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-rw-r--r--include/linux/key.h309
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diff --git a/include/linux/key.h b/include/linux/key.h
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+/* Authentication token and access key management
+ *
+ * Copyright (C) 2004, 2007 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.
+ *
+ *
+ * See Documentation/keys.txt for information on keys/keyrings.
+ */
+
+#ifndef _LINUX_KEY_H
+#define _LINUX_KEY_H
+
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/rbtree.h>
+#include <linux/rcupdate.h>
+#include <linux/sysctl.h>
+#include <linux/rwsem.h>
+#include <asm/atomic.h>
+
+#ifdef __KERNEL__
+
+/* key handle serial number */
+typedef int32_t key_serial_t;
+
+/* key handle permissions mask */
+typedef uint32_t key_perm_t;
+
+struct key;
+
+#ifdef CONFIG_KEYS
+
+#undef KEY_DEBUGGING
+
+#define KEY_POS_VIEW 0x01000000 /* possessor can view a key's attributes */
+#define KEY_POS_READ 0x02000000 /* possessor can read key payload / view keyring */
+#define KEY_POS_WRITE 0x04000000 /* possessor can update key payload / add link to keyring */
+#define KEY_POS_SEARCH 0x08000000 /* possessor can find a key in search / search a keyring */
+#define KEY_POS_LINK 0x10000000 /* possessor can create a link to a key/keyring */
+#define KEY_POS_SETATTR 0x20000000 /* possessor can set key attributes */
+#define KEY_POS_ALL 0x3f000000
+
+#define KEY_USR_VIEW 0x00010000 /* user permissions... */
+#define KEY_USR_READ 0x00020000
+#define KEY_USR_WRITE 0x00040000
+#define KEY_USR_SEARCH 0x00080000
+#define KEY_USR_LINK 0x00100000
+#define KEY_USR_SETATTR 0x00200000
+#define KEY_USR_ALL 0x003f0000
+
+#define KEY_GRP_VIEW 0x00000100 /* group permissions... */
+#define KEY_GRP_READ 0x00000200
+#define KEY_GRP_WRITE 0x00000400
+#define KEY_GRP_SEARCH 0x00000800
+#define KEY_GRP_LINK 0x00001000
+#define KEY_GRP_SETATTR 0x00002000
+#define KEY_GRP_ALL 0x00003f00
+
+#define KEY_OTH_VIEW 0x00000001 /* third party permissions... */
+#define KEY_OTH_READ 0x00000002
+#define KEY_OTH_WRITE 0x00000004
+#define KEY_OTH_SEARCH 0x00000008
+#define KEY_OTH_LINK 0x00000010
+#define KEY_OTH_SETATTR 0x00000020
+#define KEY_OTH_ALL 0x0000003f
+
+#define KEY_PERM_UNDEF 0xffffffff
+
+struct seq_file;
+struct user_struct;
+struct signal_struct;
+struct cred;
+
+struct key_type;
+struct key_owner;
+struct keyring_list;
+struct keyring_name;
+
+/*****************************************************************************/
+/*
+ * key reference with possession attribute handling
+ *
+ * NOTE! key_ref_t is a typedef'd pointer to a type that is not actually
+ * defined. This is because we abuse the bottom bit of the reference to carry a
+ * flag to indicate whether the calling process possesses that key in one of
+ * its keyrings.
+ *
+ * the key_ref_t has been made a separate type so that the compiler can reject
+ * attempts to dereference it without proper conversion.
+ *
+ * the three functions are used to assemble and disassemble references
+ */
+typedef struct __key_reference_with_attributes *key_ref_t;
+
+static inline key_ref_t make_key_ref(const struct key *key,
+ unsigned long possession)
+{
+ return (key_ref_t) ((unsigned long) key | possession);
+}
+
+static inline struct key *key_ref_to_ptr(const key_ref_t key_ref)
+{
+ return (struct key *) ((unsigned long) key_ref & ~1UL);
+}
+
+static inline unsigned long is_key_possessed(const key_ref_t key_ref)
+{
+ return (unsigned long) key_ref & 1UL;
+}
+
+/*****************************************************************************/
+/*
+ * authentication token / access credential / keyring
+ * - types of key include:
+ * - keyrings
+ * - disk encryption IDs
+ * - Kerberos TGTs and tickets
+ */
+struct key {
+ atomic_t usage; /* number of references */
+ key_serial_t serial; /* key serial number */
+ struct rb_node serial_node;
+ struct key_type *type; /* type of key */
+ struct rw_semaphore sem; /* change vs change sem */
+ struct key_user *user; /* owner of this key */
+ void *security; /* security data for this key */
+ union {
+ time_t expiry; /* time at which key expires (or 0) */
+ time_t revoked_at; /* time at which key was revoked */
+ };
+ uid_t uid;
+ gid_t gid;
+ key_perm_t perm; /* access permissions */
+ unsigned short quotalen; /* length added to quota */
+ unsigned short datalen; /* payload data length
+ * - may not match RCU dereferenced payload
+ * - payload should contain own length
+ */
+
+#ifdef KEY_DEBUGGING
+ unsigned magic;
+#define KEY_DEBUG_MAGIC 0x18273645u
+#define KEY_DEBUG_MAGIC_X 0xf8e9dacbu
+#endif
+
+ unsigned long flags; /* status flags (change with bitops) */
+#define KEY_FLAG_INSTANTIATED 0 /* set if key has been instantiated */
+#define KEY_FLAG_DEAD 1 /* set if key type has been deleted */
+#define KEY_FLAG_REVOKED 2 /* set if key had been revoked */
+#define KEY_FLAG_IN_QUOTA 3 /* set if key consumes quota */
+#define KEY_FLAG_USER_CONSTRUCT 4 /* set if key is being constructed in userspace */
+#define KEY_FLAG_NEGATIVE 5 /* set if key is negative */
+
+ /* the description string
+ * - this is used to match a key against search criteria
+ * - this should be a printable string
+ * - eg: for krb5 AFS, this might be "afs@REDHAT.COM"
+ */
+ char *description;
+
+ /* type specific data
+ * - this is used by the keyring type to index the name
+ */
+ union {
+ struct list_head link;
+ unsigned long x[2];
+ void *p[2];
+ } type_data;
+
+ /* key data
+ * - this is used to hold the data actually used in cryptography or
+ * whatever
+ */
+ union {
+ unsigned long value;
+ void *data;
+ struct keyring_list *subscriptions;
+ } payload;
+};
+
+extern struct key *key_alloc(struct key_type *type,
+ const char *desc,
+ uid_t uid, gid_t gid,
+ const struct cred *cred,
+ key_perm_t perm,
+ unsigned long flags);
+
+
+#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 */
+
+extern void key_revoke(struct key *key);
+extern void key_put(struct key *key);
+
+static inline struct key *key_get(struct key *key)
+{
+ if (key)
+ atomic_inc(&key->usage);
+ return key;
+}
+
+static inline void key_ref_put(key_ref_t key_ref)
+{
+ key_put(key_ref_to_ptr(key_ref));
+}
+
+extern struct key *request_key(struct key_type *type,
+ const char *description,
+ const char *callout_info);
+
+extern struct key *request_key_with_auxdata(struct key_type *type,
+ const char *description,
+ const void *callout_info,
+ size_t callout_len,
+ void *aux);
+
+extern struct key *request_key_async(struct key_type *type,
+ const char *description,
+ const void *callout_info,
+ size_t callout_len);
+
+extern struct key *request_key_async_with_auxdata(struct key_type *type,
+ const char *description,
+ const void *callout_info,
+ size_t callout_len,
+ void *aux);
+
+extern int wait_for_key_construction(struct key *key, bool intr);
+
+extern int key_validate(struct key *key);
+
+extern key_ref_t key_create_or_update(key_ref_t keyring,
+ const char *type,
+ const char *description,
+ const void *payload,
+ size_t plen,
+ key_perm_t perm,
+ unsigned long flags);
+
+extern int key_update(key_ref_t key,
+ const void *payload,
+ size_t plen);
+
+extern int key_link(struct key *keyring,
+ struct key *key);
+
+extern int key_unlink(struct key *keyring,
+ struct key *key);
+
+extern struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid,
+ const struct cred *cred,
+ unsigned long flags,
+ struct key *dest);
+
+extern int keyring_clear(struct key *keyring);
+
+extern key_ref_t keyring_search(key_ref_t keyring,
+ struct key_type *type,
+ const char *description);
+
+extern int keyring_add_key(struct key *keyring,
+ struct key *key);
+
+extern struct key *key_lookup(key_serial_t id);
+
+static inline key_serial_t key_serial(struct key *key)
+{
+ return key ? key->serial : 0;
+}
+
+#ifdef CONFIG_SYSCTL
+extern ctl_table key_sysctls[];
+#endif
+
+extern void key_replace_session_keyring(void);
+
+/*
+ * the userspace interface
+ */
+extern int install_thread_keyring_to_cred(struct cred *cred);
+extern void key_fsuid_changed(struct task_struct *tsk);
+extern void key_fsgid_changed(struct task_struct *tsk);
+extern void key_init(void);
+
+#else /* CONFIG_KEYS */
+
+#define key_validate(k) 0
+#define key_serial(k) 0
+#define key_get(k) ({ NULL; })
+#define key_revoke(k) do { } while(0)
+#define key_put(k) do { } while(0)
+#define key_ref_put(k) do { } while(0)
+#define make_key_ref(k, p) NULL
+#define key_ref_to_ptr(k) NULL
+#define is_key_possessed(k) 0
+#define key_fsuid_changed(t) do { } while(0)
+#define key_fsgid_changed(t) do { } while(0)
+#define key_init() do { } while(0)
+#define key_replace_session_keyring() do { } while(0)
+
+#endif /* CONFIG_KEYS */
+#endif /* __KERNEL__ */
+#endif /* _LINUX_KEY_H */
generated by cgit (git 2.34.1) at 2024-11-15 11:22:30 +0000