crypto: algif_hash - User-space interface for hash operations
authorHerbert Xu <herbert@gondor.apana.org.au>
Tue, 19 Oct 2010 13:23:00 +0000 (21:23 +0800)
committerHerbert Xu <herbert@gondor.apana.org.au>
Fri, 19 Nov 2010 09:47:58 +0000 (17:47 +0800)
commitfe869cdb89c95d060c77eea20204d6c91f233b53
treefb665d1f162e8bdf978d264ca24d8a07d7380316
parent03c8efc1ffeb6b82a22c1af8dd908af349563314
crypto: algif_hash - User-space interface for hash operations

This patch adds the af_alg plugin for hash, corresponding to
the ahash kernel operation type.

Keys can optionally be set through the setsockopt interface.

Each sendmsg call will finalise the hash unless sent with a MSG_MORE
flag.

Partial hash states can be cloned using accept(2).

The interface is completely synchronous, all operations will
complete prior to the system call returning.

Both sendmsg(2) and splice(2) support reading the user-space
data directly without copying (except that the Crypto API itself
may copy the data if alignment is off).

For now only the splice(2) interface supports performing digest
instead of init/update/final.  In future the sendmsg(2) interface
will also be modified to use digest/finup where possible so that
hardware that cannot return a partial hash state can still benefit
from this interface.

Thakns to Miloslav Trmac for reviewing this and contributing
fixes and improvements.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: David S. Miller <davem@davemloft.net>
Tested-by: Martin Willi <martin@strongswan.org>
crypto/Kconfig
crypto/Makefile
crypto/algif_hash.c [new file with mode: 0644]