[PATCH 4/6] crypto: sha512_generic - Use 64-bit counters

[Herbert Xu]

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 <herb...@gondor.apana.org.au>
---

 crypto/sha512_generic.c |   28 +++++++++++-----------------
 include/crypto/sha.h    |    6 +++---
 2 files changed, 14 insertions(+), 20 deletions(-)

diff --git a/crypto/sha512_generic.c b/crypto/sha512_generic.c
index 4fe95eb..9ed9f60 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);
 
diff --git a/include/crypto/sha.h b/include/crypto/sha.h
index 45b25cc..069e85b 100644
--- a/include/crypto/sha.h
+++ b/include/crypto/sha.h
@@ -77,9 +77,9 @@ struct sha256_state {
 };
 
 struct sha512_state {
-       u64 state[8];
-       u32 count[4];
-       u8 buf[128];
+       u64 count[2];
+       u64 state[SHA512_DIGEST_SIZE / 8];
+       u8 buf[SHA512_BLOCK_SIZE];
 };
 
 #endif
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