From 7712dc43315febf4bce07a4c549787cf5c60a428 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 30 Aug 2013 16:07:13 +0100 Subject: [PATCH 01/13] KEYS: Load *.x509 files into kernel keyring Load all the files matching the pattern "*.x509" that are to be found in kernel base source dir and base build dir into the module signing keyring. The "extra_certificates" file is then redundant. Signed-off-by: David Howells --- kernel/Makefile | 35 +++++++++++++++++++++++++++++------ kernel/modsign_certificate.S | 3 +-- 2 files changed, 30 insertions(+), 8 deletions(-) diff --git a/kernel/Makefile b/kernel/Makefile index 35ef118..ab231ac 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -142,17 +142,40 @@ $(obj)/timeconst.h: $(obj)/hz.bc $(src)/timeconst.bc FORCE $(call if_changed,bc) ifeq ($(CONFIG_MODULE_SIG),y) +############################################################################### # -# Pull the signing certificate and any extra certificates into the kernel +# Roll all the X.509 certificates that we can find together and pull +# them into the kernel. # +############################################################################### +X509_CERTIFICATES-y := $(wildcard *.x509) $(wildcard $(srctree)/*.x509) +X509_CERTIFICATES-$(CONFIG_MODULE_SIG) += signing_key.x509 +X509_CERTIFICATES := $(sort $(X509_CERTIFICATES-y)) + +ifeq ($(X509_CERTIFICATES),) +$(warning *** No X.509 certificates found ***) +endif + +ifneq ($(wildcard $(obj)/.x509.list),) +ifneq ($(shell cat $(obj)/.x509.list),$(X509_CERTIFICATES)) +$(info X.509 certificate list changed) +$(shell rm $(obj)/.x509.list) +endif +endif + +kernel/modsign_certificate.o: $(obj)/x509_certificate_list -quiet_cmd_touch = TOUCH $@ - cmd_touch = touch $@ +quiet_cmd_x509certs = CERTS $@ + cmd_x509certs = cat $(X509_CERTIFICATES) /dev/null >$@ +targets += $(obj)/x509_certificate_list +$(obj)/x509_certificate_list: $(X509_CERTIFICATES) $(obj)/.x509.list + $(call if_changed,x509certs) -extra_certificates: - $(call cmd,touch) +targets += $(obj)/.x509.list +$(obj)/.x509.list: + @echo $(X509_CERTIFICATES) >$@ -kernel/modsign_certificate.o: signing_key.x509 extra_certificates +clean-files := x509_certificate_list .x509.list ############################################################################### # diff --git a/kernel/modsign_certificate.S b/kernel/modsign_certificate.S index 4a9a86d..6fe03c7 100644 --- a/kernel/modsign_certificate.S +++ b/kernel/modsign_certificate.S @@ -7,6 +7,5 @@ .section ".init.data","aw" GLOBAL(modsign_certificate_list) - .incbin "signing_key.x509" - .incbin "extra_certificates" + .incbin "kernel/x509_certificate_list" GLOBAL(modsign_certificate_list_end) -- 1.8.3.1 From d1bf7ed78a52477636cdcb5a1bff5b19352472f5 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 30 Aug 2013 16:07:30 +0100 Subject: [PATCH 02/13] KEYS: Separate the kernel signature checking keyring from module signing Separate the kernel signature checking keyring from module signing so that it can be used by code other than the module-signing code. Signed-off-by: David Howells --- include/keys/system_keyring.h | 23 ++++++++++ init/Kconfig | 13 ++++++ kernel/Makefile | 17 ++++--- kernel/modsign_certificate.S | 11 ----- kernel/modsign_pubkey.c | 104 ------------------------------------------ kernel/module-internal.h | 2 - kernel/module_signing.c | 3 +- kernel/system_certificates.S | 11 +++++ kernel/system_keyring.c | 103 +++++++++++++++++++++++++++++++++++++++++ 9 files changed, 163 insertions(+), 124 deletions(-) create mode 100644 include/keys/system_keyring.h delete mode 100644 kernel/modsign_certificate.S delete mode 100644 kernel/modsign_pubkey.c create mode 100644 kernel/system_certificates.S create mode 100644 kernel/system_keyring.c diff --git a/include/keys/system_keyring.h b/include/keys/system_keyring.h new file mode 100644 index 0000000..8dabc39 --- /dev/null +++ b/include/keys/system_keyring.h @@ -0,0 +1,23 @@ +/* System keyring containing trusted public keys. + * + * Copyright (C) 2013 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 _KEYS_SYSTEM_KEYRING_H +#define _KEYS_SYSTEM_KEYRING_H + +#ifdef CONFIG_SYSTEM_TRUSTED_KEYRING + +#include + +extern struct key *system_trusted_keyring; + +#endif + +#endif /* _KEYS_SYSTEM_KEYRING_H */ diff --git a/init/Kconfig b/init/Kconfig index 18bd9e3..cf14d07 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1668,6 +1668,18 @@ config BASE_SMALL default 0 if BASE_FULL default 1 if !BASE_FULL +config SYSTEM_TRUSTED_KEYRING + bool "Provide system-wide ring of trusted keys" + depends on KEYS + help + Provide a system keyring to which trusted keys can be added. Keys in + the keyring are considered to be trusted. Keys may be added at will + by the kernel from compiled-in data and from hardware key stores, but + userspace may only add extra keys if those keys can be verified by + keys already in the keyring. + + Keys in this keyring are used by module signature checking. + menuconfig MODULES bool "Enable loadable module support" option modules @@ -1741,6 +1753,7 @@ config MODULE_SRCVERSION_ALL config MODULE_SIG bool "Module signature verification" depends on MODULES + select SYSTEM_TRUSTED_KEYRING select KEYS select CRYPTO select ASYMMETRIC_KEY_TYPE diff --git a/kernel/Makefile b/kernel/Makefile index ab231ac..1262c6d 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -53,8 +53,9 @@ obj-$(CONFIG_SMP) += spinlock.o obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o obj-$(CONFIG_PROVE_LOCKING) += spinlock.o obj-$(CONFIG_UID16) += uid16.o +obj-$(CONFIG_SYSTEM_TRUSTED_KEYRING) += system_keyring.o system_certificates.o obj-$(CONFIG_MODULES) += module.o -obj-$(CONFIG_MODULE_SIG) += module_signing.o modsign_pubkey.o modsign_certificate.o +obj-$(CONFIG_MODULE_SIG) += module_signing.o obj-$(CONFIG_KALLSYMS) += kallsyms.o obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o obj-$(CONFIG_KEXEC) += kexec.o @@ -141,13 +142,14 @@ targets += timeconst.h $(obj)/timeconst.h: $(obj)/hz.bc $(src)/timeconst.bc FORCE $(call if_changed,bc) -ifeq ($(CONFIG_MODULE_SIG),y) ############################################################################### # -# Roll all the X.509 certificates that we can find together and pull -# them into the kernel. +# Roll all the X.509 certificates that we can find together and pull them into +# the kernel so that they get loaded into the system trusted keyring during +# boot. # ############################################################################### +ifeq ($(CONFIG_SYSTEM_TRUSTED_KEYRING),y) X509_CERTIFICATES-y := $(wildcard *.x509) $(wildcard $(srctree)/*.x509) X509_CERTIFICATES-$(CONFIG_MODULE_SIG) += signing_key.x509 X509_CERTIFICATES := $(sort $(X509_CERTIFICATES-y)) @@ -163,10 +165,11 @@ $(shell rm $(obj)/.x509.list) endif endif -kernel/modsign_certificate.o: $(obj)/x509_certificate_list +kernel/system_certificates.o: $(obj)/x509_certificate_list quiet_cmd_x509certs = CERTS $@ - cmd_x509certs = cat $(X509_CERTIFICATES) /dev/null >$@ + cmd_x509certs = cat $(X509_CERTIFICATES) /dev/null >$@ $(foreach X509,$(X509_CERTIFICATES),; echo " - Including cert $(X509)") + targets += $(obj)/x509_certificate_list $(obj)/x509_certificate_list: $(X509_CERTIFICATES) $(obj)/.x509.list $(call if_changed,x509certs) @@ -176,7 +179,9 @@ $(obj)/.x509.list: @echo $(X509_CERTIFICATES) >$@ clean-files := x509_certificate_list .x509.list +endif +ifeq ($(CONFIG_MODULE_SIG),y) ############################################################################### # # If module signing is requested, say by allyesconfig, but a key has not been diff --git a/kernel/modsign_certificate.S b/kernel/modsign_certificate.S deleted file mode 100644 index 6fe03c7..0000000 --- a/kernel/modsign_certificate.S +++ /dev/null @@ -1,11 +0,0 @@ -#include - -#define GLOBAL(name) \ - .globl VMLINUX_SYMBOL(name); \ - VMLINUX_SYMBOL(name): - - .section ".init.data","aw" - -GLOBAL(modsign_certificate_list) - .incbin "kernel/x509_certificate_list" -GLOBAL(modsign_certificate_list_end) diff --git a/kernel/modsign_pubkey.c b/kernel/modsign_pubkey.c deleted file mode 100644 index 7cbd450..0000000 --- a/kernel/modsign_pubkey.c +++ /dev/null @@ -1,104 +0,0 @@ -/* Public keys for module signature verification - * - * 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. - */ - -#include -#include -#include -#include -#include -#include "module-internal.h" - -struct key *modsign_keyring; - -extern __initconst const u8 modsign_certificate_list[]; -extern __initconst const u8 modsign_certificate_list_end[]; - -/* - * We need to make sure ccache doesn't cache the .o file as it doesn't notice - * if modsign.pub changes. - */ -static __initconst 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 = keyring_alloc(".module_sign", - KUIDT_INIT(0), KGIDT_INIT(0), - current_cred(), - ((KEY_POS_ALL & ~KEY_POS_SETATTR) | - KEY_USR_VIEW | KEY_USR_READ), - KEY_ALLOC_NOT_IN_QUOTA, NULL); - if (IS_ERR(modsign_keyring)) - panic("Can't allocate 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 load_module_signing_keys(void) -{ - key_ref_t key; - const u8 *p, *end; - size_t plen; - - pr_notice("Loading module verification certificates\n"); - - end = modsign_certificate_list_end; - p = modsign_certificate_list; - while (p < end) { - /* Each cert begins with an ASN.1 SEQUENCE tag and must be more - * than 256 bytes in size. - */ - if (end - p < 4) - goto dodgy_cert; - if (p[0] != 0x30 && - p[1] != 0x82) - goto dodgy_cert; - plen = (p[2] << 8) | p[3]; - plen += 4; - if (plen > end - p) - goto dodgy_cert; - - key = key_create_or_update(make_key_ref(modsign_keyring, 1), - "asymmetric", - NULL, - p, - plen, - (KEY_POS_ALL & ~KEY_POS_SETATTR) | - KEY_USR_VIEW, - KEY_ALLOC_NOT_IN_QUOTA); - if (IS_ERR(key)) - pr_err("MODSIGN: Problem loading in-kernel X.509 certificate (%ld)\n", - PTR_ERR(key)); - else - pr_notice("MODSIGN: Loaded cert '%s'\n", - key_ref_to_ptr(key)->description); - p += plen; - } - - return 0; - -dodgy_cert: - pr_err("MODSIGN: Problem parsing in-kernel X.509 certificate list\n"); - return 0; -} -late_initcall(load_module_signing_keys); diff --git a/kernel/module-internal.h b/kernel/module-internal.h index 24f9247..915e123 100644 --- a/kernel/module-internal.h +++ b/kernel/module-internal.h @@ -9,6 +9,4 @@ * 2 of the Licence, or (at your option) any later version. */ -extern struct key *modsign_keyring; - extern int mod_verify_sig(const void *mod, unsigned long *_modlen); diff --git a/kernel/module_signing.c b/kernel/module_signing.c index f2970bd..0034e36 100644 --- a/kernel/module_signing.c +++ b/kernel/module_signing.c @@ -14,6 +14,7 @@ #include #include #include +#include #include "module-internal.h" /* @@ -157,7 +158,7 @@ static struct key *request_asymmetric_key(const char *signer, size_t signer_len, pr_debug("Look up: \"%s\"\n", id); - key = keyring_search(make_key_ref(modsign_keyring, 1), + key = keyring_search(make_key_ref(system_trusted_keyring, 1), &key_type_asymmetric, id); if (IS_ERR(key)) pr_warn("Request for unknown module key '%s' err %ld\n", diff --git a/kernel/system_certificates.S b/kernel/system_certificates.S new file mode 100644 index 0000000..5cffe86 --- /dev/null +++ b/kernel/system_certificates.S @@ -0,0 +1,11 @@ +#include + +#define GLOBAL(name) \ + .globl VMLINUX_SYMBOL(name); \ + VMLINUX_SYMBOL(name): + + .section ".init.data","aw" + +GLOBAL(system_certificate_list) + .incbin "kernel/x509_certificate_list" +GLOBAL(system_certificate_list_end) diff --git a/kernel/system_keyring.c b/kernel/system_keyring.c new file mode 100644 index 0000000..51c3514 --- /dev/null +++ b/kernel/system_keyring.c @@ -0,0 +1,103 @@ +/* System trusted keyring for trusted public keys + * + * 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. + */ + +#include +#include +#include +#include +#include +#include +#include +#include "module-internal.h" + +struct key *system_trusted_keyring; +EXPORT_SYMBOL_GPL(system_trusted_keyring); + +extern __initconst const u8 system_certificate_list[]; +extern __initconst const u8 system_certificate_list_end[]; + +/* + * Load the compiled-in keys + */ +static __init int system_trusted_keyring_init(void) +{ + pr_notice("Initialise system trusted keyring\n"); + + system_trusted_keyring = + keyring_alloc(".system_keyring", + KUIDT_INIT(0), KGIDT_INIT(0), current_cred(), + ((KEY_POS_ALL & ~KEY_POS_SETATTR) | + KEY_USR_VIEW | KEY_USR_READ), + KEY_ALLOC_NOT_IN_QUOTA, NULL); + if (IS_ERR(system_trusted_keyring)) + panic("Can't allocate system trusted keyring\n"); + + return 0; +} + +/* + * Must be initialised before we try and load the keys into the keyring. + */ +device_initcall(system_trusted_keyring_init); + +/* + * Load the compiled-in list of X.509 certificates. + */ +static __init int load_system_certificate_list(void) +{ + key_ref_t key; + const u8 *p, *end; + size_t plen; + + pr_notice("Loading compiled-in X.509 certificates\n"); + + end = system_certificate_list_end; + p = system_certificate_list; + while (p < end) { + /* Each cert begins with an ASN.1 SEQUENCE tag and must be more + * than 256 bytes in size. + */ + if (end - p < 4) + goto dodgy_cert; + if (p[0] != 0x30 && + p[1] != 0x82) + goto dodgy_cert; + plen = (p[2] << 8) | p[3]; + plen += 4; + if (plen > end - p) + goto dodgy_cert; + + key = key_create_or_update(make_key_ref(system_trusted_keyring, 1), + "asymmetric", + NULL, + p, + plen, + (KEY_POS_ALL & ~KEY_POS_SETATTR) | + KEY_USR_VIEW, + KEY_ALLOC_NOT_IN_QUOTA); + if (IS_ERR(key)) { + pr_err("Problem loading in-kernel X.509 certificate (%ld)\n", + PTR_ERR(key)); + } else { + pr_notice("Loaded X.509 cert '%s'\n", + key_ref_to_ptr(key)->description); + key_ref_put(key); + } + p += plen; + } + + return 0; + +dodgy_cert: + pr_err("Problem parsing in-kernel X.509 certificate list\n"); + return 0; +} +late_initcall(load_system_certificate_list); -- 1.8.3.1 From 209cfd7eda86173415d394a9ff868345197d7b3d Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 30 Aug 2013 16:07:37 +0100 Subject: [PATCH 03/13] KEYS: Add a 'trusted' flag and a 'trusted only' flag Add KEY_FLAG_TRUSTED to indicate that a key either comes from a trusted source or had a cryptographic signature chain that led back to a trusted key the kernel already possessed. Add KEY_FLAGS_TRUSTED_ONLY to indicate that a keyring will only accept links to keys marked with KEY_FLAGS_TRUSTED. Signed-off-by: David Howells Reviewed-by: Kees Cook --- include/linux/key-type.h | 1 + include/linux/key.h | 3 +++ kernel/system_keyring.c | 4 +++- security/keys/key.c | 8 ++++++++ security/keys/keyring.c | 4 ++++ 5 files changed, 19 insertions(+), 1 deletion(-) diff --git a/include/linux/key-type.h b/include/linux/key-type.h index f58737b..a74c3a8 100644 --- a/include/linux/key-type.h +++ b/include/linux/key-type.h @@ -45,6 +45,7 @@ struct key_preparsed_payload { const void *data; /* Raw data */ size_t datalen; /* Raw datalen */ size_t quotalen; /* Quota length for proposed payload */ + bool trusted; /* True if key is trusted */ }; typedef int (*request_key_actor_t)(struct key_construction *key, diff --git a/include/linux/key.h b/include/linux/key.h index 010dbb6..80d6774 100644 --- a/include/linux/key.h +++ b/include/linux/key.h @@ -168,6 +168,8 @@ struct key { #define KEY_FLAG_NEGATIVE 5 /* set if key is negative */ #define KEY_FLAG_ROOT_CAN_CLEAR 6 /* set if key can be cleared by root without permission */ #define KEY_FLAG_INVALIDATED 7 /* set if key has been invalidated */ +#define KEY_FLAG_TRUSTED 8 /* set if key is trusted */ +#define KEY_FLAG_TRUSTED_ONLY 9 /* set if keyring only accepts links to trusted keys */ /* the key type and key description string * - the desc is used to match a key against search criteria @@ -218,6 +220,7 @@ extern struct key *key_alloc(struct key_type *type, #define KEY_ALLOC_IN_QUOTA 0x0000 /* add to quota, reject if would overrun */ #define KEY_ALLOC_QUOTA_OVERRUN 0x0001 /* add to quota, permit even if overrun */ #define KEY_ALLOC_NOT_IN_QUOTA 0x0002 /* not in quota */ +#define KEY_ALLOC_TRUSTED 0x0004 /* Key should be flagged as trusted */ extern void key_revoke(struct key *key); extern void key_invalidate(struct key *key); diff --git a/kernel/system_keyring.c b/kernel/system_keyring.c index 51c3514..5296721 100644 --- a/kernel/system_keyring.c +++ b/kernel/system_keyring.c @@ -40,6 +40,7 @@ static __init int system_trusted_keyring_init(void) if (IS_ERR(system_trusted_keyring)) panic("Can't allocate system trusted keyring\n"); + set_bit(KEY_FLAG_TRUSTED_ONLY, &system_trusted_keyring->flags); return 0; } @@ -82,7 +83,8 @@ static __init int load_system_certificate_list(void) plen, (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW, - KEY_ALLOC_NOT_IN_QUOTA); + KEY_ALLOC_NOT_IN_QUOTA | + KEY_ALLOC_TRUSTED); if (IS_ERR(key)) { pr_err("Problem loading in-kernel X.509 certificate (%ld)\n", PTR_ERR(key)); diff --git a/security/keys/key.c b/security/keys/key.c index a819b5c..d331ea9 100644 --- a/security/keys/key.c +++ b/security/keys/key.c @@ -300,6 +300,8 @@ struct key *key_alloc(struct key_type *type, const char *desc, if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) key->flags |= 1 << KEY_FLAG_IN_QUOTA; + if (flags & KEY_ALLOC_TRUSTED) + key->flags |= 1 << KEY_FLAG_TRUSTED; memset(&key->type_data, 0, sizeof(key->type_data)); @@ -813,6 +815,7 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref, prep.data = payload; prep.datalen = plen; prep.quotalen = index_key.type->def_datalen; + prep.trusted = flags & KEY_ALLOC_TRUSTED; if (index_key.type->preparse) { ret = index_key.type->preparse(&prep); if (ret < 0) { @@ -827,6 +830,11 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref, } index_key.desc_len = strlen(index_key.description); + key_ref = ERR_PTR(-EPERM); + if (!prep.trusted && test_bit(KEY_FLAG_TRUSTED_ONLY, &keyring->flags)) + goto error_free_prep; + flags |= prep.trusted ? KEY_ALLOC_TRUSTED : 0; + ret = __key_link_begin(keyring, &index_key, &edit); if (ret < 0) { key_ref = ERR_PTR(ret); diff --git a/security/keys/keyring.c b/security/keys/keyring.c index f7cdea2..9b6f6e0 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -1183,6 +1183,10 @@ int key_link(struct key *keyring, struct key *key) key_check(keyring); key_check(key); + if (test_bit(KEY_FLAG_TRUSTED_ONLY, &keyring->flags) && + !test_bit(KEY_FLAG_TRUSTED, &key->flags)) + return -EPERM; + ret = __key_link_begin(keyring, &key->index_key, &edit); if (ret == 0) { kdebug("begun {%d,%d}", keyring->serial, atomic_read(&keyring->usage)); -- 1.8.3.1 From 6549cbca91abf561df8f501c763a8e7822936294 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 30 Aug 2013 16:15:10 +0100 Subject: [PATCH 04/13] KEYS: Rename public key parameter name arrays Rename the arrays of public key parameters (public key algorithm names, hash algorithm names and ID type names) so that the array name ends in "_name". Signed-off-by: David Howells Reviewed-by: Kees Cook Reviewed-by: Josh Boyer --- crypto/asymmetric_keys/public_key.c | 14 +++++++------- crypto/asymmetric_keys/x509_public_key.c | 8 ++++---- include/crypto/public_key.h | 6 +++--- kernel/module_signing.c | 4 ++-- 4 files changed, 16 insertions(+), 16 deletions(-) diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c index cb2e291..b313df1 100644 --- a/crypto/asymmetric_keys/public_key.c +++ b/crypto/asymmetric_keys/public_key.c @@ -22,13 +22,13 @@ MODULE_LICENSE("GPL"); -const char *const pkey_algo[PKEY_ALGO__LAST] = { +const char *const pkey_algo_name[PKEY_ALGO__LAST] = { [PKEY_ALGO_DSA] = "DSA", [PKEY_ALGO_RSA] = "RSA", }; -EXPORT_SYMBOL_GPL(pkey_algo); +EXPORT_SYMBOL_GPL(pkey_algo_name); -const char *const pkey_hash_algo[PKEY_HASH__LAST] = { +const char *const pkey_hash_algo_name[PKEY_HASH__LAST] = { [PKEY_HASH_MD4] = "md4", [PKEY_HASH_MD5] = "md5", [PKEY_HASH_SHA1] = "sha1", @@ -38,13 +38,13 @@ const char *const pkey_hash_algo[PKEY_HASH__LAST] = { [PKEY_HASH_SHA512] = "sha512", [PKEY_HASH_SHA224] = "sha224", }; -EXPORT_SYMBOL_GPL(pkey_hash_algo); +EXPORT_SYMBOL_GPL(pkey_hash_algo_name); -const char *const pkey_id_type[PKEY_ID_TYPE__LAST] = { +const char *const pkey_id_type_name[PKEY_ID_TYPE__LAST] = { [PKEY_ID_PGP] = "PGP", [PKEY_ID_X509] = "X509", }; -EXPORT_SYMBOL_GPL(pkey_id_type); +EXPORT_SYMBOL_GPL(pkey_id_type_name); /* * Provide a part of a description of the key for /proc/keys. @@ -56,7 +56,7 @@ static void public_key_describe(const struct key *asymmetric_key, if (key) seq_printf(m, "%s.%s", - pkey_id_type[key->id_type], key->algo->name); + pkey_id_type_name[key->id_type], key->algo->name); } /* diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c index 06007f0..afbbc36 100644 --- a/crypto/asymmetric_keys/x509_public_key.c +++ b/crypto/asymmetric_keys/x509_public_key.c @@ -49,7 +49,7 @@ static int x509_check_signature(const struct public_key *pub, /* Allocate the hashing algorithm we're going to need and find out how * big the hash operational data will be. */ - tfm = crypto_alloc_shash(pkey_hash_algo[cert->sig_hash_algo], 0, 0); + tfm = crypto_alloc_shash(pkey_hash_algo_name[cert->sig_hash_algo], 0, 0); if (IS_ERR(tfm)) return (PTR_ERR(tfm) == -ENOENT) ? -ENOPKG : PTR_ERR(tfm); @@ -117,7 +117,7 @@ static int x509_key_preparse(struct key_preparsed_payload *prep) pr_devel("Cert Issuer: %s\n", cert->issuer); pr_devel("Cert Subject: %s\n", cert->subject); - pr_devel("Cert Key Algo: %s\n", pkey_algo[cert->pkey_algo]); + pr_devel("Cert Key Algo: %s\n", pkey_algo_name[cert->pkey_algo]); pr_devel("Cert Valid From: %04ld-%02d-%02d %02d:%02d:%02d\n", cert->valid_from.tm_year + 1900, cert->valid_from.tm_mon + 1, cert->valid_from.tm_mday, cert->valid_from.tm_hour, @@ -127,8 +127,8 @@ static int x509_key_preparse(struct key_preparsed_payload *prep) cert->valid_to.tm_mday, cert->valid_to.tm_hour, cert->valid_to.tm_min, cert->valid_to.tm_sec); pr_devel("Cert Signature: %s + %s\n", - pkey_algo[cert->sig_pkey_algo], - pkey_hash_algo[cert->sig_hash_algo]); + pkey_algo_name[cert->sig_pkey_algo], + pkey_hash_algo_name[cert->sig_hash_algo]); if (!cert->fingerprint || !cert->authority) { pr_warn("Cert for '%s' must have SubjKeyId and AuthKeyId extensions\n", diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h index f5b0224..619d570 100644 --- a/include/crypto/public_key.h +++ b/include/crypto/public_key.h @@ -22,7 +22,7 @@ enum pkey_algo { PKEY_ALGO__LAST }; -extern const char *const pkey_algo[PKEY_ALGO__LAST]; +extern const char *const pkey_algo_name[PKEY_ALGO__LAST]; enum pkey_hash_algo { PKEY_HASH_MD4, @@ -36,7 +36,7 @@ enum pkey_hash_algo { PKEY_HASH__LAST }; -extern const char *const pkey_hash_algo[PKEY_HASH__LAST]; +extern const char *const pkey_hash_algo_name[PKEY_HASH__LAST]; enum pkey_id_type { PKEY_ID_PGP, /* OpenPGP generated key ID */ @@ -44,7 +44,7 @@ enum pkey_id_type { PKEY_ID_TYPE__LAST }; -extern const char *const pkey_id_type[PKEY_ID_TYPE__LAST]; +extern const char *const pkey_id_type_name[PKEY_ID_TYPE__LAST]; /* * Cryptographic data for the public-key subtype of the asymmetric key type. diff --git a/kernel/module_signing.c b/kernel/module_signing.c index 0034e36..0b6b870 100644 --- a/kernel/module_signing.c +++ b/kernel/module_signing.c @@ -55,7 +55,7 @@ static struct public_key_signature *mod_make_digest(enum pkey_hash_algo hash, /* Allocate the hashing algorithm we're going to need and find out how * big the hash operational data will be. */ - tfm = crypto_alloc_shash(pkey_hash_algo[hash], 0, 0); + tfm = crypto_alloc_shash(pkey_hash_algo_name[hash], 0, 0); if (IS_ERR(tfm)) return (PTR_ERR(tfm) == -ENOENT) ? ERR_PTR(-ENOPKG) : ERR_CAST(tfm); @@ -218,7 +218,7 @@ int mod_verify_sig(const void *mod, unsigned long *_modlen) return -ENOPKG; if (ms.hash >= PKEY_HASH__LAST || - !pkey_hash_algo[ms.hash]) + !pkey_hash_algo_name[ms.hash]) return -ENOPKG; key = request_asymmetric_key(sig, ms.signer_len, -- 1.8.3.1 From b2c8f8924f17c25209d8fe55f74b9d5830ad191c Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 30 Aug 2013 16:15:18 +0100 Subject: [PATCH 05/13] KEYS: Move the algorithm pointer array from x509 to public_key.c Move the public-key algorithm pointer array from x509_public_key.c to public_key.c as it isn't X.509 specific. Signed-off-by: David Howells Reviewed-by: Kees Cook Reviewed-by: Josh Boyer --- crypto/asymmetric_keys/public_key.c | 8 ++++++++ crypto/asymmetric_keys/x509_public_key.c | 11 +---------- include/crypto/public_key.h | 1 + 3 files changed, 10 insertions(+), 10 deletions(-) diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c index b313df1..796ce08 100644 --- a/crypto/asymmetric_keys/public_key.c +++ b/crypto/asymmetric_keys/public_key.c @@ -28,6 +28,14 @@ const char *const pkey_algo_name[PKEY_ALGO__LAST] = { }; EXPORT_SYMBOL_GPL(pkey_algo_name); +const struct public_key_algorithm *pkey_algo[PKEY_ALGO__LAST] = { +#if defined(CONFIG_PUBLIC_KEY_ALGO_RSA) || \ + defined(CONFIG_PUBLIC_KEY_ALGO_RSA_MODULE) + [PKEY_ALGO_RSA] = &RSA_public_key_algorithm, +#endif +}; +EXPORT_SYMBOL_GPL(pkey_algo); + const char *const pkey_hash_algo_name[PKEY_HASH__LAST] = { [PKEY_HASH_MD4] = "md4", [PKEY_HASH_MD5] = "md5", diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c index afbbc36..fe38628 100644 --- a/crypto/asymmetric_keys/x509_public_key.c +++ b/crypto/asymmetric_keys/x509_public_key.c @@ -23,15 +23,6 @@ #include "public_key.h" #include "x509_parser.h" -static const -struct public_key_algorithm *x509_public_key_algorithms[PKEY_ALGO__LAST] = { - [PKEY_ALGO_DSA] = NULL, -#if defined(CONFIG_PUBLIC_KEY_ALGO_RSA) || \ - defined(CONFIG_PUBLIC_KEY_ALGO_RSA_MODULE) - [PKEY_ALGO_RSA] = &RSA_public_key_algorithm, -#endif -}; - /* * Check the signature on a certificate using the provided public key */ @@ -174,7 +165,7 @@ static int x509_key_preparse(struct key_preparsed_payload *prep) goto error_free_cert; } - cert->pub->algo = x509_public_key_algorithms[cert->pkey_algo]; + cert->pub->algo = pkey_algo[cert->pkey_algo]; cert->pub->id_type = PKEY_ID_X509; /* Check the signature on the key */ diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h index 619d570..46bde25 100644 --- a/include/crypto/public_key.h +++ b/include/crypto/public_key.h @@ -23,6 +23,7 @@ enum pkey_algo { }; extern const char *const pkey_algo_name[PKEY_ALGO__LAST]; +extern const struct public_key_algorithm *pkey_algo[PKEY_ALGO__LAST]; enum pkey_hash_algo { PKEY_HASH_MD4, -- 1.8.3.1 From 760486c4376aab8cd8ce9c7d2ad67a19d713b119 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 30 Aug 2013 16:15:24 +0100 Subject: [PATCH 06/13] KEYS: Store public key algo ID in public_key struct Store public key algo ID in public_key struct for reference purposes. This allows it to be removed from the x509_certificate struct and used to find a default in public_key_verify_signature(). Signed-off-by: David Howells Reviewed-by: Kees Cook Reviewed-by: Josh Boyer --- crypto/asymmetric_keys/x509_cert_parser.c | 5 +++-- crypto/asymmetric_keys/x509_parser.h | 1 - crypto/asymmetric_keys/x509_public_key.c | 4 ++-- include/crypto/public_key.h | 1 + 4 files changed, 6 insertions(+), 5 deletions(-) diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c index facbf26..8cc253d 100644 --- a/crypto/asymmetric_keys/x509_cert_parser.c +++ b/crypto/asymmetric_keys/x509_cert_parser.c @@ -343,8 +343,9 @@ int x509_extract_key_data(void *context, size_t hdrlen, if (ctx->last_oid != OID_rsaEncryption) return -ENOPKG; - /* There seems to be an extraneous 0 byte on the front of the data */ - ctx->cert->pkey_algo = PKEY_ALGO_RSA; + ctx->cert->pub->pkey_algo = PKEY_ALGO_RSA; + + /* Discard the BIT STRING metadata */ ctx->key = value + 1; ctx->key_size = vlen - 1; return 0; diff --git a/crypto/asymmetric_keys/x509_parser.h b/crypto/asymmetric_keys/x509_parser.h index f86dc5f..e583ad0 100644 --- a/crypto/asymmetric_keys/x509_parser.h +++ b/crypto/asymmetric_keys/x509_parser.h @@ -20,7 +20,6 @@ struct x509_certificate { char *authority; /* Authority key fingerprint as hex */ struct tm valid_from; struct tm valid_to; - enum pkey_algo pkey_algo : 8; /* Public key algorithm */ enum pkey_algo sig_pkey_algo : 8; /* Signature public key algorithm */ enum pkey_hash_algo sig_hash_algo : 8; /* Signature hash algorithm */ const void *tbs; /* Signed data */ diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c index fe38628..fac574c 100644 --- a/crypto/asymmetric_keys/x509_public_key.c +++ b/crypto/asymmetric_keys/x509_public_key.c @@ -108,7 +108,7 @@ static int x509_key_preparse(struct key_preparsed_payload *prep) pr_devel("Cert Issuer: %s\n", cert->issuer); pr_devel("Cert Subject: %s\n", cert->subject); - pr_devel("Cert Key Algo: %s\n", pkey_algo_name[cert->pkey_algo]); + pr_devel("Cert Key Algo: %s\n", pkey_algo_name[cert->pub->pkey_algo]); pr_devel("Cert Valid From: %04ld-%02d-%02d %02d:%02d:%02d\n", cert->valid_from.tm_year + 1900, cert->valid_from.tm_mon + 1, cert->valid_from.tm_mday, cert->valid_from.tm_hour, @@ -165,7 +165,7 @@ static int x509_key_preparse(struct key_preparsed_payload *prep) goto error_free_cert; } - cert->pub->algo = pkey_algo[cert->pkey_algo]; + cert->pub->algo = pkey_algo[cert->pub->pkey_algo]; cert->pub->id_type = PKEY_ID_X509; /* Check the signature on the key */ diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h index 46bde25..05778df 100644 --- a/include/crypto/public_key.h +++ b/include/crypto/public_key.h @@ -60,6 +60,7 @@ struct public_key { #define PKEY_CAN_DECRYPT 0x02 #define PKEY_CAN_SIGN 0x04 #define PKEY_CAN_VERIFY 0x08 + enum pkey_algo pkey_algo : 8; enum pkey_id_type id_type : 8; union { MPI mpi[5]; -- 1.8.3.1 From 37688af0338d8c521ffefce187b03a5fbaefa423 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 30 Aug 2013 16:15:30 +0100 Subject: [PATCH 07/13] KEYS: Split public_key_verify_signature() and make available Modify public_key_verify_signature() so that it now takes a public_key struct rather than a key struct and supply a wrapper that takes a key struct. The wrapper is then used by the asymmetric key subtype and the modified function is used by X.509 self-signature checking and can be used by other things also. Signed-off-by: David Howells Reviewed-by: Kees Cook Reviewed-by: Josh Boyer --- crypto/asymmetric_keys/public_key.c | 40 +++++++++++++++++++++++++------- crypto/asymmetric_keys/public_key.h | 6 +++++ crypto/asymmetric_keys/x509_public_key.c | 2 +- 3 files changed, 39 insertions(+), 9 deletions(-) diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c index 796ce08..49ac8d8 100644 --- a/crypto/asymmetric_keys/public_key.c +++ b/crypto/asymmetric_keys/public_key.c @@ -86,21 +86,45 @@ EXPORT_SYMBOL_GPL(public_key_destroy); /* * Verify a signature using a public key. */ -static int public_key_verify_signature(const struct key *key, - const struct public_key_signature *sig) +int public_key_verify_signature(const struct public_key *pk, + const struct public_key_signature *sig) { - const struct public_key *pk = key->payload.data; + const struct public_key_algorithm *algo; + + BUG_ON(!pk); + BUG_ON(!pk->mpi[0]); + BUG_ON(!pk->mpi[1]); + BUG_ON(!sig); + BUG_ON(!sig->digest); + BUG_ON(!sig->mpi[0]); + + algo = pk->algo; + if (!algo) { + if (pk->pkey_algo >= PKEY_ALGO__LAST) + return -ENOPKG; + algo = pkey_algo[pk->pkey_algo]; + if (!algo) + return -ENOPKG; + } - if (!pk->algo->verify_signature) + if (!algo->verify_signature) return -ENOTSUPP; - if (sig->nr_mpi != pk->algo->n_sig_mpi) { + if (sig->nr_mpi != algo->n_sig_mpi) { pr_debug("Signature has %u MPI not %u\n", - sig->nr_mpi, pk->algo->n_sig_mpi); + sig->nr_mpi, algo->n_sig_mpi); return -EINVAL; } - return pk->algo->verify_signature(pk, sig); + return algo->verify_signature(pk, sig); +} +EXPORT_SYMBOL_GPL(public_key_verify_signature); + +static int public_key_verify_signature_2(const struct key *key, + const struct public_key_signature *sig) +{ + const struct public_key *pk = key->payload.data; + return public_key_verify_signature(pk, sig); } /* @@ -111,6 +135,6 @@ struct asymmetric_key_subtype public_key_subtype = { .name = "public_key", .describe = public_key_describe, .destroy = public_key_destroy, - .verify_signature = public_key_verify_signature, + .verify_signature = public_key_verify_signature_2, }; EXPORT_SYMBOL_GPL(public_key_subtype); diff --git a/crypto/asymmetric_keys/public_key.h b/crypto/asymmetric_keys/public_key.h index 5e5e356..5c37a22 100644 --- a/crypto/asymmetric_keys/public_key.h +++ b/crypto/asymmetric_keys/public_key.h @@ -28,3 +28,9 @@ struct public_key_algorithm { }; extern const struct public_key_algorithm RSA_public_key_algorithm; + +/* + * public_key.c + */ +extern int public_key_verify_signature(const struct public_key *pk, + const struct public_key_signature *sig); diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c index fac574c..8cb2f70 100644 --- a/crypto/asymmetric_keys/x509_public_key.c +++ b/crypto/asymmetric_keys/x509_public_key.c @@ -76,7 +76,7 @@ static int x509_check_signature(const struct public_key *pub, if (ret < 0) goto error_mpi; - ret = pub->algo->verify_signature(pub, sig); + ret = public_key_verify_signature(pub, sig); pr_debug("Cert Verification: %d\n", ret); -- 1.8.3.1 From 49763042e968f7342711ecf28e9465f6d77c0ddd Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 30 Aug 2013 16:15:37 +0100 Subject: [PATCH 08/13] KEYS: Store public key algo ID in public_key_signature struct Store public key algorithm ID in public_key_signature struct for reference purposes. This allows a public_key_signature struct to be embedded in struct x509_certificate and other places more easily. Signed-off-by: David Howells Reviewed-by: Kees Cook Reviewed-by: Josh Boyer --- include/crypto/public_key.h | 1 + 1 file changed, 1 insertion(+) diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h index 05778df..b34fda4 100644 --- a/include/crypto/public_key.h +++ b/include/crypto/public_key.h @@ -90,6 +90,7 @@ struct public_key_signature { u8 *digest; u8 digest_size; /* Number of bytes in digest */ u8 nr_mpi; /* Occupancy of mpi[] */ + enum pkey_algo pkey_algo : 8; enum pkey_hash_algo pkey_hash_algo : 8; union { MPI mpi[2]; -- 1.8.3.1 From d759ad5c13364bc7dcd6dd66d1a63f29f3432f72 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 30 Aug 2013 16:16:34 +0100 Subject: [PATCH 09/13] X.509: struct x509_certificate needs struct tm declaring struct x509_certificate needs struct tm declaring by #inclusion of linux/time.h prior to its definition. Signed-off-by: David Howells Reviewed-by: Kees Cook Reviewed-by: Josh Boyer --- crypto/asymmetric_keys/x509_parser.h | 1 + 1 file changed, 1 insertion(+) diff --git a/crypto/asymmetric_keys/x509_parser.h b/crypto/asymmetric_keys/x509_parser.h index e583ad0..2d01182 100644 --- a/crypto/asymmetric_keys/x509_parser.h +++ b/crypto/asymmetric_keys/x509_parser.h @@ -9,6 +9,7 @@ * 2 of the Licence, or (at your option) any later version. */ +#include #include struct x509_certificate { -- 1.8.3.1 From 779ecd05627f895cfd6970dcfbd3ed35092f7510 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 30 Aug 2013 16:18:02 +0100 Subject: [PATCH 10/13] X.509: Embed public_key_signature struct and create filler function Embed a public_key_signature struct in struct x509_certificate, eliminating now unnecessary fields, and split x509_check_signature() to create a filler function for it that attaches a digest of the signed data and an MPI that represents the signature data. x509_free_certificate() is then modified to deal with these. Whilst we're at it, export both x509_check_signature() and the new x509_get_sig_params(). Signed-off-by: David Howells Reviewed-by: Kees Cook Reviewed-by: Josh Boyer --- crypto/asymmetric_keys/x509_cert_parser.c | 30 +++++------ crypto/asymmetric_keys/x509_parser.h | 16 ++++-- crypto/asymmetric_keys/x509_public_key.c | 83 +++++++++++++++++-------------- 3 files changed, 74 insertions(+), 55 deletions(-) diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c index 8cc253d..144201c 100644 --- a/crypto/asymmetric_keys/x509_cert_parser.c +++ b/crypto/asymmetric_keys/x509_cert_parser.c @@ -47,6 +47,8 @@ void x509_free_certificate(struct x509_certificate *cert) kfree(cert->subject); kfree(cert->fingerprint); kfree(cert->authority); + kfree(cert->sig.digest); + mpi_free(cert->sig.rsa.s); kfree(cert); } } @@ -152,33 +154,33 @@ int x509_note_pkey_algo(void *context, size_t hdrlen, return -ENOPKG; /* Unsupported combination */ case OID_md4WithRSAEncryption: - ctx->cert->sig_hash_algo = PKEY_HASH_MD5; - ctx->cert->sig_pkey_algo = PKEY_ALGO_RSA; + ctx->cert->sig.pkey_hash_algo = PKEY_HASH_MD5; + ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA; break; case OID_sha1WithRSAEncryption: - ctx->cert->sig_hash_algo = PKEY_HASH_SHA1; - ctx->cert->sig_pkey_algo = PKEY_ALGO_RSA; + ctx->cert->sig.pkey_hash_algo = PKEY_HASH_SHA1; + ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA; break; case OID_sha256WithRSAEncryption: - ctx->cert->sig_hash_algo = PKEY_HASH_SHA256; - ctx->cert->sig_pkey_algo = PKEY_ALGO_RSA; + ctx->cert->sig.pkey_hash_algo = PKEY_HASH_SHA256; + ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA; break; case OID_sha384WithRSAEncryption: - ctx->cert->sig_hash_algo = PKEY_HASH_SHA384; - ctx->cert->sig_pkey_algo = PKEY_ALGO_RSA; + ctx->cert->sig.pkey_hash_algo = PKEY_HASH_SHA384; + ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA; break; case OID_sha512WithRSAEncryption: - ctx->cert->sig_hash_algo = PKEY_HASH_SHA512; - ctx->cert->sig_pkey_algo = PKEY_ALGO_RSA; + ctx->cert->sig.pkey_hash_algo = PKEY_HASH_SHA512; + ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA; break; case OID_sha224WithRSAEncryption: - ctx->cert->sig_hash_algo = PKEY_HASH_SHA224; - ctx->cert->sig_pkey_algo = PKEY_ALGO_RSA; + ctx->cert->sig.pkey_hash_algo = PKEY_HASH_SHA224; + ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA; break; } @@ -203,8 +205,8 @@ int x509_note_signature(void *context, size_t hdrlen, return -EINVAL; } - ctx->cert->sig = value; - ctx->cert->sig_size = vlen; + ctx->cert->raw_sig = value; + ctx->cert->raw_sig_size = vlen; return 0; } diff --git a/crypto/asymmetric_keys/x509_parser.h b/crypto/asymmetric_keys/x509_parser.h index 2d01182..87d9cc2 100644 --- a/crypto/asymmetric_keys/x509_parser.h +++ b/crypto/asymmetric_keys/x509_parser.h @@ -21,12 +21,11 @@ struct x509_certificate { char *authority; /* Authority key fingerprint as hex */ struct tm valid_from; struct tm valid_to; - enum pkey_algo sig_pkey_algo : 8; /* Signature public key algorithm */ - enum pkey_hash_algo sig_hash_algo : 8; /* Signature hash algorithm */ const void *tbs; /* Signed data */ - size_t tbs_size; /* Size of signed data */ - const void *sig; /* Signature data */ - size_t sig_size; /* Size of sigature */ + unsigned tbs_size; /* Size of signed data */ + unsigned raw_sig_size; /* Size of sigature */ + const void *raw_sig; /* Signature data */ + struct public_key_signature sig; /* Signature parameters */ }; /* @@ -34,3 +33,10 @@ struct x509_certificate { */ extern void x509_free_certificate(struct x509_certificate *cert); extern struct x509_certificate *x509_cert_parse(const void *data, size_t datalen); + +/* + * x509_public_key.c + */ +extern int x509_get_sig_params(struct x509_certificate *cert); +extern int x509_check_signature(const struct public_key *pub, + struct x509_certificate *cert); diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c index 8cb2f70..b7c81d8 100644 --- a/crypto/asymmetric_keys/x509_public_key.c +++ b/crypto/asymmetric_keys/x509_public_key.c @@ -24,72 +24,83 @@ #include "x509_parser.h" /* - * Check the signature on a certificate using the provided public key + * Set up the signature parameters in an X.509 certificate. This involves + * digesting the signed data and extracting the signature. */ -static int x509_check_signature(const struct public_key *pub, - const struct x509_certificate *cert) +int x509_get_sig_params(struct x509_certificate *cert) { - struct public_key_signature *sig; struct crypto_shash *tfm; struct shash_desc *desc; size_t digest_size, desc_size; + void *digest; int ret; pr_devel("==>%s()\n", __func__); - + + if (cert->sig.rsa.s) + return 0; + + cert->sig.rsa.s = mpi_read_raw_data(cert->raw_sig, cert->raw_sig_size); + if (!cert->sig.rsa.s) + return -ENOMEM; + cert->sig.nr_mpi = 1; + /* Allocate the hashing algorithm we're going to need and find out how * big the hash operational data will be. */ - tfm = crypto_alloc_shash(pkey_hash_algo_name[cert->sig_hash_algo], 0, 0); + tfm = crypto_alloc_shash(pkey_hash_algo_name[cert->sig.pkey_hash_algo], 0, 0); if (IS_ERR(tfm)) return (PTR_ERR(tfm) == -ENOENT) ? -ENOPKG : PTR_ERR(tfm); desc_size = crypto_shash_descsize(tfm) + sizeof(*desc); digest_size = crypto_shash_digestsize(tfm); - /* We allocate the hash operational data storage on the end of our - * context data. + /* We allocate the hash operational data storage on the end of the + * digest storage space. */ ret = -ENOMEM; - sig = kzalloc(sizeof(*sig) + desc_size + digest_size, GFP_KERNEL); - if (!sig) - goto error_no_sig; + digest = kzalloc(digest_size + desc_size, GFP_KERNEL); + if (!digest) + goto error; - sig->pkey_hash_algo = cert->sig_hash_algo; - sig->digest = (u8 *)sig + sizeof(*sig) + desc_size; - sig->digest_size = digest_size; + cert->sig.digest = digest; + cert->sig.digest_size = digest_size; - desc = (void *)sig + sizeof(*sig); - desc->tfm = tfm; - desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP; + desc = digest + digest_size; + desc->tfm = tfm; + desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP; ret = crypto_shash_init(desc); if (ret < 0) goto error; + might_sleep(); + ret = crypto_shash_finup(desc, cert->tbs, cert->tbs_size, digest); +error: + crypto_free_shash(tfm); + pr_devel("<==%s() = %d\n", __func__, ret); + return ret; +} +EXPORT_SYMBOL_GPL(x509_get_sig_params); - ret = -ENOMEM; - sig->rsa.s = mpi_read_raw_data(cert->sig, cert->sig_size); - if (!sig->rsa.s) - goto error; +/* + * Check the signature on a certificate using the provided public key + */ +int x509_check_signature(const struct public_key *pub, + struct x509_certificate *cert) +{ + int ret; - ret = crypto_shash_finup(desc, cert->tbs, cert->tbs_size, sig->digest); - if (ret < 0) - goto error_mpi; + pr_devel("==>%s()\n", __func__); - ret = public_key_verify_signature(pub, sig); + ret = x509_get_sig_params(cert); + if (ret < 0) + return ret; + ret = public_key_verify_signature(pub, &cert->sig); pr_debug("Cert Verification: %d\n", ret); - -error_mpi: - mpi_free(sig->rsa.s); -error: - kfree(sig); -error_no_sig: - crypto_free_shash(tfm); - - pr_devel("<==%s() = %d\n", __func__, ret); return ret; } +EXPORT_SYMBOL_GPL(x509_check_signature); /* * Attempt to parse a data blob for a key as an X509 certificate. @@ -118,8 +129,8 @@ static int x509_key_preparse(struct key_preparsed_payload *prep) cert->valid_to.tm_mday, cert->valid_to.tm_hour, cert->valid_to.tm_min, cert->valid_to.tm_sec); pr_devel("Cert Signature: %s + %s\n", - pkey_algo_name[cert->sig_pkey_algo], - pkey_hash_algo_name[cert->sig_hash_algo]); + pkey_algo_name[cert->sig.pkey_algo], + pkey_hash_algo_name[cert->sig.pkey_hash_algo]); if (!cert->fingerprint || !cert->authority) { pr_warn("Cert for '%s' must have SubjKeyId and AuthKeyId extensions\n", -- 1.8.3.1 From 81dc804bab8ac3703f237e74464054fae71c429e Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 30 Aug 2013 16:18:15 +0100 Subject: [PATCH 11/13] X.509: Check the algorithm IDs obtained from parsing an X.509 certificate Check that the algorithm IDs obtained from the ASN.1 parse by OID lookup corresponds to algorithms that are available to us. Reported-by: Kees Cook Signed-off-by: David Howells --- crypto/asymmetric_keys/x509_public_key.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c index b7c81d8..eb368d4 100644 --- a/crypto/asymmetric_keys/x509_public_key.c +++ b/crypto/asymmetric_keys/x509_public_key.c @@ -119,6 +119,17 @@ static int x509_key_preparse(struct key_preparsed_payload *prep) pr_devel("Cert Issuer: %s\n", cert->issuer); pr_devel("Cert Subject: %s\n", cert->subject); + + if (cert->pub->pkey_algo >= PKEY_ALGO__LAST || + cert->sig.pkey_algo >= PKEY_ALGO__LAST || + cert->sig.pkey_hash_algo >= PKEY_HASH__LAST || + !pkey_algo[cert->pub->pkey_algo] || + !pkey_algo[cert->sig.pkey_algo] || + !pkey_hash_algo_name[cert->sig.pkey_hash_algo]) { + ret = -ENOPKG; + goto error_free_cert; + } + pr_devel("Cert Key Algo: %s\n", pkey_algo_name[cert->pub->pkey_algo]); pr_devel("Cert Valid From: %04ld-%02d-%02d %02d:%02d:%02d\n", cert->valid_from.tm_year + 1900, cert->valid_from.tm_mon + 1, -- 1.8.3.1 From 9d3c831f1409174fcda6a21ede05f3a3155b1671 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 30 Aug 2013 16:18:31 +0100 Subject: [PATCH 12/13] X.509: Handle certificates that lack an authorityKeyIdentifier field Handle certificates that lack an authorityKeyIdentifier field by assuming they're self-signed and checking their signatures against themselves. Signed-off-by: David Howells Reviewed-by: Kees Cook Reviewed-by: Josh Boyer --- crypto/asymmetric_keys/x509_public_key.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c index eb368d4..0f55e3b 100644 --- a/crypto/asymmetric_keys/x509_public_key.c +++ b/crypto/asymmetric_keys/x509_public_key.c @@ -143,8 +143,8 @@ static int x509_key_preparse(struct key_preparsed_payload *prep) pkey_algo_name[cert->sig.pkey_algo], pkey_hash_algo_name[cert->sig.pkey_hash_algo]); - if (!cert->fingerprint || !cert->authority) { - pr_warn("Cert for '%s' must have SubjKeyId and AuthKeyId extensions\n", + if (!cert->fingerprint) { + pr_warn("Cert for '%s' must have a SubjKeyId extension\n", cert->subject); ret = -EKEYREJECTED; goto error_free_cert; @@ -190,8 +190,9 @@ static int x509_key_preparse(struct key_preparsed_payload *prep) cert->pub->algo = pkey_algo[cert->pub->pkey_algo]; cert->pub->id_type = PKEY_ID_X509; - /* Check the signature on the key */ - if (strcmp(cert->fingerprint, cert->authority) == 0) { + /* Check the signature on the key if it appears to be self-signed */ + if (!cert->authority || + strcmp(cert->fingerprint, cert->authority) == 0) { ret = x509_check_signature(cert->pub, cert); if (ret < 0) goto error_free_cert; -- 1.8.3.1 From 1a62a422d6b6e084ba88062d1d1f33e6a92dc35c Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 18 Jun 2013 17:40:44 +0100 Subject: [PATCH 13/13] X.509: Remove certificate date checks Remove the certificate date checks that are performed when a certificate is parsed. There are two checks: a valid from and a valid to. The first check is causing a lot of problems with system clocks that don't keep good time and the second places an implicit expiry date upon the kernel when used for module signing, so do we really need them? Signed-off-by: David Howells cc: David Woodhouse cc: Rusty Russell cc: Josh Boyer cc: Alexander Holler cc: stable@vger.kernel.org --- crypto/asymmetric_keys/x509_public_key.c | 38 -------------------------------- 1 file changed, 38 deletions(-) diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c index 0f55e3b..c1540e8 100644 --- a/crypto/asymmetric_keys/x509_public_key.c +++ b/crypto/asymmetric_keys/x509_public_key.c @@ -108,7 +108,6 @@ EXPORT_SYMBOL_GPL(x509_check_signature); static int x509_key_preparse(struct key_preparsed_payload *prep) { struct x509_certificate *cert; - struct tm now; size_t srlen, sulen; char *desc = NULL; int ret; @@ -150,43 +149,6 @@ static int x509_key_preparse(struct key_preparsed_payload *prep) goto error_free_cert; } - time_to_tm(CURRENT_TIME.tv_sec, 0, &now); - pr_devel("Now: %04ld-%02d-%02d %02d:%02d:%02d\n", - now.tm_year + 1900, now.tm_mon + 1, now.tm_mday, - now.tm_hour, now.tm_min, now.tm_sec); - if (now.tm_year < cert->valid_from.tm_year || - (now.tm_year == cert->valid_from.tm_year && - (now.tm_mon < cert->valid_from.tm_mon || - (now.tm_mon == cert->valid_from.tm_mon && - (now.tm_mday < cert->valid_from.tm_mday || - (now.tm_mday == cert->valid_from.tm_mday && - (now.tm_hour < cert->valid_from.tm_hour || - (now.tm_hour == cert->valid_from.tm_hour && - (now.tm_min < cert->valid_from.tm_min || - (now.tm_min == cert->valid_from.tm_min && - (now.tm_sec < cert->valid_from.tm_sec - ))))))))))) { - pr_warn("Cert %s is not yet valid\n", cert->fingerprint); - ret = -EKEYREJECTED; - goto error_free_cert; - } - if (now.tm_year > cert->valid_to.tm_year || - (now.tm_year == cert->valid_to.tm_year && - (now.tm_mon > cert->valid_to.tm_mon || - (now.tm_mon == cert->valid_to.tm_mon && - (now.tm_mday > cert->valid_to.tm_mday || - (now.tm_mday == cert->valid_to.tm_mday && - (now.tm_hour > cert->valid_to.tm_hour || - (now.tm_hour == cert->valid_to.tm_hour && - (now.tm_min > cert->valid_to.tm_min || - (now.tm_min == cert->valid_to.tm_min && - (now.tm_sec > cert->valid_to.tm_sec - ))))))))))) { - pr_warn("Cert %s has expired\n", cert->fingerprint); - ret = -EKEYEXPIRED; - goto error_free_cert; - } - cert->pub->algo = pkey_algo[cert->pub->pkey_algo]; cert->pub->id_type = PKEY_ID_X509; -- 1.8.3.1