commit 0c4c78de0417ced1da92351a3013e631860ea576
author LABBE Corentin <clabbe.montjoie@gmail.com> Thu Dec 17 13:45:39 2015 +0100
committer Herbert Xu <herbert@gondor.apana.org.au> Tue Dec 22 20:43:35 2015 +0800
tree 1901728828a5891d3a8e1f5db23226682a9bb41d
parent 51d77dddfff4a554744bfa0e67cf571319635645

crypto: hash - add zero length message hash for shax and md5

Some crypto drivers cannot process empty data message and return a
precalculated hash for md5/sha1/sha224/sha256.

This patch add thoses precalculated hash in include/crypto.

Signed-off-by: LABBE Corentin <clabbe.montjoie@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

include/crypto/sha.h

diff --git a/include/crypto/sha.h b/include/crypto/sha.h
index dd7905a..c94d3eb 100644
--- a/include/crypto/sha.h
+++ b/include/crypto/sha.h
@@ -64,6 +64,12 @@
 #define SHA512_H6	0x1f83d9abfb41bd6bULL
 #define SHA512_H7	0x5be0cd19137e2179ULL
 
+extern const u8 sha1_zero_message_hash[SHA1_DIGEST_SIZE];
+
+extern const u8 sha224_zero_message_hash[SHA224_DIGEST_SIZE];
+
+extern const u8 sha256_zero_message_hash[SHA256_DIGEST_SIZE];
+
 struct sha1_state {
 	u32 state[SHA1_DIGEST_SIZE / 4];
 	u64 count;