keyctl: Allow add, padd and suchlike to take hex-encoded data

Allow add, padd, update, pupdate, instantiate, pinstantiate and
dh_compute_kdf_oi to take hex-encoded data which is then converted into
binary before being passed to the kernel, e.g.:

	$ keyctl add -x user foo 686578 @s
	$ echo 686578 | keyctl padd -x user foo @s

This makes it easier to stash data in scripts.

Signed-off-by: David Howells <>
8 files changed