linux/security/keys/request_key.c, branch v4.9

KEYS: Strip trailing spaces

2016-06-14T09:29:44Z

Strip some trailing spaces. Signed-off-by: David Howells

KEYS: Add a facility to restrict new links into a keyring

2016-04-11T21:37:37Z

Add a facility whereby proposed new links to be added to a keyring can be vetted, permitting them to be rejected if necessary. This can be used to block public keys from which the signature cannot be verified or for which the signature verification fails. It could also be used to provide blacklisting. This affects operations like add_key(), KEYCTL_LINK and KEYCTL_INSTANTIATE. To this end: (1) A function pointer is added to the key struct that, if set, points to the vetting function. This is called as: int (*restrict_link)(struct key *keyring, const struct key_type *key_type, unsigned long key_flags, const union key_payload *key_payload), where 'keyring' will be the keyring being added to, key_type and key_payload will describe the key being added and key_flags[*] can be AND'ed with KEY_FLAG_TRUSTED. [*] This parameter will be removed in a later patch when KEY_FLAG_TRUSTED is removed. The function should return 0 to allow the link to take place or an error (typically -ENOKEY, -ENOPKG or -EKEYREJECTED) to reject the link. The pointer should not be set directly, but rather should be set through keyring_alloc(). Note that if called during add_key(), preparse is called before this method, but a key isn't actually allocated until after this function is called. (2) KEY_ALLOC_BYPASS_RESTRICTION is added. This can be passed to key_create_or_update() or key_instantiate_and_link() to bypass the restriction check. (3) KEY_FLAG_TRUSTED_ONLY is removed. The entire contents of a keyring with this restriction emplaced can be considered 'trustworthy' by virtue of being in the keyring when that keyring is consulted. (4) key_alloc() and keyring_alloc() take an extra argument that will be used to set restrict_link in the new key. This ensures that the pointer is set before the key is published, thus preventing a window of unrestrictedness. Normally this argument will be NULL. (5) As a temporary affair, keyring_restrict_trusted_only() is added. It should be passed to keyring_alloc() as the extra argument instead of setting KEY_FLAG_TRUSTED_ONLY on a keyring. This will be replaced in a later patch with functions that look in the appropriate places for authoritative keys. Signed-off-by: David Howells Reviewed-by: Mimi Zohar

Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

2015-11-05T23:32:38Z

Pull security subsystem update from James Morris: "This is mostly maintenance updates across the subsystem, with a notable update for TPM 2.0, and addition of Jarkko Sakkinen as a maintainer of that" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (40 commits) apparmor: clarify CRYPTO dependency selinux: Use a kmem_cache for allocation struct file_security_struct selinux: ioctl_has_perm should be static selinux: use sprintf return value selinux: use kstrdup() in security_get_bools() selinux: use kmemdup in security_sid_to_context_core() selinux: remove pointless cast in selinux_inode_setsecurity() selinux: introduce security_context_str_to_sid selinux: do not check open perm on ftruncate call selinux: change CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE default KEYS: Merge the type-specific data with the payload data KEYS: Provide a script to extract a module signature KEYS: Provide a script to extract the sys cert list from a vmlinux file keys: Be more consistent in selection of union members used certs: add .gitignore to stop git nagging about x509_certificate_list KEYS: use kvfree() in add_key Smack: limited capability for changing process label TPM: remove unnecessary little endian conversion vTPM: support little endian guests char: Drop owner assignment from i2c_driver ...

KEYS: Merge the type-specific data with the payload data

2015-10-21T14:18:36Z

Merge the type-specific data with the payload data into one four-word chunk as it seems pointless to keep them separate. Use user_key_payload() for accessing the payloads of overloaded user-defined keys. Signed-off-by: David Howells cc: linux-cifs@vger.kernel.org cc: ecryptfs@vger.kernel.org cc: linux-ext4@vger.kernel.org cc: linux-f2fs-devel@lists.sourceforge.net cc: linux-nfs@vger.kernel.org cc: ceph-devel@vger.kernel.org cc: linux-ima-devel@lists.sourceforge.net

KEYS: Don't permit request_key() to construct a new keyring

2015-10-19T10:24:51Z

If request_key() is used to find a keyring, only do the search part - don't do the construction part if the keyring was not found by the search. We don't really want keyrings in the negative instantiated state since the rejected/negative instantiation error value in the payload is unioned with keyring metadata. Now the kernel gives an error: request_key("keyring", "#selinux,bdekeyring", "keyring", KEY_SPEC_USER_SESSION_KEYRING) = -1 EPERM (Operation not permitted) Signed-off-by: David Howells

Don't leak a key reference if request_key() tries to use a revoked keyring

2015-02-16T02:45:16Z

If a request_key() call to allocate and fill out a key attempts to insert the key structure into a revoked keyring, the key will leak, using memory and part of the user's key quota until the system reboots. This is from a failure of construct_alloc_key() to decrement the key's reference count after the attempt to insert into the requested keyring is rejected. key_put() needs to be called in the link_prealloc_failed callpath to ensure the unused key is released. Signed-off-by: David Jeffery Signed-off-by: David Howells Signed-off-by: James Morris

KEYS: request_key() should reget expired keys rather than give EKEYEXPIRED

2014-12-01T22:52:53Z

Since the keyring facility can be viewed as a cache (at least in some applications), the local expiration time on the key should probably be viewed as a 'needs updating after this time' property rather than an absolute 'anyone now wanting to use this object is out of luck' property. Since request_key() is the main interface for the usage of keys, this should update or replace an expired key rather than issuing EKEYEXPIRED if the local expiration has been reached (ie. it should refresh the cache). For absolute conditions where refreshing the cache probably doesn't help, the key can be negatively instantiated using KEYCTL_REJECT_KEY with EKEYEXPIRED given as the error to issue. This will still cause request_key() to return EKEYEXPIRED as that was explicitly set. In the future, if the key type has an update op available, we might want to upcall with the expired key and allow the upcall to update it. We would pass a different operation name (the first column in /etc/request-key.conf) to the request-key program. request_key() returning EKEYEXPIRED is causing an NFS problem which Chuck Lever describes thusly: After about 10 minutes, my NFSv4 functional tests fail because the ownership of the test files goes to "-2". Looking at /proc/keys shows that the id_resolv keys that map to my test user ID have expired. The ownership problem persists until the expired keys are purged from the keyring, and fresh keys are obtained. I bisected the problem to 3.13 commit b2a4df200d57 ("KEYS: Expand the capacity of a keyring"). This commit inadvertantly changes the API contract of the internal function keyring_search_aux(). The root cause appears to be that b2a4df200d57 made "no state check" the default behavior. "No state check" means the keyring search iterator function skips checking the key's expiry timeout, and returns expired keys. request_key_and_link() depends on getting an -EAGAIN result code to know when to perform an upcall to refresh an expired key. This patch can be tested directly by: keyctl request2 user debug:fred a @s keyctl timeout %user:debug:fred 3 sleep 4 keyctl request2 user debug:fred a @s Without the patch, the last command gives error EKEYEXPIRED, but with the command it gives a new key. Reported-by: Carl Hetherington Reported-by: Chuck Lever Signed-off-by: David Howells Tested-by: Chuck Lever

KEYS: Simplify KEYRING_SEARCH_{NO,DO}_STATE_CHECK flags

2014-12-01T22:52:50Z

Simplify KEYRING_SEARCH_{NO,DO}_STATE_CHECK flags to be two variations of the same flag. They are effectively mutually exclusive and one or the other should be provided, but not both. Keyring cycle detection and key possession determination are the only things that set NO_STATE_CHECK, except that neither flag really does anything there because neither purpose makes use of the keyring_search_iterator() function, but rather provides their own. For cycle detection we definitely want to check inside of expired keyrings, just so that we don't create a cycle we can't get rid of. Revoked keyrings are cleared at revocation time and can't then be reused, so shouldn't be a problem either way. For possession determination, we *might* want to validate each keyring before searching it: do you possess a key that's hidden behind an expired or just plain inaccessible keyring? Currently, the answer is yes. Note that you cannot, however, possess a key behind a revoked keyring because they are cleared on revocation. keyring_search() sets DO_STATE_CHECK, which is correct. request_key_and_link() currently doesn't specify whether to check the key state or not - but it should set DO_STATE_CHECK. key_get_instantiation_authkey() also currently doesn't specify whether to check the key state or not - but it probably should also set DO_STATE_CHECK. Signed-off-by: David Howells Tested-by: Chuck Lever

Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

2014-10-12T14:13:55Z

Pull security subsystem updates from James Morris. Mostly ima, selinux, smack and key handling updates. * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (65 commits) integrity: do zero padding of the key id KEYS: output last portion of fingerprint in /proc/keys KEYS: strip 'id:' from ca_keyid KEYS: use swapped SKID for performing partial matching KEYS: Restore partial ID matching functionality for asymmetric keys X.509: If available, use the raw subjKeyId to form the key description KEYS: handle error code encoded in pointer selinux: normalize audit log formatting selinux: cleanup error reporting in selinux_nlmsg_perm() KEYS: Check hex2bin()'s return when generating an asymmetric key ID ima: detect violations for mmaped files ima: fix race condition on ima_rdwr_violation_check and process_measurement ima: added ima_policy_flag variable ima: return an error code from ima_add_boot_aggregate() ima: provide 'ima_appraise=log' kernel option ima: move keyring initialization to ima_init() PKCS#7: Handle PKCS#7 messages that contain no X.509 certs PKCS#7: Better handling of unsupported crypto KEYS: Overhaul key identification when searching for asymmetric keys KEYS: Implement binary asymmetric key ID handling ...

KEYS: Remove key_type::match in favour of overriding default by match_preparse

2014-09-16T16:36:06Z

A previous patch added a ->match_preparse() method to the key type. This is allowed to override the function called by the iteration algorithm. Therefore, we can just set a default that simply checks for an exact match of the key description with the original criterion data and allow match_preparse to override it as needed. The key_type::match op is then redundant and can be removed, as can the user_match() function. Signed-off-by: David Howells Acked-by: Vivek Goyal