From 70a5bb72b55e82fbfbf1e22cae6975fac58a1e2d Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 29 Apr 2008 01:01:26 -0700 Subject: keys: add keyctl function to get a security label Add a keyctl() function to get the security label of a key. The following is added to Documentation/keys.txt: (*) Get the LSM security context attached to a key. long keyctl(KEYCTL_GET_SECURITY, key_serial_t key, char *buffer, size_t buflen) This function returns a string that represents the LSM security context attached to a key in the buffer provided. Unless there's an error, it always returns the amount of data it could produce, even if that's too big for the buffer, but it won't copy more than requested to userspace. If the buffer pointer is NULL then no copy will take place. A NUL character is included at the end of the string if the buffer is sufficiently big. This is included in the returned count. If no LSM is in force then an empty string will be returned. A process must have view permission on the key for this function to be successful. [akpm@linux-foundation.org: declare keyctl_get_security()] Signed-off-by: David Howells Acked-by: Stephen Smalley Cc: Paul Moore Cc: Chris Wright Cc: James Morris Cc: Kevin Coffman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- security/selinux/hooks.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'security/selinux') diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 047365ac9fa..838d1e5e63a 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -5300,6 +5300,20 @@ static int selinux_key_permission(key_ref_t key_ref, SECCLASS_KEY, perm, NULL); } +static int selinux_key_getsecurity(struct key *key, char **_buffer) +{ + struct key_security_struct *ksec = key->security; + char *context = NULL; + unsigned len; + int rc; + + rc = security_sid_to_context(ksec->sid, &context, &len); + if (!rc) + rc = len; + *_buffer = context; + return rc; +} + #endif static struct security_operations selinux_ops = { @@ -5488,6 +5502,7 @@ static struct security_operations selinux_ops = { .key_alloc = selinux_key_alloc, .key_free = selinux_key_free, .key_permission = selinux_key_permission, + .key_getsecurity = selinux_key_getsecurity, #endif #ifdef CONFIG_AUDIT -- cgit v1.2.3-70-g09d2