crypto: lib/sha1 - rename "sha" to "sha1"

The library implementation of the SHA-1 compression function is
confusingly called just "sha_transform()".  Alongside it are some "SHA_"
constants and "sha_init()".  Presumably these are left over from a time
when SHA just meant SHA-1.  But now there are also SHA-2 and SHA-3, and
moreover SHA-1 is now considered insecure and thus shouldn't be used.

Therefore, rename these functions and constants to make it very clear
that they are for SHA-1.  Also add a comment to make it clear that these
shouldn't be used.

For the extra-misleadingly named "SHA_MESSAGE_BYTES", rename it to
SHA1_BLOCK_SIZE and define it to just '64' rather than '(512/8)' so that
it matches the same definition in <crypto/sha.h>.  This prepares for
merging <linux/cryptohash.h> into <crypto/sha.h>.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 12 insertions, 10 deletions

diff --git a/lib/sha1.c b/lib/sha1.c
index 1d96d2c02b82..b381e8cd4fe4 100644
--- a/lib/sha1.c
+++ b/lib/sha1.c
@@ -64,22 +64,24 @@
 #define T_60_79(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, (B^C^D) ,  0xca62c1d6, A, B, C, D, E )
 
 /**
- * sha_transform - single block SHA1 transform
+ * sha1_transform - single block SHA1 transform (deprecated)
  *
  * @digest: 160 bit digest to update
  * @data:   512 bits of data to hash
  * @array:  16 words of workspace (see note)
  *
- * This function generates a SHA1 digest for a single 512-bit block.
- * Be warned, it does not handle padding and message digest, do not
- * confuse it with the full FIPS 180-1 digest algorithm for variable
- * length messages.
+ * This function executes SHA-1's internal compression function.  It updates the
+ * 160-bit internal state (@digest) with a single 512-bit data block (@data).
+ *
+ * Don't use this function.  SHA-1 is no longer considered secure.  And even if
+ * you do have to use SHA-1, this isn't the correct way to hash something with
+ * SHA-1 as this doesn't handle padding and finalization.
  *
  * Note: If the hash is security sensitive, the caller should be sure
  * to clear the workspace. This is left to the caller to avoid
  * unnecessary clears between chained hashing operations.
  */
-void sha_transform(__u32 *digest, const char *data, __u32 *array)
+void sha1_transform(__u32 *digest, const char *data, __u32 *array)
 {
 	__u32 A, B, C, D, E;
 
@@ -185,13 +187,13 @@ void sha_transform(__u32 *digest, const char *data, __u32 *array)
 	digest[3] += D;
 	digest[4] += E;
 }
-EXPORT_SYMBOL(sha_transform);
+EXPORT_SYMBOL(sha1_transform);
 
 /**
- * sha_init - initialize the vectors for a SHA1 digest
+ * sha1_init - initialize the vectors for a SHA1 digest
  * @buf: vector to initialize
  */
-void sha_init(__u32 *buf)
+void sha1_init(__u32 *buf)
 {
 	buf[0] = 0x67452301;
 	buf[1] = 0xefcdab89;
@@ -199,4 +201,4 @@ void sha_init(__u32 *buf)
 	buf[3] = 0x10325476;
 	buf[4] = 0xc3d2e1f0;
 }
-EXPORT_SYMBOL(sha_init);
+EXPORT_SYMBOL(sha1_init);