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authorDenis Vlasenko2009-03-12 19:06:18 +0000
committerDenis Vlasenko2009-03-12 19:06:18 +0000
commitc8329c956816656364e54d54932c5898a29bed70 (patch)
tree82f055e1ef31d209bd5d5c16bd09be6ed6071552 /libbb
parent4a43057268a29c613f5482e6795a0a8ead9974ef (diff)
downloadbusybox-c8329c956816656364e54d54932c5898a29bed70.zip
busybox-c8329c956816656364e54d54932c5898a29bed70.tar.gz
sha: reduce sha256/512 context size. Make sha1/sha256 code more similar
function old new delta sha512_end 182 204 +22 sha256_end 137 147 +10 sha1_hash 113 108 -5 sha1_end 143 129 -14 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 2/2 up/down: 32/-19) Total: 13 bytes
Diffstat (limited to 'libbb')
-rw-r--r--libbb/sha1.c145
1 files changed, 76 insertions, 69 deletions
diff --git a/libbb/sha1.c b/libbb/sha1.c
index 765fedd..efdb0f5 100644
--- a/libbb/sha1.c
+++ b/libbb/sha1.c
@@ -60,12 +60,13 @@ static void sha1_process_block64(sha1_ctx_t *ctx)
{
unsigned i;
uint32_t w[80], a, b, c, d, e, t;
+ uint32_t *words;
- /* note that words are compiled from the buffer into 32-bit */
- /* words in big-endian order so an order reversal is needed */
- /* here on little endian machines */
- for (i = 0; i < SHA1_BLOCK_SIZE / 4; ++i)
- w[i] = ntohl(ctx->wbuffer[i]);
+ words = (uint32_t*) ctx->wbuffer;
+ for (i = 0; i < SHA1_BLOCK_SIZE / 4; ++i) {
+ w[i] = ntohl(*words);
+ words++;
+ }
for (/*i = SHA1_BLOCK_SIZE / 4*/; i < 80; ++i) {
t = w[i - 3] ^ w[i - 8] ^ w[i - 14] ^ w[i - 16];
@@ -232,7 +233,7 @@ static void sha256_process_block64(const void *buffer, size_t len, sha256_ctx_t
/* Compute the message schedule according to FIPS 180-2:6.2.2 step 2. */
for (t = 0; t < 16; ++t) {
W[t] = ntohl(*words);
- ++words;
+ words++;
}
for (/*t = 16*/; t < 64; ++t)
@@ -302,7 +303,7 @@ static void sha512_process_block128(const void *buffer, size_t len, sha512_ctx_t
/* Compute the message schedule according to FIPS 180-2:6.3.2 step 2. */
for (t = 0; t < 16; ++t) {
W[t] = ntoh64(*words);
- ++words;
+ words++;
}
for (/*t = 16*/; t < 80; ++t)
W[t] = R1(W[t - 2]) + W[t - 7] + R0(W[t - 15]) + W[t - 16];
@@ -399,7 +400,7 @@ void FAST_FUNC sha1_hash(const void *buffer, size_t len, sha1_ctx_t *ctx)
ctx->total64 += len;
while (len >= add) { /* transfer whole blocks while possible */
- memcpy(((unsigned char *) ctx->wbuffer) + in_buf, buffer, add);
+ memcpy(ctx->wbuffer + in_buf, buffer, add);
buffer = (const char *)buffer + add;
len -= add;
add = SHA1_BLOCK_SIZE;
@@ -407,7 +408,7 @@ void FAST_FUNC sha1_hash(const void *buffer, size_t len, sha1_ctx_t *ctx)
sha1_process_block64(ctx);
}
- memcpy(((unsigned char *) ctx->wbuffer) + in_buf, buffer, len);
+ memcpy(ctx->wbuffer + in_buf, buffer, len);
}
void FAST_FUNC sha256_hash(const void *buffer, size_t len, sha256_ctx_t *ctx)
@@ -424,19 +425,14 @@ void FAST_FUNC sha256_hash(const void *buffer, size_t len, sha256_ctx_t *ctx)
if (in_buf != 0) {
unsigned add;
- /* NB: 1/2 of wbuffer is used only in sha256_end
- * when length field is added and hashed.
- * With buffer twice as small, it may happen that
- * we have it almost full and can't add length field. */
-
- add = sizeof(ctx->wbuffer)/2 - in_buf;
+ add = sizeof(ctx->wbuffer) - in_buf;
if (add > len)
add = len;
- memcpy(&ctx->wbuffer[in_buf], buffer, add);
+ memcpy(ctx->wbuffer + in_buf, buffer, add);
in_buf += add;
/* If we still didn't collect full wbuffer, bail out */
- if (in_buf < sizeof(ctx->wbuffer)/2)
+ if (in_buf < sizeof(ctx->wbuffer))
return;
sha256_process_block64(ctx->wbuffer, 64, ctx);
@@ -460,9 +456,8 @@ void FAST_FUNC sha256_hash(const void *buffer, size_t len, sha256_ctx_t *ctx)
}
/* Move remaining bytes into internal buffer. */
- if (len > 0) {
+ if (len > 0)
memcpy(ctx->wbuffer, buffer, len);
- }
}
void FAST_FUNC sha512_hash(const void *buffer, size_t len, sha512_ctx_t *ctx)
@@ -479,13 +474,13 @@ void FAST_FUNC sha512_hash(const void *buffer, size_t len, sha512_ctx_t *ctx)
if (in_buf != 0) {
unsigned add;
- add = sizeof(ctx->wbuffer)/2 - in_buf;
+ add = sizeof(ctx->wbuffer) - in_buf;
if (add > len)
add = len;
- memcpy(&ctx->wbuffer[in_buf], buffer, add);
+ memcpy(ctx->wbuffer + in_buf, buffer, add);
in_buf += add;
- if (in_buf < sizeof(ctx->wbuffer)/2)
+ if (in_buf < sizeof(ctx->wbuffer))
return;
sha512_process_block128(ctx->wbuffer, 128, ctx);
@@ -507,9 +502,8 @@ void FAST_FUNC sha512_hash(const void *buffer, size_t len, sha512_ctx_t *ctx)
}
}
- if (len > 0) {
+ if (len > 0)
memcpy(ctx->wbuffer, buffer, len);
- }
}
@@ -517,31 +511,29 @@ void FAST_FUNC sha1_end(void *resbuf, sha1_ctx_t *ctx)
{
unsigned i, pad, in_buf;
- /* Pad the buffer to the next 64-byte boundary with 0x80,0,0,0... */
in_buf = ctx->total64 & SHA1_MASK;
- ((uint8_t *)ctx->wbuffer)[in_buf++] = 0x80;
- pad = SHA1_BLOCK_SIZE - in_buf;
- memset(((uint8_t *)ctx->wbuffer) + in_buf, 0, pad);
-
- /* We need 1+8 or more empty positions, one for the padding byte
- * (above) and eight for the length count.
- * If there is not enough space, empty the buffer. */
- if (pad < 8) {
- sha1_process_block64(ctx);
- memset(ctx->wbuffer, 0, SHA1_BLOCK_SIZE - 8);
- ((uint8_t *)ctx->wbuffer)[0] = 0x80;
- }
+ /* Pad the buffer to the next 64-byte boundary with 0x80,0,0,0... */
+ ctx->wbuffer[in_buf++] = 0x80;
- /* Store the 64-bit counter of bits in the buffer in BE format */
- {
- uint64_t t = ctx->total64 << 3;
- t = hton64(t);
- /* wbuffer is suitably aligned for this */
- *(uint64_t *) &ctx->wbuffer[14] = t;
+ /* This loop iterates either once or twice, no more, no less */
+ while (1) {
+ pad = SHA1_BLOCK_SIZE - in_buf;
+ memset(ctx->wbuffer + in_buf, 0, pad);
+ in_buf = 0;
+ /* Do we have enough space for the length count? */
+ if (pad >= 8) {
+ /* Store the 64-bit counter of bits in the buffer in BE format */
+ uint64_t t = ctx->total64 << 3;
+ t = hton64(t);
+ /* wbuffer is suitably aligned for this */
+ *(uint64_t *) (&ctx->wbuffer[SHA1_BLOCK_SIZE - 8]) = t;
+ }
+ sha1_process_block64(ctx);
+ if (pad >= 8)
+ break;
}
- sha1_process_block64(ctx);
-
+ /* This way we do not impose alignment constraints on resbuf: */
#if BB_LITTLE_ENDIAN
for (i = 0; i < ARRAY_SIZE(ctx->hash); ++i)
ctx->hash[i] = htonl(ctx->hash[i]);
@@ -553,23 +545,25 @@ void FAST_FUNC sha256_end(void *resbuf, sha256_ctx_t *ctx)
{
unsigned i, pad, in_buf;
- /* Pad the buffer to the next 64-byte boundary with 0x80,0,0,0...
- (FIPS 180-2:5.1.1) */
in_buf = ctx->total64 & 63;
- pad = (in_buf >= 56 ? 64 + 56 - in_buf : 56 - in_buf);
- memset(&ctx->wbuffer[in_buf], 0, pad);
- ctx->wbuffer[in_buf] = 0x80;
-
- /* Put the 64-bit file length in *bits* at the end of the buffer. */
- {
- uint64_t t = ctx->total64 << 3;
- t = hton64(t);
- /* wbuffer is suitably aligned for this */
- *(uint64_t *) &ctx->wbuffer[in_buf + pad] = t;
- }
+ /* Pad the buffer to the next 64-byte boundary with 0x80,0,0,0...
+ * (FIPS 180-2:5.1.1)
+ */
+ ctx->wbuffer[in_buf++] = 0x80;
- /* Process last bytes. */
- sha256_process_block64(ctx->wbuffer, in_buf + pad + 8, ctx);
+ while (1) {
+ pad = 64 - in_buf;
+ memset(ctx->wbuffer + in_buf, 0, pad);
+ in_buf = 0;
+ if (pad >= 8) {
+ uint64_t t = ctx->total64 << 3;
+ t = hton64(t);
+ *(uint64_t *) (&ctx->wbuffer[64 - 8]) = t;
+ }
+ sha256_process_block64(ctx->wbuffer, 64, ctx);
+ if (pad >= 8)
+ break;
+ }
#if BB_LITTLE_ENDIAN
for (i = 0; i < ARRAY_SIZE(ctx->hash); ++i)
@@ -582,17 +576,30 @@ void FAST_FUNC sha512_end(void *resbuf, sha512_ctx_t *ctx)
{
unsigned i, pad, in_buf;
- /* Pad the buffer to the next 128-byte boundary with 0x80,0,0,0...
- (FIPS 180-2:5.1.2) */
in_buf = ctx->total64[0] & 127;
- pad = in_buf >= 112 ? 128 + 112 - in_buf : 112 - in_buf;
- memset(&ctx->wbuffer[in_buf], 0, pad);
- ctx->wbuffer[in_buf] = 0x80;
-
- *(uint64_t *) &ctx->wbuffer[in_buf + pad + 8] = hton64(ctx->total64[0] << 3);
- *(uint64_t *) &ctx->wbuffer[in_buf + pad] = hton64((ctx->total64[1] << 3) | (ctx->total64[0] >> 61));
+ /* Pad the buffer to the next 128-byte boundary with 0x80,0,0,0...
+ * (FIPS 180-2:5.1.2)
+ */
+ ctx->wbuffer[in_buf++] = 0x80;
- sha512_process_block128(ctx->wbuffer, in_buf + pad + 16, ctx);
+ while (1) {
+ pad = 128 - in_buf;
+ memset(ctx->wbuffer + in_buf, 0, pad);
+ in_buf = 0;
+ if (pad >= 16) {
+ /* Store the 128-bit counter of bits in the buffer in BE format */
+ uint64_t t;
+ t = ctx->total64[0] << 3;
+ t = hton64(t);
+ *(uint64_t *) (&ctx->wbuffer[128 - 8]) = t;
+ t = (ctx->total64[1] << 3) | (ctx->total64[0] >> 61);
+ t = hton64(t);
+ *(uint64_t *) (&ctx->wbuffer[128 - 16]) = t;
+ }
+ sha512_process_block128(ctx->wbuffer, 128, ctx);
+ if (pad >= 16)
+ break;
+ }
#if BB_LITTLE_ENDIAN
for (i = 0; i < ARRAY_SIZE(ctx->hash); ++i)