crypto: sha256_generic - Use 64-bit counter like sha1
This patch replaces the two 32-bit counter code in sha256_generic
with the simpler 64-bit counter code from sha1.
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
---
crypto/sha256_generic.c | 65 ++++++++++++++++++++++--------------------------
1 file changed, 30 insertions(+), 35 deletions(-)
diff --git a/crypto/sha256_generic.c b/crypto/sha256_generic.c
index 6349d83..e58c71b 100644
--- a/crypto/sha256_generic.c
+++ b/crypto/sha256_generic.c
@@ -26,7 +26,7 @@
#include <asm/byteorder.h>
struct sha256_ctx {
- u32 count[2];
+ u64 count;
u32 state[8];
u8 buf[128];
};
@@ -231,8 +231,7 @@ static int sha224_init(struct shash_desc *desc)
sctx->state[5] = SHA224_H5;
sctx->state[6] = SHA224_H6;
sctx->state[7] = SHA224_H7;
- sctx->count[0] = 0;
- sctx->count[1] = 0;
+ sctx->count = 0;
return 0;
}
@@ -248,7 +247,7 @@ static int sha256_init(struct shash_desc *desc)
sctx->state[5] = SHA256_H5;
sctx->state[6] = SHA256_H6;
sctx->state[7] = SHA256_H7;
- sctx->count[0] = sctx->count[1] = 0;
+ sctx->count = 0;
return 0;
}
@@ -257,33 +256,30 @@ static int sha256_update(struct shash_desc *desc, const u8 *data,
unsigned int len)
{
struct sha256_ctx *sctx = shash_desc_ctx(desc);
- unsigned int i, index, part_len;
-
- /* Compute number of bytes mod 128 */
- index = (unsigned int)((sctx->count[0] >> 3) & 0x3f);
-
- /* Update number of bits */
- if ((sctx->count[0] += (len << 3)) < (len << 3)) {
- sctx->count[1]++;
- sctx->count[1] += (len >> 29);
+ unsigned int partial, done;
+ const u8 *src;
+
+ partial = sctx->count & 0x3f;
+ sctx->count += len;
+ done = 0;
+ src = data;
+
+ if ((partial + len) > 63) {
+ if (partial) {
+ done = -partial;
+ memcpy(sctx->buf + partial, data, done + 64);
+ src = sctx->buf;
+ }
+
+ do {
+ sha256_transform(sctx->state, src);
+ done += 64;
+ src = data + done;
+ } while (done + 63 < len);
+
+ partial = 0;
}
-
- part_len = 64 - index;
-
- /* Transform as many times as possible. */
- if (len >= part_len) {
- memcpy(&sctx->buf[index], data, part_len);
- sha256_transform(sctx->state, sctx->buf);
-
- for (i = part_len; i + 63 < len; i += 64)
- sha256_transform(sctx->state, &data[i]);
- index = 0;
- } else {
- i = 0;
- }
-
- /* Buffer remaining input */
- memcpy(&sctx->buf[index], &data[i], len-i);
+ memcpy(sctx->buf + partial, src, len - done);
return 0;
}
@@ -292,22 +288,21 @@ static int sha256_final(struct shash_desc *desc, u8 *out)
{
struct sha256_ctx *sctx = shash_desc_ctx(desc);
__be32 *dst = (__be32 *)out;
- __be32 bits[2];
+ __be64 bits;
unsigned int index, pad_len;
int i;
static const u8 padding[64] = { 0x80, };
/* Save number of bits */
- bits[1] = cpu_to_be32(sctx->count[0]);
- bits[0] = cpu_to_be32(sctx->count[1]);
+ bits = cpu_to_be64(sctx->count << 3);
/* Pad out to 56 mod 64. */
- index = (sctx->count[0] >> 3) & 0x3f;
+ index = sctx->count & 0x3f;
pad_len = (index < 56) ? (56 - index) : ((64+56) - index);
sha256_update(desc, padding, pad_len);
/* Append length (before padding) */
- sha256_update(desc, (const u8 *)bits, sizeof(bits));
+ sha256_update(desc, (const u8 *)&bits, sizeof(bits));
/* Store state in digest */
for (i = 0; i < 8; i++)
--
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