crypto: sha1 - export sha1_update for reuse

Export the update function as crypto_sha1_update() to not have the need
to reimplement the same algorithm for each SHA-1 implementation. This
way the generic SHA-1 implementation can be used as fallback for other
implementations that fail to run under certain circumstances, like the
need for an FPU context while executing in IRQ context.
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/sha1_generic.c

@@ -36,7 +36,7 @@ static int sha1_init(struct shash_desc *desc)
 	return 0;
 }
 
-static int sha1_update(struct shash_desc *desc, const u8 *data,
+int crypto_sha1_update(struct shash_desc *desc, const u8 *data,
 			unsigned int len)
 {
 	struct sha1_state *sctx = shash_desc_ctx(desc);
@@ -71,6 +71,7 @@ static int sha1_update(struct shash_desc *desc, const u8 *data,
 
 	return 0;
 }
+EXPORT_SYMBOL(crypto_sha1_update);
 
 
 /* Add padding and return the message digest. */
@@ -87,10 +88,10 @@ static int sha1_final(struct shash_desc *desc, u8 *out)
 	/* Pad out to 56 mod 64 */
 	index = sctx->count & 0x3f;
 	padlen = (index < 56) ? (56 - index) : ((64+56) - index);
-	sha1_update(desc, padding, padlen);
+	crypto_sha1_update(desc, padding, padlen);
 
 	/* Append length */
-	sha1_update(desc, (const u8 *)&bits, sizeof(bits));
+	crypto_sha1_update(desc, (const u8 *)&bits, sizeof(bits));
 
 	/* Store state in digest */
 	for (i = 0; i < 5; i++)
@@ -121,7 +122,7 @@ static int sha1_import(struct shash_desc *desc, const void *in)
 static struct shash_alg alg = {
 	.digestsize	=	SHA1_DIGEST_SIZE,
 	.init		=	sha1_init,
-	.update		=	sha1_update,
+	.update		=	crypto_sha1_update,
 	.final		=	sha1_final,
 	.export		=	sha1_export,
 	.import		=	sha1_import,

include/crypto/sha.h

@@ -82,4 +82,7 @@ struct sha512_state {
 	u8 buf[SHA512_BLOCK_SIZE];
 };
 
+extern int crypto_sha1_update(struct shash_desc *desc, const u8 *data,
+			      unsigned int len);
+
 #endif