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 <[e-mail]>

crypto/sha512_generic.c

···
 	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;
 }
···
 	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;
 }
···
 	unsigned int i, index, part_len;
 
 	/* Compute number of bytes mod 128 */
-	index = (unsigned int)((sctx->count[0] >> 3) & 0x7F);
+	index = sctx->count[0] & 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);
-	}
+	/* Update number of bytes */
+	if (!(sctx->count[0] += len))
+		sctx->count[1]++;
 
         part_len = 128 - index;
 
···
 	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);
 

include/crypto/sha.h

···
 };
 
 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