Smack: getting the Smack security context of keys

With this commit, the LSM Smack implements the LSM
side part of the system call keyctl with the action
code KEYCTL_GET_SECURITY.

It is now possible to get the context of, for example,
the user session key using the command "keyctl security @s".

The original patch has been modified for merge.

Signed-off-by: José Bollo <jose.bollo@open.eurogiciel.org>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
This commit is contained in:
José Bollo 2015-02-17 15:41:22 +01:00 committed by Casey Schaufler
parent 7412301b76
commit 7fc5f36e98
1 changed files with 31 additions and 0 deletions

View File

@ -4000,6 +4000,36 @@ static int smack_key_permission(key_ref_t key_ref,
rc = smk_bu_note("key access", tkp, keyp->security, request, rc);
return rc;
}
/*
* smack_key_getsecurity - Smack label tagging the key
* @key points to the key to be queried
* @_buffer points to a pointer that should be set to point to the
* resulting string (if no label or an error occurs).
* Return the length of the string (including terminating NUL) or -ve if
* an error.
* May also return 0 (and a NULL buffer pointer) if there is no label.
*/
static int smack_key_getsecurity(struct key *key, char **_buffer)
{
struct smack_known *skp = key->security;
size_t length;
char *copy;
if (key->security == NULL) {
*_buffer = NULL;
return 0;
}
copy = kstrdup(skp->smk_known, GFP_KERNEL);
if (copy == NULL)
return -ENOMEM;
length = strlen(copy) + 1;
*_buffer = copy;
return length;
}
#endif /* CONFIG_KEYS */
/*
@ -4324,6 +4354,7 @@ struct security_operations smack_ops = {
.key_alloc = smack_key_alloc,
.key_free = smack_key_free,
.key_permission = smack_key_permission,
.key_getsecurity = smack_key_getsecurity,
#endif /* CONFIG_KEYS */
/* Audit hooks */