crypto: sha512_generic - Use 64-bit counters

This patch replaces the 32-bit counters in sha512_generic with
64-bit counters.  It also switches the bit count to the simpler
byte count.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 11 insertions, 17 deletions

diff --git a/crypto/sha512_generic.c b/crypto/sha512_generic.c
index 4fe95eb03226..9ed9f60316e5 100644
--- a/crypto/sha512_generic.c
+++ b/crypto/sha512_generic.c
@@ -144,7 +144,7 @@ sha512_init(struct shash_desc *desc)
         sctx->state[5] = SHA512_H5;
         sctx->state[6] = SHA512_H6;
         sctx->state[7] = SHA512_H7;
-        sctx->count[0] = sctx->count[1] = sctx->count[2] = sctx->count[3] = 0;
+        sctx->count[0] = sctx->count[1] = 0;
 
         return 0;
 }
@@ -161,7 +161,7 @@ sha384_init(struct shash_desc *desc)
         sctx->state[5] = SHA384_H5;
         sctx->state[6] = SHA384_H6;
         sctx->state[7] = SHA384_H7;
-        sctx->count[0] = sctx->count[1] = sctx->count[2] = sctx->count[3] = 0;
+        sctx->count[0] = sctx->count[1] = 0;
 
         return 0;
 }
@@ -174,15 +174,11 @@ sha512_update(struct shash_desc *desc, const u8 *data, unsigned int len)
         unsigned int i, index, part_len;
 
         /* Compute number of bytes mod 128 */
-        index = (unsigned int)((sctx->count[0] >> 3) & 0x7F);
-
-        /* Update number of bits */
-        if ((sctx->count[0] += (len << 3)) < (len << 3)) {
-                if ((sctx->count[1] += 1) < 1)
-                        if ((sctx->count[2] += 1) < 1)
-                                sctx->count[3]++;
-                sctx->count[1] += (len >> 29);
-        }
+        index = sctx->count[0] & 0x7f;
+
+        /* Update number of bytes */
+        if (!(sctx->count[0] += len))
+                sctx->count[1]++;
 
         part_len = 128 - index;
 
@@ -211,18 +207,16 @@ sha512_final(struct shash_desc *desc, u8 *hash)
         struct sha512_state *sctx = shash_desc_ctx(desc);
         static u8 padding[128] = { 0x80, };
         __be64 *dst = (__be64 *)hash;
-        __be32 bits[4];
+        __be64 bits[2];
         unsigned int index, pad_len;
         int i;
 
         /* Save number of bits */
-        bits[3] = cpu_to_be32(sctx->count[0]);
-        bits[2] = cpu_to_be32(sctx->count[1]);
-        bits[1] = cpu_to_be32(sctx->count[2]);
-        bits[0] = cpu_to_be32(sctx->count[3]);
+        bits[1] = cpu_to_be64(sctx->count[0] << 3);
+        bits[0] = cpu_to_be64(sctx->count[1] << 3 | sctx->count[0] >> 61);
 
         /* Pad out to 112 mod 128. */
-        index = (sctx->count[0] >> 3) & 0x7f;
+        index = sctx->count[0] & 0x7f;
         pad_len = (index < 112) ? (112 - index) : ((128+112) - index);
         sha512_update(desc, padding, pad_len);