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: NDavid Howells <dhowells@redhat.com> Acked-by: NStephen Smalley <sds@tycho.nsa.gov> Cc: Paul Moore <paul.moore@hp.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: James Morris <jmorris@namei.org> Cc: Kevin Coffman <kwc@citi.umich.edu> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Showing
想要评论请 注册 或 登录