From d4f65b5d2497b2fd9c45f06b71deb4ab084a5b66 Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 13 Sep 2012 13:06:29 +0100 Subject: KEYS: Add payload preparsing opportunity prior to key instantiate or update Give the key type the opportunity to preparse the payload prior to the instantiation and update routines being called. This is done with the provision of two new key type operations: int (*preparse)(struct key_preparsed_payload *prep); void (*free_preparse)(struct key_preparsed_payload *prep); If the first operation is present, then it is called before key creation (in the add/update case) or before the key semaphore is taken (in the update and instantiate cases). The second operation is called to clean up if the first was called. preparse() is given the opportunity to fill in the following structure: struct key_preparsed_payload { char *description; void *type_data[2]; void *payload; const void *data; size_t datalen; size_t quotalen; }; Before the preparser is called, the first three fields will have been cleared, the payload pointer and size will be stored in data and datalen and the default quota size from the key_type struct will be stored into quotalen. The preparser may parse the payload in any way it likes and may store data in the type_data[] and payload fields for use by the instantiate() and update() ops. The preparser may also propose a description for the key by attaching it as a string to the description field. This can be used by passing a NULL or "" description to the add_key() system call or the key_create_or_update() function. This cannot work with request_key() as that required the description to tell the upcall about the key to be created. This, for example permits keys that store PGP public keys to generate their own name from the user ID and public key fingerprint in the key. The instantiate() and update() operations are then modified to look like this: int (*instantiate)(struct key *key, struct key_preparsed_payload *prep); int (*update)(struct key *key, struct key_preparsed_payload *prep); and the new payload data is passed in *prep, whether or not it was preparsed. Signed-off-by: David Howells --- fs/cifs/cifsacl.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'fs/cifs/cifsacl.c') diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c index 05f4dc263a23..f3c60e264ca8 100644 --- a/fs/cifs/cifsacl.c +++ b/fs/cifs/cifsacl.c @@ -167,17 +167,17 @@ static struct shrinker cifs_shrinker = { }; static int -cifs_idmap_key_instantiate(struct key *key, const void *data, size_t datalen) +cifs_idmap_key_instantiate(struct key *key, struct key_preparsed_payload *prep) { char *payload; - payload = kmalloc(datalen, GFP_KERNEL); + payload = kmalloc(prep->datalen, GFP_KERNEL); if (!payload) return -ENOMEM; - memcpy(payload, data, datalen); + memcpy(payload, prep->data, prep->datalen); key->payload.data = payload; - key->datalen = datalen; + key->datalen = prep->datalen; return 0; } -- cgit v1.2.3 From f8aa23a55f813c9bddec2a6176e0e67274e6e7c1 Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 2 Oct 2012 19:24:56 +0100 Subject: KEYS: Use keyring_alloc() to create special keyrings Use keyring_alloc() to create special keyrings now that it has a permissions parameter rather than using key_alloc() + key_instantiate_and_link(). Also document and export keyring_alloc() so that modules can use it too. Signed-off-by: David Howells --- Documentation/security/keys.txt | 17 +++++++++++++++++ fs/cifs/cifsacl.c | 12 ++++-------- fs/nfs/idmap.c | 12 ++++-------- net/dns_resolver/dns_key.c | 13 +++++-------- security/keys/keyring.c | 1 + 5 files changed, 31 insertions(+), 24 deletions(-) (limited to 'fs/cifs/cifsacl.c') diff --git a/Documentation/security/keys.txt b/Documentation/security/keys.txt index aa0dbd74b71b..a4f9125c0333 100644 --- a/Documentation/security/keys.txt +++ b/Documentation/security/keys.txt @@ -990,6 +990,23 @@ payload contents" for more information. reference pointer if successful. +(*) A keyring can be created by: + + struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid, + const struct cred *cred, + key_perm_t perm, + unsigned long flags, + struct key *dest); + + This creates a keyring with the given attributes and returns it. If dest + is not NULL, the new keyring will be linked into the keyring to which it + points. No permission checks are made upon the destination keyring. + + Error EDQUOT can be returned if the keyring would overload the quota (pass + KEY_ALLOC_NOT_IN_QUOTA in flags if the keyring shouldn't be accounted + towards the user's quota). Error ENOMEM can also be returned. + + (*) To check the validity of a key, this function can be called: int validate_key(struct key *key); diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c index 05f4dc263a23..a8a753c8fcd5 100644 --- a/fs/cifs/cifsacl.c +++ b/fs/cifs/cifsacl.c @@ -537,19 +537,15 @@ init_cifs_idmap(void) if (!cred) return -ENOMEM; - keyring = key_alloc(&key_type_keyring, ".cifs_idmap", 0, 0, cred, - (KEY_POS_ALL & ~KEY_POS_SETATTR) | - KEY_USR_VIEW | KEY_USR_READ, - KEY_ALLOC_NOT_IN_QUOTA); + keyring = keyring_alloc(".cifs_idmap", 0, 0, cred, + (KEY_POS_ALL & ~KEY_POS_SETATTR) | + KEY_USR_VIEW | KEY_USR_READ, + KEY_ALLOC_NOT_IN_QUOTA, NULL); if (IS_ERR(keyring)) { ret = PTR_ERR(keyring); goto failed_put_cred; } - ret = key_instantiate_and_link(keyring, NULL, 0, NULL, NULL); - if (ret < 0) - goto failed_put_key; - ret = register_key_type(&cifs_idmap_key_type); if (ret < 0) goto failed_put_key; diff --git a/fs/nfs/idmap.c b/fs/nfs/idmap.c index a850079467d8..957134b4c0fd 100644 --- a/fs/nfs/idmap.c +++ b/fs/nfs/idmap.c @@ -192,19 +192,15 @@ static int nfs_idmap_init_keyring(void) if (!cred) return -ENOMEM; - keyring = key_alloc(&key_type_keyring, ".id_resolver", 0, 0, cred, - (KEY_POS_ALL & ~KEY_POS_SETATTR) | - KEY_USR_VIEW | KEY_USR_READ, - KEY_ALLOC_NOT_IN_QUOTA); + keyring = keyring_alloc(".id_resolver", 0, 0, cred, + (KEY_POS_ALL & ~KEY_POS_SETATTR) | + KEY_USR_VIEW | KEY_USR_READ, + KEY_ALLOC_NOT_IN_QUOTA, NULL); if (IS_ERR(keyring)) { ret = PTR_ERR(keyring); goto failed_put_cred; } - ret = key_instantiate_and_link(keyring, NULL, 0, NULL, NULL); - if (ret < 0) - goto failed_put_key; - ret = register_key_type(&key_type_id_resolver); if (ret < 0) goto failed_put_key; diff --git a/net/dns_resolver/dns_key.c b/net/dns_resolver/dns_key.c index d9507dd05818..f2c379d835e3 100644 --- a/net/dns_resolver/dns_key.c +++ b/net/dns_resolver/dns_key.c @@ -259,19 +259,15 @@ static int __init init_dns_resolver(void) if (!cred) return -ENOMEM; - keyring = key_alloc(&key_type_keyring, ".dns_resolver", 0, 0, cred, - (KEY_POS_ALL & ~KEY_POS_SETATTR) | - KEY_USR_VIEW | KEY_USR_READ, - KEY_ALLOC_NOT_IN_QUOTA); + keyring = keyring_alloc(".dns_resolver", 0, 0, cred, + (KEY_POS_ALL & ~KEY_POS_SETATTR) | + KEY_USR_VIEW | KEY_USR_READ, + KEY_ALLOC_NOT_IN_QUOTA, NULL); if (IS_ERR(keyring)) { ret = PTR_ERR(keyring); goto failed_put_cred; } - ret = key_instantiate_and_link(keyring, NULL, 0, NULL, NULL); - if (ret < 0) - goto failed_put_key; - ret = register_key_type(&key_type_dns_resolver); if (ret < 0) goto failed_put_key; @@ -303,3 +299,4 @@ static void __exit exit_dns_resolver(void) module_init(init_dns_resolver) module_exit(exit_dns_resolver) MODULE_LICENSE("GPL"); + diff --git a/security/keys/keyring.c b/security/keys/keyring.c index cf704a92083f..8c25558da14e 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -275,6 +275,7 @@ struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid, return keyring; } +EXPORT_SYMBOL(keyring_alloc); /** * keyring_search_aux - Search a keyring tree for a key matching some criteria -- cgit v1.2.3