emo/busybox
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

sha: reduce sha256/512 context size. Make sha1/sha256 code more similar

Browse Source 
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
This commit is contained in:
Denis Vlasenko 2009-03-12 19:06:18 +00:00
parent 4a43057268
commit c8329c9568
2 changed files with 77 additions and 70 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
include/libbb.h
View File

@ -1322,7 +1322,7 @@ void bb_uuencode(char *store, const void *s, int length, const char *tbl) FAST_F
typedef struct sha1_ctx_t { typedef struct sha1_ctx_t {
uint64_t total64; uint64_t total64;
uint32_t wbuffer[16]; /* NB: always correctly aligned for uint64_t */ uint8_t wbuffer[64]; /* NB: always correctly aligned for uint64_t */
uint32_t hash[5]; uint32_t hash[5];
} sha1_ctx_t; } sha1_ctx_t;
void sha1_begin(sha1_ctx_t *ctx) FAST_FUNC; void sha1_begin(sha1_ctx_t *ctx) FAST_FUNC;
@ -1331,7 +1331,7 @@ void sha1_end(void *resbuf, sha1_ctx_t *ctx) FAST_FUNC;
typedef struct sha256_ctx_t { typedef struct sha256_ctx_t {
uint64_t total64; uint64_t total64;
uint32_t hash[8]; uint32_t hash[8];
char wbuffer[64*2]; /* NB: always correctly aligned for uint64_t */ uint8_t wbuffer[64]; /* NB: always correctly aligned for uint64_t */
} sha256_ctx_t; } sha256_ctx_t;
void sha256_begin(sha256_ctx_t *ctx) FAST_FUNC; void sha256_begin(sha256_ctx_t *ctx) FAST_FUNC;
void sha256_hash(const void *buffer, size_t len, sha256_ctx_t *ctx) FAST_FUNC; void sha256_hash(const void *buffer, size_t len, sha256_ctx_t *ctx) FAST_FUNC;
@ -1339,7 +1339,7 @@ void sha256_end(void *resbuf, sha256_ctx_t *ctx) FAST_FUNC;
typedef struct sha512_ctx_t { typedef struct sha512_ctx_t {
uint64_t total64[2]; uint64_t total64[2];
uint64_t hash[8]; uint64_t hash[8];
char wbuffer[128*2]; /* NB: always correctly aligned for uint64_t */ uint8_t wbuffer[128]; /* NB: always correctly aligned for uint64_t */
} sha512_ctx_t; } sha512_ctx_t;
void sha512_begin(sha512_ctx_t *ctx) FAST_FUNC; void sha512_begin(sha512_ctx_t *ctx) FAST_FUNC;
void sha512_hash(const void *buffer, size_t len, sha512_ctx_t *ctx) FAST_FUNC; void sha512_hash(const void *buffer, size_t len, sha512_ctx_t *ctx) FAST_FUNC;

141
libbb/sha1.c
View File

@ -60,12 +60,13 @@ static void sha1_process_block64(sha1_ctx_t *ctx)
{ {
unsigned i; unsigned i;
uint32_t w[80], a, b, c, d, e, t; 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 = (uint32_t*) ctx->wbuffer;
/* words in big-endian order so an order reversal is needed */ for (i = 0; i < SHA1_BLOCK_SIZE / 4; ++i) {
/* here on little endian machines */ w[i] = ntohl(*words);
for (i = 0; i < SHA1_BLOCK_SIZE / 4; ++i) words++;
w[i] = ntohl(ctx->wbuffer[i]); }
for (/*i = SHA1_BLOCK_SIZE / 4*/; i < 80; ++i) { for (/*i = SHA1_BLOCK_SIZE / 4*/; i < 80; ++i) {
t = w[i - 3] ^ w[i - 8] ^ w[i - 14] ^ w[i - 16]; 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. */ /* Compute the message schedule according to FIPS 180-2:6.2.2 step 2. */
for (t = 0; t < 16; ++t) { for (t = 0; t < 16; ++t) {
W[t] = ntohl(*words); W[t] = ntohl(*words);
++words; words++;
} }
for (/*t = 16*/; t < 64; ++t) 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. */ /* Compute the message schedule according to FIPS 180-2:6.3.2 step 2. */
for (t = 0; t < 16; ++t) { for (t = 0; t < 16; ++t) {
W[t] = ntoh64(*words); W[t] = ntoh64(*words);
++words; words++;
} }
for (/*t = 16*/; t < 80; ++t) for (/*t = 16*/; t < 80; ++t)
W[t] = R1(W[t - 2]) + W[t - 7] + R0(W[t - 15]) + W[t - 16]; 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; ctx->total64 += len;
while (len >= add) { /* transfer whole blocks while possible */ 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; buffer = (const char *)buffer + add;
len -= add; len -= add;
add = SHA1_BLOCK_SIZE; 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); 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) 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) { if (in_buf != 0) {
unsigned add; unsigned add;
/* NB: 1/2 of wbuffer is used only in sha256_end add = sizeof(ctx->wbuffer) - in_buf;
* 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;
if (add > len) if (add > len)
add = len; add = len;
memcpy(&ctx->wbuffer[in_buf], buffer, add); memcpy(ctx->wbuffer + in_buf, buffer, add);
in_buf += add; in_buf += add;
/* If we still didn't collect full wbuffer, bail out */ /* If we still didn't collect full wbuffer, bail out */
if (in_buf < sizeof(ctx->wbuffer)/2) if (in_buf < sizeof(ctx->wbuffer))
return; return;
sha256_process_block64(ctx->wbuffer, 64, ctx); 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. */ /* Move remaining bytes into internal buffer. */
if (len > 0) { if (len > 0)
memcpy(ctx->wbuffer, buffer, len); memcpy(ctx->wbuffer, buffer, len);
}
} }
void FAST_FUNC sha512_hash(const void *buffer, size_t len, sha512_ctx_t *ctx) 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) { if (in_buf != 0) {
unsigned add; unsigned add;
add = sizeof(ctx->wbuffer)/2 - in_buf; add = sizeof(ctx->wbuffer) - in_buf;
if (add > len) if (add > len)
add = len; add = len;
memcpy(&ctx->wbuffer[in_buf], buffer, add); memcpy(ctx->wbuffer + in_buf, buffer, add);
in_buf += add; in_buf += add;
if (in_buf < sizeof(ctx->wbuffer)/2) if (in_buf < sizeof(ctx->wbuffer))
return; return;
sha512_process_block128(ctx->wbuffer, 128, ctx); 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); 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; 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; in_buf = ctx->total64 & SHA1_MASK;
((uint8_t *)ctx->wbuffer)[in_buf++] = 0x80; /* Pad the buffer to the next 64-byte boundary with 0x80,0,0,0... */
pad = SHA1_BLOCK_SIZE - in_buf; ctx->wbuffer[in_buf++] = 0x80;
memset(((uint8_t *)ctx->wbuffer) + in_buf, 0, pad);
/* We need 1+8 or more empty positions, one for the padding byte /* This loop iterates either once or twice, no more, no less */
* (above) and eight for the length count. while (1) {
* If there is not enough space, empty the buffer. */ pad = SHA1_BLOCK_SIZE - in_buf;
if (pad < 8) { 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); sha1_process_block64(ctx);
memset(ctx->wbuffer, 0, SHA1_BLOCK_SIZE - 8); if (pad >= 8)
((uint8_t *)ctx->wbuffer)[0] = 0x80; break;
} }
/* Store the 64-bit counter of bits in the buffer in BE format */ /* This way we do not impose alignment constraints on resbuf: */
{
uint64_t t = ctx->total64 << 3;
t = hton64(t);
/* wbuffer is suitably aligned for this */
*(uint64_t *) &ctx->wbuffer[14] = t;
}
sha1_process_block64(ctx);
#if BB_LITTLE_ENDIAN #if BB_LITTLE_ENDIAN
for (i = 0; i < ARRAY_SIZE(ctx->hash); ++i) for (i = 0; i < ARRAY_SIZE(ctx->hash); ++i)
ctx->hash[i] = htonl(ctx->hash[i]); ctx->hash[i] = htonl(ctx->hash[i]);
@ -553,24 +545,26 @@ void FAST_FUNC sha256_end(void *resbuf, sha256_ctx_t *ctx)
{ {
unsigned i, pad, in_buf; 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; in_buf = ctx->total64 & 63;
pad = (in_buf >= 56 ? 64 + 56 - in_buf : 56 - in_buf); /* Pad the buffer to the next 64-byte boundary with 0x80,0,0,0...
memset(&ctx->wbuffer[in_buf], 0, pad); * (FIPS 180-2:5.1.1)
ctx->wbuffer[in_buf] = 0x80; */
ctx->wbuffer[in_buf++] = 0x80;
/* Put the 64-bit file length in *bits* at the end of the buffer. */ while (1) {
{ pad = 64 - in_buf;
uint64_t t = ctx->total64 << 3; memset(ctx->wbuffer + in_buf, 0, pad);
t = hton64(t); in_buf = 0;
/* wbuffer is suitably aligned for this */ if (pad >= 8) {
*(uint64_t *) &ctx->wbuffer[in_buf + pad] = t; 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;
} }
/* Process last bytes. */
sha256_process_block64(ctx->wbuffer, in_buf + pad + 8, ctx);
#if BB_LITTLE_ENDIAN #if BB_LITTLE_ENDIAN
for (i = 0; i < ARRAY_SIZE(ctx->hash); ++i) for (i = 0; i < ARRAY_SIZE(ctx->hash); ++i)
ctx->hash[i] = htonl(ctx->hash[i]); ctx->hash[i] = htonl(ctx->hash[i]);
@ -582,17 +576,30 @@ void FAST_FUNC sha512_end(void *resbuf, sha512_ctx_t *ctx)
{ {
unsigned i, pad, in_buf; 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; in_buf = ctx->total64[0] & 127;
pad = in_buf >= 112 ? 128 + 112 - in_buf : 112 - in_buf; /* Pad the buffer to the next 128-byte boundary with 0x80,0,0,0...
memset(&ctx->wbuffer[in_buf], 0, pad); * (FIPS 180-2:5.1.2)
ctx->wbuffer[in_buf] = 0x80; */
ctx->wbuffer[in_buf++] = 0x80;
*(uint64_t *) &ctx->wbuffer[in_buf + pad + 8] = hton64(ctx->total64[0] << 3); while (1) {
*(uint64_t *) &ctx->wbuffer[in_buf + pad] = hton64((ctx->total64[1] << 3) | (ctx->total64[0] >> 61)); pad = 128 - in_buf;
memset(ctx->wbuffer + in_buf, 0, pad);
sha512_process_block128(ctx->wbuffer, in_buf + pad + 16, ctx); 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 #if BB_LITTLE_ENDIAN
for (i = 0; i < ARRAY_SIZE(ctx->hash); ++i) for (i = 0; i < ARRAY_SIZE(ctx->hash); ++i)