0,0 → 1,415 |
/* sha1.c - Functions to compute SHA1 message digest of files or |
memory blocks according to the NIST specification FIPS-180-1. |
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Copyright (C) 2000, 2001, 2003, 2004, 2005, 2006, 2008 Free Software |
Foundation, Inc. |
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This program is free software; you can redistribute it and/or modify it |
under the terms of the GNU General Public License as published by the |
Free Software Foundation; either version 2, or (at your option) any |
later version. |
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This program is distributed in the hope that it will be useful, |
but WITHOUT ANY WARRANTY; without even the implied warranty of |
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
GNU General Public License for more details. |
|
You should have received a copy of the GNU General Public License |
along with this program; if not, write to the Free Software Foundation, |
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ |
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/* Written by Scott G. Miller |
Credits: |
Robert Klep <robert@ilse.nl> -- Expansion function fix |
*/ |
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#include <config.h> |
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#include "sha1.h" |
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#include <stddef.h> |
#include <string.h> |
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#if USE_UNLOCKED_IO |
# include "unlocked-io.h" |
#endif |
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#ifdef WORDS_BIGENDIAN |
# define SWAP(n) (n) |
#else |
# define SWAP(n) \ |
(((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24)) |
#endif |
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#define BLOCKSIZE 4096 |
#if BLOCKSIZE % 64 != 0 |
# error "invalid BLOCKSIZE" |
#endif |
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/* This array contains the bytes used to pad the buffer to the next |
64-byte boundary. (RFC 1321, 3.1: Step 1) */ |
static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ }; |
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/* Take a pointer to a 160 bit block of data (five 32 bit ints) and |
initialize it to the start constants of the SHA1 algorithm. This |
must be called before using hash in the call to sha1_hash. */ |
void |
sha1_init_ctx (struct sha1_ctx *ctx) |
{ |
ctx->A = 0x67452301; |
ctx->B = 0xefcdab89; |
ctx->C = 0x98badcfe; |
ctx->D = 0x10325476; |
ctx->E = 0xc3d2e1f0; |
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ctx->total[0] = ctx->total[1] = 0; |
ctx->buflen = 0; |
} |
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/* Put result from CTX in first 20 bytes following RESBUF. The result |
must be in little endian byte order. |
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IMPORTANT: On some systems it is required that RESBUF is correctly |
aligned for a 32-bit value. */ |
void * |
sha1_read_ctx (const struct sha1_ctx *ctx, void *resbuf) |
{ |
((sha1_uint32 *) resbuf)[0] = SWAP (ctx->A); |
((sha1_uint32 *) resbuf)[1] = SWAP (ctx->B); |
((sha1_uint32 *) resbuf)[2] = SWAP (ctx->C); |
((sha1_uint32 *) resbuf)[3] = SWAP (ctx->D); |
((sha1_uint32 *) resbuf)[4] = SWAP (ctx->E); |
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return resbuf; |
} |
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/* Process the remaining bytes in the internal buffer and the usual |
prolog according to the standard and write the result to RESBUF. |
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IMPORTANT: On some systems it is required that RESBUF is correctly |
aligned for a 32-bit value. */ |
void * |
sha1_finish_ctx (struct sha1_ctx *ctx, void *resbuf) |
{ |
/* Take yet unprocessed bytes into account. */ |
sha1_uint32 bytes = ctx->buflen; |
size_t size = (bytes < 56) ? 64 / 4 : 64 * 2 / 4; |
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/* Now count remaining bytes. */ |
ctx->total[0] += bytes; |
if (ctx->total[0] < bytes) |
++ctx->total[1]; |
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/* Put the 64-bit file length in *bits* at the end of the buffer. */ |
ctx->buffer[size - 2] = SWAP ((ctx->total[1] << 3) | (ctx->total[0] >> 29)); |
ctx->buffer[size - 1] = SWAP (ctx->total[0] << 3); |
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memcpy (&((char *) ctx->buffer)[bytes], fillbuf, (size - 2) * 4 - bytes); |
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/* Process last bytes. */ |
sha1_process_block (ctx->buffer, size * 4, ctx); |
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return sha1_read_ctx (ctx, resbuf); |
} |
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/* Compute SHA1 message digest for bytes read from STREAM. The |
resulting message digest number will be written into the 16 bytes |
beginning at RESBLOCK. */ |
int |
sha1_stream (FILE *stream, void *resblock) |
{ |
struct sha1_ctx ctx; |
char buffer[BLOCKSIZE + 72]; |
size_t sum; |
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/* Initialize the computation context. */ |
sha1_init_ctx (&ctx); |
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/* Iterate over full file contents. */ |
while (1) |
{ |
/* We read the file in blocks of BLOCKSIZE bytes. One call of the |
computation function processes the whole buffer so that with the |
next round of the loop another block can be read. */ |
size_t n; |
sum = 0; |
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/* Read block. Take care for partial reads. */ |
while (1) |
{ |
n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream); |
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sum += n; |
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if (sum == BLOCKSIZE) |
break; |
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if (n == 0) |
{ |
/* Check for the error flag IFF N == 0, so that we don't |
exit the loop after a partial read due to e.g., EAGAIN |
or EWOULDBLOCK. */ |
if (ferror (stream)) |
return 1; |
goto process_partial_block; |
} |
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/* We've read at least one byte, so ignore errors. But always |
check for EOF, since feof may be true even though N > 0. |
Otherwise, we could end up calling fread after EOF. */ |
if (feof (stream)) |
goto process_partial_block; |
} |
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/* Process buffer with BLOCKSIZE bytes. Note that |
BLOCKSIZE % 64 == 0 |
*/ |
sha1_process_block (buffer, BLOCKSIZE, &ctx); |
} |
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process_partial_block:; |
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/* Process any remaining bytes. */ |
if (sum > 0) |
sha1_process_bytes (buffer, sum, &ctx); |
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/* Construct result in desired memory. */ |
sha1_finish_ctx (&ctx, resblock); |
return 0; |
} |
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/* Compute SHA1 message digest for LEN bytes beginning at BUFFER. The |
result is always in little endian byte order, so that a byte-wise |
output yields to the wanted ASCII representation of the message |
digest. */ |
void * |
sha1_buffer (const char *buffer, size_t len, void *resblock) |
{ |
struct sha1_ctx ctx; |
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/* Initialize the computation context. */ |
sha1_init_ctx (&ctx); |
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/* Process whole buffer but last len % 64 bytes. */ |
sha1_process_bytes (buffer, len, &ctx); |
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/* Put result in desired memory area. */ |
return sha1_finish_ctx (&ctx, resblock); |
} |
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void |
sha1_process_bytes (const void *buffer, size_t len, struct sha1_ctx *ctx) |
{ |
/* When we already have some bits in our internal buffer concatenate |
both inputs first. */ |
if (ctx->buflen != 0) |
{ |
size_t left_over = ctx->buflen; |
size_t add = 128 - left_over > len ? len : 128 - left_over; |
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memcpy (&((char *) ctx->buffer)[left_over], buffer, add); |
ctx->buflen += add; |
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if (ctx->buflen > 64) |
{ |
sha1_process_block (ctx->buffer, ctx->buflen & ~63, ctx); |
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ctx->buflen &= 63; |
/* The regions in the following copy operation cannot overlap. */ |
memcpy (ctx->buffer, |
&((char *) ctx->buffer)[(left_over + add) & ~63], |
ctx->buflen); |
} |
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buffer = (const char *) buffer + add; |
len -= add; |
} |
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/* Process available complete blocks. */ |
if (len >= 64) |
{ |
#if !_STRING_ARCH_unaligned |
# define alignof(type) offsetof (struct { char c; type x; }, x) |
# define UNALIGNED_P(p) (((size_t) p) % alignof (sha1_uint32) != 0) |
if (UNALIGNED_P (buffer)) |
while (len > 64) |
{ |
sha1_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx); |
buffer = (const char *) buffer + 64; |
len -= 64; |
} |
else |
#endif |
{ |
sha1_process_block (buffer, len & ~63, ctx); |
buffer = (const char *) buffer + (len & ~63); |
len &= 63; |
} |
} |
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/* Move remaining bytes in internal buffer. */ |
if (len > 0) |
{ |
size_t left_over = ctx->buflen; |
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memcpy (&((char *) ctx->buffer)[left_over], buffer, len); |
left_over += len; |
if (left_over >= 64) |
{ |
sha1_process_block (ctx->buffer, 64, ctx); |
left_over -= 64; |
memcpy (ctx->buffer, &ctx->buffer[16], left_over); |
} |
ctx->buflen = left_over; |
} |
} |
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/* --- Code below is the primary difference between md5.c and sha1.c --- */ |
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/* SHA1 round constants */ |
#define K1 0x5a827999 |
#define K2 0x6ed9eba1 |
#define K3 0x8f1bbcdc |
#define K4 0xca62c1d6 |
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/* Round functions. Note that F2 is the same as F4. */ |
#define F1(B,C,D) ( D ^ ( B & ( C ^ D ) ) ) |
#define F2(B,C,D) (B ^ C ^ D) |
#define F3(B,C,D) ( ( B & C ) | ( D & ( B | C ) ) ) |
#define F4(B,C,D) (B ^ C ^ D) |
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/* Process LEN bytes of BUFFER, accumulating context into CTX. |
It is assumed that LEN % 64 == 0. |
Most of this code comes from GnuPG's cipher/sha1.c. */ |
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void |
sha1_process_block (const void *buffer, size_t len, struct sha1_ctx *ctx) |
{ |
const sha1_uint32 *words = (const sha1_uint32*) buffer; |
size_t nwords = len / sizeof (sha1_uint32); |
const sha1_uint32 *endp = words + nwords; |
sha1_uint32 x[16]; |
sha1_uint32 a = ctx->A; |
sha1_uint32 b = ctx->B; |
sha1_uint32 c = ctx->C; |
sha1_uint32 d = ctx->D; |
sha1_uint32 e = ctx->E; |
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/* First increment the byte count. RFC 1321 specifies the possible |
length of the file up to 2^64 bits. Here we only compute the |
number of bytes. Do a double word increment. */ |
ctx->total[0] += len; |
ctx->total[1] += ((len >> 31) >> 1) + (ctx->total[0] < len); |
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#define rol(x, n) (((x) << (n)) | ((sha1_uint32) (x) >> (32 - (n)))) |
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#define M(I) ( tm = x[I&0x0f] ^ x[(I-14)&0x0f] \ |
^ x[(I-8)&0x0f] ^ x[(I-3)&0x0f] \ |
, (x[I&0x0f] = rol(tm, 1)) ) |
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#define R(A,B,C,D,E,F,K,M) do { E += rol( A, 5 ) \ |
+ F( B, C, D ) \ |
+ K \ |
+ M; \ |
B = rol( B, 30 ); \ |
} while(0) |
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while (words < endp) |
{ |
sha1_uint32 tm; |
int t; |
for (t = 0; t < 16; t++) |
{ |
x[t] = SWAP (*words); |
words++; |
} |
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R( a, b, c, d, e, F1, K1, x[ 0] ); |
R( e, a, b, c, d, F1, K1, x[ 1] ); |
R( d, e, a, b, c, F1, K1, x[ 2] ); |
R( c, d, e, a, b, F1, K1, x[ 3] ); |
R( b, c, d, e, a, F1, K1, x[ 4] ); |
R( a, b, c, d, e, F1, K1, x[ 5] ); |
R( e, a, b, c, d, F1, K1, x[ 6] ); |
R( d, e, a, b, c, F1, K1, x[ 7] ); |
R( c, d, e, a, b, F1, K1, x[ 8] ); |
R( b, c, d, e, a, F1, K1, x[ 9] ); |
R( a, b, c, d, e, F1, K1, x[10] ); |
R( e, a, b, c, d, F1, K1, x[11] ); |
R( d, e, a, b, c, F1, K1, x[12] ); |
R( c, d, e, a, b, F1, K1, x[13] ); |
R( b, c, d, e, a, F1, K1, x[14] ); |
R( a, b, c, d, e, F1, K1, x[15] ); |
R( e, a, b, c, d, F1, K1, M(16) ); |
R( d, e, a, b, c, F1, K1, M(17) ); |
R( c, d, e, a, b, F1, K1, M(18) ); |
R( b, c, d, e, a, F1, K1, M(19) ); |
R( a, b, c, d, e, F2, K2, M(20) ); |
R( e, a, b, c, d, F2, K2, M(21) ); |
R( d, e, a, b, c, F2, K2, M(22) ); |
R( c, d, e, a, b, F2, K2, M(23) ); |
R( b, c, d, e, a, F2, K2, M(24) ); |
R( a, b, c, d, e, F2, K2, M(25) ); |
R( e, a, b, c, d, F2, K2, M(26) ); |
R( d, e, a, b, c, F2, K2, M(27) ); |
R( c, d, e, a, b, F2, K2, M(28) ); |
R( b, c, d, e, a, F2, K2, M(29) ); |
R( a, b, c, d, e, F2, K2, M(30) ); |
R( e, a, b, c, d, F2, K2, M(31) ); |
R( d, e, a, b, c, F2, K2, M(32) ); |
R( c, d, e, a, b, F2, K2, M(33) ); |
R( b, c, d, e, a, F2, K2, M(34) ); |
R( a, b, c, d, e, F2, K2, M(35) ); |
R( e, a, b, c, d, F2, K2, M(36) ); |
R( d, e, a, b, c, F2, K2, M(37) ); |
R( c, d, e, a, b, F2, K2, M(38) ); |
R( b, c, d, e, a, F2, K2, M(39) ); |
R( a, b, c, d, e, F3, K3, M(40) ); |
R( e, a, b, c, d, F3, K3, M(41) ); |
R( d, e, a, b, c, F3, K3, M(42) ); |
R( c, d, e, a, b, F3, K3, M(43) ); |
R( b, c, d, e, a, F3, K3, M(44) ); |
R( a, b, c, d, e, F3, K3, M(45) ); |
R( e, a, b, c, d, F3, K3, M(46) ); |
R( d, e, a, b, c, F3, K3, M(47) ); |
R( c, d, e, a, b, F3, K3, M(48) ); |
R( b, c, d, e, a, F3, K3, M(49) ); |
R( a, b, c, d, e, F3, K3, M(50) ); |
R( e, a, b, c, d, F3, K3, M(51) ); |
R( d, e, a, b, c, F3, K3, M(52) ); |
R( c, d, e, a, b, F3, K3, M(53) ); |
R( b, c, d, e, a, F3, K3, M(54) ); |
R( a, b, c, d, e, F3, K3, M(55) ); |
R( e, a, b, c, d, F3, K3, M(56) ); |
R( d, e, a, b, c, F3, K3, M(57) ); |
R( c, d, e, a, b, F3, K3, M(58) ); |
R( b, c, d, e, a, F3, K3, M(59) ); |
R( a, b, c, d, e, F4, K4, M(60) ); |
R( e, a, b, c, d, F4, K4, M(61) ); |
R( d, e, a, b, c, F4, K4, M(62) ); |
R( c, d, e, a, b, F4, K4, M(63) ); |
R( b, c, d, e, a, F4, K4, M(64) ); |
R( a, b, c, d, e, F4, K4, M(65) ); |
R( e, a, b, c, d, F4, K4, M(66) ); |
R( d, e, a, b, c, F4, K4, M(67) ); |
R( c, d, e, a, b, F4, K4, M(68) ); |
R( b, c, d, e, a, F4, K4, M(69) ); |
R( a, b, c, d, e, F4, K4, M(70) ); |
R( e, a, b, c, d, F4, K4, M(71) ); |
R( d, e, a, b, c, F4, K4, M(72) ); |
R( c, d, e, a, b, F4, K4, M(73) ); |
R( b, c, d, e, a, F4, K4, M(74) ); |
R( a, b, c, d, e, F4, K4, M(75) ); |
R( e, a, b, c, d, F4, K4, M(76) ); |
R( d, e, a, b, c, F4, K4, M(77) ); |
R( c, d, e, a, b, F4, K4, M(78) ); |
R( b, c, d, e, a, F4, K4, M(79) ); |
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a = ctx->A += a; |
b = ctx->B += b; |
c = ctx->C += c; |
d = ctx->D += d; |
e = ctx->E += e; |
} |
} |