_t datalen, + struct pgp_parse_context *ctx); + +This is configured on with CONFIG_PGP_LIBRARY. + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + include/linux/pgp.h | 25 ++++ + security/keys/crypto/Kconfig | 6 + + security/keys/crypto/Makefile | 1 + + security/keys/crypto/pgp_library.c | 254 ++++++++++++++++++++++++++++++++++++ + 4 files changed, 286 insertions(+) + create mode 100644 security/keys/crypto/pgp_library.c + +diff --git a/include/linux/pgp.h b/include/linux/pgp.h +index 1359f64..235270a 100644 +--- a/include/linux/pgp.h ++++ b/include/linux/pgp.h +@@ -203,4 +203,29 @@ struct pgp_key_v4_packet { + u8 key_material[0]; + } __packed; + ++/* ++ * PGP library packet parser ++ */ ++struct pgp_parse_context { ++ u64 types_of_interest; ++ int (*process_packet)(struct pgp_parse_context *context, ++ enum pgp_packet_tag type, ++ u8 headerlen, ++ const u8 *data, ++ size_t datalen); ++}; ++ ++extern int pgp_parse_packets(const u8 *data, size_t datalen, ++ struct pgp_parse_context *ctx); ++ ++struct pgp_parse_pubkey { ++ enum pgp_key_version version : 8; ++ enum pgp_pubkey_algo pubkey_algo : 8; ++ time_t creation_time; ++ time_t expires_at; ++}; ++ ++extern int pgp_parse_public_key(const u8 **_data, size_t *_datalen, ++ struct pgp_parse_pubkey *pk); ++ + #endif /* _LINUX_PGP_H */ +diff --git a/security/keys/crypto/Kconfig b/security/keys/crypto/Kconfig +index 4e3777e..88ce0e2 100644 +--- a/security/keys/crypto/Kconfig ++++ b/security/keys/crypto/Kconfig +@@ -22,3 +22,9 @@ config CRYPTO_KEY_PKEY_ALGO_RSA + select MPILIB_EXTRA + help + This option enables support for the RSA algorithm (PKCS#1, RFC3447). ++ ++config PGP_LIBRARY ++ tristate "PGP parsing library" ++ help ++ This option enables a library that provides a number of simple ++ utility functions for parsing PGP (RFC 4880) packet-based messages. +diff --git a/security/keys/crypto/Makefile b/security/keys/crypto/Makefile +index b6b1a5a..5fbe54e 100644 +--- a/security/keys/crypto/Makefile ++++ b/security/keys/crypto/Makefile +@@ -7,3 +7,4 @@ crypto_keys-y := crypto_type.o crypto_verify.o + + obj-$(CONFIG_CRYPTO_KEY_PUBLIC_KEY_SUBTYPE) += public_key.o + obj-$(CONFIG_CRYPTO_KEY_PKEY_ALGO_RSA) += crypto_rsa.o ++obj-$(CONFIG_PGP_LIBRARY) += pgp_library.o +diff --git a/security/keys/crypto/pgp_library.c b/security/keys/crypto/pgp_library.c +new file mode 100644 +index 0000000..685660f +--- /dev/null ++++ b/security/keys/crypto/pgp_library.c +@@ -0,0 +1,254 @@ ++/* PGP packet parser (RFC 4880) ++ * ++ * Copyright (C) 2011 Red Hat, Inc. All Rights Reserved. ++ * Written by David Howells (dhowells@redhat.com) ++ * ++ * This program is free software; you can redistribute it and/or ++ * modify it under the terms of the GNU General Public Licence ++ * as published by the Free Software Foundation; either version ++ * 2 of the Licence, or (at your option) any later version. ++ */ ++#define pr_fmt(fmt) "PGP: "fmt ++#include <linux/pgp.h> ++#include <linux/errno.h> ++#include <linux/kernel.h> ++#include <linux/module.h> ++ ++MODULE_LICENSE("GPL"); ++ ++const char *const pgp_hash_algorithms[PGP_HASH__LAST] = { ++ [PGP_HASH_MD5] = "md5", ++ [PGP_HASH_SHA1] = "sha1", ++ [PGP_HASH_RIPE_MD_160] = "rmd160", ++ [PGP_HASH_SHA256] = "sha256", ++ [PGP_HASH_SHA384] = "sha384", ++ [PGP_HASH_SHA512] = "sha512", ++ [PGP_HASH_SHA224] = "sha224", ++}; ++EXPORT_SYMBOL_GPL(pgp_hash_algorithms); ++ ++/** ++ * pgp_parse_packet_header - Parse a PGP packet header ++ * @_data: Start of the PGP packet (updated to PGP packet data) ++ * @_datalen: Amount of data remaining in buffer (decreased) ++ * @_type: Where the packet type will be returned ++ * @_headerlen: Where the header length will be returned ++ * ++ * Parse a set of PGP packet header [RFC 4880: 4.2]. ++ * ++ * Returns packet data size on success; non-zero on error. If successful, ++ * *_data and *_datalen will have been updated and *_headerlen will be set to ++ * hold the length of the packet header. ++ */ ++ssize_t pgp_parse_packet_header(const u8 **_data, size_t *_datalen, ++ enum pgp_packet_tag *_type, ++ u8 *_headerlen) ++{ ++ enum pgp_packet_tag type; ++ const u8 *data = *_data; ++ size_t size, datalen = *_datalen; ++ ++ pr_devel("-->pgp_parse_packet_header(,%zu,,)", datalen); ++ ++ if (datalen < 2) ++ goto short_packet; ++ ++ pr_devel("pkthdr %02x, %02x\n", data[0], data[1]); ++ ++ type = *data++; ++ datalen--; ++ if (!(type & 0x80)) { ++ pr_debug("Packet type does not have MSB set\n"); ++ return -EBADMSG; ++ } ++ type &= ~0x80; ++ ++ if (type & 0x40) { ++ /* New packet length format */ ++ type &= ~0x40; ++ pr_devel("new format: t=%u\n", type); ++ switch (data[0]) { ++ case 0x00 ... 0xbf: ++ /* One-byte length */ ++ size = data[0]; ++ data++; ++ datalen--; ++ *_headerlen = 2; ++ break; ++ case 0xc0 ... 0xdf: ++ /* Two-byte length */ ++ if (datalen < 2) ++ goto short_packet; ++ size = (data[0] - 192) * 256; ++ size += data[1] + 192; ++ data += 2; ++ datalen -= 2; ++ *_headerlen = 3; ++ break; ++ case 0xff: ++ pr_debug("Five-byte packet length not supported\n"); ++ return -EBADMSG; ++ default: ++ pr_debug("Error parsing packet length\n"); ++ return -EBADMSG; ++ } ++ } else { ++ /* Old packet length format */ ++ u8 length_type = type & 0x03; ++ type >>= 2; ++ pr_devel("old format: t=%u lt=%u\n", type, length_type); ++ ++ switch (length_type) { ++ case 0: ++ /* One-byte length */ ++ size = data[0]; ++ data++; ++ datalen--; ++ *_headerlen = 2; ++ break; ++ case 1: ++ /* Two-byte length */ ++ if (datalen < 2) ++ goto short_packet; ++ size = data[0] << 8; ++ size |= data[1]; ++ data += 2; ++ datalen -= 2; ++ *_headerlen = 3; ++ break; ++ case 2: ++ /* Four-byte length */ ++ if (datalen < 4) ++ goto short_packet; ++ size = data[0] << 24; ++ size |= data[1] << 16; ++ size |= data[2] << 8; ++ size |= data[3]; ++ data += 4; ++ datalen -= 4; ++ *_headerlen = 5; ++ break; ++ default: ++ pr_debug("Indefinite length packet not supported\n"); ++ return -EBADMSG; ++ } ++ } ++ ++ pr_devel("datalen=%zu size=%zu", datalen, size); ++ if (datalen < size) ++ goto short_packet; ++ ++ *_data = data; ++ *_datalen = datalen; ++ *_type = type; ++ pr_devel("Found packet type=%u size=%zd\n", type, size); ++ return size; ++ ++short_packet: ++ pr_debug("Attempt to parse short packet\n"); ++ return -EBADMSG; ++} ++ ++/** ++ * pgp_parse_packets - Parse a set of PGP packets ++ * @_data: Data to be parsed (updated) ++ * @_datalen: Amount of data (updated) ++ * @ctx: Parsing context ++ * ++ * Parse a set of PGP packets [RFC 4880: 4]. ++ */ ++int pgp_parse_packets(const u8 *data, size_t datalen, ++ struct pgp_parse_context *ctx) ++{ ++ enum pgp_packet_tag type; ++ ssize_t pktlen; ++ u8 headerlen; ++ int ret; ++ ++ while (datalen > 2) { ++ pktlen = pgp_parse_packet_header(&data, &datalen, &type, ++ &headerlen); ++ if (pktlen < 0) ++ return pktlen; ++ ++ if ((ctx->types_of_interest >> type) & 1) { ++ ret = ctx->process_packet(ctx, type, headerlen, ++ data, pktlen); ++ if (ret < 0) ++ return ret; ++ } ++ data += pktlen; ++ datalen -= pktlen; ++ } ++ ++ if (datalen != 0) { ++ pr_debug("Excess octets in packet stream\n"); ++ return -EBADMSG; ++ } ++ ++ return 0; ++} ++EXPORT_SYMBOL_GPL(pgp_parse_packets); ++ ++/** ++ * pgp_parse_public_key - Parse the common part of a PGP pubkey packet ++ * @_data: Content of packet (updated) ++ * @_datalen: Length of packet remaining (updated) ++ * @pk: Public key data ++ * ++ * Parse the common data struct for a PGP pubkey packet [RFC 4880: 5.5.2]. ++ */ ++int pgp_parse_public_key(const u8 **_data, size_t *_datalen, ++ struct pgp_parse_pubkey *pk) ++{ ++ const u8 *data = *_data; ++ size_t datalen = *_datalen; ++ __be32 tmp; ++ ++ if (datalen < 12) { ++ pr_debug("Public key packet too short\n"); ++ return -EBADMSG; ++ } ++ ++ pk->version = *data++; ++ switch (pk->version) { ++ case PGP_KEY_VERSION_2: ++ case PGP_KEY_VERSION_3: ++ case PGP_KEY_VERSION_4: ++ break; ++ default: ++ pr_debug("Public key packet with unhandled version %d\n", ++ pk->version); ++ return -EBADMSG; ++ } ++ ++ tmp = *data++ << 24; ++ tmp |= *data++ << 16; ++ tmp |= *data++ << 8; ++ tmp |= *data++; ++ pk->creation_time = tmp; ++ if (pk->version == PGP_KEY_VERSION_4) { ++ pk->expires_at = 0; /* Have to get it from the selfsignature */ ++ } else { ++ unsigned short ndays; ++ ndays = *data++ << 8; ++ ndays |= *data++; ++ if (ndays) ++ pk->expires_at = pk->creation_time + ndays * 86400UL; ++ else ++ pk->expires_at = 0; ++ datalen -= 2; ++ } ++ ++ pk->pubkey_algo = *data++; ++ datalen -= 6; ++ ++ pr_devel("%x,%x,%lx,%lx", ++ pk->version, pk->pubkey_algo, pk->creation_time, ++ pk->expires_at); ++ ++ *_data = data; ++ *_datalen = datalen; ++ return 0; ++} ++EXPORT_SYMBOL_GPL(pgp_parse_public_key); +-- +1.7.10.2 + + +From 1123a360effa696546dbce1273c680b45c5cf946 Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Fri, 4 May 2012 16:33:30 +0100 +Subject: [PATCH 12/36] PGPLIB: Signature parser + +Provide some PGP signature parsing helpers: + + (1) A function to parse V4 signature subpackets and pass the desired ones to + a processor function: + + int pgp_parse_sig_subpkts(const u8 *data, size_t datalen, + struct pgp_parse_sig_context *ctx); + + (2) A function to parse out basic signature parameters from any PGP signature + such that the algorithms and public key can be selected: + + int pgp_parse_sig_params(const u8 **_data, size_t *_datalen, + struct pgp_sig_parameters *p); + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + include/linux/pgp.h | 24 ++++ + security/keys/crypto/pgp_library.c | 277 ++++++++++++++++++++++++++++++++++++ + 2 files changed, 301 insertions(+) + +diff --git a/include/linux/pgp.h b/include/linux/pgp.h +index 235270a..ab1a8fa 100644 +--- a/include/linux/pgp.h ++++ b/include/linux/pgp.h +@@ -228,4 +228,28 @@ struct pgp_parse_pubkey { + extern int pgp_parse_public_key(const u8 **_data, size_t *_datalen, + struct pgp_parse_pubkey *pk); + ++struct pgp_parse_sig_context { ++ unsigned long types_of_interest[128 / BITS_PER_LONG]; ++ int (*process_packet)(struct pgp_parse_sig_context *context, ++ enum pgp_sig_subpkt_type type, ++ const u8 *data, ++ size_t datalen); ++}; ++ ++extern int pgp_parse_sig_packets(const u8 *data, size_t datalen, ++ struct pgp_parse_sig_context *ctx); ++ ++struct pgp_sig_parameters { ++ enum pgp_signature_type signature_type : 8; ++ union { ++ struct pgp_key_ID issuer; ++ __be32 issuer32[2]; ++ }; ++ enum pgp_pubkey_algo pubkey_algo : 8; ++ enum pgp_hash_algo hash_algo : 8; ++}; ++ ++extern int pgp_parse_sig_params(const u8 **_data, size_t *_datalen, ++ struct pgp_sig_parameters *p); ++ + #endif /* _LINUX_PGP_H */ +diff --git a/security/keys/crypto/pgp_library.c b/security/keys/crypto/pgp_library.c +index 685660f..f6b831f 100644 +--- a/security/keys/crypto/pgp_library.c ++++ b/security/keys/crypto/pgp_library.c +@@ -252,3 +252,280 @@ int pgp_parse_public_key(const u8 **_data, size_t *_datalen, + return 0; + } + EXPORT_SYMBOL_GPL(pgp_parse_public_key); ++ ++/** ++ * pgp_parse_sig_subpkt_header - Parse a PGP V4 signature subpacket header ++ * @_data: Start of the subpacket (updated to subpacket data) ++ * @_datalen: Amount of data remaining in buffer (decreased) ++ * @_type: Where the subpacket type will be returned ++ * ++ * Parse a PGP V4 signature subpacket header [RFC 4880: 5.2.3.1]. ++ * ++ * Returns packet data size on success; non-zero on error. If successful, ++ * *_data and *_datalen will have been updated and *_headerlen will be set to ++ * hold the length of the packet header. ++ */ ++ssize_t pgp_parse_sig_subpkt_header(const u8 **_data, size_t *_datalen, ++ enum pgp_sig_subpkt_type *_type) ++{ ++ enum pgp_sig_subpkt_type type; ++ const u8 *data = *_data; ++ size_t size, datalen = *_datalen; ++ ++ pr_devel("-->pgp_parse_sig_subpkt_header(,%zu,,)", datalen); ++ ++ if (datalen < 2) ++ goto short_subpacket; ++ ++ pr_devel("subpkt hdr %02x, %02x\n", data[0], data[1]); ++ ++ switch (data[0]) { ++ case 0x00 ... 0xbf: ++ /* One-byte length */ ++ size = data[0]; ++ data++; ++ datalen--; ++ break; ++ case 0xc0 ... 0xfe: ++ /* Two-byte length */ ++ if (datalen < 3) ++ goto short_subpacket; ++ size = (data[0] - 192) * 256; ++ size += data[1] + 192; ++ data += 2; ++ datalen -= 2; ++ break; ++ case 0xff: ++ if (datalen < 6) ++ goto short_subpacket; ++ size = data[1] << 24; ++ size |= data[2] << 16; ++ size |= data[3] << 8; ++ size |= data[4]; ++ data += 5; ++ datalen -= 5; ++ break; ++ } ++ ++ /* The type octet is included in the size */ ++ if (size == 0) { ++ pr_debug("Signature subpacket size can't be zero\n"); ++ return -EBADMSG; ++ } ++ ++ type = *data++ & ~PGP_SIG_SUBPKT_TYPE_CRITICAL_MASK; ++ datalen--; ++ size--; ++ ++ pr_devel("datalen=%zu size=%zu", datalen, size); ++ if (datalen < size) ++ goto short_subpacket; ++ ++ *_data = data; ++ *_datalen = datalen; ++ *_type = type; ++ pr_devel("Found subpkt type=%u size=%zd\n", type, size); ++ return size; ++ ++short_subpacket: ++ pr_debug("Attempt to parse short signature subpacket\n"); ++ return -EBADMSG; ++} ++ ++/** ++ * pgp_parse_sig_subpkts - Parse a set of PGP V4 signatute subpackets ++ * @_data: Data to be parsed (updated) ++ * @_datalen: Amount of data (updated) ++ * @ctx: Parsing context ++ * ++ * Parse a set of PGP signature subpackets [RFC 4880: 5.2.3]. ++ */ ++int pgp_parse_sig_subpkts(const u8 *data, size_t datalen, ++ struct pgp_parse_sig_context *ctx) ++{ ++ enum pgp_sig_subpkt_type type; ++ ssize_t pktlen; ++ int ret; ++ ++ pr_devel("-->pgp_parse_sig_subpkts(,%zu,,)", datalen); ++ ++ while (datalen > 2) { ++ pktlen = pgp_parse_sig_subpkt_header(&data, &datalen, &type); ++ if (pktlen < 0) ++ return pktlen; ++ if (test_bit(type, ctx->types_of_interest)) { ++ ret = ctx->process_packet(ctx, type, data, pktlen); ++ if (ret < 0) ++ return ret; ++ } ++ data += pktlen; ++ datalen -= pktlen; ++ } ++ ++ if (datalen != 0) { ++ pr_debug("Excess octets in signature subpacket stream\n"); ++ return -EBADMSG; ++ } ++ ++ return 0; ++} ++EXPORT_SYMBOL_GPL(pgp_parse_sig_subpkts); ++ ++struct pgp_parse_sig_params_ctx { ++ struct pgp_parse_sig_context base; ++ struct pgp_sig_parameters *params; ++ bool got_the_issuer; ++}; ++ ++/* ++ * Process a V4 signature subpacket. ++ */ ++static int pgp_process_sig_params_subpkt(struct pgp_parse_sig_context *context, ++ enum pgp_sig_subpkt_type type, ++ const u8 *data, ++ size_t datalen) ++{ ++ struct pgp_parse_sig_params_ctx *ctx = ++ container_of(context, struct pgp_parse_sig_params_ctx, base); ++ ++ if (ctx->got_the_issuer) { ++ pr_debug("V4 signature packet has multiple issuers\n"); ++ return -EBADMSG; ++ } ++ ++ if (datalen != 8) { ++ pr_debug("V4 signature issuer subpkt not 8 long (%zu)\n", ++ datalen); ++ return -EBADMSG; ++ } ++ ++ memcpy(&ctx->params->issuer, data, 8); ++ ctx->got_the_issuer = true; ++ return 0; ++} ++ ++/** ++ * pgp_parse_sig_params - Parse basic parameters from a PGP signature packet ++ * @_data: Content of packet (updated) ++ * @_datalen: Length of packet remaining (updated) ++ * @p: The basic parameters ++ * ++ * Parse the basic parameters from a PGP signature packet [RFC 4880: 5.2] that ++ * are needed to start off a signature verification operation. The only ones ++ * actually necessary are the signature type (which affects how the data is ++ * transformed) and the has algorithm. ++ * ++ * We also extract the public key algorithm and the issuer's key ID as we'll ++ * need those to determine if we actually have the public key available. If ++ * not, then we can't verify the signature anyway. ++ * ++ * Returns 0 if successful or a negative error code. *_data and *_datalen are ++ * updated to point to the 16-bit subset of the hash value and the set of MPIs. ++ */ ++int pgp_parse_sig_params(const u8 **_data, size_t *_datalen, ++ struct pgp_sig_parameters *p) ++{ ++ enum pgp_signature_version version; ++ const u8 *data = *_data; ++ size_t datalen = *_datalen; ++ int ret; ++ ++ pr_devel("-->pgp_parse_sig_params(,%zu,,)", datalen); ++ ++ if (datalen < 1) ++ return -EBADMSG; ++ version = *data; ++ ++ if (version == PGP_SIG_VERSION_3) { ++ const struct pgp_signature_v3_packet *v3 = (const void *)data; ++ ++ if (datalen < sizeof(*v3)) { ++ pr_debug("Short V3 signature packet\n"); ++ return -EBADMSG; ++ } ++ datalen -= sizeof(*v3); ++ data += sizeof(*v3); ++ ++ /* V3 has everything we need in the header */ ++ p->signature_type = v3->hashed.signature_type; ++ p->issuer = v3->issuer; ++ p->pubkey_algo = v3->pubkey_algo; ++ p->hash_algo = v3->hash_algo; ++ ++ } else if (version == PGP_SIG_VERSION_4) { ++ const struct pgp_signature_v4_packet *v4 = (const void *)data; ++ struct pgp_parse_sig_params_ctx ctx = { ++ .base.process_packet = pgp_process_sig_params_subpkt, ++ .params = p, ++ .got_the_issuer = false, ++ }; ++ size_t subdatalen; ++ ++ if (datalen < sizeof(*v4) + 2 + 2 + 2) { ++ pr_debug("Short V4 signature packet\n"); ++ return -EBADMSG; ++ } ++ datalen -= sizeof(*v4); ++ data += sizeof(*v4); ++ ++ /* V4 has most things in the header... */ ++ p->signature_type = v4->signature_type; ++ p->pubkey_algo = v4->pubkey_algo; ++ p->hash_algo = v4->hash_algo; ++ ++ /* ... but we have to get the key ID from the subpackets, of ++ * which there are two sets. */ ++ __set_bit(PGP_SIG_ISSUER, ctx.base.types_of_interest); ++ ++ subdatalen = *data++ << 8; ++ subdatalen |= *data++; ++ datalen -= 2; ++ if (subdatalen) { ++ /* Hashed subpackets */ ++ pr_devel("hashed data: %zu (after %zu)\n", ++ subdatalen, sizeof(*v4)); ++ if (subdatalen > datalen + 2 + 2) { ++ pr_debug("Short V4 signature packet [hdata]\n"); ++ return -EBADMSG; ++ } ++ ret = pgp_parse_sig_subpkts(data, subdatalen, ++ &ctx.base); ++ if (ret < 0) ++ return ret; ++ data += subdatalen; ++ datalen += subdatalen; ++ } ++ ++ subdatalen = *data++ << 8; ++ subdatalen |= *data++; ++ datalen -= 2; ++ if (subdatalen) { ++ /* Unhashed subpackets */ ++ pr_devel("unhashed data: %zu\n", subdatalen); ++ if (subdatalen > datalen + 2) { ++ pr_debug("Short V4 signature packet [udata]\n"); ++ return -EBADMSG; ++ } ++ ret = pgp_parse_sig_subpkts(data, subdatalen, ++ &ctx.base); ++ if (ret < 0) ++ return ret; ++ data += subdatalen; ++ datalen += subdatalen; ++ } ++ ++ if (!ctx.got_the_issuer) { ++ pr_debug("V4 signature packet lacks issuer\n"); ++ return -EBADMSG; ++ } ++ } else { ++ pr_debug("Signature packet with unhandled version %d\n", ++ version); ++ return -EBADMSG; ++ } ++ ++ *_data = data; ++ *_datalen = datalen; ++ return 0; ++} ++EXPORT_SYMBOL_GPL(pgp_parse_sig_params); +-- +1.7.10.2 + + +From 53f01a04d44b822af15cd31bb451ca13695bdf1c Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Fri, 4 May 2012 16:36:35 +0100 +Subject: [PATCH 13/36] KEYS: PGP data parser + +Implement a PGP data parser for the crypto key type to use when instantiating a +key. + +This parser attempts to parse the instantiation data as a PGP packet sequence +(RFC 4880) and if it parses okay, attempts to extract a public-key algorithm +key or subkey from it. + +If it finds such a key, it will set up a public_key subtype payload with +appropriate handler routines (DSA or RSA) and attach it to the key. + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + security/keys/crypto/Kconfig | 12 ++ + security/keys/crypto/Makefile | 4 + + security/keys/crypto/pgp_key_parser.c | 343 +++++++++++++++++++++++++++++++++ + security/keys/crypto/pgp_parser.h | 23 +++ + 4 files changed, 382 insertions(+) + create mode 100644 security/keys/crypto/pgp_key_parser.c + create mode 100644 security/keys/crypto/pgp_parser.h + +diff --git a/security/keys/crypto/Kconfig b/security/keys/crypto/Kconfig +index 88ce0e2..1c2ae55 100644 +--- a/security/keys/crypto/Kconfig ++++ b/security/keys/crypto/Kconfig +@@ -28,3 +28,15 @@ config PGP_LIBRARY + help + This option enables a library that provides a number of simple + utility functions for parsing PGP (RFC 4880) packet-based messages. ++ ++config CRYPTO_KEY_PGP_PARSER ++ tristate "PGP key blob parser" ++ depends on CRYPTO_KEY_TYPE ++ select CRYPTO_KEY_PUBLIC_KEY_SUBTYPE ++ select PGP_LIBRARY ++ select MD5 # V3 fingerprint generation ++ select SHA1 # V4 fingerprint generation ++ help ++ This option provides support for parsing PGP (RFC 4880) format blobs ++ for key data and provides the ability to instantiate a crypto key ++ from a public key packet found inside the blob. +diff --git a/security/keys/crypto/Makefile b/security/keys/crypto/Makefile +index 5fbe54e..3bb2e61 100644 +--- a/security/keys/crypto/Makefile ++++ b/security/keys/crypto/Makefile +@@ -8,3 +8,7 @@ crypto_keys-y := crypto_type.o crypto_verify.o + obj-$(CONFIG_CRYPTO_KEY_PUBLIC_KEY_SUBTYPE) += public_key.o + obj-$(CONFIG_CRYPTO_KEY_PKEY_ALGO_RSA) += crypto_rsa.o + obj-$(CONFIG_PGP_LIBRARY) += pgp_library.o ++ ++obj-$(CONFIG_CRYPTO_KEY_PGP_PARSER) += pgp_parser.o ++pgp_parser-y := \ ++ pgp_key_parser.o +diff --git a/security/keys/crypto/pgp_key_parser.c b/security/keys/crypto/pgp_key_parser.c +new file mode 100644 +index 0000000..4efc4de +--- /dev/null ++++ b/security/keys/crypto/pgp_key_parser.c +@@ -0,0 +1,343 @@ ++/* Parser for PGP format key data [RFC 4880] ++ * ++ * Copyright (C) 2011 Red Hat, Inc. All Rights Reserved. ++ * Written by David Howells (dhowells@redhat.com) ++ * ++ * This program is free software; you can redistribute it and/or ++ * modify it under the terms of the GNU General Public Licence ++ * as published by the Free Software Foundation; either version ++ * 2 of the Licence, or (at your option) any later version. ++ */ ++ ++#define pr_fmt(fmt) "PGP: "fmt ++#include <keys/crypto-subtype.h> ++#include <linux/module.h> ++#include <linux/kernel.h> ++#include <linux/slab.h> ++#include <linux/mpi.h> ++#include <linux/pgp.h> ++#include <crypto/hash.h> ++#include "public_key.h" ++#include "pgp_parser.h" ++ ++MODULE_LICENSE("GPL"); ++ ++const ++struct public_key_algorithm *pgp_public_key_algorithms[PGP_PUBKEY__LAST] = { ++#if defined(CONFIG_CRYPTO_KEY_PKEY_ALGO_RSA) || \ ++ defined(CONFIG_CRYPTO_KEY_PKEY_ALGO_RSA_MODULE) ++ [PGP_PUBKEY_RSA_ENC_OR_SIG] = &RSA_public_key_algorithm, ++ [PGP_PUBKEY_RSA_ENC_ONLY] = &RSA_public_key_algorithm, ++ [PGP_PUBKEY_RSA_SIG_ONLY] = &RSA_public_key_algorithm, ++#endif ++ [PGP_PUBKEY_ELGAMAL] = NULL, ++ [PGP_PUBKEY_DSA] = NULL, ++}; ++ ++static const u8 pgp_public_key_capabilities[PGP_PUBKEY__LAST] = { ++ [PGP_PUBKEY_RSA_ENC_OR_SIG] = PKEY_CAN_ENCDEC | PKEY_CAN_SIGVER, ++ [PGP_PUBKEY_RSA_ENC_ONLY] = PKEY_CAN_ENCDEC, ++ [PGP_PUBKEY_RSA_SIG_ONLY] = PKEY_CAN_SIGVER, ++ [PGP_PUBKEY_ELGAMAL] = 0, ++ [PGP_PUBKEY_DSA] = 0, ++}; ++ ++static inline void digest_putc(struct shash_desc *digest, uint8_t ch) ++{ ++ crypto_shash_update(digest, &ch, 1); ++} ++ ++struct pgp_key_data_parse_context { ++ struct pgp_parse_context pgp; ++ struct crypto_key_subtype *subtype; ++ char *fingerprint; ++ void *payload; ++}; ++ ++/* ++ * Calculate the public key ID (RFC4880 12.2) ++ */ ++static int pgp_calc_pkey_keyid(struct shash_desc *digest, ++ struct pgp_parse_pubkey *pgp, ++ struct public_key *key) ++{ ++ unsigned nb[ARRAY_SIZE(key->mpi)]; ++ unsigned nn[ARRAY_SIZE(key->mpi)]; ++ unsigned n; ++ u8 *pp[ARRAY_SIZE(key->mpi)]; ++ u32 a32; ++ int npkey = key->algo->n_pub_mpi; ++ int i, ret = -ENOMEM; ++ ++ kenter(""); ++ ++ n = (pgp->version < PGP_KEY_VERSION_4) ? 8 : 6; ++ for (i = 0; i < npkey; i++) { ++ nb[i] = mpi_get_nbits(key->mpi[i]); ++ pp[i] = mpi_get_buffer(key->mpi[i], nn + i, NULL); ++ if (!pp[i]) ++ goto error; ++ n += 2 + nn[i]; ++ } ++ ++ digest_putc(digest, 0x99); /* ctb */ ++ digest_putc(digest, n >> 8); /* 16-bit header length */ ++ digest_putc(digest, n); ++ digest_putc(digest, pgp->version); ++ ++ a32 = pgp->creation_time; ++ digest_putc(digest, a32 >> 24); ++ digest_putc(digest, a32 >> 16); ++ digest_putc(digest, a32 >> 8); ++ digest_putc(digest, a32 >> 0); ++ ++ if (pgp->version < PGP_KEY_VERSION_4) { ++ u16 a16; ++ ++ if( pgp->expires_at) ++ a16 = (pgp->expires_at - pgp->creation_time) / 86400UL; ++ else ++ a16 = 0; ++ digest_putc(digest, a16 >> 8); ++ digest_putc(digest, a16 >> 0); ++ } ++ ++ digest_putc(digest, pgp->pubkey_algo); ++ ++ for (i = 0; i < npkey; i++) { ++ digest_putc(digest, nb[i] >> 8); ++ digest_putc(digest, nb[i]); ++ crypto_shash_update(digest, pp[i], nn[i]); ++ } ++ ret = 0; ++ ++error: ++ for (i = 0; i < npkey; i++) ++ kfree(pp[i]); ++ kleave(" = %d", ret); ++ return ret; ++} ++ ++/* ++ * Calculate the public key ID fingerprint ++ */ ++static int pgp_generate_fingerprint(struct pgp_key_data_parse_context *ctx, ++ struct pgp_parse_pubkey *pgp, ++ struct public_key *key) ++{ ++ struct crypto_shash *tfm; ++ struct shash_desc *digest; ++ char *fingerprint; ++ u8 *raw_fingerprint; ++ int digest_size, offset; ++ int ret, i; ++ ++ ret = -ENOMEM; ++ tfm = crypto_alloc_shash(pgp->version < PGP_KEY_VERSION_4 ? ++ "md5" : "sha1", 0, 0); ++ if (!tfm) ++ goto cleanup; ++ ++ digest = kmalloc(sizeof(*digest) + crypto_shash_descsize(tfm), ++ GFP_KERNEL); ++ if (!digest) ++ goto cleanup_tfm; ++ ++ digest->tfm = tfm; ++ digest->flags = CRYPTO_TFM_REQ_MAY_SLEEP; ++ ret = crypto_shash_init(digest); ++ if (ret < 0) ++ goto cleanup_hash; ++ ++ ret = pgp_calc_pkey_keyid(digest, pgp, key); ++ if (ret < 0) ++ goto cleanup_hash; ++ ++ digest_size = crypto_shash_digestsize(tfm); ++ ++ raw_fingerprint = kmalloc(digest_size, GFP_KERNEL); ++ if (!raw_fingerprint) ++ goto cleanup_hash; ++ ++ ret = crypto_shash_final(digest, raw_fingerprint); ++ if (ret < 0) ++ goto cleanup_raw_fingerprint; ++ ++ fingerprint = kmalloc(digest_size * 2 + 1, GFP_KERNEL); ++ if (!fingerprint) ++ goto cleanup_raw_fingerprint; ++ ++ offset = digest_size - 8; ++ pr_debug("offset %u/%u\n", offset, digest_size); ++ ++ for (i = 0; i < digest_size; i++) ++ sprintf(fingerprint + i * 2, "%02x", raw_fingerprint[i]); ++ pr_debug("fingerprint %s\n", fingerprint); ++ ++ memcpy(&key->key_id, raw_fingerprint + offset, 8); ++ key->key_id_size = 8; ++ ++ ctx->fingerprint = fingerprint; ++ ret = 0; ++cleanup_raw_fingerprint: ++ kfree(raw_fingerprint); ++cleanup_hash: ++ kfree(digest); ++cleanup_tfm: ++ crypto_free_shash(tfm); ++cleanup: ++ kleave(" = %d", ret); ++ return ret; ++} ++ ++/* ++ * Extract a public key or public subkey from the PGP stream. ++ */ ++static int pgp_process_public_key(struct pgp_parse_context *context, ++ enum pgp_packet_tag type, ++ u8 headerlen, ++ const u8 *data, ++ size_t datalen) ++{ ++ const struct public_key_algorithm *algo; ++ struct pgp_key_data_parse_context *ctx = ++ container_of(context, struct pgp_key_data_parse_context, pgp); ++ struct pgp_parse_pubkey pgp; ++ struct public_key *key; ++ int i, ret; ++ ++ kenter(",%u,%u,,%zu", type, headerlen, datalen); ++ ++ if (ctx->subtype) { ++ kleave(" = -ENOKEY [already]"); ++ return -EBADMSG; ++ } ++ ++ key = kzalloc(sizeof(struct public_key), GFP_KERNEL); ++ if (!key) ++ return -ENOMEM; ++ ++ ret = pgp_parse_public_key(&data, &datalen, &pgp); ++ if (ret < 0) ++ goto cleanup; ++ ++ if (pgp.pubkey_algo >= PGP_PUBKEY__LAST || ++ !pgp_public_key_algorithms[pgp.pubkey_algo]) { ++ pr_debug("Unsupported public key algorithm %u\n", ++ pgp.pubkey_algo); ++ ret = -ENOPKG; ++ goto cleanup; ++ } ++ ++ algo = key->algo = pgp_public_key_algorithms[pgp.pubkey_algo]; ++ ++ /* It's a public key, so that only gives us encrypt and verify ++ * capabilities. ++ */ ++ key->capabilities = pgp_public_key_capabilities[pgp.pubkey_algo] & ++ (PKEY_CAN_ENCRYPT | PKEY_CAN_VERIFY); ++ ++ ret = -ENOMEM; ++ for (i = 0; i < algo->n_pub_mpi; i++) { ++ unsigned int remaining = datalen; ++ ret = -EBADMSG; ++ if (remaining == 0) { ++ pr_debug("short %zu mpi %d\n", datalen, i); ++ goto cleanup; ++ } ++ key->mpi[i] = mpi_read_from_buffer(data, &remaining); ++ if (!key->mpi[i]) ++ goto cleanup; ++ data += remaining; ++ datalen -= remaining; ++ } ++ ++ ret = -EBADMSG; ++ if (datalen != 0) { ++ pr_debug("excess %zu\n", datalen); ++ goto cleanup; ++ } ++ ++ ret = pgp_generate_fingerprint(ctx, &pgp, key); ++ if (ret < 0) ++ goto cleanup; ++ ++ /* We're pinning the module by being linked against it */ ++ __module_get(public_key_crypto_key_subtype.owner); ++ ctx->subtype = &public_key_crypto_key_subtype; ++ ctx->payload = key; ++ kleave(" = 0 [use]"); ++ return 0; ++ ++cleanup: ++ pr_devel("cleanup"); ++ if (key) { ++ for (i = 0; i < ARRAY_SIZE(key->mpi); i++) ++ mpi_free(key->mpi[i]); ++ kfree(key); ++ } ++ kleave(" = %d", ret); ++ return ret; ++} ++ ++/* ++ * Attempt to parse the instantiation data blob for a key as a PGP packet ++ * message holding a key. ++ */ ++static int pgp_key_instantiate(struct key *key, ++ const void *data, size_t datalen) ++{ ++ struct pgp_key_data_parse_context ctx; ++ int ret; ++ ++ kenter(""); ++ ++ ret = key_payload_reserve(key, datalen); ++ if (ret < 0) ++ return ret; ++ ++ ctx.pgp.types_of_interest = ++ (1 << PGP_PKT_PUBLIC_KEY) | (1 << PGP_PKT_PUBLIC_SUBKEY); ++ ctx.pgp.process_packet = pgp_process_public_key; ++ ctx.subtype = NULL; ++ ctx.fingerprint = NULL; ++ ctx.payload = NULL; ++ ++ ret = pgp_parse_packets(data, datalen, &ctx.pgp); ++ if (ret < 0) { ++ if (ctx.payload) ++ ctx.subtype->destroy(ctx.payload); ++ if (ctx.subtype) ++ module_put(ctx.subtype->owner); ++ kfree(ctx.fingerprint); ++ key_payload_reserve(key, 0); ++ return ret; ++ } ++ ++ key->type_data.p[0] = ctx.subtype; ++ key->type_data.p[1] = ctx.fingerprint; ++ key->payload.data = ctx.payload; ++ return 0; ++} ++ ++static struct crypto_key_parser pgp_key_parser = { ++ .owner = THIS_MODULE, ++ .name = "pgp", ++ .instantiate = pgp_key_instantiate, ++}; ++ ++/* ++ * Module stuff ++ */ ++static int __init pgp_key_init(void) ++{ ++ return register_crypto_key_parser(&pgp_key_parser); ++} ++ ++static void __exit pgp_key_exit(void) ++{ ++ unregister_crypto_key_parser(&pgp_key_parser); ++} ++ ++module_init(pgp_key_init); ++module_exit(pgp_key_exit); +diff --git a/security/keys/crypto/pgp_parser.h b/security/keys/crypto/pgp_parser.h +new file mode 100644 +index 0000000..1cda231 +--- /dev/null ++++ b/security/keys/crypto/pgp_parser.h +@@ -0,0 +1,23 @@ ++/* PGP crypto data parser internal definitions ++ * ++ * Copyright (C) 2011 Red Hat, Inc. All Rights Reserved. ++ * Written by David Howells (dhowells@redhat.com) ++ * ++ * This program is free software; you can redistribute it and/or ++ * modify it under the terms of the GNU General Public Licence ++ * as published by the Free Software Foundation; either version ++ * 2 of the Licence, or (at your option) any later version. ++ */ ++ ++#include <linux/pgp.h> ++ ++#define kenter(FMT, ...) \ ++ pr_devel("==> %s("FMT")\n", __func__, ##__VA_ARGS__) ++#define kleave(FMT, ...) \ ++ pr_devel("<== %s()"FMT"\n", __func__, ##__VA_ARGS__) ++ ++/* ++ * pgp_key_parser.c ++ */ ++extern const ++struct public_key_algorithm *pgp_public_key_algorithms[PGP_PUBKEY__LAST]; +-- +1.7.10.2 + + +From 3e401cdc0ae1768ecbc301a631a2a34f56834313 Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Fri, 4 May 2012 16:40:17 +0100 +Subject: [PATCH 14/36] KEYS: PGP-based public key signature verification + +Provide handlers for PGP-based public-key algorithm signature verification. +This does most of the work involved in signature verification as most of it is +public-key algorithm agnostic. The public-key verification algorithm itself +is just the last little bit and is supplied the complete hash data to process. + +This requires glue logic putting on top to make use of it - something the next +patch provides. + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + security/keys/crypto/Makefile | 3 +- + security/keys/crypto/pgp_parser.h | 6 + + security/keys/crypto/pgp_pubkey_sig.c | 323 +++++++++++++++++++++++++++++++++ + 3 files changed, 331 insertions(+), 1 deletion(-) + create mode 100644 security/keys/crypto/pgp_pubkey_sig.c + +diff --git a/security/keys/crypto/Makefile b/security/keys/crypto/Makefile +index 3bb2e61..d4ac8ac 100644 +--- a/security/keys/crypto/Makefile ++++ b/security/keys/crypto/Makefile +@@ -11,4 +11,5 @@ obj-$(CONFIG_PGP_LIBRARY) += pgp_library.o + + obj-$(CONFIG_CRYPTO_KEY_PGP_PARSER) += pgp_parser.o + pgp_parser-y := \ +- pgp_key_parser.o ++ pgp_key_parser.o \ ++ pgp_pubkey_sig.o +diff --git a/security/keys/crypto/pgp_parser.h b/security/keys/crypto/pgp_parser.h +index 1cda231..a6192ce 100644 +--- a/security/keys/crypto/pgp_parser.h ++++ b/security/keys/crypto/pgp_parser.h +@@ -21,3 +21,9 @@ + */ + extern const + struct public_key_algorithm *pgp_public_key_algorithms[PGP_PUBKEY__LAST]; ++ ++/* ++ * pgp_pubkey_sig.c ++ */ ++extern struct crypto_key_verify_context *pgp_pkey_verify_sig_begin( ++ struct key *crypto_key, const u8 *sigdata, size_t siglen); +diff --git a/security/keys/crypto/pgp_pubkey_sig.c b/security/keys/crypto/pgp_pubkey_sig.c +new file mode 100644 +index 0000000..b4b7cb0 +--- /dev/null ++++ b/security/keys/crypto/pgp_pubkey_sig.c +@@ -0,0 +1,323 @@ ++/* Handling for PGP public key signature data [RFC 4880] ++ * ++ * Copyright (C) 2011 Red Hat, Inc. All Rights Reserved. ++ * Written by David Howells (dhowells@redhat.com) ++ * ++ * This program is free software; you can redistribute it and/or ++ * modify it under the terms of the GNU General Public Licence ++ * as published by the Free Software Foundation; either version ++ * 2 of the Licence, or (at your option) any later version. ++ */ ++ ++#define pr_fmt(fmt) "PGPSIG: "fmt ++#include <linux/module.h> ++#include <linux/kernel.h> ++#include <linux/slab.h> ++#include <linux/pgp.h> ++#include "public_key.h" ++#include "pgp_parser.h" ++ ++const struct { ++ enum pkey_hash_algo algo : 8; ++} pgp_pubkey_hash[PGP_HASH__LAST] = { ++ [PGP_HASH_MD5].algo = PKEY_HASH_MD5, ++ [PGP_HASH_SHA1].algo = PKEY_HASH_SHA1, ++ [PGP_HASH_RIPE_MD_160].algo = PKEY_HASH_RIPE_MD_160, ++ [PGP_HASH_SHA256].algo = PKEY_HASH_SHA256, ++ [PGP_HASH_SHA384].algo = PKEY_HASH_SHA384, ++ [PGP_HASH_SHA512].algo = PKEY_HASH_SHA512, ++ [PGP_HASH_SHA224].algo = PKEY_HASH_SHA224, ++}; ++ ++static int pgp_pkey_verify_sig_add_data(struct crypto_key_verify_context *ctx, ++ const void *data, size_t datalen); ++static int pgp_pkey_verify_sig_end(struct crypto_key_verify_context *ctx, ++ const u8 *sig, size_t siglen); ++static void pgp_pkey_verify_sig_cancel(struct crypto_key_verify_context *ctx); ++ ++struct pgp_pkey_sig_parse_context { ++ struct pgp_parse_context pgp; ++ struct pgp_sig_parameters params; ++}; ++ ++static int pgp_pkey_parse_signature(struct pgp_parse_context *context, ++ enum pgp_packet_tag type, ++ u8 headerlen, ++ const u8 *data, ++ size_t datalen) ++{ ++ struct pgp_pkey_sig_parse_context *ctx = ++ container_of(context, struct pgp_pkey_sig_parse_context, pgp); ++ ++ return pgp_parse_sig_params(&data, &datalen, &ctx->params); ++} ++ ++/* ++ * Begin the process of verifying a DSA signature. ++ * ++ * This involves allocating the hash into which first the data and then the ++ * metadata will be put, and parsing the signature to check that it matches the ++ * key. ++ */ ++struct crypto_key_verify_context *pgp_pkey_verify_sig_begin( ++ struct key *crypto_key, const u8 *sigdata, size_t siglen) ++{ ++ struct pgp_pkey_sig_parse_context p; ++ struct public_key_signature *sig; ++ struct crypto_shash *tfm; ++ const struct public_key *key = crypto_key->payload.data; ++ size_t digest_size, desc_size; ++ int ret; ++ ++ kenter("{%d},,%zu", key_serial(crypto_key), siglen); ++ ++ if (!key) { ++ kleave(" = -ENOKEY [no public key]"); ++ return ERR_PTR(-ENOKEY); ++ } ++ ++ p.pgp.types_of_interest = (1 << PGP_PKT_SIGNATURE); ++ p.pgp.process_packet = pgp_pkey_parse_signature; ++ ret = pgp_parse_packets(sigdata, siglen, &p.pgp); ++ if (ret < 0) ++ return ERR_PTR(ret); ++ ++ if (p.params.pubkey_algo >= PGP_PUBKEY__LAST || ++ !pgp_public_key_algorithms[p.params.pubkey_algo]) { ++ pr_debug("Unsupported public key algorithm %u\n", ++ p.params.pubkey_algo); ++ return ERR_PTR(-ENOKEY); ++ } ++ ++ if (pgp_public_key_algorithms[p.params.pubkey_algo] != key->algo) { ++ kleave(" = -ENOKEY [wrong pk algo]"); ++ return ERR_PTR(-ENOKEY); ++ } ++ ++ if (!(key->capabilities & PKEY_CAN_VERIFY)) { ++ kleave(" = -EKEYREJECTED [key can't verify]"); ++ return ERR_PTR(-EKEYREJECTED); ++ } ++ ++ if (p.params.hash_algo >= PGP_HASH__LAST || ++ !pgp_hash_algorithms[p.params.hash_algo]) { ++ kleave(" = -ENOPKG [hash]"); ++ return ERR_PTR(-ENOPKG); ++ } ++ ++ pr_debug("Signature generated with %s hash\n", ++ pgp_hash_algorithms[p.params.hash_algo]); ++ ++ if (memcmp(&p.params.issuer, key->key_id, 8) != 0) { ++ kleave(" = -ENOKEY [wrong key ID]"); ++ return ERR_PTR(-ENOKEY); ++ } ++ ++ if (p.params.signature_type != PGP_SIG_BINARY_DOCUMENT_SIG && ++ p.params.signature_type != PGP_SIG_STANDALONE_SIG) { ++ /* We don't want to canonicalise */ ++ kleave(" = -EOPNOTSUPP [canon]"); ++ return ERR_PTR(-EOPNOTSUPP); ++ } ++ ++ /* Allocate the hashing algorithm we're going to need and find out how ++ * big the hash operational data will be. ++ */ ++ tfm = crypto_alloc_shash(pgp_hash_algorithms[p.params.hash_algo], 0, 0); ++ if (IS_ERR(tfm)) ++ return PTR_ERR(tfm) == -ENOENT ? ++ ERR_PTR(-ENOPKG) : ERR_CAST(tfm); ++ ++ desc_size = crypto_shash_descsize(tfm); ++ digest_size = crypto_shash_digestsize(tfm); ++ ++ /* We allocate the hash operational data storage on the end of our ++ * context data. ++ */ ++ sig = kzalloc(sizeof(*sig) + desc_size + digest_size, GFP_KERNEL); ++ if (!sig) { ++ crypto_free_shash(tfm); ++ return ERR_PTR(-ENOMEM); ++ } ++ ++ sig->base.key = crypto_key; ++ sig->base.add_data = pgp_pkey_verify_sig_add_data; ++ sig->base.end = pgp_pkey_verify_sig_end; ++ sig->base.cancel = pgp_pkey_verify_sig_cancel; ++ sig->pkey_hash_algo = pgp_pubkey_hash[p.params.hash_algo].algo; ++ sig->digest = (u8 *)sig + sizeof(*sig) + desc_size; ++ sig->digest_size = digest_size; ++ sig->hash.tfm = tfm; ++ sig->hash.flags = CRYPTO_TFM_REQ_MAY_SLEEP; ++ ++ ret = crypto_shash_init(&sig->hash); ++ if (ret < 0) { ++ crypto_free_shash(sig->hash.tfm); ++ kfree(sig); ++ return ERR_PTR(ret); ++ } ++ ++ key_get(sig->base.key); ++ kleave(" = %p", sig); ++ return &sig->base; ++} ++ ++/* ++ * Load data into the hash ++ */ ++static int pgp_pkey_verify_sig_add_data(struct crypto_key_verify_context *ctx, ++ const void *data, size_t datalen) ++{ ++ struct public_key_signature *sig = ++ container_of(ctx, struct public_key_signature, base); ++ ++ return crypto_shash_update(&sig->hash, data, datalen); ++} ++ ++struct pgp_pkey_sig_digest_context { ++ struct pgp_parse_context pgp; ++ const struct public_key *key; ++ struct public_key_signature *sig; ++}; ++ ++/* ++ * Extract required metadata from the signature packet and add what we need to ++ * to the hash. ++ */ ++static int pgp_pkey_digest_signature(struct pgp_parse_context *context, ++ enum pgp_packet_tag type, ++ u8 headerlen, ++ const u8 *data, ++ size_t datalen) ++{ ++ struct pgp_pkey_sig_digest_context *ctx = ++ container_of(context, struct pgp_pkey_sig_digest_context, pgp); ++ enum pgp_signature_version version; ++ int i; ++ ++ kenter(",%u,%u,,%zu", type, headerlen, datalen); ++ ++ version = *data; ++ if (version == PGP_SIG_VERSION_3) { ++ /* We just include an excerpt of the metadata from a V3 ++ * signature. ++ */ ++ crypto_shash_update(&ctx->sig->hash, data + 1, 5); ++ data += sizeof(struct pgp_signature_v3_packet); ++ datalen -= sizeof(struct pgp_signature_v3_packet); ++ } else if (version == PGP_SIG_VERSION_4) { ++ /* We add the whole metadata header and some of the hashed data ++ * for a V4 signature, plus a trailer. ++ */ ++ size_t hashedsz, unhashedsz; ++ u8 trailer[6]; ++ ++ hashedsz = 4 + 2 + (data[4] << 8) + data[5]; ++ crypto_shash_update(&ctx->sig->hash, data, hashedsz); ++ ++ trailer[0] = version; ++ trailer[1] = 0xffU; ++ trailer[2] = hashedsz >> 24; ++ trailer[3] = hashedsz >> 16; ++ trailer[4] = hashedsz >> 8; ++ trailer[5] = hashedsz; ++ ++ crypto_shash_update(&ctx->sig->hash, trailer, 6); ++ data += hashedsz; ++ datalen -= hashedsz; ++ ++ unhashedsz = 2 + (data[0] << 8) + data[1]; ++ data += unhashedsz; ++ datalen -= unhashedsz; ++ } ++ ++ if (datalen <= 2) { ++ kleave(" = -EBADMSG"); ++ return -EBADMSG; ++ } ++ ++ /* There's a quick check on the hash available. */ ++ ctx->sig->signed_hash_msw[0] = *data++; ++ ctx->sig->signed_hash_msw[1] = *data++; ++ datalen -= 2; ++ ++ /* And then the cryptographic data, which we'll need for the ++ * algorithm. ++ */ ++ for (i = 0; i < ctx->key->algo->n_sig_mpi; i++) { ++ unsigned int remaining = datalen; ++ if (remaining == 0) { ++ pr_debug("short %zu mpi %d\n", datalen, i); ++ return -EBADMSG; ++ } ++ ctx->sig->mpi[i] = mpi_read_from_buffer(data, &remaining); ++ if (!ctx->sig->mpi[i]) ++ return -ENOMEM; ++ data += remaining; ++ datalen -= remaining; ++ } ++ ++ if (datalen != 0) { ++ kleave(" = -EBADMSG [trailer %zu]", datalen); ++ return -EBADMSG; ++ } ++ ++ kleave(" = 0"); ++ return 0; ++} ++ ++/* ++ * The data is now all loaded into the hash; load the metadata, finalise the ++ * hash and perform the verification step. ++ */ ++static int pgp_pkey_verify_sig_end(struct crypto_key_verify_context *ctx, ++ const u8 *sigdata, size_t siglen) ++{ ++ struct public_key_signature *sig = ++ container_of(ctx, struct public_key_signature, base); ++ const struct public_key *key = sig->base.key->payload.data; ++ struct pgp_pkey_sig_digest_context p; ++ int ret; ++ ++ kenter(""); ++ ++ /* Firstly we add metadata, starting with some of the data from the ++ * signature packet */ ++ p.pgp.types_of_interest = (1 << PGP_PKT_SIGNATURE); ++ p.pgp.process_packet = pgp_pkey_digest_signature; ++ p.key = key; ++ p.sig = sig; ++ ret = pgp_parse_packets(sigdata, siglen, &p.pgp); ++ if (ret < 0) ++ goto error_free_ctx; ++ ++ crypto_shash_final(&sig->hash, sig->digest); ++ ++ ret = key->algo->verify(key, sig); ++ ++error_free_ctx: ++ pgp_pkey_verify_sig_cancel(ctx); ++ kleave(" = %d", ret); ++ return ret; ++} ++ ++/* ++ * Cancel an in-progress data loading ++ */ ++static void pgp_pkey_verify_sig_cancel(struct crypto_key_verify_context *ctx) ++{ ++ struct public_key_signature *sig = ++ container_of(ctx, struct public_key_signature, base); ++ int i; ++ ++ kenter(""); ++ ++ /* !!! Do we need to tell the crypto layer to cancel too? */ ++ crypto_free_shash(sig->hash.tfm); ++ key_put(sig->base.key); ++ for (i = 0; i < ARRAY_SIZE(sig->mpi); i++) ++ mpi_free(sig->mpi[i]); ++ kfree(sig); ++ ++ kleave(""); ++} +-- +1.7.10.2 + + +From 55e67eca050ff43915912e50dda49ecafdc816aa Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Fri, 4 May 2012 16:40:39 +0100 +Subject: [PATCH 15/36] KEYS: PGP format signature parser + +Implement a signature parser that will attempt to parse a signature blob as a +PGP packet format message. If it can, it will find an appropriate crypto key +and set the public-key algorithm according to the data in the signature. + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + security/keys/crypto/Makefile | 1 + + security/keys/crypto/pgp_key_parser.c | 1 + + security/keys/crypto/pgp_parser.h | 6 ++ + security/keys/crypto/pgp_sig_parser.c | 104 +++++++++++++++++++++++++++++++++ + 4 files changed, 112 insertions(+) + create mode 100644 security/keys/crypto/pgp_sig_parser.c + +diff --git a/security/keys/crypto/Makefile b/security/keys/crypto/Makefile +index d4ac8ac..fa7746d 100644 +--- a/security/keys/crypto/Makefile ++++ b/security/keys/crypto/Makefile +@@ -12,4 +12,5 @@ obj-$(CONFIG_PGP_LIBRARY) += pgp_library.o + obj-$(CONFIG_CRYPTO_KEY_PGP_PARSER) += pgp_parser.o + pgp_parser-y := \ + pgp_key_parser.o \ ++ pgp_sig_parser.o \ + pgp_pubkey_sig.o +diff --git a/security/keys/crypto/pgp_key_parser.c b/security/keys/crypto/pgp_key_parser.c +index 4efc4de..1407e2e 100644 +--- a/security/keys/crypto/pgp_key_parser.c ++++ b/security/keys/crypto/pgp_key_parser.c +@@ -324,6 +324,7 @@ static struct crypto_key_parser pgp_key_parser = { + .owner = THIS_MODULE, + .name = "pgp", + .instantiate = pgp_key_instantiate, ++ .verify_sig_begin = pgp_verify_sig_begin, + }; + + /* +diff --git a/security/keys/crypto/pgp_parser.h b/security/keys/crypto/pgp_parser.h +index a6192ce..73c900e 100644 +--- a/security/keys/crypto/pgp_parser.h ++++ b/security/keys/crypto/pgp_parser.h +@@ -23,6 +23,12 @@ extern const + struct public_key_algorithm *pgp_public_key_algorithms[PGP_PUBKEY__LAST]; + + /* ++ * pgp_sig_parser.c ++ */ ++extern struct crypto_key_verify_context *pgp_verify_sig_begin( ++ struct key *keyring, const u8 *sig, size_t siglen); ++ ++/* + * pgp_pubkey_sig.c + */ + extern struct crypto_key_verify_context *pgp_pkey_verify_sig_begin( +diff --git a/security/keys/crypto/pgp_sig_parser.c b/security/keys/crypto/pgp_sig_parser.c +new file mode 100644 +index 0000000..b72c505 +--- /dev/null ++++ b/security/keys/crypto/pgp_sig_parser.c +@@ -0,0 +1,104 @@ ++/* Handling for PGP public key signature data [RFC 4880] ++ * ++ * Copyright (C) 2011 Red Hat, Inc. All Rights Reserved. ++ * Written by David Howells (dhowells@redhat.com) ++ * ++ * This program is free software; you can redistribute it and/or ++ * modify it under the terms of the GNU General Public Licence ++ * as published by the Free Software Foundation; either version ++ * 2 of the Licence, or (at your option) any later version. ++ */ ++ ++#define pr_fmt(fmt) "PGPSIG: "fmt ++#include <linux/module.h> ++#include <linux/kernel.h> ++#include <linux/pgp.h> ++#include "public_key.h" ++#include "pgp_parser.h" ++ ++struct PGP_sig_parse_context { ++ struct pgp_parse_context pgp; ++ struct pgp_sig_parameters params; ++ bool found_sig; ++}; ++ ++/* ++ * Look inside signature sections for a key ID ++ */ ++static int pgp_process_signature(struct pgp_parse_context *context, ++ enum pgp_packet_tag type, ++ u8 headerlen, ++ const u8 *data, ++ size_t datalen) ++{ ++ struct PGP_sig_parse_context *ctx = ++ container_of(context, struct PGP_sig_parse_context, pgp); ++ ++ ctx->found_sig = true; ++ return pgp_parse_sig_params(&data, &datalen, &ctx->params); ++} ++ ++/* ++ * Attempt to find a key to use for PGP signature verification, starting off by ++ * looking in the supplied keyring. ++ * ++ * The function may also look for other key sources such as a TPM. If an ++ * alternative key is found it can be added to the keyring for future ++ * reference. ++ */ ++static struct key *find_key_for_pgp_sig(struct key *keyring, ++ const u8 *sig, size_t siglen) ++{ ++ struct PGP_sig_parse_context p; ++ key_ref_t key; ++ char criterion[3 + 8 * 2 + 1]; ++ int ret; ++ ++ if (!keyring) ++ return ERR_PTR(-ENOKEY); ++ ++ /* Need to find the key ID */ ++ p.pgp.types_of_interest = (1 << PGP_PKT_SIGNATURE); ++ p.pgp.process_packet = pgp_process_signature; ++ p.found_sig = false; ++ ret = pgp_parse_packets(sig, siglen, &p.pgp); ++ if (ret < 0) ++ return ERR_PTR(ret); ++ ++ if (!p.found_sig) ++ return ERR_PTR(-EINVAL); ++ ++ sprintf(criterion, "id:%08x%08x", ++ be32_to_cpu(p.params.issuer32[0]), ++ be32_to_cpu(p.params.issuer32[1])); ++ ++ pr_debug("Look up: %s\n", criterion); ++ ++ key = keyring_search(make_key_ref(keyring, 1), ++ &key_type_crypto, criterion); ++ if (IS_ERR(key)) ++ return ERR_CAST(key); ++ ++ pr_debug("Found key %x\n", key_serial(key_ref_to_ptr(key))); ++ return key_ref_to_ptr(key); ++} ++ ++/* ++ * Attempt to parse a signature as a PGP packet format blob and find a ++ * matching key. ++ */ ++struct crypto_key_verify_context *pgp_verify_sig_begin( ++ struct key *keyring, const u8 *sig, size_t siglen) ++{ ++ struct crypto_key_verify_context *ctx; ++ struct key *key; ++ ++ key = find_key_for_pgp_sig(keyring, sig, siglen); ++ if (IS_ERR(key)) ++ return ERR_CAST(key); ++ ++ /* We only handle in-kernel public key signatures for the moment */ ++ ctx = pgp_pkey_verify_sig_begin(key, sig, siglen); ++ key_put(key); ++ return ctx; ++} +-- +1.7.10.2 + + +From 0760cf6519e184298944df0d9f6fe5a097fb16ff Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Fri, 4 May 2012 16:41:12 +0100 +Subject: [PATCH 16/36] KEYS: Provide a function to load keys from a PGP + keyring blob + +Provide a function to load keys from a PGP keyring blob for use in initialising +the module signing key keyring: + + int load_PGP_keys(const u8 *pgpdata, size_t pgpdatalen, + struct key *keyring, const char *descprefix); + +The keys are labelled with descprefix plus a number to uniquify them. The keys +will actually be identified by the ID calculated from the PGP data rather than +by the description, so this shouldn't be a problem. + +The keys are attached to the keyring supplied. + +Looking as root in /proc/keys after the module signing keyring has been loaded: + +24460d1c I----- 1 perm 3f010000 0 0 crypto modsign.0: dsa 5acc2142 [] +3ca85723 I----- 1 perm 1f010000 0 0 keyring .module_sign: 1/4 + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + Documentation/security/keys-crypto.txt | 20 +++++++ + include/keys/crypto-type.h | 3 ++ + security/keys/crypto/Kconfig | 9 ++++ + security/keys/crypto/Makefile | 1 + + security/keys/crypto/pgp_preload.c | 90 ++++++++++++++++++++++++++++++++ + 5 files changed, 123 insertions(+) + create mode 100644 security/keys/crypto/pgp_preload.c + +diff --git a/Documentation/security/keys-crypto.txt b/Documentation/security/keys-crypto.txt +index a964717..ba2ab55 100644 +--- a/Documentation/security/keys-crypto.txt ++++ b/Documentation/security/keys-crypto.txt +@@ -10,6 +10,7 @@ Contents: + - Signature verification. + - Implementing crypto parsers. + - Implementing crypto subtypes. ++ - Initial PGP key preloading. + + + ======== +@@ -280,3 +281,22 @@ There are a number of operations defined by the subtype: + Mandatory. This should free the memory associated with the key. The + crypto key will look after freeing the fingerprint and releasing the + reference on the subtype module. ++ ++ ++======================= ++INITIAL PGP KEY LOADING ++======================= ++ ++A function is provided to perform an initial load of a set of public keys bound ++into a PGP packet format blob: ++ ++ int preload_pgp_keys(const u8 *pgpdata, size_t pgpdatalen, ++ struct key *keyring, const char *descprefix); ++ ++This takes the blob of data defined by pgpdata and pgpdatalen, extracts keys ++from them and adds them to the specified keyring. The keys are labelled with ++descprefix plus a simple uniquifier - it is not expected that the description ++will be used to identify the key. The description is required to prevent all ++but the last key being discarded when the keys are linked into the keyring. ++ ++This function is only available during initial kernel set up. +diff --git a/include/keys/crypto-type.h b/include/keys/crypto-type.h +index 6b93366..710e77f 100644 +--- a/include/keys/crypto-type.h ++++ b/include/keys/crypto-type.h +@@ -31,4 +31,7 @@ extern void verify_sig_cancel(struct crypto_key_verify_context *ctx); + * The payload is at the discretion of the subtype. + */ + ++extern __init int preload_pgp_keys(const u8 *pgpdata, size_t pgpdatalen, ++ struct key *keyring, const char *descprefix); ++ + #endif /* _KEYS_CRYPTO_TYPE_H */ +diff --git a/security/keys/crypto/Kconfig b/security/keys/crypto/Kconfig +index 1c2ae55..8af0155 100644 +--- a/security/keys/crypto/Kconfig ++++ b/security/keys/crypto/Kconfig +@@ -40,3 +40,12 @@ config CRYPTO_KEY_PGP_PARSER + This option provides support for parsing PGP (RFC 4880) format blobs + for key data and provides the ability to instantiate a crypto key + from a public key packet found inside the blob. ++ ++config PGP_PRELOAD ++ bool "PGP public key preloading facility" ++ select PGP_LIBRARY ++ select CRYPTO_KEY_PGP_PARSER ++ help ++ This option provides a facility for the kernel to preload PGP-wrapped ++ bundles of keys during boot. It is used by module signing to load ++ the module signing keys for example. +diff --git a/security/keys/crypto/Makefile b/security/keys/crypto/Makefile +index fa7746d..4162ecb 100644 +--- a/security/keys/crypto/Makefile ++++ b/security/keys/crypto/Makefile +@@ -8,6 +8,7 @@ crypto_keys-y := crypto_type.o crypto_verify.o + obj-$(CONFIG_CRYPTO_KEY_PUBLIC_KEY_SUBTYPE) += public_key.o + obj-$(CONFIG_CRYPTO_KEY_PKEY_ALGO_RSA) += crypto_rsa.o + obj-$(CONFIG_PGP_LIBRARY) += pgp_library.o ++obj-$(CONFIG_PGP_PRELOAD) += pgp_preload.o + + obj-$(CONFIG_CRYPTO_KEY_PGP_PARSER) += pgp_parser.o + pgp_parser-y := \ +diff --git a/security/keys/crypto/pgp_preload.c b/security/keys/crypto/pgp_preload.c +new file mode 100644 +index 0000000..25154e3 +--- /dev/null ++++ b/security/keys/crypto/pgp_preload.c +@@ -0,0 +1,90 @@ ++/* Cryptographic key request handling ++ * ++ * Copyright (C) 2011 Red Hat, Inc. All Rights Reserved. ++ * Written by David Howells (dhowells@redhat.com) ++ * ++ * This program is free software; you can redistribute it and/or ++ * modify it under the terms of the GNU General Public Licence ++ * as published by the Free Software Foundation; either version ++ * 2 of the Licence, or (at your option) any later version. ++ * ++ * See Documentation/security/keys-crypto.txt ++ */ ++ ++#include <linux/module.h> ++#include <linux/key.h> ++#include <linux/pgp.h> ++#include "crypto_keys.h" ++ ++struct preload_pgp_keys_context { ++ struct pgp_parse_context pgp; ++ key_ref_t keyring; ++ char descbuf[20]; ++ u8 key_n; ++ u8 dsize; ++}; ++ ++/* ++ * Extract a public key or subkey from the PGP stream. ++ */ ++static int __init found_pgp_key(struct pgp_parse_context *context, ++ enum pgp_packet_tag type, u8 headerlen, ++ const u8 *data, size_t datalen) ++{ ++ struct preload_pgp_keys_context *ctx = ++ container_of(context, struct preload_pgp_keys_context, pgp); ++ key_ref_t key; ++ ++ sprintf(ctx->descbuf + ctx->dsize, "%d", ctx->key_n++); ++ ++ key = key_create_or_update(ctx->keyring, "crypto", ctx->descbuf, ++ data - headerlen, datalen + headerlen, ++ KEY_POS_ALL | KEY_USR_VIEW, ++ KEY_ALLOC_NOT_IN_QUOTA); ++ ++ if (IS_ERR(key)) ++ return PTR_ERR(key); ++ ++ pr_notice("Loaded %s key: %s\n", ++ key_ref_to_ptr(key)->description, ++ crypto_key_id(key_ref_to_ptr(key))); ++ ++ key_ref_put(key); ++ return 0; ++} ++ ++/** ++ * preload_pgp_keys - Load keys from a PGP keyring blob ++ * @pgpdata: The PGP keyring blob containing the keys. ++ * @pgpdatalen: The size of the @pgpdata blob. ++ * @keyring: The keyring to add the new keys to. ++ * @descprefix: The key description prefix. ++ * ++ * Preload a pack of keys from a PGP keyring blob. ++ * ++ * The keys are given description of @descprefix + the number of the key in the ++ * list. Since keys can be matched on their key IDs independently of the key ++ * description, the description is mostly irrelevant apart from the fact that ++ * keys of the same description displace one another from a keyring. ++ * ++ * The caller should override the current creds if they want the keys to be ++ * owned by someone other than the current process's owner. Keys will not be ++ * accounted towards the owner's quota. ++ * ++ * This function may only be called whilst the kernel is booting. ++ */ ++int __init preload_pgp_keys(const u8 *pgpdata, size_t pgpdatalen, ++ struct key *keyring, const char *descprefix) ++{ ++ struct preload_pgp_keys_context ctx; ++ ++ ctx.pgp.types_of_interest = ++ (1 << PGP_PKT_PUBLIC_KEY) | (1 << PGP_PKT_PUBLIC_SUBKEY); ++ ctx.pgp.process_packet = found_pgp_key; ++ ctx.keyring = make_key_ref(keyring, 1); ++ ctx.key_n = 0; ++ ctx.dsize = strlen(descprefix); ++ strcpy(ctx.descbuf, descprefix); ++ ++ return pgp_parse_packets(pgpdata, pgpdatalen, &ctx.pgp); ++} +-- +1.7.10.2 + + +From 8f7d6b082b6b7357e44f9345c8c040f53aa60a7f Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Thu, 10 May 2012 23:46:56 +0100 +Subject: [PATCH 17/36] Provide macros for forming the name of an ELF note and + its section + +Provide macros for stringifying the name of an ELF note and its section +appropriately so that the macro can be used in both C and assembly. + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + include/linux/elfnote.h | 4 ++++ + 1 file changed, 4 insertions(+) + +diff --git a/include/linux/elfnote.h b/include/linux/elfnote.h +index 278e3ef..949d494 100644 +--- a/include/linux/elfnote.h ++++ b/include/linux/elfnote.h +@@ -58,6 +58,7 @@ + ELFNOTE_END + + #else /* !__ASSEMBLER__ */ ++#include <linux/stringify.h> + #include <linux/elf.h> + /* + * Use an anonymous structure which matches the shape of +@@ -93,6 +94,9 @@ + + #define ELFNOTE32(name, type, desc) ELFNOTE(32, name, type, desc) + #define ELFNOTE64(name, type, desc) ELFNOTE(64, name, type, desc) ++ ++#define ELFNOTE_NAME(name) __stringify(name) ++#define ELFNOTE_SECTION(name) ".note."ELFNOTE_NAME(name) + #endif /* __ASSEMBLER__ */ + + #endif /* _LINUX_ELFNOTE_H */ +-- +1.7.10.2 + + +From b37a512b3d6593d541e05550316bd407515c1ec2 Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Thu, 10 May 2012 23:49:44 +0100 +Subject: [PATCH 18/36] Guard check in module loader against integer overflow + +The check: + + if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr)) + +may not work if there's an overflow in the right-hand side of the condition. + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + kernel/module.c | 3 ++- + 1 file changed, 2 insertions(+), 1 deletion(-) + +diff --git a/kernel/module.c b/kernel/module.c +index 78ac6ec..377cb06 100644 +--- a/kernel/module.c ++++ b/kernel/module.c +@@ -2429,7 +2429,8 @@ static int copy_and_check(struct load_info *info, + goto free_hdr; + } + +- if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr)) { ++ if (hdr->e_shoff >= len || ++ hdr->e_shnum * sizeof(Elf_Shdr) > len - hdr->e_shoff) { + err = -ENOEXEC; + goto free_hdr; + } +-- +1.7.10.2 + + +From a7f2ec2a77490ed84bf8020cd5b41d7c7ea3f3cb Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Thu, 10 May 2012 23:49:52 +0100 +Subject: [PATCH 19/36] MODSIGN: Add indications of module ELF types + +Add per-arch indications of module ELF types and relocation table entry types. + +Signed-Off-By: David Howells <dhowells@redhat.com> +--- + arch/alpha/include/asm/module.h | 3 +++ + arch/arm/include/asm/module.h | 5 +++++ + arch/cris/include/asm/module.h | 5 +++++ + arch/h8300/include/asm/module.h | 5 +++++ + arch/ia64/include/asm/module.h | 5 +++++ + arch/m32r/include/asm/module.h | 5 +++++ + arch/m68k/include/asm/module.h | 5 +++++ + arch/mips/include/asm/module.h | 12 ++++++++++-- + arch/parisc/include/asm/module.h | 8 ++++++++ + arch/powerpc/include/asm/module.h | 10 ++++++++++ + arch/s390/include/asm/module.h | 3 +++ + arch/x86/include/asm/module.h | 6 ++++++ + include/asm-generic/module.h | 10 ++++++++++ + 13 files changed, 80 insertions(+), 2 deletions(-) + +diff --git a/arch/alpha/include/asm/module.h b/arch/alpha/include/asm/module.h +index 7b63743..3d5a3ea 100644 +--- a/arch/alpha/include/asm/module.h ++++ b/arch/alpha/include/asm/module.h +@@ -6,6 +6,7 @@ struct mod_arch_specific + unsigned int gotsecindex; + }; + ++#define MODULES_ARE_ELF64 + #define Elf_Sym Elf64_Sym + #define Elf_Shdr Elf64_Shdr + #define Elf_Ehdr Elf64_Ehdr +@@ -13,6 +14,8 @@ struct mod_arch_specific + #define Elf_Dyn Elf64_Dyn + #define Elf_Rel Elf64_Rel + #define Elf_Rela Elf64_Rela ++#define ELF_R_TYPE(X) ELF64_R_TYPE(X) ++#define ELF_R_SYM(X) ELF64_R_SYM(X) + + #define ARCH_SHF_SMALL SHF_ALPHA_GPREL + +diff --git a/arch/arm/include/asm/module.h b/arch/arm/include/asm/module.h +index 6c6809f..f47d9cd 100644 +--- a/arch/arm/include/asm/module.h ++++ b/arch/arm/include/asm/module.h +@@ -1,9 +1,14 @@ + #ifndef _ASM_ARM_MODULE_H + #define _ASM_ARM_MODULE_H + ++#define MODULES_ARE_ELF32 + #define Elf_Shdr Elf32_Shdr + #define Elf_Sym Elf32_Sym + #define Elf_Ehdr Elf32_Ehdr ++#define Elf_Rel Elf32_Rel ++#define Elf_Rela Elf32_Rela ++#define ELF_R_TYPE(X) ELF32_R_TYPE(X) ++#define ELF_R_SYM(X) ELF32_R_SYM(X) + + struct unwind_table; + +diff --git a/arch/cris/include/asm/module.h b/arch/cris/include/asm/module.h +index 7ee7231..03f7b2e 100644 +--- a/arch/cris/include/asm/module.h ++++ b/arch/cris/include/asm/module.h +@@ -3,7 +3,12 @@ + /* cris is simple */ + struct mod_arch_specific { }; + ++#define MODULES_ARE_ELF32 + #define Elf_Shdr Elf32_Shdr + #define Elf_Sym Elf32_Sym + #define Elf_Ehdr Elf32_Ehdr ++#define Elf_Rel Elf32_Rel ++#define Elf_Rela Elf32_Rela ++#define ELF_R_TYPE(X) ELF32_R_TYPE(X) ++#define ELF_R_SYM(X) ELF32_R_SYM(X) + #endif /* _ASM_CRIS_MODULE_H */ +diff --git a/arch/h8300/include/asm/module.h b/arch/h8300/include/asm/module.h +index 8e46724..5140128 100644 +--- a/arch/h8300/include/asm/module.h ++++ b/arch/h8300/include/asm/module.h +@@ -4,8 +4,13 @@ + * This file contains the H8/300 architecture specific module code. + */ + struct mod_arch_specific { }; ++#define MODULES_ARE_ELF32 + #define Elf_Shdr Elf32_Shdr + #define Elf_Sym Elf32_Sym + #define Elf_Ehdr Elf32_Ehdr ++#define Elf_Rel Elf32_Rel ++#define Elf_Rela Elf32_Rela ++#define ELF_R_TYPE(X) ELF32_R_TYPE(X) ++#define ELF_R_SYM(X) ELF32_R_SYM(X) + + #endif /* _ASM_H8/300_MODULE_H */ +diff --git a/arch/ia64/include/asm/module.h b/arch/ia64/include/asm/module.h +index 908eaef..3c4cd94 100644 +--- a/arch/ia64/include/asm/module.h ++++ b/arch/ia64/include/asm/module.h +@@ -29,9 +29,14 @@ struct mod_arch_specific { + unsigned int next_got_entry; /* index of next available got entry */ + }; + ++#define MODULES_ARE_ELF64 + #define Elf_Shdr Elf64_Shdr + #define Elf_Sym Elf64_Sym + #define Elf_Ehdr Elf64_Ehdr ++#define Elf_Rel Elf64_Rel ++#define Elf_Rela Elf64_Rela ++#define ELF_R_TYPE(X) ELF64_R_TYPE(X) ++#define ELF_R_SYM(X) ELF64_R_SYM(X) + + #define MODULE_PROC_FAMILY "ia64" + #define MODULE_ARCH_VERMAGIC MODULE_PROC_FAMILY \ +diff --git a/arch/m32r/include/asm/module.h b/arch/m32r/include/asm/module.h +index eb73ee0..7146455 100644 +--- a/arch/m32r/include/asm/module.h ++++ b/arch/m32r/include/asm/module.h +@@ -3,8 +3,13 @@ + + struct mod_arch_specific { }; + ++#define MODULES_ARE_ELF32 + #define Elf_Shdr Elf32_Shdr + #define Elf_Sym Elf32_Sym + #define Elf_Ehdr Elf32_Ehdr ++#define Elf_Rel Elf32_Rel ++#define Elf_Rela Elf32_Rela ++#define ELF_R_TYPE(X) ELF32_R_TYPE(X) ++#define ELF_R_SYM(X) ELF32_R_SYM(X) + + #endif /* _ASM_M32R_MODULE_H */ +diff --git a/arch/m68k/include/asm/module.h b/arch/m68k/include/asm/module.h +index edffe66..9e2cd74 100644 +--- a/arch/m68k/include/asm/module.h ++++ b/arch/m68k/include/asm/module.h +@@ -36,8 +36,13 @@ struct module; + extern void module_fixup(struct module *mod, struct m68k_fixup_info *start, + struct m68k_fixup_info *end); + ++#define MODULES_ARE_ELF32 + #define Elf_Shdr Elf32_Shdr + #define Elf_Sym Elf32_Sym + #define Elf_Ehdr Elf32_Ehdr ++#define Elf_Rel Elf32_Rel ++#define Elf_Rela Elf32_Rela ++#define ELF_R_TYPE(X) ELF32_R_TYPE(X) ++#define ELF_R_SYM(X) ELF32_R_SYM(X) + + #endif /* _ASM_M68K_MODULE_H */ +diff --git a/arch/mips/include/asm/module.h b/arch/mips/include/asm/module.h +index 7467d1d..4404cca 100644 +--- a/arch/mips/include/asm/module.h ++++ b/arch/mips/include/asm/module.h +@@ -33,11 +33,15 @@ typedef struct { + } Elf64_Mips_Rela; + + #ifdef CONFIG_32BIT +- ++#define MODULES_ARE_ELF32 + #define Elf_Shdr Elf32_Shdr + #define Elf_Sym Elf32_Sym + #define Elf_Ehdr Elf32_Ehdr + #define Elf_Addr Elf32_Addr ++#define Elf_Rel Elf32_Rel ++#define Elf_Rela Elf32_Rela ++#define ELF_R_TYPE(X) ELF32_R_TYPE(X) ++#define ELF_R_SYM(X) ELF32_R_SYM(X) + + #define Elf_Mips_Rel Elf32_Rel + #define Elf_Mips_Rela Elf32_Rela +@@ -48,11 +52,15 @@ typedef struct { + #endif + + #ifdef CONFIG_64BIT +- ++#define MODULES_ARE_ELF64 + #define Elf_Shdr Elf64_Shdr + #define Elf_Sym Elf64_Sym + #define Elf_Ehdr Elf64_Ehdr + #define Elf_Addr Elf64_Addr ++#define Elf_Rel Elf64_Rel ++#define Elf_Rela Elf64_Rela ++#define ELF_R_TYPE(X) ELF64_R_TYPE(X) ++#define ELF_R_SYM(X) ELF64_R_SYM(X) + + #define Elf_Mips_Rel Elf64_Mips_Rel + #define Elf_Mips_Rela Elf64_Mips_Rela +diff --git a/arch/parisc/include/asm/module.h b/arch/parisc/include/asm/module.h +index 1f41234..3e13f69 100644 +--- a/arch/parisc/include/asm/module.h ++++ b/arch/parisc/include/asm/module.h +@@ -4,17 +4,25 @@ + * This file contains the parisc architecture specific module code. + */ + #ifdef CONFIG_64BIT ++#define MODULES_ARE_ELF64 + #define Elf_Shdr Elf64_Shdr + #define Elf_Sym Elf64_Sym + #define Elf_Ehdr Elf64_Ehdr + #define Elf_Addr Elf64_Addr ++#define Elf_Rel Elf64_Rel + #define Elf_Rela Elf64_Rela ++#define ELF_R_TYPE(X) ELF64_R_TYPE(X) ++#define ELF_R_SYM(X) ELF64_R_SYM(X) + #else ++#define MODULES_ARE_ELF32 + #define Elf_Shdr Elf32_Shdr + #define Elf_Sym Elf32_Sym + #define Elf_Ehdr Elf32_Ehdr + #define Elf_Addr Elf32_Addr ++#define Elf_Rel Elf32_Rel + #define Elf_Rela Elf32_Rela ++#define ELF_R_TYPE(X) ELF32_R_TYPE(X) ++#define ELF_R_SYM(X) ELF32_R_SYM(X) + #endif + + struct unwind_table; +diff --git a/arch/powerpc/include/asm/module.h b/arch/powerpc/include/asm/module.h +index 0192a4e..e949704 100644 +--- a/arch/powerpc/include/asm/module.h ++++ b/arch/powerpc/include/asm/module.h +@@ -60,16 +60,26 @@ struct mod_arch_specific { + */ + + #ifdef __powerpc64__ ++# define MODULES_ARE_ELF64 + # define Elf_Shdr Elf64_Shdr + # define Elf_Sym Elf64_Sym + # define Elf_Ehdr Elf64_Ehdr ++# define Elf_Rel Elf64_Rel ++# define Elf_Rela Elf64_Rela ++# define ELF_R_TYPE(X) ELF64_R_TYPE(X) ++# define ELF_R_SYM(X) ELF64_R_SYM(X) + # ifdef MODULE + asm(".section .stubs,\"ax\",@nobits; .align 3; .previous"); + # endif + #else ++# define MODULES_ARE_ELF32 + # define Elf_Shdr Elf32_Shdr + # define Elf_Sym Elf32_Sym + # define Elf_Ehdr Elf32_Ehdr ++# define Elf_Rel Elf32_Rel ++# define Elf_Rela Elf32_Rela ++# define ELF_R_TYPE(X) ELF32_R_TYPE(X) ++# define ELF_R_SYM(X) ELF32_R_SYM(X) + # ifdef MODULE + asm(".section .plt,\"ax\",@nobits; .align 3; .previous"); + asm(".section .init.plt,\"ax\",@nobits; .align 3; .previous"); +diff --git a/arch/s390/include/asm/module.h b/arch/s390/include/asm/module.h +index 1cc1c5a..b64dab0 100644 +--- a/arch/s390/include/asm/module.h ++++ b/arch/s390/include/asm/module.h +@@ -29,14 +29,17 @@ struct mod_arch_specific + }; + + #ifdef __s390x__ ++#define MODULES_ARE_ELF64 + #define ElfW(x) Elf64_ ## x + #define ELFW(x) ELF64_ ## x + #else ++#define MODULES_ARE_ELF32 + #define ElfW(x) Elf32_ ## x + #define ELFW(x) ELF32_ ## x + #endif + + #define Elf_Addr ElfW(Addr) ++#define Elf_Rel ElfW(Rel) + #define Elf_Rela ElfW(Rela) + #define Elf_Shdr ElfW(Shdr) + #define Elf_Sym ElfW(Sym) +diff --git a/arch/x86/include/asm/module.h b/arch/x86/include/asm/module.h +index 9eae775..724f173 100644 +--- a/arch/x86/include/asm/module.h ++++ b/arch/x86/include/asm/module.h +@@ -63,4 +63,10 @@ + # define MODULE_ARCH_VERMAGIC MODULE_PROC_FAMILY + #endif + ++#ifdef CONFIG_X86_32 ++#define MODULE_HAS_ELF_REL_ONLY ++#else ++#define MODULE_HAS_ELF_RELA_ONLY ++#endif ++ + #endif /* _ASM_X86_MODULE_H */ +diff --git a/include/asm-generic/module.h b/include/asm-generic/module.h +index ed5b44d..e053617b 100644 +--- a/include/asm-generic/module.h ++++ b/include/asm-generic/module.h +@@ -10,13 +10,23 @@ struct mod_arch_specific + }; + + #ifdef CONFIG_64BIT ++#define MODULES_ARE_ELF64 + #define Elf_Shdr Elf64_Shdr + #define Elf_Sym Elf64_Sym + #define Elf_Ehdr Elf64_Ehdr ++#define Elf_Rel Elf64_Rel ++#define Elf_Rela Elf64_Rela ++#define ELF_R_TYPE(X) ELF64_R_TYPE(X) ++#define ELF_R_SYM(X) ELF64_R_SYM(X) + #else ++#define MODULES_ARE_ELF32 + #define Elf_Shdr Elf32_Shdr + #define Elf_Sym Elf32_Sym + #define Elf_Ehdr Elf32_Ehdr ++#define Elf_Rel Elf32_Rel ++#define Elf_Rela Elf32_Rela ++#define ELF_R_TYPE(X) ELF32_R_TYPE(X) ++#define ELF_R_SYM(X) ELF32_R_SYM(X) + #endif + + #endif /* __ASM_GENERIC_MODULE_H */ +-- +1.7.10.2 + + +From b31d1ea8afb0b63e872a1bed3a3c88d7696bf2e7 Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Thu, 10 May 2012 23:49:53 +0100 +Subject: [PATCH 20/36] MODSIGN: Provide gitignore and make clean rules for + extra files + +Provide gitignore and make clean rules for extra files to hide and clean up the +extra files produced by module signing stuff once it is added. Also add a +clean up rule for the module content extractor program used to extract the data +to be signed. + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + .gitignore | 12 ++++++++++++ + Makefile | 1 + + scripts/mod/.gitignore | 1 + + 3 files changed, 14 insertions(+) + +diff --git a/.gitignore b/.gitignore +index 57af07c..7948eeb 100644 +--- a/.gitignore ++++ b/.gitignore +@@ -14,6 +14,9 @@ + *.o.* + *.a + *.s ++*.ko.unsigned ++*.ko.digest ++*.ko.digest.sig + *.ko + *.so + *.so.dbg +@@ -84,3 +87,12 @@ GTAGS + *.orig + *~ + \#*# ++ ++# ++# GPG leavings from module signing ++# ++genkey ++modsign.pub ++modsign.sec ++random_seed ++trustdb.gpg +diff --git a/Makefile b/Makefile +index a06ee9f..1df8b14 100644 +--- a/Makefile ++++ b/Makefile +@@ -1407,6 +1407,7 @@ clean: $(clean-dirs) + $(call cmd,rmfiles) + @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \ + \( -name '*.[oas]' -o -name '*.ko' -o -name '.*.cmd' \ ++ -o -name '*.ko.*' \ + -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \ + -o -name '*.symtypes' -o -name 'modules.order' \ + -o -name modules.builtin -o -name '.tmp_*.o.*' \ +diff --git a/scripts/mod/.gitignore b/scripts/mod/.gitignore +index e9b7abe..223dfd6 100644 +--- a/scripts/mod/.gitignore ++++ b/scripts/mod/.gitignore +@@ -1,4 +1,5 @@ + elfconfig.h + mk_elfconfig + modpost ++mod-extract + +-- +1.7.10.2 + + +From dce3a6eca8dda09a28cb2f45b87e70e1c2d52139 Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Thu, 10 May 2012 23:49:53 +0100 +Subject: [PATCH 21/36] MODSIGN: Provide Documentation and Kconfig options + +Provide documentation and kernel configuration options for module signing. + +The documentation can be found in: + + Documentation/module-signing.txt + +The following configuration options are added: + + (1) CONFIG_MODULE_SIG + + Enable module signing. This will both cause the build process to sign + modules and the kernel to check modules when they're loaded. + + (2) CONFIG_MODULE_SIG_SHA1 + CONFIG_MODULE_SIG_SHA224 + CONFIG_MODULE_SIG_SHA256 + CONFIG_MODULE_SIG_SHA384 + CONFIG_MODULE_SIG_SHA512 + + Select the cryptographic hash used to digest the data prior to signing. + Additionally, the crypto module selected will be built into the kernel as + it won't be possible to load it as a module without incurring a circular + dependency when the kernel tries to check its signature. + + (3) CONFIG_MODULE_SIG_FORCE + + Require that any module loaded must be signed with a key compiled into + the kernel. All other modules are rejected with EKEYREJECTED. + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + Documentation/module-signing.txt | 194 ++++++++++++++++++++++++++++++++++++++ + include/linux/modsign.h | 27 ++++++ + init/Kconfig | 53 +++++++++++ + 3 files changed, 274 insertions(+) + create mode 100644 Documentation/module-signing.txt + create mode 100644 include/linux/modsign.h + +diff --git a/Documentation/module-signing.txt b/Documentation/module-signing.txt +new file mode 100644 +index 0000000..d75d473 +--- /dev/null ++++ b/Documentation/module-signing.txt +@@ -0,0 +1,194 @@ ++ ============================== ++ KERNEL MODULE SIGNING FACILITY ++ ============================== ++ ++The module signing facility applies cryptographic signature checking to modules ++on module load, checking the signature against a ring of public keys compiled ++into the kernel. GPG is used to do the cryptographic work and determines the ++format of the signature and key data. The facility uses GPG's MPI library to ++handle the huge numbers involved. ++ ++This facility is enabled through CONFIG_MODULE_SIG. Turning on signature ++checking will also force the module's ELF metadata to be verified before the ++signature is checked. ++ ++The signature checker in the kernel is capable of handling multiple keys of ++either DSA or RSA type, and can support any of MD5, RIPE-MD-160, SHA-1, ++SHA-224, SHA-256, SHA-384 and SHA-512 hashes - PROVIDED(!) the requisite ++algorithms are compiled into the kernel. ++ ++(!) NOTE: Modules may only be verified initially with algorithms compiled into ++the kernel. Further algorithm modules may be loaded and used - but these must ++first pass a verification step using already loaded/compiled-in algorithms. ++ ++ ++===================== ++SUPPLYING PUBLIC KEYS ++===================== ++ ++A set of public keys must be supplied at kernel image build time. This is done ++by taking a GPG public key file and placing it in the base of the kernel ++directory in a file called modsign.pub. ++ ++For example, a throwaway key could be generated automatically by something like ++the following: ++ ++ cat >genkey <<EOF ++ %pubring modsign.pub ++ %secring modsign.sec ++ Key-Type: RSA ++ Key-Length: 4096 ++ Name-Real: A. N. Other ++ Name-Comment: Kernel Module GPG key ++ %commit ++ EOF ++ gpg --homedir . --batch --gen-key genkey ++ ++The above generates fresh keys using /dev/random. If there's insufficient data ++in /dev/random, more can be provided using the rngd program if there's a ++hardware random number generator available. ++ ++Note that no GPG password is used in the above scriptlet. ++ ++The modsign.pub file is compiled into the kernel directly by the assembler by ++means of an ".incbin" directive in kernel/modsign-pubkey.c. ++ ++Once the kernel is running, the keys are visible to root as kernel crypto keys ++in /proc/keys in a keyring called .module_sign: ++ ++335ab517 I----- 1 perm 1f030000 0 0 keyring .module_sign: 2/4 ++38d7d169 I----- 1 perm 3f010000 0 0 crypto modsign.0: rsa 57532ca5 [] ++195fa736 I----- 1 perm 3f010000 0 0 crypto modsign.1: dsa 5acc2142 [] ++ ++This keyring can be listed with the keyctl program. See: ++ ++ Documentation/security/keys-crypto.txt ++ ++for more information of crypto keys. ++ ++ ++============================ ++SELECTING THE HASH ALGORITHM ++============================ ++ ++The hash algorithm to be used is selected by a multiple choice configuration ++item that enables one of the following variables: ++ ++ CONFIG_SIG_SHA1 ++ CONFIG_SIG_SHA224 ++ CONFIG_SIG_SHA256 ++ CONFIG_SIG_SHA384 ++ CONFIG_SIG_SHA512 ++ ++These cause an appropriate "--digest-algo=" parameter to be passed to gpg when ++signing a module and force the appropriate hash algorithm to be compiled ++directly into the kernel rather than being built as a module. ++ ++ ++============== ++MODULE SIGNING ++============== ++ ++Modules will then be signed automatically. The kernel make command line can ++include the following options: ++ ++ (*) MODSECKEY=<secret-key-ring-path> ++ ++ This indicates the whereabouts of the GPG keyring that is the source of ++ the secret key to be used. The default is "./modsign.sec". ++ ++ (*) MODPUBKEY=<public-key-ring-path> ++ ++ This indicates the whereabouts of the GPG keyring that is the source of ++ the public key to be used. The default is "./modsign.pub". ++ ++ (*) MODKEYNAME=<key-name> ++ ++ The name of the key pair to be used from the aforementioned keyrings. ++ This defaults to being unset, thus leaving the choice of default key to ++ gpg. ++ ++ (*) KEYFLAGS="gpg-options" ++ ++ Override the complete gpg command line, including the preceding three ++ options. The default options supplied to gpg are: ++ ++ --no-default-keyring ++ --secret-keyring $(MODSECKEY) ++ --keyring $(MODPUBKEY) ++ --no-default-keyring ++ --homedir . ++ --no-options ++ --no-auto-check-trustdb ++ --no-permission-warning ++ --digest-algo=<hash-algorithm> ++ ++ with: ++ ++ --default-key $(MODKEYNAME) ++ ++ being added if requested. ++ ++The resulting module.ko file will be the signed module. ++ ++ ++======================== ++STRIPPING SIGNED MODULES ++======================== ++ ++Signed modules may be safely stripped with any of the following: ++ ++ strip -x ++ strip -g ++ eu-strip ++ ++as the signature only covers those parts of the module the kernel actually uses ++and any ELF metadata required to deal with them. Any necessary ELF metadata ++that is affected by stripping is canonicalised by the sig generator and the sig ++checker to hide strip effects. ++ ++This permits the debuginfo to be detached from the module and placed in another ++spot so that gdb can find it when referring to that module without the need for ++multiple signed versions of the module. Such is done by rpmbuild when ++producing RPMs. ++ ++It also permits the module to be stripped as far as possible for when modules ++are being reduced prior to being included in an initial ramdisk composition. ++ ++Note that "strip" and "strip -s" may not be used on a module, signed or ++otherwise, as they remove the symbol table and render the relocation tables ++unusable. ++ ++ ++====================== ++LOADING SIGNED MODULES ++====================== ++ ++Modules are loaded with insmod, exactly as for unsigned modules. The signature ++is inserted into the module object file during the build process as an ELF note ++called "module.sig" in an ELF section called ".note.module.sig". The signature ++checker will detect it and apply signature checking. ++ ++ ++========================================= ++NON-VALID SIGNATURES AND UNSIGNED MODULES ++========================================= ++ ++If CONFIG_MODULE_SIG_FORCE is enabled or "enforcemodulesig=1" is supplied on ++the kernel command line, the kernel will _only_ load validly signed modules ++for which it has a public key. Otherwise, it will also load modules that are ++unsigned. Any module for which the kernel has a key, but which proves to have ++a signature mismatch will not be permitted to load (returning EKEYREJECTED). ++ ++This table indicates the behaviours of the various situations: ++ ++ MODULE STATE PERMISSIVE MODE ENFORCING MODE ++ ======================================= =============== =============== ++ Unsigned Ok EKEYREJECTED ++ Signed, no public key ENOKEY ENOKEY ++ Validly signed, public key Ok Ok ++ Invalidly signed, public key EKEYREJECTED EKEYREJECTED ++ Validly signed, expired key EKEYEXPIRED EKEYEXPIRED ++ Signed, hash algorithm unavailable ENOPKG ENOPKG ++ Corrupt signature EBADMSG EBADMSG ++ Corrupt ELF ELIBBAD ELIBBAD +diff --git a/include/linux/modsign.h b/include/linux/modsign.h +new file mode 100644 +index 0000000..c5ac87a +--- /dev/null ++++ b/include/linux/modsign.h +@@ -0,0 +1,27 @@ ++/* Module signing definitions ++ * ++ * Copyright (C) 2009 Red Hat, Inc. All Rights Reserved. ++ * Written by David Howells (dhowells@redhat.com) ++ * ++ * This program is free software; you can redistribute it and/or ++ * modify it under the terms of the GNU General Public Licence ++ * as published by the Free Software Foundation; either version ++ * 2 of the Licence, or (at your option) any later version. ++ */ ++ ++#ifndef _LINUX_MODSIGN_H ++#define _LINUX_MODSIGN_H ++ ++#ifdef CONFIG_MODULE_SIG ++ ++#include <linux/elfnote.h> ++ ++/* ++ * The parameters of the ELF note used to carry the signature ++ */ ++#define MODSIGN_NOTE_NAME module.sig ++#define MODSIGN_NOTE_TYPE 100 ++ ++#endif ++ ++#endif /* _LINUX_MODSIGN_H */ +diff --git a/init/Kconfig b/init/Kconfig +index 6cfd71d..7cda3e6 100644 +--- a/init/Kconfig ++++ b/init/Kconfig +@@ -1409,6 +1409,59 @@ config MODULE_SRCVERSION_ALL + the version). With this option, such a "srcversion" field + will be created for all modules. If unsure, say N. + ++config MODULE_SIG ++ bool "Module signature verification" ++ depends on MODULES ++ select CRYPTO_KEY_TYPE ++ select CRYPTO_KEY_PKEY_ALGO_DSA ++ select CRYPTO_KEY_PKEY_ALGO_RSA ++ select PGP_PARSER ++ select PGP_PRELOAD ++ help ++ Check modules for valid signatures upon load. For more information ++ see: ++ ++ Documentation/module-signing.txt ++ ++choice ++ prompt "Which hash algorithm should modules be signed with?" ++ depends on MODULE_SIG ++ help ++ This determines which sort of hashing algorithm will be used during ++ signature generation. This algorithm _must_ be built into the kernel ++ directly so that signature verification can take place. It is not ++ possible to load a signed module containing the algorithm to check ++ the signature on that module. ++ ++config MODULE_SIG_SHA1 ++ bool "Sign modules with SHA-1" ++ select CRYPTO_SHA1 ++ ++config MODULE_SIG_SHA224 ++ bool "Sign modules with SHA-224" ++ select CRYPTO_SHA224 ++ ++config MODULE_SIG_SHA256 ++ bool "Sign modules with SHA-256" ++ select CRYPTO_SHA256 ++ ++config MODULE_SIG_SHA384 ++ bool "Sign modules with SHA-384" ++ select CRYPTO_SHA384 ++ ++config MODULE_SIG_SHA512 ++ bool "Sign modules with SHA-512" ++ select CRYPTO_SHA512 ++ ++endchoice ++ ++config MODULE_SIG_FORCE ++ bool "Required modules to be validly signed (EXPERIMENTAL)" ++ depends on MODULE_SIG ++ help ++ Reject unsigned modules or signed modules for which we don't have a ++ key. ++ + endif # MODULES + + config INIT_ALL_POSSIBLE +-- +1.7.10.2 + + +From f9980a27c5d2d02af2feb578957145a206088fff Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Thu, 10 May 2012 23:49:54 +0100 +Subject: [PATCH 22/36] MODSIGN: Sign modules during the build process + +If CONFIG_MODULE_SIG is set, then this patch will cause the module to get a +signature installed. The following steps will occur: + + (1) The module will be linked to foo.ko.unsigned instead of foo.ko + + (2) The module's signable content will be extracted to foo.ko.digest by the + mod-extract program. + + (3) The signature will be generated on foo.ko.digest by gpg and placed in + foo.ko.digest.sig + + (4) The signature will be encapsulated into an ELF note and placed into a file + called foo.ko.note.o using the output from modsign-note.sh piped into the + assembler. + + (5) The unsigned module from (1) and the signature ELF note from (4) will be + linked together to produce foo.ko + +Step (3) requires private and public keys to be available. By default these +are expected to be found in PGP keyring files called modsign.sec (the secret +key) and modsign.pub (the public key) in the build root. + +If the secret key is not found then signing will be skipped and the unsigned +module from (1) will just be copied to foo.ko. + +If signing occurs, lines like the following will be seen: + + LD [M] fs/foo/foo.ko.unsigned + SIGN [M] fs/foo/foo.ko + +will appear in the build log. If it is skipped, the following will be seen: + + LD [M] fs/foo/foo.ko.unsigned + NO SIGN [M] fs/foo/foo.ko + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + scripts/Makefile.modpost | 87 ++++- + scripts/mod/Makefile | 2 +- + scripts/mod/mod-extract.c | 913 +++++++++++++++++++++++++++++++++++++++++++ + scripts/mod/modsign-note.sh | 16 + + 4 files changed, 1016 insertions(+), 2 deletions(-) + create mode 100644 scripts/mod/mod-extract.c + create mode 100644 scripts/mod/modsign-note.sh + +diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost +index 08dce14..17465d8 100644 +--- a/scripts/Makefile.modpost ++++ b/scripts/Makefile.modpost +@@ -14,7 +14,8 @@ + # 3) create one <module>.mod.c file pr. module + # 4) create one Module.symvers file with CRC for all exported symbols + # 5) compile all <module>.mod.c files +-# 6) final link of the module to a <module.ko> file ++# 6) final link of the module to a <module.ko> (or <module.unsigned>) file ++# 7) signs the modules to a <module.ko> file + + # Step 3 is used to place certain information in the module's ELF + # section, including information such as: +@@ -32,6 +33,8 @@ + # Step 4 is solely used to allow module versioning in external modules, + # where the CRC of each module is retrieved from the Module.symvers file. + ++# Step 7 is dependent on CONFIG_MODULE_SIG being enabled. ++ + # KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined + # symbols in the final module linking stage + # KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules. +@@ -116,6 +119,7 @@ $(modules:.ko=.mod.o): %.mod.o: %.mod.c FORCE + targets += $(modules:.ko=.mod.o) + + # Step 6), final link of the modules ++ifneq ($(CONFIG_MODULE_SIG),y) + quiet_cmd_ld_ko_o = LD [M] $@ + cmd_ld_ko_o = $(LD) -r $(LDFLAGS) \ + $(KBUILD_LDFLAGS_MODULE) $(LDFLAGS_MODULE) \ +@@ -125,7 +129,88 @@ $(modules): %.ko :%.o %.mod.o FORCE + $(call if_changed,ld_ko_o) + + targets += $(modules) ++else ++quiet_cmd_ld_ko_unsigned_o = LD [M] $@ ++ cmd_ld_ko_unsigned_o = \ ++ $(LD) -r $(LDFLAGS) \ ++ $(KBUILD_LDFLAGS_MODULE) $(LDFLAGS_MODULE) \ ++ -o $@ $(filter-out FORCE,$^) \ ++ $(if $(AFTER_LINK),; $(AFTER_LINK)) ++ ++$(modules:.ko=.ko.unsigned): %.ko.unsigned :%.o %.mod.o FORCE ++ $(call if_changed,ld_ko_unsigned_o) ++ ++targets += $(modules:.ko=.ko.unsigned) ++ ++# Step 7), sign the modules ++MODSECKEY = ./modsign.sec ++MODPUBKEY = ./modsign.pub ++KEYFLAGS = --no-default-keyring --secret-keyring $(MODSECKEY) --keyring $(MODPUBKEY) --no-default-keyring --homedir . --no-options --no-auto-check-trustdb --no-permission-warning ++ ++ifdef CONFIG_MODULE_SIG_SHA1 ++KEYFLAGS += --digest-algo=SHA1 ++else ++ifdef CONFIG_MODULE_SIG_SHA224 ++KEYFLAGS += --digest-algo=SHA224 ++else ++ifdef CONFIG_MODULE_SIG_SHA256 ++KEYFLAGS += --digest-algo=SHA256 ++else ++ifdef CONFIG_MODULE_SIG_SHA384 ++KEYFLAGS += --digest-algo=SHA384 ++else ++ifdef CONFIG_MODULE_SIG_SHA512 ++KEYFLAGS += --digest-algo=SHA512 ++else ++endif ++endif ++endif ++endif ++endif ++ ++ifdef MODKEYNAME ++KEYFLAGS += --default-key $(MODKEYNAME) ++endif + ++ifeq ($(wildcard $(MODSECKEY))+$(wildcard $(MODPUBKEY)),$(MODSECKEY)+$(MODPUBKEY)) ++ifeq ($(KBUILD_SRC),) ++ # no O= is being used ++ SCRIPTS_DIR := scripts ++else ++ SCRIPTS_DIR := $(KBUILD_SRC)/scripts ++endif ++SIGN_MODULES := 1 ++else ++SIGN_MODULES := 0 ++endif ++ ++# only sign if it's an in-tree module ++ifneq ($(KBUILD_EXTMOD),) ++SIGN_MODULES := 0 ++endif ++ ++ifeq ($(SIGN_MODULES),1) ++KEYRING_DEP := modsign.sec modsign.pub ++quiet_cmd_sign_ko_ko_unsigned = SIGN [M] $@ ++ cmd_sign_ko_ko_unsigned = \ ++ scripts/mod/mod-extract $< $@.digest && \ ++ rm -f $@.digest.sig && \ ++ gpg --batch --no-greeting $(KEYFLAGS) -b $@.digest && \ ++ sh $(SCRIPTS_DIR)/mod/modsign-note.sh $@.digest.sig | \ ++ $(CC) -x assembler-with-cpp $(c_flags) $(CFLAGS_MODULE) -c -o $@.note.o - && \ ++ $(LD) -r $(LDFLAGS) -o $@ $< $@.note.o ++else ++KEYRING_DEP := ++quiet_cmd_sign_ko_ko_unsigned = NO SIGN [M] $@ ++ cmd_sign_ko_ko_unsigned = \ ++ cp $< $@ ++endif ++ ++$(modules): %.ko :%.ko.unsigned $(KEYRING_DEP) FORCE ++ $(call if_changed,sign_ko_ko_unsigned) ++ ++targets += $(modules) ++endif + + # Add FORCE to the prequisites of a target to force it to be always rebuilt. + # --------------------------------------------------------------------------- +diff --git a/scripts/mod/Makefile b/scripts/mod/Makefile +index ff954f8..4654e3b 100644 +--- a/scripts/mod/Makefile ++++ b/scripts/mod/Makefile +@@ -1,4 +1,4 @@ +-hostprogs-y := modpost mk_elfconfig ++hostprogs-y := modpost mk_elfconfig mod-extract + always := $(hostprogs-y) empty.o + + modpost-objs := modpost.o file2alias.o sumversion.o +diff --git a/scripts/mod/mod-extract.c b/scripts/mod/mod-extract.c +new file mode 100644 +index 0000000..0c0e3e3 +--- /dev/null ++++ b/scripts/mod/mod-extract.c +@@ -0,0 +1,913 @@ ++/* mod-extract.c: module extractor for signing ++ * ++ * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. ++ * Written by David Howells (dhowells@redhat.com) ++ * ++ * This program is free software; you can redistribute it and/or ++ * modify it under the terms of the GNU General Public License ++ * as published by the Free Software Foundation; either version ++ * 2 of the License, or (at your option) any later version. ++ */ ++ ++#include <stdio.h> ++#include <stdlib.h> ++#include <stdint.h> ++#include <stdarg.h> ++#include <string.h> ++#include <unistd.h> ++#include <fcntl.h> ++#include <sys/mman.h> ++#include <sys/stat.h> ++#include <elf.h> ++#include <asm/byteorder.h> ++ ++static void extract_elf64(void *buffer, size_t size, Elf64_Ehdr *hdr); ++static void extract_elf32(void *buffer, size_t size, Elf32_Ehdr *hdr); ++ ++struct byteorder { ++ uint16_t (*get16)(const uint16_t *); ++ uint32_t (*get32)(const uint32_t *); ++ uint64_t (*get64)(const uint64_t *); ++ void (*set16)(uint16_t *, uint16_t); ++ void (*set32)(uint32_t *, uint32_t); ++ void (*set64)(uint64_t *, uint64_t); ++}; ++ ++static uint16_t get16_le(const uint16_t *p) { return __le16_to_cpu(*p); } ++static uint32_t get32_le(const uint32_t *p) { return __le32_to_cpu(*p); } ++static uint64_t get64_le(const uint64_t *p) { return __le64_to_cpu(*p); } ++static uint16_t get16_be(const uint16_t *p) { return __be16_to_cpu(*p); } ++static uint32_t get32_be(const uint32_t *p) { return __be32_to_cpu(*p); } ++static uint64_t get64_be(const uint64_t *p) { return __be64_to_cpu(*p); } ++ ++static void set16_le(uint16_t *p, uint16_t n) { *p = __cpu_to_le16(n); } ++static void set32_le(uint32_t *p, uint32_t n) { *p = __cpu_to_le32(n); } ++static void set64_le(uint64_t *p, uint64_t n) { *p = __cpu_to_le64(n); } ++static void set16_be(uint16_t *p, uint16_t n) { *p = __cpu_to_be16(n); } ++static void set32_be(uint32_t *p, uint32_t n) { *p = __cpu_to_be32(n); } ++static void set64_be(uint64_t *p, uint64_t n) { *p = __cpu_to_be64(n); } ++ ++static const struct byteorder byteorder_le = { ++ get16_le, get32_le, get64_le, ++ set16_le, set32_le, set64_le ++}; ++static const struct byteorder byteorder_be = { ++ get16_be, get32_be, get64_be, ++ set16_be, set32_be, set64_be ++}; ++static const struct byteorder *order; ++ ++static inline uint16_t get16(const uint16_t *p) { return order->get16(p); } ++static inline uint32_t get32(const uint32_t *p) { return order->get32(p); } ++static inline uint64_t get64(const uint64_t *p) { return order->get64(p); } ++static inline void set16(uint16_t *p, uint16_t n) { order->set16(p, n); } ++static inline void set32(uint32_t *p, uint32_t n) { order->set32(p, n); } ++static inline void set64(uint64_t *p, uint64_t n) { order->set64(p, n); } ++ ++static FILE *outfd; ++static uint8_t csum, xcsum; ++ ++static void write_out(const void *data, size_t size) ++{ ++ const uint8_t *p = data; ++ size_t loop; ++ ++ for (loop = 0; loop < size; loop++) { ++ csum += p[loop]; ++ xcsum += p[loop]; ++ } ++ ++ if (fwrite(data, 1, size, outfd) != size) { ++ perror("write"); ++ exit(1); ++ } ++} ++ ++#define write_out_val(VAL) write_out(&(VAL), sizeof(VAL)) ++ ++static int is_verbose; ++ ++static __attribute__((format(printf, 1, 2))) ++void verbose(const char *fmt, ...) ++{ ++ va_list va; ++ ++ if (is_verbose) { ++ va_start(va, fmt); ++ vprintf(fmt, va); ++ va_end(va); ++ } ++} ++ ++static __attribute__((noreturn)) ++void usage(void) ++{ ++ fprintf(stderr, "Usage: mod-extract [-v] <modulefile> <extractfile>\n"); ++ exit(2); ++} ++ ++/* ++ * ++ */ ++int main(int argc, char **argv) ++{ ++ struct stat st; ++ Elf32_Ehdr *hdr32; ++ Elf64_Ehdr *hdr64; ++ size_t len; ++ void *buffer; ++ int fd, be, b64; ++ ++ while (argc > 1 && strcmp("-v", argv[1]) == 0) { ++ argv++; ++ argc--; ++ is_verbose++; ++ } ++ ++ if (argc != 3) ++ usage(); ++ ++ /* map the module into memory */ ++ fd = open(argv[1], O_RDONLY); ++ if (fd < 0) { ++ perror("open input"); ++ exit(1); ++ } ++ ++ if (fstat(fd, &st) < 0) { ++ perror("fstat"); ++ exit(1); ++ } ++ ++ len = st.st_size; ++ ++ buffer = mmap(NULL, len, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); ++ if (buffer == MAP_FAILED) { ++ perror("mmap"); ++ exit(1); ++ } ++ ++ if (close(fd) < 0) { ++ perror("close input"); ++ exit(1); ++ } ++ ++ /* check it's an ELF object */ ++ hdr32 = buffer; ++ hdr64 = buffer; ++ ++ if (hdr32->e_ident[EI_MAG0] != ELFMAG0 || ++ hdr32->e_ident[EI_MAG1] != ELFMAG1 || ++ hdr32->e_ident[EI_MAG2] != ELFMAG2 || ++ hdr32->e_ident[EI_MAG3] != ELFMAG3 ++ ) { ++ fprintf(stderr, "Module does not appear to be ELF\n"); ++ exit(3); ++ } ++ ++ /* determine endianness and word size */ ++ b64 = (hdr32->e_ident[EI_CLASS] == ELFCLASS64); ++ be = (hdr32->e_ident[EI_DATA] == ELFDATA2MSB); ++ order = be ? &byteorder_be : &byteorder_le; ++ ++ verbose("Module is %s-bit %s-endian\n", ++ b64 ? "64" : "32", ++ be ? "big" : "little"); ++ ++ /* open the output file */ ++ outfd = fopen(argv[2], "w"); ++ if (!outfd) { ++ perror("open output"); ++ exit(1); ++ } ++ ++ /* perform the extraction */ ++ if (b64) ++ extract_elf64(buffer, len, hdr64); ++ else ++ extract_elf32(buffer, len, hdr32); ++ ++ /* done */ ++ if (fclose(outfd) == EOF) { ++ perror("close output"); ++ exit(1); ++ } ++ ++ return 0; ++} ++ ++/* ++ * extract a RELA table ++ * - need to canonicalise the entries in case section addition/removal has ++ * rearranged the symbol table and the section table ++ */ ++static void extract_elf64_rela(const void *buffer, int secix, int targetix, ++ const Elf64_Rela *relatab, size_t nrels, ++ const Elf64_Sym *symbols, size_t nsyms, ++ const Elf64_Shdr *sections, size_t nsects, int *canonmap, ++ const char *strings, size_t nstrings, ++ const char *sh_name) ++{ ++ struct { ++ uint64_t r_offset; ++ uint64_t r_addend; ++ uint64_t st_value; ++ uint64_t st_size; ++ uint32_t r_type; ++ uint16_t st_shndx; ++ uint8_t st_info; ++ uint8_t st_other; ++ ++ } __attribute__((packed)) relocation; ++ ++ const Elf64_Sym *symbol; ++ size_t loop; ++ ++ /* contribute the relevant bits from a join of { RELA, SYMBOL, SECTION } */ ++ for (loop = 0; loop < nrels; loop++) { ++ Elf64_Section st_shndx; ++ Elf64_Xword r_info; ++ ++ /* decode the relocation */ ++ r_info = get64(&relatab[loop].r_info); ++ relocation.r_offset = relatab[loop].r_offset; ++ relocation.r_addend = relatab[loop].r_addend; ++ set32(&relocation.r_type, ELF64_R_TYPE(r_info)); ++ ++ if (ELF64_R_SYM(r_info) >= nsyms) { ++ fprintf(stderr, "Invalid symbol ID %zx in relocation %zu\n", ++ (size_t)ELF64_R_SYM(r_info), loop); ++ exit(1); ++ } ++ ++ /* decode the symbol referenced by the relocation */ ++ symbol = &symbols[ELF64_R_SYM(r_info)]; ++ relocation.st_info = symbol->st_info; ++ relocation.st_other = symbol->st_other; ++ relocation.st_value = symbol->st_value; ++ relocation.st_size = symbol->st_size; ++ relocation.st_shndx = symbol->st_shndx; ++ st_shndx = get16(&symbol->st_shndx); ++ ++ /* canonicalise the section used by the symbol */ ++ if (st_shndx > SHN_UNDEF && st_shndx < nsects) ++ set16(&relocation.st_shndx, canonmap[st_shndx]); ++ ++ write_out_val(relocation); ++ ++ /* undefined symbols must be named if referenced */ ++ if (st_shndx == SHN_UNDEF) { ++ const char *name = strings + get32(&symbol->st_name); ++ write_out(name, strlen(name) + 1); ++ } ++ } ++ ++ verbose("%02x %4d %s [canon]\n", csum, secix, sh_name); ++} ++ ++/* ++ * extract a REL table ++ * - need to canonicalise the entries in case section addition/removal has ++ * rearranged the symbol table and the section table ++ */ ++static void extract_elf64_rel(const void *buffer, int secix, int targetix, ++ const Elf64_Rel *relatab, size_t nrels, ++ const Elf64_Sym *symbols, size_t nsyms, ++ const Elf64_Shdr *sections, size_t nsects, int *canonmap, ++ const char *strings, size_t nstrings, ++ const char *sh_name) ++{ ++ struct { ++ uint64_t r_offset; ++ uint64_t st_value; ++ uint64_t st_size; ++ uint32_t r_type; ++ uint16_t st_shndx; ++ uint8_t st_info; ++ uint8_t st_other; ++ ++ } __attribute__((packed)) relocation; ++ ++ const Elf64_Sym *symbol; ++ size_t loop; ++ ++ /* contribute the relevant bits from a join of { RELA, SYMBOL, SECTION } */ ++ for (loop = 0; loop < nrels; loop++) { ++ Elf64_Section st_shndx; ++ Elf64_Xword r_info; ++ ++ /* decode the relocation */ ++ r_info = get64(&relatab[loop].r_info); ++ relocation.r_offset = relatab[loop].r_offset; ++ set32(&relocation.r_type, ELF64_R_TYPE(r_info)); ++ ++ if (ELF64_R_SYM(r_info) >= nsyms) { ++ fprintf(stderr, "Invalid symbol ID %zx in relocation %zu\n", ++ (size_t)ELF64_R_SYM(r_info), loop); ++ exit(1); ++ } ++ ++ /* decode the symbol referenced by the relocation */ ++ symbol = &symbols[ELF64_R_SYM(r_info)]; ++ relocation.st_info = symbol->st_info; ++ relocation.st_other = symbol->st_other; ++ relocation.st_value = symbol->st_value; ++ relocation.st_size = symbol->st_size; ++ relocation.st_shndx = symbol->st_shndx; ++ st_shndx = get16(&symbol->st_shndx); ++ ++ /* canonicalise the section used by the symbol */ ++ if (st_shndx > SHN_UNDEF && st_shndx < nsects) ++ set16(&relocation.st_shndx, canonmap[st_shndx]); ++ ++ write_out_val(relocation); ++ ++ /* undefined symbols must be named if referenced */ ++ if (st_shndx == SHN_UNDEF) { ++ const char *name = strings + get32(&symbol->st_name); ++ write_out(name, strlen(name) + 1); ++ } ++ } ++ ++ verbose("%02x %4d %s [canon]\n", csum, secix, sh_name); ++} ++ ++/* ++ * extract the data from a 64-bit module ++ */ ++static void extract_elf64(void *buffer, size_t len, Elf64_Ehdr *hdr) ++{ ++ const Elf64_Sym *symbols; ++ Elf64_Shdr *sections; ++ const char *secstrings, *strings; ++ size_t nsyms, nstrings; ++ int loop, shnum, *canonlist, *canonmap, canon, changed, tmp; ++ ++ sections = buffer + get64(&hdr->e_shoff); ++ secstrings = buffer + get64(§ions[get16(&hdr->e_shstrndx)].sh_offset); ++ shnum = get16(&hdr->e_shnum); ++ ++ /* find the symbol table and the string table and produce a list of ++ * index numbers of sections that contribute to the kernel's module ++ * image ++ */ ++ canonlist = calloc(sizeof(int), shnum * 2); ++ if (!canonlist) { ++ perror("calloc"); ++ exit(1); ++ } ++ canonmap = canonlist + shnum; ++ canon = 0; ++ ++ symbols = NULL; ++ strings = NULL; ++ nstrings = 0; ++ nsyms = 0; ++ ++ for (loop = 1; loop < shnum; loop++) { ++ const char *sh_name = secstrings + get32(§ions[loop].sh_name); ++ Elf64_Word sh_type = get32(§ions[loop].sh_type); ++ Elf64_Xword sh_size = get64(§ions[loop].sh_size); ++ Elf64_Xword sh_flags = get64(§ions[loop].sh_flags); ++ Elf64_Word sh_info = get32(§ions[loop].sh_info); ++ Elf64_Off sh_offset = get64(§ions[loop].sh_offset); ++ void *data = buffer + sh_offset; ++ ++ /* quick sanity check */ ++ if (sh_type != SHT_NOBITS && len < sh_offset + sh_size) { ++ fprintf(stderr, "Section goes beyond EOF\n"); ++ exit(3); ++ } ++ ++ /* we only need to canonicalise allocatable sections */ ++ if (sh_flags & SHF_ALLOC) ++ canonlist[canon++] = loop; ++ else if ((sh_type == SHT_REL || sh_type == SHT_RELA) && ++ get64(§ions[sh_info].sh_flags) & SHF_ALLOC) ++ canonlist[canon++] = loop; ++ ++ /* keep track of certain special sections */ ++ switch (sh_type) { ++ case SHT_SYMTAB: ++ if (strcmp(sh_name, ".symtab") == 0) { ++ symbols = data; ++ nsyms = sh_size / sizeof(Elf64_Sym); ++ } ++ break; ++ ++ case SHT_STRTAB: ++ if (strcmp(sh_name, ".strtab") == 0) { ++ strings = data; ++ nstrings = sh_size; ++ } ++ break; ++ ++ default: ++ break; ++ } ++ } ++ ++ if (!symbols) { ++ fprintf(stderr, "Couldn't locate symbol table\n"); ++ exit(3); ++ } ++ ++ if (!strings) { ++ fprintf(stderr, "Couldn't locate strings table\n"); ++ exit(3); ++ } ++ ++ /* canonicalise the index numbers of the contributing section */ ++ do { ++ changed = 0; ++ ++ for (loop = 0; loop < canon - 1; loop++) { ++ const char *x = secstrings + get32(§ions[canonlist[loop + 0]].sh_name); ++ const char *y = secstrings + get32(§ions[canonlist[loop + 1]].sh_name); ++ if (strcmp(x, y) > 0) { ++ tmp = canonlist[loop + 0]; ++ canonlist[loop + 0] = canonlist[loop + 1]; ++ canonlist[loop + 1] = tmp; ++ changed = 1; ++ } ++ } ++ ++ } while (changed); ++ ++ for (loop = 0; loop < canon; loop++) ++ canonmap[canonlist[loop]] = loop + 1; ++ ++ if (is_verbose > 1) { ++ printf("\nSection canonicalisation map:\n"); ++ for (loop = 1; loop < shnum; loop++) { ++ const char *x = secstrings + get32(§ions[loop].sh_name); ++ printf("%4d %s\n", canonmap[loop], x); ++ } ++ ++ printf("\nAllocated section list in canonical order:\n"); ++ for (loop = 0; loop < canon; loop++) { ++ const char *x = secstrings + get32(§ions[canonlist[loop]].sh_name); ++ printf("%4d %s\n", canonlist[loop], x); ++ } ++ } ++ ++ /* iterate through the section table looking for sections we want to ++ * contribute to the signature */ ++ verbose("\n"); ++ verbose("CAN FILE POS CS SECT NAME\n"); ++ verbose("=== ======== == ==== ==============================\n"); ++ ++ for (loop = 0; loop < canon; loop++) { ++ int sect = canonlist[loop]; ++ const char *sh_name = secstrings + get32(§ions[sect].sh_name); ++ Elf64_Word sh_type = get32(§ions[sect].sh_type); ++ Elf64_Xword sh_size = get64(§ions[sect].sh_size); ++ Elf64_Xword sh_flags = get64(§ions[sect].sh_flags); ++ Elf64_Word sh_info = get32(§ions[sect].sh_info); ++ Elf64_Off sh_offset = get64(§ions[sect].sh_offset); ++ void *data = buffer + sh_offset; ++ ++ csum = 0; ++ ++ /* include canonicalised relocation sections */ ++ if (sh_type == SHT_REL || sh_type == SHT_RELA) { ++ Elf32_Word canon_sh_info; ++ ++ if (sh_info <= 0 && sh_info >= hdr->e_shnum) { ++ fprintf(stderr, ++ "Invalid ELF - REL/RELA sh_info does" ++ " not refer to a valid section\n"); ++ exit(3); ++ } ++ ++ verbose("%3u %08lx ", loop, ftell(outfd)); ++ ++ set32(&canon_sh_info, canonmap[sh_info]); ++ ++ /* write out selected portions of the section header */ ++ write_out(sh_name, strlen(sh_name)); ++ write_out_val(sections[sect].sh_type); ++ write_out_val(sections[sect].sh_flags); ++ write_out_val(sections[sect].sh_size); ++ write_out_val(sections[sect].sh_addralign); ++ write_out_val(canon_sh_info); ++ ++ if (sh_type == SHT_RELA) ++ extract_elf64_rela(buffer, sect, sh_info, ++ data, sh_size / sizeof(Elf64_Rela), ++ symbols, nsyms, ++ sections, shnum, canonmap, ++ strings, nstrings, ++ sh_name); ++ else ++ extract_elf64_rel(buffer, sect, sh_info, ++ data, sh_size / sizeof(Elf64_Rel), ++ symbols, nsyms, ++ sections, shnum, canonmap, ++ strings, nstrings, ++ sh_name); ++ continue; ++ } ++ ++ /* include the headers of BSS sections */ ++ if (sh_type == SHT_NOBITS && sh_flags & SHF_ALLOC) { ++ verbose("%3u %08lx ", loop, ftell(outfd)); ++ ++ /* write out selected portions of the section header */ ++ write_out(sh_name, strlen(sh_name)); ++ write_out_val(sections[sect].sh_type); ++ write_out_val(sections[sect].sh_flags); ++ write_out_val(sections[sect].sh_size); ++ write_out_val(sections[sect].sh_addralign); ++ ++ verbose("%02x %4d %s\n", csum, sect, sh_name); ++ } ++ ++ /* include allocatable loadable sections */ ++ if (sh_type != SHT_NOBITS && sh_flags & SHF_ALLOC) ++ goto include_section; ++ ++ /* not this section */ ++ continue; ++ ++ include_section: ++ verbose("%3u %08lx ", loop, ftell(outfd)); ++ ++ /* write out selected portions of the section header */ ++ write_out(sh_name, strlen(sh_name)); ++ write_out_val(sections[sect].sh_type); ++ write_out_val(sections[sect].sh_flags); ++ write_out_val(sections[sect].sh_size); ++ write_out_val(sections[sect].sh_addralign); ++ ++ /* write out the section data */ ++ write_out(data, sh_size); ++ ++ verbose("%02x %4d %s\n", csum, sect, sh_name); ++ } ++ ++ verbose("%08lx (%lu bytes csum 0x%02x)\n", ++ ftell(outfd), ftell(outfd), xcsum); ++} ++ ++/* ++ * extract a RELA table ++ * - need to canonicalise the entries in case section addition/removal has ++ * rearranged the symbol table and the section table ++ */ ++static void extract_elf32_rela(const void *buffer, int secix, int targetix, ++ const Elf32_Rela *relatab, size_t nrels, ++ const Elf32_Sym *symbols, size_t nsyms, ++ const Elf32_Shdr *sections, size_t nsects, ++ int *canonmap, ++ const char *strings, size_t nstrings, ++ const char *sh_name) ++{ ++ struct { ++ uint32_t r_offset; ++ uint32_t r_addend; ++ uint32_t st_value; ++ uint32_t st_size; ++ uint16_t st_shndx; ++ uint8_t r_type; ++ uint8_t st_info; ++ uint8_t st_other; ++ ++ } __attribute__((packed)) relocation; ++ ++ const Elf32_Sym *symbol; ++ size_t loop; ++ ++ /* contribute the relevant bits from a join of { RELA, SYMBOL, SECTION } */ ++ for (loop = 0; loop < nrels; loop++) { ++ Elf32_Section st_shndx; ++ Elf32_Word r_info; ++ ++ /* decode the relocation */ ++ r_info = get32(&relatab[loop].r_info); ++ relocation.r_offset = relatab[loop].r_offset; ++ relocation.r_addend = relatab[loop].r_addend; ++ relocation.r_type = ELF32_R_TYPE(r_info); ++ ++ if (ELF32_R_SYM(r_info) >= nsyms) { ++ fprintf(stderr, "Invalid symbol ID %x in relocation %zu\n", ++ ELF32_R_SYM(r_info), loop); ++ exit(1); ++ } ++ ++ /* decode the symbol referenced by the relocation */ ++ symbol = &symbols[ELF32_R_SYM(r_info)]; ++ relocation.st_info = symbol->st_info; ++ relocation.st_other = symbol->st_other; ++ relocation.st_value = symbol->st_value; ++ relocation.st_size = symbol->st_size; ++ relocation.st_shndx = symbol->st_shndx; ++ st_shndx = get16(&symbol->st_shndx); ++ ++ /* canonicalise the section used by the symbol */ ++ if (st_shndx > SHN_UNDEF && st_shndx < nsects) ++ set16(&relocation.st_shndx, canonmap[st_shndx]); ++ ++ write_out_val(relocation); ++ ++ /* undefined symbols must be named if referenced */ ++ if (st_shndx == SHN_UNDEF) { ++ const char *name = strings + get32(&symbol->st_name); ++ write_out(name, strlen(name) + 1); ++ } ++ } ++ ++ verbose("%02x %4d %s [canon]\n", csum, secix, sh_name); ++} ++ ++/* ++ * extract a REL table ++ * - need to canonicalise the entries in case section addition/removal has ++ * rearranged the symbol table and the section table ++ */ ++static void extract_elf32_rel(const void *buffer, int secix, int targetix, ++ const Elf32_Rel *relatab, size_t nrels, ++ const Elf32_Sym *symbols, size_t nsyms, ++ const Elf32_Shdr *sections, size_t nsects, ++ int *canonmap, ++ const char *strings, size_t nstrings, ++ const char *sh_name) ++{ ++ struct { ++ uint32_t r_offset; ++ uint32_t st_value; ++ uint32_t st_size; ++ uint16_t st_shndx; ++ uint8_t r_type; ++ uint8_t st_info; ++ uint8_t st_other; ++ ++ } __attribute__((packed)) relocation; ++ ++ const Elf32_Sym *symbol; ++ size_t loop; ++ ++ /* contribute the relevant bits from a join of { RELA, SYMBOL, SECTION } */ ++ for (loop = 0; loop < nrels; loop++) { ++ Elf32_Section st_shndx; ++ Elf32_Word r_info; ++ ++ /* decode the relocation */ ++ r_info = get32(&relatab[loop].r_info); ++ relocation.r_offset = relatab[loop].r_offset; ++ relocation.r_type = ELF32_R_TYPE(r_info); ++ ++ if (ELF32_R_SYM(r_info) >= nsyms) { ++ fprintf(stderr, "Invalid symbol ID %x in relocation %zu\n", ++ ELF32_R_SYM(r_info), loop); ++ exit(1); ++ } ++ ++ /* decode the symbol referenced by the relocation */ ++ symbol = &symbols[ELF32_R_SYM(r_info)]; ++ relocation.st_info = symbol->st_info; ++ relocation.st_other = symbol->st_other; ++ relocation.st_value = symbol->st_value; ++ relocation.st_size = symbol->st_size; ++ relocation.st_shndx = symbol->st_shndx; ++ st_shndx = get16(&symbol->st_shndx); ++ ++ /* canonicalise the section used by the symbol */ ++ if (st_shndx > SHN_UNDEF && st_shndx < nsects) ++ set16(&relocation.st_shndx, canonmap[st_shndx]); ++ ++ write_out_val(relocation); ++ ++ /* undefined symbols must be named if referenced */ ++ if (st_shndx == SHN_UNDEF) { ++ const char *name = strings + get32(&symbol->st_name); ++ write_out(name, strlen(name) + 1); ++ } ++ } ++ ++ verbose("%02x %4d %s [canon]\n", csum, secix, sh_name); ++} ++ ++/* ++ * extract the data from a 32-bit module ++ */ ++static void extract_elf32(void *buffer, size_t len, Elf32_Ehdr *hdr) ++{ ++ const Elf32_Sym *symbols; ++ Elf32_Shdr *sections; ++ const char *secstrings, *strings; ++ size_t nsyms, nstrings; ++ int loop, shnum, *canonlist, *canonmap, canon, changed, tmp; ++ ++ sections = buffer + get32(&hdr->e_shoff); ++ secstrings = buffer + get32(§ions[get16(&hdr->e_shstrndx)].sh_offset); ++ shnum = get16(&hdr->e_shnum); ++ ++ /* find the symbol table and the string table and produce a list of ++ * index numbers of sections that contribute to the kernel's module ++ * image ++ */ ++ canonlist = calloc(sizeof(int), shnum * 2); ++ if (!canonlist) { ++ perror("calloc"); ++ exit(1); ++ } ++ canonmap = canonlist + shnum; ++ canon = 0; ++ ++ symbols = NULL; ++ strings = NULL; ++ nstrings = 0; ++ nsyms = 0; ++ ++ for (loop = 1; loop < shnum; loop++) { ++ const char *sh_name = secstrings + get32(§ions[loop].sh_name); ++ Elf32_Word sh_type = get32(§ions[loop].sh_type); ++ Elf32_Xword sh_size = get32(§ions[loop].sh_size); ++ Elf32_Xword sh_flags = get32(§ions[loop].sh_flags); ++ Elf64_Word sh_info = get32(§ions[loop].sh_info); ++ Elf32_Off sh_offset = get32(§ions[loop].sh_offset); ++ void *data = buffer + sh_offset; ++ ++ /* quick sanity check */ ++ if (sh_type != SHT_NOBITS && len < sh_offset + sh_size) { ++ fprintf(stderr, "Section goes beyond EOF\n"); ++ exit(3); ++ } ++ ++ /* we only need to canonicalise allocatable sections */ ++ if (sh_flags & SHF_ALLOC) ++ canonlist[canon++] = loop; ++ else if ((sh_type == SHT_REL || sh_type == SHT_RELA) && ++ get32(§ions[sh_info].sh_flags) & SHF_ALLOC) ++ canonlist[canon++] = loop; ++ ++ /* keep track of certain special sections */ ++ switch (sh_type) { ++ case SHT_SYMTAB: ++ if (strcmp(sh_name, ".symtab") == 0) { ++ symbols = data; ++ nsyms = sh_size / sizeof(Elf32_Sym); ++ } ++ break; ++ ++ case SHT_STRTAB: ++ if (strcmp(sh_name, ".strtab") == 0) { ++ strings = data; ++ nstrings = sh_size; ++ } ++ break; ++ ++ default: ++ break; ++ } ++ } ++ ++ if (!symbols) { ++ fprintf(stderr, "Couldn't locate symbol table\n"); ++ exit(3); ++ } ++ ++ if (!strings) { ++ fprintf(stderr, "Couldn't locate strings table\n"); ++ exit(3); ++ } ++ ++ /* canonicalise the index numbers of the contributing section */ ++ do { ++ changed = 0; ++ ++ for (loop = 0; loop < canon - 1; loop++) { ++ const char *x = secstrings + get32(§ions[canonlist[loop + 0]].sh_name); ++ const char *y = secstrings + get32(§ions[canonlist[loop + 1]].sh_name); ++ if (strcmp(x, y) > 0) { ++ tmp = canonlist[loop + 0]; ++ canonlist[loop + 0] = canonlist[loop + 1]; ++ canonlist[loop + 1] = tmp; ++ changed = 1; ++ } ++ } ++ ++ } while (changed); ++ ++ for (loop = 0; loop < canon; loop++) ++ canonmap[canonlist[loop]] = loop + 1; ++ ++ if (is_verbose > 1) { ++ printf("\nSection canonicalisation map:\n"); ++ for (loop = 1; loop < shnum; loop++) { ++ const char *x = secstrings + get32(§ions[loop].sh_name); ++ printf("%4d %s\n", canonmap[loop], x); ++ } ++ ++ printf("\nAllocated section list in canonical order:\n"); ++ for (loop = 0; loop < canon; loop++) { ++ const char *x = secstrings + get32(§ions[canonlist[loop]].sh_name); ++ printf("%4d %s\n", canonlist[loop], x); ++ } ++ } ++ ++ /* iterate through the section table looking for sections we want to ++ * contribute to the signature */ ++ verbose("\n"); ++ verbose("CAN FILE POS CS SECT NAME\n"); ++ verbose("=== ======== == ==== ==============================\n"); ++ ++ for (loop = 0; loop < canon; loop++) { ++ int sect = canonlist[loop]; ++ const char *sh_name = secstrings + get32(§ions[sect].sh_name); ++ Elf32_Word sh_type = get32(§ions[sect].sh_type); ++ Elf32_Xword sh_size = get32(§ions[sect].sh_size); ++ Elf32_Xword sh_flags = get32(§ions[sect].sh_flags); ++ Elf32_Word sh_info = get32(§ions[sect].sh_info); ++ Elf32_Off sh_offset = get32(§ions[sect].sh_offset); ++ void *data = buffer + sh_offset; ++ ++ csum = 0; ++ ++ /* quick sanity check */ ++ if (sh_type != SHT_NOBITS && len < sh_offset + sh_size) { ++ fprintf(stderr, "section goes beyond EOF\n"); ++ exit(3); ++ } ++ ++ /* include canonicalised relocation sections */ ++ if (sh_type == SHT_REL || sh_type == SHT_RELA) { ++ Elf32_Word canon_sh_info; ++ ++ if (sh_info <= 0 && sh_info >= hdr->e_shnum) { ++ fprintf(stderr, ++ "Invalid ELF - REL/RELA sh_info does" ++ " not refer to a valid section\n"); ++ exit(3); ++ } ++ ++ verbose("%3u %08lx ", loop, ftell(outfd)); ++ ++ set32(&canon_sh_info, canonmap[sh_info]); ++ ++ /* write out selected portions of the section header */ ++ write_out(sh_name, strlen(sh_name)); ++ write_out_val(sections[sect].sh_type); ++ write_out_val(sections[sect].sh_flags); ++ write_out_val(sections[sect].sh_size); ++ write_out_val(sections[sect].sh_addralign); ++ write_out_val(canon_sh_info); ++ ++ if (sh_type == SHT_RELA) ++ extract_elf32_rela(buffer, sect, sh_info, ++ data, sh_size / sizeof(Elf32_Rela), ++ symbols, nsyms, ++ sections, shnum, canonmap, ++ strings, nstrings, ++ sh_name); ++ else ++ extract_elf32_rel(buffer, sect, sh_info, ++ data, sh_size / sizeof(Elf32_Rel), ++ symbols, nsyms, ++ sections, shnum, canonmap, ++ strings, nstrings, ++ sh_name); ++ continue; ++ } ++ ++ /* include the headers of BSS sections */ ++ if (sh_type == SHT_NOBITS && sh_flags & SHF_ALLOC) { ++ verbose("%3u %08lx ", loop, ftell(outfd)); ++ ++ /* write out selected portions of the section header */ ++ write_out(sh_name, strlen(sh_name)); ++ write_out_val(sections[sect].sh_type); ++ write_out_val(sections[sect].sh_flags); ++ write_out_val(sections[sect].sh_size); ++ write_out_val(sections[sect].sh_addralign); ++ ++ verbose("%02x %4d %s\n", csum, sect, sh_name); ++ } ++ ++ /* include allocatable loadable sections */ ++ if (sh_type != SHT_NOBITS && sh_flags & SHF_ALLOC) ++ goto include_section; ++ ++ /* not this section */ ++ continue; ++ ++ include_section: ++ verbose("%3u %08lx ", loop, ftell(outfd)); ++ ++ /* write out selected portions of the section header */ ++ write_out(sh_name, strlen(sh_name)); ++ write_out_val(sections[sect].sh_type); ++ write_out_val(sections[sect].sh_flags); ++ write_out_val(sections[sect].sh_size); ++ write_out_val(sections[sect].sh_addralign); ++ ++ /* write out the section data */ ++ write_out(data, sh_size); ++ ++ verbose("%02x %4d %s\n", csum, sect, sh_name); ++ } ++ ++ verbose("%08lx (%lu bytes csum 0x%02x)\n", ++ ftell(outfd), ftell(outfd), xcsum); ++} +diff --git a/scripts/mod/modsign-note.sh b/scripts/mod/modsign-note.sh +new file mode 100644 +index 0000000..bca67c0 +--- /dev/null ++++ b/scripts/mod/modsign-note.sh +@@ -0,0 +1,16 @@ ++#!/bin/sh ++# ++# Generate a module signature note source file ++# ++# mod-sign.sh <sig-file> ><note-src-file> ++# ++ ++SIG=$1 ++ ++cat <<EOF ++#include <linux/modsign.h> ++ ++ELFNOTE(MODSIGN_NOTE_NAME, MODSIGN_NOTE_TYPE, .incbin "$SIG") ++EOF ++ ++exit 0 +-- +1.7.10.2 + + +From 38ddca03060502e8134320b732758fd6b6a98247 Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Thu, 10 May 2012 23:49:55 +0100 +Subject: [PATCH 23/36] MODSIGN: Module signature verification stub + +Create a stub for the module signature verifier and link it into module.c so +that it gets called. A field is added to struct module to record whether or +not a valid module signature was detected. + +The stub also implements the policy for handling unsigned modules and the +printing of error messages to indicate various problems with the module. + +If CONFIG_MODULE_SIG_FORCE is enabled or "enforcemodulesig=1" is supplied on +the kernel command line, the kernel will _only_ load validly signed modules +for which it has a public key. Otherwise, it will also load modules that are +unsigned. Any module for which the kernel has a key, but which proves to have +a signature mismatch will not be permitted to load. + +This table indicates the behaviours in the various situations: + + MODULE STATE PERMISSIVE MODE ENFORCING MODE + ======================================= =============== =============== + Unsigned Ok EKEYREJECTED + Signed, no public key ENOKEY ENOKEY + Validly signed, public key Ok Ok + Invalidly signed, public key EKEYREJECTED EKEYREJECTED + Validly signed, expired key EKEYEXPIRED EKEYEXPIRED + Signed, hash algorithm unavailable ENOPKG ENOPKG + Corrupt signature EBADMSG EBADMSG + Corrupt ELF ELIBBAD ELIBBAD + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + include/linux/module.h | 3 ++ + kernel/Makefile | 1 + + kernel/module-verify-defs.h | 77 ++++++++++++++++++++++++++++++ + kernel/module-verify.c | 109 +++++++++++++++++++++++++++++++++++++++++++ + kernel/module-verify.h | 19 ++++++++ + kernel/module.c | 26 +++++++++-- + 6 files changed, 230 insertions(+), 5 deletions(-) + create mode 100644 kernel/module-verify-defs.h + create mode 100644 kernel/module-verify.c + create mode 100644 kernel/module-verify.h + +diff --git a/include/linux/module.h b/include/linux/module.h +index fbcafe2..7391833 100644 +--- a/include/linux/module.h ++++ b/include/linux/module.h +@@ -227,6 +227,9 @@ struct module + /* Unique handle for this module */ + char name[MODULE_NAME_LEN]; + ++ /* Is this module GPG signed */ ++ bool gpgsig_ok; ++ + /* Sysfs stuff. */ + struct module_kobject mkobj; + struct module_attribute *modinfo_attrs; +diff --git a/kernel/Makefile b/kernel/Makefile +index cb41b95..7608053 100644 +--- a/kernel/Makefile ++++ b/kernel/Makefile +@@ -51,6 +51,7 @@ obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o + obj-$(CONFIG_PROVE_LOCKING) += spinlock.o + obj-$(CONFIG_UID16) += uid16.o + obj-$(CONFIG_MODULES) += module.o ++obj-$(CONFIG_MODULE_SIG) += module-verify.o + obj-$(CONFIG_KALLSYMS) += kallsyms.o + obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o + obj-$(CONFIG_KEXEC) += kexec.o +diff --git a/kernel/module-verify-defs.h b/kernel/module-verify-defs.h +new file mode 100644 +index 0000000..292d2ba +--- /dev/null ++++ b/kernel/module-verify-defs.h +@@ -0,0 +1,77 @@ ++/* Module verification internal definitions ++ * ++ * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved. ++ * Written by David Howells (dhowells@redhat.com) ++ * ++ * This program is free software; you can redistribute it and/or ++ * modify it under the terms of the GNU General Public Licence ++ * as published by the Free Software Foundation; either version ++ * 2 of the Licence, or (at your option) any later version. ++ */ ++ ++#ifdef CONFIG_MODULE_SIG ++ ++/* ++ * Internal state ++ */ ++struct module_verify_data { ++ struct crypto_key_verify_context *mod_sig; /* Module signing context */ ++ union { ++ const void *buffer; /* module buffer */ ++ const Elf_Ehdr *hdr; /* ELF header */ ++ }; ++ const Elf_Shdr *sections; /* ELF section table */ ++ const char *secstrings; /* ELF section string table */ ++ const void *sig; /* Signature note content */ ++ size_t size; /* module object size */ ++ size_t nsects; /* number of sections */ ++ size_t sig_size; /* Size of signature */ ++ size_t signed_size; /* count of bytes contributed to digest */ ++ unsigned *canonlist; /* list of canonicalised sections */ ++ unsigned *canonmap; /* section canonicalisation map */ ++ unsigned ncanon; /* number of canonicalised sections */ ++ unsigned sig_index; /* module signature section index */ ++ uint8_t xcsum; /* checksum of bytes contributed to digest */ ++ uint8_t csum; /* checksum of bytes representing a section */ ++}; ++ ++/* ++ * Whether or not we support various types of ELF relocation record ++ */ ++#if defined(MODULE_HAS_ELF_REL_ONLY) ++#define is_elf_rel(sh_type) ((sh_type) == SHT_REL) ++#define is_elf_rela(sh_type) (0) ++#elif defined(MODULE_HAS_ELF_RELA_ONLY) ++#define is_elf_rel(sh_type) (0) ++#define is_elf_rela(sh_type) ((sh_type) == SHT_RELA) ++#else ++#define is_elf_rel(sh_type) ((sh_type) == SHT_REL) ++#define is_elf_rela(sh_type) ((sh_type) == SHT_RELA) ++#endif ++ ++/* ++ * Debugging. Define DEBUG to enable. ++ */ ++#define _debug(FMT, ...) \ ++ do { \ ++ if (unlikely(modsign_debug)) \ ++ pr_debug(FMT, ##__VA_ARGS__); \ ++ } while(0) ++ ++#ifdef DEBUG ++#define count_and_csum(C, __p, __n) \ ++do { \ ++ int __loop; \ ++ for (__loop = 0; __loop < __n; __loop++) { \ ++ (C)->csum += __p[__loop]; \ ++ (C)->xcsum += __p[__loop]; \ ++ } \ ++ (C)->signed_size += __n; \ ++} while (0) ++#else ++#define count_and_csum(C, __p, __n) \ ++do { \ ++} while (0) ++#endif ++ ++#endif /* CONFIG_MODULE_SIG */ +diff --git a/kernel/module-verify.c b/kernel/module-verify.c +new file mode 100644 +index 0000000..0a3eb4b +--- /dev/null ++++ b/kernel/module-verify.c +@@ -0,0 +1,109 @@ ++/* Module signature verification ++ * ++ * The code in this file examines a signed kernel module and attempts to ++ * determine if the PGP signature inside the module matches a digest of the ++ * allocatable sections and the canonicalised relocation tables for those ++ * allocatable sections. ++ * ++ * The module signature is included in an ELF note within the ELF structure of ++ * the module blob. This, combined with the minimal canonicalisation performed ++ * here, permits the module to pass through "strip -x", "strip -g" and ++ * "eu-strip" without becoming corrupt. "strip" and "strip -s" will render a ++ * module unusable by removing the symbol table. ++ * ++ * Copyright (C) 2004, 2011, 2012 Red Hat, Inc. All Rights Reserved. ++ * Written by David Howells (dhowells@redhat.com) ++ * - Derived from GregKH's RSA module signer ++ * ++ * This program is free software; you can redistribute it and/or ++ * modify it under the terms of the GNU General Public License ++ * as published by the Free Software Foundation; either version ++ * 2 of the License, or (at your option) any later version. ++ */ ++ ++#undef DEBUG ++#include <linux/kernel.h> ++#include <linux/module.h> ++#include <linux/slab.h> ++#include <linux/elf.h> ++#include <linux/elfnote.h> ++#include <linux/sched.h> ++#include <linux/cred.h> ++#include <linux/modsign.h> ++#include <linux/moduleparam.h> ++#include <keys/crypto-type.h> ++#include "module-verify.h" ++#include "module-verify-defs.h" ++ ++#ifdef DEBUG ++static int modsign_debug; ++core_param(modsign_debug, modsign_debug, int, 0644); ++#else ++#define modsign_debug false ++#endif ++ ++#ifdef CONFIG_MODULE_SIG_FORCE ++#define modsign_signedonly true ++#else ++static bool modsign_signedonly; ++#endif ++ ++static const char modsign_note_name[] = ELFNOTE_NAME(MODSIGN_NOTE_NAME); ++static const char modsign_note_section[] = ELFNOTE_SECTION(MODSIGN_NOTE_NAME); ++ ++/* ++ * Verify a module's integrity ++ */ ++int module_verify(const Elf_Ehdr *hdr, size_t size, bool *_gpgsig_ok) ++{ ++ struct module_verify_data mvdata; ++ int ret; ++ ++ memset(&mvdata, 0, sizeof(mvdata)); ++ mvdata.buffer = hdr; ++ mvdata.size = size; ++ ++ if (mvdata.sig_index <= 0) { ++ /* Deal with an unsigned module */ ++ if (modsign_signedonly) { ++ pr_err("An attempt to load unsigned module was rejected\n"); ++ return -EKEYREJECTED; ++ } else { ++ return 0; ++ } ++ goto out; ++ } ++ ++ ret = 0; ++ ++out: ++ switch (ret) { ++ case 0: /* Good signature */ ++ *_gpgsig_ok = true; ++ break; ++ case -ELIBBAD: ++ pr_err("Module format error encountered\n"); ++ break; ++ case -EBADMSG: ++ pr_err("Module signature error encountered\n"); ++ break; ++ case -EKEYREJECTED: /* Signature mismatch or number format error */ ++ pr_err("Module signature verification failed\n"); ++ break; ++ case -ENOKEY: /* Signed, but we don't have the public key */ ++ pr_err("Module signed with unknown public key\n"); ++ break; ++ default: /* Other error (probably ENOMEM) */ ++ break; ++ } ++ return ret; ++} ++ ++static int __init sign_setup(char *str) ++{ ++#ifndef CONFIG_MODULE_SIG_FORCE ++ modsign_signedonly = true; ++#endif ++ return 0; ++} ++__setup("enforcemodulesig", sign_setup); +diff --git a/kernel/module-verify.h b/kernel/module-verify.h +new file mode 100644 +index 0000000..6bb6b56 +--- /dev/null ++++ b/kernel/module-verify.h +@@ -0,0 +1,19 @@ ++/* Module verification definitions ++ * ++ * Copyright (C) 2004, 2012 Red Hat, Inc. All Rights Reserved. ++ * Written by David Howells (dhowells@redhat.com) ++ * ++ * This program is free software; you can redistribute it and/or ++ * modify it under the terms of the GNU General Public License ++ * as published by the Free Software Foundation; either version ++ * 2 of the License, or (at your option) any later version. ++ */ ++ ++#ifdef CONFIG_MODULE_SIG ++extern int module_verify(const Elf_Ehdr *hdr, size_t size, bool *_gpgsig_ok); ++#else ++static inline int module_verify(const Elf_Ehdr *hdr, size_t size, bool *_gpgsig_ok) ++{ ++ return 0; ++} ++#endif +diff --git a/kernel/module.c b/kernel/module.c +index 377cb06..c3797f7 100644 +--- a/kernel/module.c ++++ b/kernel/module.c +@@ -58,6 +58,7 @@ + #include <linux/jump_label.h> + #include <linux/pfn.h> + #include <linux/bsearch.h> ++#include "module-verify.h" + + #define CREATE_TRACE_POINTS + #include <trace/events/module.h> +@@ -2402,7 +2403,8 @@ static inline void kmemleak_load_module(const struct module *mod, + /* Sets info->hdr and info->len. */ + static int copy_and_check(struct load_info *info, + const void __user *umod, unsigned long len, +- const char __user *uargs) ++ const char __user *uargs, ++ bool *_gpgsig_ok) + { + int err; + Elf_Ehdr *hdr; +@@ -2435,6 +2437,12 @@ static int copy_and_check(struct load_info *info, + goto free_hdr; + } + ++ /* Verify the module's contents */ ++ *_gpgsig_ok = false; ++ err = module_verify(hdr, len, _gpgsig_ok); ++ if (err < 0) ++ goto free_hdr; ++ + info->hdr = hdr; + info->len = len; + return 0; +@@ -2777,7 +2785,8 @@ int __weak module_frob_arch_sections(Elf_Ehdr *hdr, + return 0; + } + +-static struct module *layout_and_allocate(struct load_info *info) ++static struct module *layout_and_allocate(struct load_info *info, ++ bool gpgsig_ok) + { + /* Module within temporary copy. */ + struct module *mod; +@@ -2787,6 +2796,7 @@ static struct module *layout_and_allocate(struct load_info *info) + mod = setup_load_info(info); + if (IS_ERR(mod)) + return mod; ++ mod->gpgsig_ok = gpgsig_ok; + + err = check_modinfo(mod, info); + if (err) +@@ -2870,17 +2880,18 @@ static struct module *load_module(void __user *umod, + struct load_info info = { NULL, }; + struct module *mod; + long err; ++ bool gpgsig_ok; + + pr_debug("load_module: umod=%p, len=%lu, uargs=%p\n", + umod, len, uargs); + + /* Copy in the blobs from userspace, check they are vaguely sane. */ +- err = copy_and_check(&info, umod, len, uargs); ++ err = copy_and_check(&info, umod, len, uargs, &gpgsig_ok); + if (err) + return ERR_PTR(err); + + /* Figure out module layout, and allocate all the memory. */ +- mod = layout_and_allocate(&info); ++ mod = layout_and_allocate(&info, gpgsig_ok); + if (IS_ERR(mod)) { + err = PTR_ERR(mod); + goto free_copy; +@@ -3517,8 +3528,13 @@ void print_modules(void) + printk(KERN_DEFAULT "Modules linked in:"); + /* Most callers should already have preempt disabled, but make sure */ + preempt_disable(); +- list_for_each_entry_rcu(mod, &modules, list) ++ list_for_each_entry_rcu(mod, &modules, list) { + printk(" %s%s", mod->name, module_flags(mod, buf)); ++#ifdef CONFIG_MODULE_SIG ++ if (!mod->gpgsig_ok) ++ printk("(U)"); ++#endif ++ } + preempt_enable(); + if (last_unloaded_module[0]) + printk(" [last unloaded: %s]", last_unloaded_module); +-- +1.7.10.2 + + +From 6f5323e52cdc37969939ef82036783da67afe69f Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Thu, 10 May 2012 23:49:55 +0100 +Subject: [PATCH 24/36] MODSIGN: Provide module signing public keys to the + kernel + +Include a PGP keyring containing the public keys required to perform module +verification in the kernel image during build and create a special keyring +during boot which is then populated with keys of crypto type holding the public +keys found in the PGP keyring. + +These can be seen by root: + +[root@andromeda ~]# cat /proc/keys +07ad4ee0 I----- 1 perm 3f010000 0 0 crypto modsign.0: RSA 87b9b3bd [] +15c7f8c3 I----- 1 perm 1f030000 0 0 keyring .module_sign: 1/4 +... + +It is probably worth permitting root to invalidate these keys, resulting in +their removal and preventing further modules from being loaded with that key. + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + kernel/Makefile | 3 +- + kernel/modsign-pubkey.c | 74 +++++++++++++++++++++++++++++++++++++++++++ + kernel/module-verify-defs.h | 4 +++ + kernel/module-verify.c | 2 -- + 4 files changed, 80 insertions(+), 3 deletions(-) + create mode 100644 kernel/modsign-pubkey.c + +diff --git a/kernel/Makefile b/kernel/Makefile +index 7608053..986ed7f 100644 +--- a/kernel/Makefile ++++ b/kernel/Makefile +@@ -51,7 +51,8 @@ obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o + obj-$(CONFIG_PROVE_LOCKING) += spinlock.o + obj-$(CONFIG_UID16) += uid16.o + obj-$(CONFIG_MODULES) += module.o +-obj-$(CONFIG_MODULE_SIG) += module-verify.o ++obj-$(CONFIG_MODULE_SIG) += module-verify.o modsign-pubkey.o ++kernel/modsign-pubkey.o: modsign.pub + obj-$(CONFIG_KALLSYMS) += kallsyms.o + obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o + obj-$(CONFIG_KEXEC) += kexec.o +diff --git a/kernel/modsign-pubkey.c b/kernel/modsign-pubkey.c +new file mode 100644 +index 0000000..2ada460 +--- /dev/null ++++ b/kernel/modsign-pubkey.c +@@ -0,0 +1,74 @@ ++/* Public keys for module signature verification ++ * ++ * Copyright (C) 2011 Red Hat, Inc. All Rights Reserved. ++ * Written by David Howells (dhowells@redhat.com) ++ * ++ * This program is free software; you can redistribute it and/or ++ * modify it under the terms of the GNU General Public Licence ++ * as published by the Free Software Foundation; either version ++ * 2 of the Licence, or (at your option) any later version. ++ */ ++ ++#include <linux/kernel.h> ++#include <linux/sched.h> ++#include <linux/cred.h> ++#include <keys/crypto-type.h> ++#include "module-verify-defs.h" ++ ++struct key *modsign_keyring; ++ ++extern __initdata const u8 modsign_public_keys[]; ++extern __initdata const u8 modsign_public_keys_end[]; ++asm(".section .init.data,\"aw\"\n" ++ "modsign_public_keys:\n" ++ ".incbin \"modsign.pub\"\n" ++ "modsign_public_keys_end:" ++ ); ++ ++/* ++ * We need to make sure ccache doesn't cache the .o file as it doesn't notice ++ * if modsign.pub changes. ++ */ ++static __initdata const char annoy_ccache[] = __TIME__ "foo"; ++ ++/* ++ * Load the compiled-in keys ++ */ ++static __init int module_verify_init(void) ++{ ++ pr_notice("Initialise module verification\n"); ++ ++ modsign_keyring = key_alloc(&key_type_keyring, ".module_sign", ++ 0, 0, current_cred(), ++ (KEY_POS_ALL & ~KEY_POS_SETATTR) | ++ KEY_USR_VIEW | KEY_USR_READ, ++ KEY_ALLOC_NOT_IN_QUOTA); ++ if (IS_ERR(modsign_keyring)) ++ panic("Can't allocate module signing keyring\n"); ++ ++ if (key_instantiate_and_link(modsign_keyring, NULL, 0, NULL, NULL) < 0) ++ panic("Can't instantiate module signing keyring\n"); ++ ++ return 0; ++} ++ ++/* ++ * Must be initialised before we try and load the keys into the keyring. ++ */ ++device_initcall(module_verify_init); ++ ++/* ++ * Load the compiled-in keys ++ */ ++static __init int modsign_pubkey_init(void) ++{ ++ pr_notice("Load module verification keys\n"); ++ ++ if (preload_pgp_keys(modsign_public_keys, ++ modsign_public_keys_end - modsign_public_keys, ++ modsign_keyring, "modsign.") < 0) ++ panic("Can't load module signing keys\n"); ++ ++ return 0; ++} ++late_initcall(modsign_pubkey_init); +diff --git a/kernel/module-verify-defs.h b/kernel/module-verify-defs.h +index 292d2ba..45bea45 100644 +--- a/kernel/module-verify-defs.h ++++ b/kernel/module-verify-defs.h +@@ -11,6 +11,10 @@ + + #ifdef CONFIG_MODULE_SIG + ++#include <linux/module.h> ++ ++extern struct key *modsign_keyring; ++ + /* + * Internal state + */ +diff --git a/kernel/module-verify.c b/kernel/module-verify.c +index 0a3eb4b..b1c1d4c 100644 +--- a/kernel/module-verify.c ++++ b/kernel/module-verify.c +@@ -27,8 +27,6 @@ + #include <linux/slab.h> + #include <linux/elf.h> + #include <linux/elfnote.h> +-#include <linux/sched.h> +-#include <linux/cred.h> + #include <linux/modsign.h> + #include <linux/moduleparam.h> + #include <keys/crypto-type.h> +-- +1.7.10.2 + + +From 5727333d123ef9d7fa2666069306bf3ec2d7f110 Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Thu, 10 May 2012 23:49:56 +0100 +Subject: [PATCH 25/36] MODSIGN: Check the ELF container + +Check the ELF container of the kernel module to prevent the kernel from +crashing or getting corrupted whilst trying to use it and locate the module +signature note if present. + +We try to check as little as possible. We check the metadata that the +signature checker actually has to use, and leave anything that it doesn't +actually need to the signature to catch. + +The stuff we need to check is: + + (1) The locations and offsets in the ELF header of important parts like the + section table. + + (2) The section table. Note that we only check sh_info for section types that + we're actually interested in (string, symbol and relocation tables). We + also check that alignments are what we expect for those tables. + + (3) That non-empty string tables have the required NUL at the end so that we + can be sure that all strings therein are NUL-terminated. We don't bother + checking for the required NUL at the beginning as it shouldn't cause a + problem to us. + + (4) The name offset and section index in each symbol. We could defer this to + when we deal with the relocation tables so that we only check symbols that + are used by relocations - but we would then end up checking some symbols + multiple times. + + (5) The module signature note section and the first note in it if present. + + (6) That relocations applied to an allocatable section only refer to + symbols in allocatable sections and absolute symbols (done in the module + signing code rather than here). + +Note that these checks survive "strip -x", "strip -g" and "eu-strip" being +applied to a module and detect if the module was given to "strip" or "strip -s" +and report an error. + +We can skip some direct checks that turn out unnecessary or redundant: + + (1) That sh_link has a greater than 0 value for symbol tables and relocation + tables. These require the index of a string table and a symbol table + respectively - and since we have already checked section 0 is of SHT_NULL + type, checking the symbol type renders the sh_link > 0 check redundant. + + (2) That a non-empty string table begins with a NUL. Since we check the + string table ends with a NUL, any string in there will be NUL-terminated + and shouldn't cause us to transgress beyond the bounds of the string table + when using strlen(). + + (3) That strings in a string table actually make sense. We don't care, so + long as it is NUL terminated. Any string that refers to an undefined + symbol is added to the crypto digest and will be checked that way. + Strings that we directly look for (such as ".modinfo") will be validated + by that. + + (4) That sections don't overlap. We don't actually care if sections overlap + in the file, provided we don't see bad metadata. If the sections holding + the allocatable content overlap, then the signature check is likely to + fail. + + (5) That symbol values and relocation offsets and addends make sense. We just + add this data to the digest if it pertains to an allocatable section. + + (6) That allocatable note sections, other than the signature note, make sense. + The contents of these get added to the digest in their entirety, so we + don't need to check them manually. + +If bad ELF is detected, ELIBBAD is indicated. + +Note! The "noinline" attribute on the module_verify_elf() function results in +somewhat smaller code. Similarly, having separate loops to check basic section +parameters and to check type-specific features of sections results in smaller +code, presumably because some local variables can be discarded. + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + kernel/module-verify.c | 226 ++++++++++++++++++++++++++++++++++++++++++++++++ + 1 file changed, 226 insertions(+) + +diff --git a/kernel/module-verify.c b/kernel/module-verify.c +index b1c1d4c..5711aeb 100644 +--- a/kernel/module-verify.c ++++ b/kernel/module-verify.c +@@ -50,6 +50,224 @@ static const char modsign_note_name[] = ELFNOTE_NAME(MODSIGN_NOTE_NAME); + static const char modsign_note_section[] = ELFNOTE_SECTION(MODSIGN_NOTE_NAME); + + /* ++ * Verify the minimum amount of ELF structure of a module needed to check the ++ * module's signature without bad ELF crashing the kernel. ++ */ ++static noinline int module_verify_elf(struct module_verify_data *mvdata) ++{ ++ const struct elf_note *note; ++ const Elf_Ehdr *hdr = mvdata->hdr; ++ const Elf_Shdr *section, *secstop; ++ const Elf_Sym *symbols, *symbol, *symstop; ++ const char *strtab; ++ size_t size, secsize, secstrsize, strsize, notesize, notemetasize; ++ unsigned line; ++ ++ size = mvdata->size; ++ ++#define elfcheck(X) \ ++do { if (unlikely(!(X))) { line = __LINE__; goto elfcheck_error; } } while(0) ++ ++#define seccheck(X) \ ++do { if (unlikely(!(X))) { line = __LINE__; goto seccheck_error; } } while(0) ++ ++#define symcheck(X) \ ++do { if (unlikely(!(X))) { line = __LINE__; goto symcheck_error; } } while(0) ++ ++ /* Validate the ELF header */ ++ elfcheck(size > sizeof(Elf_Ehdr)); ++ elfcheck(hdr->e_ehsize < size); ++ ++ elfcheck(hdr->e_shnum < SHN_LORESERVE); ++ elfcheck(hdr->e_shstrndx < hdr->e_shnum); ++ elfcheck(hdr->e_shentsize == sizeof(Elf_Shdr)); ++ elfcheck(hdr->e_shoff < size); ++ elfcheck(hdr->e_shoff >= hdr->e_ehsize); ++ elfcheck(hdr->e_shoff % sizeof(long) == 0); ++ elfcheck(hdr->e_shnum * sizeof(Elf_Shdr) <= size - hdr->e_shoff); ++ ++ /* Validate the section table contents */ ++ mvdata->nsects = hdr->e_shnum; ++ mvdata->sections = mvdata->buffer + hdr->e_shoff; ++ secstop = mvdata->sections + mvdata->nsects; ++ ++ /* Section 0 is special, usually indicating an undefined symbol */ ++ seccheck(mvdata->sections[SHN_UNDEF].sh_type == SHT_NULL); ++ ++ /* We also want access to the section name table */ ++ seccheck(mvdata->sections[hdr->e_shstrndx].sh_type == SHT_STRTAB); ++ secstrsize = mvdata->sections[hdr->e_shstrndx].sh_size; ++ ++ for (section = mvdata->sections + 1; section < secstop; section++) { ++ seccheck(section->sh_name < secstrsize); ++ seccheck(section->sh_link < hdr->e_shnum); ++ ++ /* Section file offsets must reside within the file, though ++ * they don't have to actually consume file space (.bss for ++ * example). ++ */ ++ seccheck(section->sh_offset >= hdr->e_ehsize); ++ seccheck((section->sh_offset & (section->sh_addralign - 1)) == 0); ++ seccheck(section->sh_offset <= size); ++ if (section->sh_type != SHT_NOBITS) ++ seccheck(section->sh_size <= size - section->sh_offset); ++ ++ /* Some types of section should contain arrays of fixed-length ++ * records of a predetermined size and mustn't contain partial ++ * records. Also, records we're going to access directly must ++ * have appropriate alignment that we don't get a misalignment ++ * exception. ++ */ ++ if (section->sh_entsize > 1) ++ seccheck(section->sh_size % section->sh_entsize == 0); ++ ++ switch (section->sh_type) { ++ case SHT_SYMTAB: ++ seccheck(section->sh_entsize == sizeof(Elf_Sym)); ++ seccheck(section->sh_addralign % sizeof(long) == 0); ++ break; ++ case SHT_REL: ++#ifndef MODULE_HAS_ELF_RELA_ONLY ++ seccheck(section->sh_entsize == sizeof(Elf_Rel)); ++ seccheck(section->sh_addralign % sizeof(long) == 0); ++ break; ++#else ++ seccheck(false); ++ break; ++#endif ++ case SHT_RELA: ++#ifndef MODULE_HAS_ELF_REL_ONLY ++ seccheck(section->sh_entsize == sizeof(Elf_Rela)); ++ seccheck(section->sh_addralign % sizeof(long) == 0); ++ break; ++#else ++ seccheck(false); ++ break; ++#endif ++ case SHT_NOTE: ++ seccheck(section->sh_addralign % 4 == 0); ++ break; ++ case SHT_STRTAB: ++ /* We require all string tables to be non-empty. If ++ * not empty, a string table must end in a NUL (it ++ * should also begin with a NUL, but it's not a problem ++ * for us if it doesn't). ++ */ ++ seccheck(section->sh_size >= 2); ++ strtab = mvdata->buffer + section->sh_offset; ++ seccheck(strtab[section->sh_size - 1] == '\0'); ++ break; ++ } ++ } ++ ++ /* Check features specific to the type of each section. ++ * ++ * Note that having a separate loop here allows the compiler to discard ++ * some local variables used in the above loop thus making the code ++ * smaller. ++ */ ++ for (section = mvdata->sections + 1; section < secstop; section++) { ++ switch (section->sh_type) { ++ case SHT_SYMTAB: ++ /* Symbol tables nominate a string table. */ ++ seccheck(mvdata->sections[section->sh_link].sh_type == ++ SHT_STRTAB); ++ ++ /* Validate the symbols in the table. The first symbol ++ * (STN_UNDEF) is special. ++ */ ++ symbol = symbols = mvdata->buffer + section->sh_offset; ++ symstop = mvdata->buffer + ++ (section->sh_offset + section->sh_size); ++ ++ symcheck(ELF_ST_TYPE(symbols[0].st_info) == STT_NOTYPE); ++ symcheck(symbol[0].st_shndx == SHN_UNDEF); ++ ++ strsize = mvdata->sections[section->sh_link].sh_size; ++ for (symbol++; symbol < symstop; symbol++) { ++ symcheck(symbol->st_name < strsize); ++ symcheck(symbol->st_shndx < hdr->e_shnum || ++ symbol->st_shndx >= SHN_LORESERVE); ++ } ++ break; ++ ++#ifndef MODULE_HAS_ELF_RELA_ONLY ++ case SHT_REL: ++#endif ++#ifndef MODULE_HAS_ELF_REL_ONLY ++ case SHT_RELA: ++#endif ++ /* Relocation tables nominate a symbol table and a ++ * target section to which the relocations will be ++ * applied. ++ */ ++ seccheck(mvdata->sections[section->sh_link].sh_type == ++ SHT_SYMTAB); ++ seccheck(section->sh_info > 0); ++ seccheck(section->sh_info < hdr->e_shnum); ++ break; ++ } ++ } ++ ++ /* We can now use section name string table section as we checked its ++ * bounds in the loop above. ++ * ++ * Each name is NUL-terminated, and the table as a whole should have a ++ * NUL at either end as there to be at least one named section for the ++ * module information. ++ */ ++ section = &mvdata->sections[hdr->e_shstrndx]; ++ mvdata->secstrings = mvdata->buffer + section->sh_offset; ++ ++ for (section = mvdata->sections + 1; section < secstop; section++) { ++ const char *name = mvdata->secstrings + section->sh_name; ++ ++ switch (section->sh_type) { ++ case SHT_NOTE: ++ if (strcmp(name, modsign_note_section) != 0) ++ continue; ++ ++ /* We've found a note purporting to contain a signature ++ * so we should check the structure of that. ++ */ ++ notemetasize = sizeof(struct elf_note) + ++ roundup(sizeof(modsign_note_name), 4); ++ ++ seccheck(mvdata->sig_index == 0); ++ seccheck(section->sh_size > notemetasize); ++ note = mvdata->buffer + section->sh_offset; ++ seccheck(note->n_type == MODSIGN_NOTE_TYPE); ++ seccheck(note->n_namesz == sizeof(modsign_note_name)); ++ ++ notesize = section->sh_size - notemetasize; ++ seccheck(note->n_descsz <= notesize); ++ ++ seccheck(memcmp(note + 1, modsign_note_name, ++ note->n_namesz) == 0); ++ ++ mvdata->sig_size = note->n_descsz; ++ mvdata->sig = (void *)note + notemetasize; ++ mvdata->sig_index = section - mvdata->sections; ++ break; ++ } ++ } ++ ++ return 0; ++ ++elfcheck_error: ++ _debug("Verify ELF error (check %u)\n", line); ++ return -ELIBBAD; ++seccheck_error: ++ _debug("Verify ELF error [sec %ld] (check %u)\n", ++ (long)(section - mvdata->sections), line); ++ return -ELIBBAD; ++symcheck_error: ++ _debug("Verify ELF error [sym %ld] (check %u)\n", ++ (long)(symbol - symbols), line); ++ return -ELIBBAD; ++} ++ ++/* + * Verify a module's integrity + */ + int module_verify(const Elf_Ehdr *hdr, size_t size, bool *_gpgsig_ok) +@@ -61,6 +279,14 @@ int module_verify(const Elf_Ehdr *hdr, size_t size, bool *_gpgsig_ok) + mvdata.buffer = hdr; + mvdata.size = size; + ++ /* Minimally check the ELF to make sure building the signature digest ++ * won't crash the kernel. ++ */ ++ ret = module_verify_elf(&mvdata); ++ if (ret < 0) ++ goto out; ++ ++ /* The ELF checker found the sig for us if it exists */ + if (mvdata.sig_index <= 0) { + /* Deal with an unsigned module */ + if (modsign_signedonly) { +-- +1.7.10.2 + + +From 21a28e681f53685960f2780b7884e8b391122259 Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Thu, 10 May 2012 23:49:56 +0100 +Subject: [PATCH 26/36] MODSIGN: Produce a filtered and canonicalised section + list + +Build a list of the sections in which we're interested and canonicalise the +section indices to avoid the problems of the section table being altered by ld +when the signature is linked into the binary and by strip. + +The only sections in which we're actually interested are those that are marked +allocatable (which will be kept in memory) and relocation tables that are +applicable to those sections. + +Canonicalisation is done by sorting the filtered list in order of section name. + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + kernel/module-verify.c | 80 ++++++++++++++++++++++++++++++++++++++++++++++++ + 1 file changed, 80 insertions(+) + +diff --git a/kernel/module-verify.c b/kernel/module-verify.c +index 5711aeb..13c60c2 100644 +--- a/kernel/module-verify.c ++++ b/kernel/module-verify.c +@@ -268,6 +268,80 @@ symcheck_error: + } + + /* ++ * Canonicalise the section table index numbers. ++ * ++ * We build a list of the sections we want to add to the digest and sort it by ++ * name. We're only interested in adding two types of section: ++ * ++ * (1) Allocatable sections. These should have no references to other ++ * sections. ++ * ++ * (2) Relocation tables for allocatable sections. The section table entry ++ * has a reference to the target section to which the relocations will be ++ * applied. The relocation entries have references to symbols in ++ * non-allocatable sections. Symbols can be replaced by their contents, ++ * but do include a further reference to a section - which must be ++ * canonicalised. ++ * ++ * We also build a map of raw section index to canonical section index. ++ */ ++static int module_verify_canonicalise(struct module_verify_data *mvdata) ++{ ++ const Elf_Shdr *sechdrs = mvdata->sections; ++ unsigned *canonlist, canon, loop, tmp; ++ bool changed; ++ ++ canonlist = kmalloc(sizeof(unsigned) * mvdata->nsects * 2, GFP_KERNEL); ++ if (!canonlist) ++ return -ENOMEM; ++ ++ mvdata->canonlist = canonlist; ++ mvdata->canonmap = canonlist + mvdata->nsects; ++ canon = 0; ++ ++ for (loop = 1; loop < mvdata->nsects; loop++) { ++ const Elf_Shdr *section = mvdata->sections + loop; ++ ++ if (loop == mvdata->sig_index) ++ continue; ++ ++ /* We only want allocatable sections and relocation tables */ ++ if (section->sh_flags & SHF_ALLOC) ++ canonlist[canon++] = loop; ++ else if ((is_elf_rel(section->sh_type) || ++ is_elf_rela(section->sh_type)) && ++ mvdata->sections[section->sh_info].sh_flags & SHF_ALLOC) ++ canonlist[canon++] = loop; ++ } ++ ++ /* Sort the canonicalisation list */ ++ do { ++ changed = false; ++ ++ for (loop = 0; loop < canon - 1; loop++) { ++ const char *x, *y; ++ ++ x = mvdata->secstrings + sechdrs[canonlist[loop + 0]].sh_name; ++ y = mvdata->secstrings + sechdrs[canonlist[loop + 1]].sh_name; ++ ++ if (strcmp(x, y) > 0) { ++ tmp = canonlist[loop + 0]; ++ canonlist[loop + 0] = canonlist[loop + 1]; ++ canonlist[loop + 1] = tmp; ++ changed = true; ++ } ++ } ++ } while (changed); ++ ++ /* What we really want is a raw-to-canon lookup table */ ++ memset(mvdata->canonmap, 0xff, mvdata->nsects * sizeof(unsigned)); ++ for (loop = 0; loop < canon; loop++) ++ mvdata->canonmap[mvdata->canonlist[loop]] = loop + 1; ++ mvdata->ncanon = canon; ++ return 0; ++} ++ ++/* + * Verify a module's integrity + */ + int module_verify(const Elf_Ehdr *hdr, size_t size, bool *_gpgsig_ok) +@@ -298,7 +372,13 @@ int module_verify(const Elf_Ehdr *hdr, size_t size, bool *_gpgsig_ok) + goto out; + } + ++ /* Produce a canonicalisation map for the sections */ ++ ret = module_verify_canonicalise(&mvdata); ++ if (ret < 0) ++ goto out; ++ + ret = 0; ++ kfree(mvdata.canonlist); + + out: + switch (ret) { +-- +1.7.10.2 + + +From 92fb97859c50a0dd63886baf057477a7a336b2a1 Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Thu, 10 May 2012 23:49:56 +0100 +Subject: [PATCH 27/36] MODSIGN: Create digest of module content and check + signature + +Apply signature checking to modules on module load, checking the signature +against the ring of public keys compiled into the kernel (if enabled by +CONFIG_MODULE_SIG). Turning on signature checking will also force the module's +ELF metadata to be verified first. + +There are several reasons why these patches are useful, amongst which are: + + (1) to prevent accidentally corrupted modules from causing damage; + + (2) to prevent maliciously modified modules from causing damage; + + (3) to allow a sysadmin (or more likely an IT department) to enforce a policy + that only known and approved modules shall be loaded onto machines which + they're expected to support; + + (4) to allow other support providers to do likewise, or at least to _detect_ + the fact that unsupported modules are loaded; + + (5) to allow the detection of modules replaced by a second-order distro or a + preloaded Linux purveyor. + +These patches have two main appeals: (a) preventing malicious modules from +being loaded, and (b) reducing support workload by pointing out modules on a +crashing box that aren't what they're expected to be. + +Note that this is not a complete solution by any means: the core kernel is not +protected, and nor are /dev/mem or /dev/kmem, but it denies (or at least +controls) one relatively simple attack vector. To protect the kernel image +would be the responsibility of the boot loader or the system BIOS. + +This facility is optional: the builder of a kernel is by no means under any +requirement to actually enable it, let alone force the set of loadable modules +to be restricted to just those that the builder provides (there are degrees of +restriction available). + +Note! The "noinline" attribute on module_verify_signature() results in +somewhat smaller code. + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + kernel/module-verify.c | 321 +++++++++++++++++++++++++++++++++++++++++++++++- + 1 file changed, 320 insertions(+), 1 deletion(-) + +diff --git a/kernel/module-verify.c b/kernel/module-verify.c +index 13c60c2..a31b39c 100644 +--- a/kernel/module-verify.c ++++ b/kernel/module-verify.c +@@ -49,6 +49,22 @@ static bool modsign_signedonly; + static const char modsign_note_name[] = ELFNOTE_NAME(MODSIGN_NOTE_NAME); + static const char modsign_note_section[] = ELFNOTE_SECTION(MODSIGN_NOTE_NAME); + ++#define crypto_digest_update_data(C, PTR, N) \ ++do { \ ++ uint8_t *__p = (uint8_t *)(PTR); \ ++ size_t __n = (N); \ ++ count_and_csum((C), __p, __n); \ ++ verify_sig_add_data((C)->mod_sig, __p, __n); \ ++} while (0) ++ ++#define crypto_digest_update_val(C, VAL) \ ++do { \ ++ uint8_t *__p = (uint8_t *)&(VAL); \ ++ size_t __n = sizeof(VAL); \ ++ count_and_csum((C), __p, __n); \ ++ verify_sig_add_data((C)->mod_sig, __p, __n); \ ++} while (0) ++ + /* + * Verify the minimum amount of ELF structure of a module needed to check the + * module's signature without bad ELF crashing the kernel. +@@ -342,6 +358,309 @@ static int module_verify_canonicalise(struct module_verify_data *mvdata) + } + + /* ++ * Extract an ELF REL table ++ * ++ * We need to canonicalise the entries in case section/symbol addition/removal ++ * has rearranged the symbol table and the section table. ++ */ ++static int extract_elf_rel(struct module_verify_data *mvdata, ++ unsigned secix, ++ const Elf_Rel *reltab, size_t nrels, ++ const char *sh_name) ++{ ++ struct { ++#if defined(MODULES_ARE_ELF32) ++ uint32_t r_offset; ++ uint32_t st_value; ++ uint32_t st_size; ++ uint16_t st_shndx; ++ uint8_t r_type; ++ uint8_t st_info; ++ uint8_t st_other; ++#elif defined(MODULES_ARE_ELF64) ++ uint64_t r_offset; ++ uint64_t st_value; ++ uint64_t st_size; ++ uint32_t r_type; ++ uint16_t st_shndx; ++ uint8_t st_info; ++ uint8_t st_other; ++#else ++#error unsupported module type ++#endif ++ } __attribute__((packed)) relocation; ++ ++ const Elf_Rel *reloc; ++ const Elf_Sym *symbols, *symbol; ++ const char *strings; ++ unsigned long r_sym; ++ size_t nsyms, loop; ++ ++ nsyms = mvdata->sections[secix].sh_size / sizeof(Elf_Sym); ++ symbols = mvdata->buffer + mvdata->sections[secix].sh_offset; ++ strings = mvdata->buffer + ++ mvdata->sections[mvdata->sections[secix].sh_link].sh_offset; ++ ++ /* Contribute the relevant bits from a join of { REL, SYMBOL, SECTION } */ ++ for (loop = 0; loop < nrels; loop++) { ++ unsigned st_shndx; ++ ++ reloc = &reltab[loop]; ++ ++ /* Decode the relocation */ ++ relocation.r_offset = reloc->r_offset; ++ relocation.r_type = ELF_R_TYPE(reloc->r_info); ++ ++ /* Decode the symbol referenced by the relocation */ ++ r_sym = ELF_R_SYM(reloc->r_info); ++ if (r_sym >= nsyms) ++ return -ELIBBAD; ++ symbol = &symbols[r_sym]; ++ relocation.st_info = symbol->st_info; ++ relocation.st_other = symbol->st_other; ++ relocation.st_value = symbol->st_value; ++ relocation.st_size = symbol->st_size; ++ relocation.st_shndx = symbol->st_shndx; ++ st_shndx = symbol->st_shndx; ++ ++ /* Canonicalise the section used by the symbol */ ++ if (st_shndx > SHN_UNDEF && st_shndx < mvdata->nsects) { ++ if (!(mvdata->sections[st_shndx].sh_flags & SHF_ALLOC)) ++ return -ELIBBAD; ++ relocation.st_shndx = mvdata->canonmap[st_shndx]; ++ } ++ ++ crypto_digest_update_val(mvdata, relocation); ++ ++ /* Undefined symbols must be named if referenced */ ++ if (st_shndx == SHN_UNDEF) { ++ const char *name = strings + symbol->st_name; ++ crypto_digest_update_data(mvdata, ++ name, strlen(name) + 1); ++ } ++ } ++ ++ _debug("%08zx %02x digested the %s section, nrels %zu\n", ++ mvdata->signed_size, mvdata->csum, sh_name, nrels); ++ ++ return 0; ++} ++ ++/* ++ * Extract an ELF RELA table ++ * ++ * We need to canonicalise the entries in case section/symbol addition/removal ++ * has rearranged the symbol table and the section table. ++ */ ++static int extract_elf_rela(struct module_verify_data *mvdata, ++ unsigned secix, ++ const Elf_Rela *relatab, size_t nrels, ++ const char *sh_name) ++{ ++ struct { ++#if defined(MODULES_ARE_ELF32) ++ uint32_t r_offset; ++ uint32_t r_addend; ++ uint32_t st_value; ++ uint32_t st_size; ++ uint16_t st_shndx; ++ uint8_t r_type; ++ uint8_t st_info; ++ uint8_t st_other; ++#elif defined(MODULES_ARE_ELF64) ++ uint64_t r_offset; ++ uint64_t r_addend; ++ uint64_t st_value; ++ uint64_t st_size; ++ uint32_t r_type; ++ uint16_t st_shndx; ++ uint8_t st_info; ++ uint8_t st_other; ++#else ++#error unsupported module type ++#endif ++ } __attribute__((packed)) relocation; ++ ++ const Elf_Shdr *relsec, *symsec, *strsec; ++ const Elf_Rela *reloc; ++ const Elf_Sym *symbols, *symbol; ++ unsigned long r_sym; ++ const char *strings; ++ size_t nsyms, loop; ++ ++ relsec = &mvdata->sections[secix]; ++ symsec = &mvdata->sections[relsec->sh_link]; ++ strsec = &mvdata->sections[symsec->sh_link]; ++ nsyms = symsec->sh_size / sizeof(Elf_Sym); ++ symbols = mvdata->buffer + symsec->sh_offset; ++ strings = mvdata->buffer + strsec->sh_offset; ++ ++ /* Contribute the relevant bits from a join of { RELA, SYMBOL, SECTION } */ ++ for (loop = 0; loop < nrels; loop++) { ++ unsigned st_shndx; ++ ++ reloc = &relatab[loop]; ++ ++ /* Decode the relocation */ ++ relocation.r_offset = reloc->r_offset; ++ relocation.r_addend = reloc->r_addend; ++ relocation.r_type = ELF_R_TYPE(reloc->r_info); ++ ++ /* Decode the symbol referenced by the relocation */ ++ r_sym = ELF_R_SYM(reloc->r_info); ++ if (r_sym >= nsyms) ++ return -ELIBBAD; ++ symbol = &symbols[r_sym]; ++ relocation.st_info = symbol->st_info; ++ relocation.st_other = symbol->st_other; ++ relocation.st_value = symbol->st_value; ++ relocation.st_size = symbol->st_size; ++ relocation.st_shndx = 0; ++ st_shndx = symbol->st_shndx; ++ ++ /* Canonicalise the section used by the symbol */ ++ if (st_shndx > SHN_UNDEF && st_shndx < mvdata->nsects) { ++ if (!(mvdata->sections[st_shndx].sh_flags & SHF_ALLOC)) ++ return -ELIBBAD; ++ relocation.st_shndx = mvdata->canonmap[st_shndx]; ++ } ++ ++ crypto_digest_update_val(mvdata, relocation); ++ ++ /* Undefined symbols must be named if referenced */ ++ if (st_shndx == SHN_UNDEF) { ++ const char *name = strings + symbol->st_name; ++ crypto_digest_update_data(mvdata, ++ name, strlen(name) + 1); ++ } ++ } ++ ++ _debug("%08zx %02x digested the %s section, nrels %zu\n", ++ mvdata->signed_size, mvdata->csum, sh_name, nrels); ++ ++ return 0; ++} ++ ++/* ++ * Verify a module's signature ++ */ ++static noinline int module_verify_signature(struct module_verify_data *mvdata) ++{ ++ struct crypto_key_verify_context *mod_sig; ++ const Elf_Shdr *sechdrs = mvdata->sections; ++ const char *secstrings = mvdata->secstrings; ++ const u8 *sig = mvdata->sig; ++ size_t sig_size = mvdata->sig_size; ++ int loop, ret; ++ ++ _debug("sig in section %u (size %zu)\n", ++ mvdata->sig_index, mvdata->sig_size); ++ _debug("%02x%02x%02x%02x%02x%02x%02x%02x\n", ++ sig[0], sig[1], sig[2], sig[3], ++ sig[4], sig[5], sig[6], sig[7]); ++ ++ /* Find the crypto key for the module signature ++ * - !!! if this tries to load the required hash algorithm module, ++ * we will deadlock!!! ++ */ ++ mod_sig = verify_sig_begin(modsign_keyring, sig, sig_size); ++ if (IS_ERR(mod_sig)) { ++ pr_err("Couldn't initiate module signature verification: %ld\n", ++ PTR_ERR(mod_sig)); ++ return PTR_ERR(mod_sig); ++ } ++ ++ mvdata->mod_sig = mod_sig; ++#ifdef DEBUG ++ mvdata->xcsum = 0; ++#endif ++ ++ /* Load data from each relevant section into the digest. Note that ++ * canonlist[] is a filtered list and only contains the sections we ++ * actually want. ++ */ ++ for (loop = 0; loop < mvdata->ncanon; loop++) { ++ int sect = mvdata->canonlist[loop]; ++ unsigned long sh_type = sechdrs[sect].sh_type; ++ unsigned long sh_info = sechdrs[sect].sh_info; ++ unsigned long sh_size = sechdrs[sect].sh_size; ++ const char *sh_name = secstrings + sechdrs[sect].sh_name; ++ const void *data = mvdata->buffer + sechdrs[sect].sh_offset; ++ ++#ifdef DEBUG ++ mvdata->csum = 0; ++#endif ++ ++ /* Digest the headers of any section we include. */ ++ crypto_digest_update_data(mvdata, sh_name, strlen(sh_name)); ++ crypto_digest_update_val(mvdata, sechdrs[sect].sh_type); ++ crypto_digest_update_val(mvdata, sechdrs[sect].sh_flags); ++ crypto_digest_update_val(mvdata, sechdrs[sect].sh_size); ++ crypto_digest_update_val(mvdata, sechdrs[sect].sh_addralign); ++ ++ /* Relocation record sections refer to the section to be ++ * relocated, but this needs to be canonicalised to survive ++ * stripping. ++ */ ++ if (is_elf_rel(sh_type) || is_elf_rela(sh_type)) ++ crypto_digest_update_val(mvdata, ++ mvdata->canonmap[sh_info]); ++ ++ /* Since relocation records give details of how we have to ++ * alter the allocatable sections, we need to digest these too. ++ * ++ * These, however, refer to metadata (symbols and sections) ++ * that may have been altered by the process of adding the ++ * signature section or the process of being stripped. ++ * ++ * To deal with this, we substitute the referenced metadata for ++ * the references to that metadata. So, for instance, the ++ * symbol ref from the relocation record is replaced with the ++ * contents of the symbol to which it refers, and the symbol's ++ * section ref is replaced with a canonicalised section number. ++ */ ++ if (is_elf_rel(sh_type)) { ++ ret = extract_elf_rel(mvdata, sect, ++ data, ++ sh_size / sizeof(Elf_Rel), ++ sh_name); ++ if (ret < 0) ++ goto format_error; ++ continue; ++ } ++ ++ if (is_elf_rela(sh_type)) { ++ ret = extract_elf_rela(mvdata, sect, ++ data, ++ sh_size / sizeof(Elf_Rela), ++ sh_name); ++ if (ret < 0) ++ goto format_error; ++ continue; ++ } ++ ++ /* Include allocatable loadable sections */ ++ if (sh_type != SHT_NOBITS) ++ crypto_digest_update_data(mvdata, data, sh_size); ++ ++ _debug("%08zx %02x digested the %s section, size %ld\n", ++ mvdata->signed_size, mvdata->csum, sh_name, sh_size); ++ } ++ ++ _debug("Contributed %zu bytes to the digest (csum 0x%02x)\n", ++ mvdata->signed_size, mvdata->xcsum); ++ ++ /* Do the actual signature verification */ ++ ret = verify_sig_end(mvdata->mod_sig, sig, sig_size); ++ _debug("verify-sig : %d\n", ret); ++ return ret; ++ ++format_error: ++ verify_sig_cancel(mvdata->mod_sig); ++ return -ELIBBAD; ++} ++ ++/* + * Verify a module's integrity + */ + int module_verify(const Elf_Ehdr *hdr, size_t size, bool *_gpgsig_ok) +@@ -377,7 +696,7 @@ int module_verify(const Elf_Ehdr *hdr, size_t size, bool *_gpgsig_ok) + if (ret < 0) + goto out; + +- ret = 0; ++ ret = module_verify_signature(&mvdata); + kfree(mvdata.canonlist); + + out: +-- +1.7.10.2 + + +From 2e9f557c1235027c0c7223a8a072333758905066 Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Thu, 10 May 2012 23:49:57 +0100 +Subject: [PATCH 28/36] MODSIGN: Automatically generate module signing keys if + missing + +Automatically generate keys for module signing if they're absent so that +allyesconfig doesn't break. The builder should consider generating their own +keyrings, however, so that the keys are appropriately named and any extra keys +required get imported. + +Also change the names of the keyring files to modsign.pub and modsign.sec so +that they are then a more obvious what they're about and add a dependency for +the signing rules on the keyring files so that the signatures get regenerated +if the keyrings change. + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + kernel/Makefile | 42 +++++++++++++++++++++++++++++++++++++++++- + 1 file changed, 41 insertions(+), 1 deletion(-) + +diff --git a/kernel/Makefile b/kernel/Makefile +index 986ed7f..d8139bb 100644 +--- a/kernel/Makefile ++++ b/kernel/Makefile +@@ -52,7 +52,6 @@ obj-$(CONFIG_PROVE_LOCKING) += spinlock.o + obj-$(CONFIG_UID16) += uid16.o + obj-$(CONFIG_MODULES) += module.o + obj-$(CONFIG_MODULE_SIG) += module-verify.o modsign-pubkey.o +-kernel/modsign-pubkey.o: modsign.pub + obj-$(CONFIG_KALLSYMS) += kallsyms.o + obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o + obj-$(CONFIG_KEXEC) += kexec.o +@@ -129,3 +128,44 @@ quiet_cmd_timeconst = TIMEC $@ + targets += timeconst.h + $(obj)/timeconst.h: $(src)/timeconst.pl FORCE + $(call if_changed,timeconst) ++ ++############################################################################### ++# ++# If module signing is requested, say by allyesconfig, but a key has not been ++# supplied, then one will need to be generated to make sure the build does not ++# fail and that the kernel may be used afterwards. ++# ++############################################################################### ++ifeq ($(CONFIG_MODULE_SIG),y) ++kernel/modsign-pubkey.o: modsign.pub ++ ++modsign.pub modsign.sec: genkey ++ @echo "###" ++ @echo "### Now generating a PGP key pair to be used for signing modules." ++ @echo "###" ++ @echo "### If this takes a long time, you might wish to run rngd in the" ++ @echo "### background to keep the supply of entropy topped up. It" ++ @echo "### needs to be run as root, and should use a hardware random" ++ @echo "### number generator if one is available, eg:" ++ @echo "###" ++ @echo "### rngd -r /dev/hwrandom" ++ @echo "###" ++ gpg --homedir . --batch --gen-key genkey ++ @echo "###" ++ @echo "### Key pair generated." ++ @echo "###" ++ rm -f pubring.gpg secring.gpg trustdb.gpg ++ ++genkey: ++ echo "%pubring modsign.pub" >genkey ++ echo "%secring modsign.sec" >>genkey ++ echo "%no-protection: yes" >> genkey ++ echo "%transient-key: yes" >>genkey ++ echo "Key-Type: RSA" >>genkey ++ echo "Key-Length: 4096" >>genkey ++ echo "Name-Real: Sample kernel key" >>genkey ++ echo "Name-Comment: Sample kernel module signing key" >>genkey ++ echo "%commit" >>genkey ++ ++endif ++CLEAN_FILES += modsign.pub modsign.sec genkey random_seed +-- +1.7.10.2 + + +From 958049a9def253735019a5acf19b4c2aeec9f01c Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Thu, 10 May 2012 23:55:35 +0100 +Subject: [PATCH 29/36] MODSIGN: Suppress some redundant ELF checks + +Suppress some redundant ELF checks in module_verify_elf() that are also done +by copy_and_check() in the core module loader code prior to calling +module_verify(). + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + kernel/module-verify.c | 8 ++++---- + 1 file changed, 4 insertions(+), 4 deletions(-) + +diff --git a/kernel/module-verify.c b/kernel/module-verify.c +index a31b39c..e1bfd28 100644 +--- a/kernel/module-verify.c ++++ b/kernel/module-verify.c +@@ -76,7 +76,7 @@ static noinline int module_verify_elf(struct module_verify_data *mvdata) + const Elf_Shdr *section, *secstop; + const Elf_Sym *symbols, *symbol, *symstop; + const char *strtab; +- size_t size, secsize, secstrsize, strsize, notesize, notemetasize; ++ size_t size, secstrsize, strsize, notesize, notemetasize; + unsigned line; + + size = mvdata->size; +@@ -96,11 +96,11 @@ do { if (unlikely(!(X))) { line = __LINE__; goto symcheck_error; } } while(0) + + elfcheck(hdr->e_shnum < SHN_LORESERVE); + elfcheck(hdr->e_shstrndx < hdr->e_shnum); +- elfcheck(hdr->e_shentsize == sizeof(Elf_Shdr)); +- elfcheck(hdr->e_shoff < size); ++ /* elfcheck(hdr->e_shentsize == sizeof(Elf_Shdr)); */ ++ /* elfcheck(hdr->e_shoff < size); */ + elfcheck(hdr->e_shoff >= hdr->e_ehsize); + elfcheck(hdr->e_shoff % sizeof(long) == 0); +- elfcheck(hdr->e_shnum * sizeof(Elf_Shdr) <= size - hdr->e_shoff); ++ /* elfcheck(hdr->e_shnum * sizeof(Elf_Shdr) <= size - hdr->e_shoff); */ + + /* Validate the section table contents */ + mvdata->nsects = hdr->e_shnum; +-- +1.7.10.2 + + +From b5df4e7900852395a1ccb70190827cccc0c0de2d Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Fri, 11 May 2012 16:56:05 +0100 +Subject: [PATCH 30/36] MODSIGN: Fix some checkpatch noise + +Fix some warnings and errors produced by checkpatch. + +Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> +Signed-off-by: David Howells <dhowells@redhat.com> +--- + kernel/module-verify-defs.h | 24 ++++++++++++------------ + kernel/module-verify.c | 18 +++++++++++------- + kernel/module-verify.h | 3 ++- + security/keys/crypto/pgp_key_parser.c | 2 +- + 4 files changed, 26 insertions(+), 21 deletions(-) + +diff --git a/kernel/module-verify-defs.h b/kernel/module-verify-defs.h +index 45bea45..2fe31e1 100644 +--- a/kernel/module-verify-defs.h ++++ b/kernel/module-verify-defs.h +@@ -60,22 +60,22 @@ struct module_verify_data { + do { \ + if (unlikely(modsign_debug)) \ + pr_debug(FMT, ##__VA_ARGS__); \ +- } while(0) ++ } while (0) + + #ifdef DEBUG +-#define count_and_csum(C, __p, __n) \ +-do { \ +- int __loop; \ +- for (__loop = 0; __loop < __n; __loop++) { \ +- (C)->csum += __p[__loop]; \ +- (C)->xcsum += __p[__loop]; \ +- } \ +- (C)->signed_size += __n; \ +-} while (0) ++#define count_and_csum(C, __p, __n) \ ++ do { \ ++ int __loop; \ ++ for (__loop = 0; __loop < __n; __loop++) { \ ++ (C)->csum += __p[__loop]; \ ++ (C)->xcsum += __p[__loop]; \ ++ } \ ++ (C)->signed_size += __n; \ ++ } while (0) + #else + #define count_and_csum(C, __p, __n) \ +-do { \ +-} while (0) ++ do { \ ++ } while (0) + #endif + + #endif /* CONFIG_MODULE_SIG */ +diff --git a/kernel/module-verify.c b/kernel/module-verify.c +index e1bfd28..161cf3e 100644 +--- a/kernel/module-verify.c ++++ b/kernel/module-verify.c +@@ -82,13 +82,13 @@ static noinline int module_verify_elf(struct module_verify_data *mvdata) + size = mvdata->size; + + #define elfcheck(X) \ +-do { if (unlikely(!(X))) { line = __LINE__; goto elfcheck_error; } } while(0) ++do { if (unlikely(!(X))) { line = __LINE__; goto elfcheck_error; } } while (0) + + #define seccheck(X) \ +-do { if (unlikely(!(X))) { line = __LINE__; goto seccheck_error; } } while(0) ++do { if (unlikely(!(X))) { line = __LINE__; goto seccheck_error; } } while (0) + + #define symcheck(X) \ +-do { if (unlikely(!(X))) { line = __LINE__; goto symcheck_error; } } while(0) ++do { if (unlikely(!(X))) { line = __LINE__; goto symcheck_error; } } while (0) + + /* Validate the ELF header */ + elfcheck(size > sizeof(Elf_Ehdr)); +@@ -388,7 +388,7 @@ static int extract_elf_rel(struct module_verify_data *mvdata, + #else + #error unsupported module type + #endif +- } __attribute__((packed)) relocation; ++ } __packed relocation; + + const Elf_Rel *reloc; + const Elf_Sym *symbols, *symbol; +@@ -401,7 +401,9 @@ static int extract_elf_rel(struct module_verify_data *mvdata, + strings = mvdata->buffer + + mvdata->sections[mvdata->sections[secix].sh_link].sh_offset; + +- /* Contribute the relevant bits from a join of { REL, SYMBOL, SECTION } */ ++ /* Contribute the relevant bits from a join of ++ * { REL, SYMBOL, SECTION } ++ */ + for (loop = 0; loop < nrels; loop++) { + unsigned st_shndx; + +@@ -479,7 +481,7 @@ static int extract_elf_rela(struct module_verify_data *mvdata, + #else + #error unsupported module type + #endif +- } __attribute__((packed)) relocation; ++ } __packed relocation; + + const Elf_Shdr *relsec, *symsec, *strsec; + const Elf_Rela *reloc; +@@ -495,7 +497,9 @@ static int extract_elf_rela(struct module_verify_data *mvdata, + symbols = mvdata->buffer + symsec->sh_offset; + strings = mvdata->buffer + strsec->sh_offset; + +- /* Contribute the relevant bits from a join of { RELA, SYMBOL, SECTION } */ ++ /* Contribute the relevant bits from a join of ++ * { RELA, SYMBOL, SECTION } ++ */ + for (loop = 0; loop < nrels; loop++) { + unsigned st_shndx; + +diff --git a/kernel/module-verify.h b/kernel/module-verify.h +index 6bb6b56..c640634 100644 +--- a/kernel/module-verify.h ++++ b/kernel/module-verify.h +@@ -12,7 +12,8 @@ + #ifdef CONFIG_MODULE_SIG + extern int module_verify(const Elf_Ehdr *hdr, size_t size, bool *_gpgsig_ok); + #else +-static inline int module_verify(const Elf_Ehdr *hdr, size_t size, bool *_gpgsig_ok) ++static inline int module_verify(const Elf_Ehdr *hdr, size_t size, ++ bool *_gpgsig_ok) + { + return 0; + } +diff --git a/security/keys/crypto/pgp_key_parser.c b/security/keys/crypto/pgp_key_parser.c +index 1407e2e..d913538 100644 +--- a/security/keys/crypto/pgp_key_parser.c ++++ b/security/keys/crypto/pgp_key_parser.c +@@ -94,7 +94,7 @@ static int pgp_calc_pkey_keyid(struct shash_desc *digest, + if (pgp->version < PGP_KEY_VERSION_4) { + u16 a16; + +- if( pgp->expires_at) ++ if (pgp->expires_at) + a16 = (pgp->expires_at - pgp->creation_time) / 86400UL; + else + a16 = 0; +-- +1.7.10.2 + + +From 27ecab7d7ee104299133c9ffd51d00ea378ed56b Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Wed, 16 May 2012 15:13:41 +0100 +Subject: [PATCH 31/36] PGPLIB: Preclear array on stack + +Preclear an array on the stack so that the error handling that frees what the +array might point to won't crash. + +Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> +Signed-off-by: David Howells <dhowells@redhat.com> +--- + security/keys/crypto/pgp_key_parser.c | 3 +++ + 1 file changed, 3 insertions(+) + +diff --git a/security/keys/crypto/pgp_key_parser.c b/security/keys/crypto/pgp_key_parser.c +index d913538..84ce457 100644 +--- a/security/keys/crypto/pgp_key_parser.c ++++ b/security/keys/crypto/pgp_key_parser.c +@@ -71,6 +71,9 @@ static int pgp_calc_pkey_keyid(struct shash_desc *digest, + + kenter(""); + ++ for (i = 0; i < ARRAY_SIZE(pp); i++) ++ pp[i] = NULL; ++ + n = (pgp->version < PGP_KEY_VERSION_4) ? 8 : 6; + for (i = 0; i < npkey; i++) { + nb[i] = mpi_get_nbits(key->mpi[i]); +-- +1.7.10.2 + + +From a382a46fe70ee35cfb6fe97faa8abffd82368cbe Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Wed, 16 May 2012 15:19:24 +0100 +Subject: [PATCH 32/36] PGPLIB: Check the length in a packet or subpacket + +Check the length in a packet or subpacket to make sure there isn't an overflow +should the length not fit into the lower 31 bits of an integer. + +It is possible that both pgp_parse_packet_header() and +pgp_parse_sig_subpkt_header() could see packets that purport to be >2G in size. +Normally this will not be a problem because EBADMSG is indicated if the size +indicated is greater than the remnant size of the data - but just in case we do +end up parsing a >2G blob, a couple of simple checks can prevent an overflow +from occurring. + +Reported-by: Stephan Mueller <stephan.mueller@atsec.com> +Signed-off-by: David Howells <dhowells@redhat.com> +--- + security/keys/crypto/pgp_library.c | 10 ++++++++++ + 1 file changed, 10 insertions(+) + +diff --git a/security/keys/crypto/pgp_library.c b/security/keys/crypto/pgp_library.c +index f6b831f..a9462f5 100644 +--- a/security/keys/crypto/pgp_library.c ++++ b/security/keys/crypto/pgp_library.c +@@ -137,6 +137,8 @@ ssize_t pgp_parse_packet_header(const u8 **_data, size_t *_datalen, + pr_devel("datalen=%zu size=%zu", datalen, size); + if (datalen < size) + goto short_packet; ++ if ((int)size < 0) ++ goto too_big; + + *_data = data; + *_datalen = datalen; +@@ -147,6 +149,9 @@ ssize_t pgp_parse_packet_header(const u8 **_data, size_t *_datalen, + short_packet: + pr_debug("Attempt to parse short packet\n"); + return -EBADMSG; ++too_big: ++ pr_debug("Signature subpacket size >2G\n"); ++ return -EMSGSIZE; + } + + /** +@@ -312,6 +317,8 @@ ssize_t pgp_parse_sig_subpkt_header(const u8 **_data, size_t *_datalen, + pr_debug("Signature subpacket size can't be zero\n"); + return -EBADMSG; + } ++ if ((int)size < 0) ++ goto too_big; + + type = *data++ & ~PGP_SIG_SUBPKT_TYPE_CRITICAL_MASK; + datalen--; +@@ -330,6 +337,9 @@ ssize_t pgp_parse_sig_subpkt_header(const u8 **_data, size_t *_datalen, + short_subpacket: + pr_debug("Attempt to parse short signature subpacket\n"); + return -EBADMSG; ++too_big: ++ pr_debug("Signature subpacket size >2G\n"); ++ return -EMSGSIZE; + } + + /** +-- +1.7.10.2 + + +From a577fc904c197d97b028863989d9a891c3e1ea17 Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Thu, 17 May 2012 17:41:36 +0100 +Subject: [PATCH 33/36] PGPLIB: Remnant length should be decreased in + pgp_parse_sig_params() + +The remnant length of the signature packet should be decreased rather than +being increased as we parse in pgp_parse_sig_params(). + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + security/keys/crypto/pgp_library.c | 4 ++-- + 1 file changed, 2 insertions(+), 2 deletions(-) + +diff --git a/security/keys/crypto/pgp_library.c b/security/keys/crypto/pgp_library.c +index a9462f5..1ff3628 100644 +--- a/security/keys/crypto/pgp_library.c ++++ b/security/keys/crypto/pgp_library.c +@@ -503,7 +503,7 @@ int pgp_parse_sig_params(const u8 **_data, size_t *_datalen, + if (ret < 0) + return ret; + data += subdatalen; +- datalen += subdatalen; ++ datalen -= subdatalen; + } + + subdatalen = *data++ << 8; +@@ -521,7 +521,7 @@ int pgp_parse_sig_params(const u8 **_data, size_t *_datalen, + if (ret < 0) + return ret; + data += subdatalen; +- datalen += subdatalen; ++ datalen -= subdatalen; + } + + if (!ctx.got_the_issuer) { +-- +1.7.10.2 + + +From ab7204f60a1cedecb24bb2888db5d03bdcf20488 Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Thu, 17 May 2012 17:41:36 +0100 +Subject: [PATCH 34/36] PGPLIB: Parse 5-octet length new-format packet headers + +Parse 5-octet length new-format packet headers to extract the 32-bit length +encoded therein [RFC4880 4.2.2.3]. + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + security/keys/crypto/pgp_library.c | 13 +++++++++++-- + 1 file changed, 11 insertions(+), 2 deletions(-) + +diff --git a/security/keys/crypto/pgp_library.c b/security/keys/crypto/pgp_library.c +index 1ff3628..310ee2f 100644 +--- a/security/keys/crypto/pgp_library.c ++++ b/security/keys/crypto/pgp_library.c +@@ -86,8 +86,17 @@ ssize_t pgp_parse_packet_header(const u8 **_data, size_t *_datalen, + *_headerlen = 3; + break; + case 0xff: +- pr_debug("Five-byte packet length not supported\n"); +- return -EBADMSG; ++ /* Five-byte length */ ++ if (datalen < 5) ++ goto short_packet; ++ size = data[1] << 24; ++ size |= data[2] << 16; ++ size |= data[3] << 8; ++ size |= data[4]; ++ data += 5; ++ datalen -= 5; ++ *_headerlen = 6; ++ break; + default: + pr_debug("Error parsing packet length\n"); + return -EBADMSG; +-- +1.7.10.2 + + +From df233b65b833e085f39d80dc6f77c383b32786ce Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Thu, 17 May 2012 17:41:36 +0100 +Subject: [PATCH 35/36] PGPLIB: Change the debug message for Partial Body + Length specifier + +Change the debug message displayed if we encounter a Partial Body Length +specifier whilst parsing a PGP stream [RFC4880 4.2.2.4]. + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + security/keys/crypto/pgp_library.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +diff --git a/security/keys/crypto/pgp_library.c b/security/keys/crypto/pgp_library.c +index 310ee2f..111cbd7 100644 +--- a/security/keys/crypto/pgp_library.c ++++ b/security/keys/crypto/pgp_library.c +@@ -98,7 +98,7 @@ ssize_t pgp_parse_packet_header(const u8 **_data, size_t *_datalen, + *_headerlen = 6; + break; + default: +- pr_debug("Error parsing packet length\n"); ++ pr_debug("Partial body length packet not supported\n"); + return -EBADMSG; + } + } else { +-- +1.7.10.2 + + +From 3ac676c62cceabdbf814bbc3495f36abd1848a97 Mon Sep 17 00:00:00 2001 +From: David Howells <dhowells@redhat.com> +Date: Fri, 18 May 2012 16:44:14 +0100 +Subject: [PATCH 36/36] PGPLIB: Adjust error handling + +Adjust the error handling in the following ways: + + (1) When parsing signature subpacket header, do the size checks before + accessing the subpacket type (which is in the subpacket payload governed + by the size). + + (2) Indicate ENOPKG when we are asked to use a public key algorithm we don't + support rather than returning ENOKEY. + + (3) Indicate EKEYREJECTED if the key that matches the signature demands a + different key algorithm to the signature. + + (4) Indicate ENOMSG if the signature blob does not contain a signature + packet. Possibly this should be EBADMSG - though that causes the next + packet parser to be tried if available. + + (5) Give a better debug message in the case of an unsupported hash. + + (6) Don't return keyring-related errors when searching for a key containing + the public key (EACCES, ENOTDIR, EAGAIN), but rather map them to ENOKEY. + Possibly EACCES should be passed through as you also get that if there + *is* a matching key, but it cannot be accessed. + +Signed-off-by: David Howells <dhowells@redhat.com> +--- + Documentation/module-signing.txt | 2 ++ + security/keys/crypto/pgp_library.c | 16 ++++++++-------- + security/keys/crypto/pgp_pubkey_sig.c | 9 +++++---- + security/keys/crypto/pgp_sig_parser.c | 15 ++++++++++++--- + 4 files changed, 27 insertions(+), 15 deletions(-) + +diff --git a/Documentation/module-signing.txt b/Documentation/module-signing.txt +index d75d473..d3beb1e 100644 +--- a/Documentation/module-signing.txt ++++ b/Documentation/module-signing.txt +@@ -185,10 +185,12 @@ This table indicates the behaviours of the various situations: + MODULE STATE PERMISSIVE MODE ENFORCING MODE + ======================================= =============== =============== + Unsigned Ok EKEYREJECTED ++ No signature packet in the signature ENOMSG ENOMSG + Signed, no public key ENOKEY ENOKEY + Validly signed, public key Ok Ok + Invalidly signed, public key EKEYREJECTED EKEYREJECTED + Validly signed, expired key EKEYEXPIRED EKEYEXPIRED ++ Signed, pubkey algorithm unavailable ENOPKG ENOPKG + Signed, hash algorithm unavailable ENOPKG ENOPKG + Corrupt signature EBADMSG EBADMSG + Corrupt ELF ELIBBAD ELIBBAD +diff --git a/security/keys/crypto/pgp_library.c b/security/keys/crypto/pgp_library.c +index 111cbd7..ee08b86 100644 +--- a/security/keys/crypto/pgp_library.c ++++ b/security/keys/crypto/pgp_library.c +@@ -322,10 +322,11 @@ ssize_t pgp_parse_sig_subpkt_header(const u8 **_data, size_t *_datalen, + } + + /* The type octet is included in the size */ +- if (size == 0) { +- pr_debug("Signature subpacket size can't be zero\n"); +- return -EBADMSG; +- } ++ pr_devel("datalen=%zu size=%zu", datalen, size); ++ if (datalen < size) ++ goto short_subpacket; ++ if (size == 0) ++ goto very_short_subpacket; + if ((int)size < 0) + goto too_big; + +@@ -333,16 +334,15 @@ ssize_t pgp_parse_sig_subpkt_header(const u8 **_data, size_t *_datalen, + datalen--; + size--; + +- pr_devel("datalen=%zu size=%zu", datalen, size); +- if (datalen < size) +- goto short_subpacket; +- + *_data = data; + *_datalen = datalen; + *_type = type; + pr_devel("Found subpkt type=%u size=%zd\n", type, size); + return size; + ++very_short_subpacket: ++ pr_debug("Signature subpacket size can't be zero\n"); ++ return -EBADMSG; + short_subpacket: + pr_debug("Attempt to parse short signature subpacket\n"); + return -EBADMSG; +diff --git a/security/keys/crypto/pgp_pubkey_sig.c b/security/keys/crypto/pgp_pubkey_sig.c +index b4b7cb0..bc02dfa 100644 +--- a/security/keys/crypto/pgp_pubkey_sig.c ++++ b/security/keys/crypto/pgp_pubkey_sig.c +@@ -86,12 +86,12 @@ struct crypto_key_verify_context *pgp_pkey_verify_sig_begin( + !pgp_public_key_algorithms[p.params.pubkey_algo]) { + pr_debug("Unsupported public key algorithm %u\n", + p.params.pubkey_algo); +- return ERR_PTR(-ENOKEY); ++ return ERR_PTR(-ENOPKG); + } + + if (pgp_public_key_algorithms[p.params.pubkey_algo] != key->algo) { +- kleave(" = -ENOKEY [wrong pk algo]"); +- return ERR_PTR(-ENOKEY); ++ kleave(" = -EKEYREJECTED [wrong pk algo]"); ++ return ERR_PTR(-EKEYREJECTED); + } + + if (!(key->capabilities & PKEY_CAN_VERIFY)) { +@@ -101,7 +101,8 @@ struct crypto_key_verify_context *pgp_pkey_verify_sig_begin( + + if (p.params.hash_algo >= PGP_HASH__LAST || + !pgp_hash_algorithms[p.params.hash_algo]) { +- kleave(" = -ENOPKG [hash]"); ++ pr_debug("Unsupported hash algorithm %u\n", ++ p.params.hash_algo); + return ERR_PTR(-ENOPKG); + } + +diff --git a/security/keys/crypto/pgp_sig_parser.c b/security/keys/crypto/pgp_sig_parser.c +index b72c505..3dd223f 100644 +--- a/security/keys/crypto/pgp_sig_parser.c ++++ b/security/keys/crypto/pgp_sig_parser.c +@@ -66,7 +66,7 @@ static struct key *find_key_for_pgp_sig(struct key *keyring, + return ERR_PTR(ret); + + if (!p.found_sig) +- return ERR_PTR(-EINVAL); ++ return ERR_PTR(-ENOMSG); + + sprintf(criterion, "id:%08x%08x", + be32_to_cpu(p.params.issuer32[0]), +@@ -76,8 +76,17 @@ static struct key *find_key_for_pgp_sig(struct key *keyring, + + key = keyring_search(make_key_ref(keyring, 1), + &key_type_crypto, criterion); +- if (IS_ERR(key)) +- return ERR_CAST(key); ++ if (IS_ERR(key)) { ++ switch (PTR_ERR(key)) { ++ /* Hide some search errors */ ++ case -EACCES: ++ case -ENOTDIR: ++ case -EAGAIN: ++ return ERR_PTR(-ENOKEY); ++ default: ++ return ERR_CAST(key); ++ } ++ } + + pr_debug("Found key %x\n", key_serial(key_ref_to_ptr(key))); + return key_ref_to_ptr(key); +-- +1.7.10.2 + |