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>

1 files changed, 6 insertions, 0 deletions

diff --git a/crypto/md5.c b/crypto/md5.c
index 33d17e9a8702..2355a7c25c45 100644
--- a/crypto/md5.c
+++ b/crypto/md5.c
@@ -24,6 +24,12 @@
 #include <linux/cryptohash.h>
 #include <asm/byteorder.h>
 
+const u8 md5_zero_message_hash[MD5_DIGEST_SIZE] = {
+        0xd4, 0x1d, 0x8c, 0xd9, 0x8f, 0x00, 0xb2, 0x04,
+        0xe9, 0x80, 0x09, 0x98, 0xec, 0xf8, 0x42, 0x7e,
+};
+EXPORT_SYMBOL_GPL(md5_zero_message_hash);
+
 /* XXX: this stuff can be optimized */
 static inline void le32_to_cpu_array(u32 *buf, unsigned int words)
 {