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pacman/lib/libalpm/sha1.c
2006-10-15 22:20:21 +00:00

416 lines
13 KiB
C

/* sha.c - Functions to compute SHA1 message digest of files or
memory blocks according to the NIST specification FIPS-180-1.
Copyright (C) 2000, 2001, 2003 Free Software Foundation, Inc.
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.
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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
/* Written by Scott G. Miller
Credits:
Robert Klep <robert@ilse.nl> -- Expansion function fix
*/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <libintl.h>
#include "util.h"
#include "sha1.h"
#include <sys/types.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>
/*
Not-swap is a macro that does an endian swap on architectures that are
big-endian, as SHA needs some data in a little-endian format
*/
#ifdef WORDS_BIGENDIAN
# define NOTSWAP(n) (n)
# define SWAP(n) \
(((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
#else
# define NOTSWAP(n) \
(((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
# define SWAP(n) (n)
#endif
#define BLOCKSIZE 4096
/* Ensure that BLOCKSIZE is a multiple of 64. */
#if BLOCKSIZE % 64 != 0
/* FIXME-someday (soon?): use #error instead of this kludge. */
"invalid BLOCKSIZE"
#endif
/* 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, ... */ };
/* Starting with the result of former calls of this function (or the
initialization function update the context for the next LEN bytes
starting at BUFFER.
It is necessary that LEN is a multiple of 64!!! */
static void sha_process_block (const void *buffer, size_t len,
struct sha_ctx *ctx);
/* Starting with the result of former calls of this function (or the
initialization function update the context for the next LEN bytes
starting at BUFFER.
It is NOT required that LEN is a multiple of 64. */
static void sha_process_bytes (const void *buffer, size_t len,
struct sha_ctx *ctx);
/* Put result from CTX in first 20 bytes following RESBUF. 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.
IMPORTANT: On some systems it is required that RESBUF is correctly
aligned for a 32 bits value. */
static void *sha_read_ctx (const struct sha_ctx *ctx, void *resbuf);
/*
Takes a pointer to a 160 bit block of data (five 32 bit ints) and
intializes it to the start constants of the SHA1 algorithm. This
must be called before using hash in the call to sha_hash
*/
static void
sha_init_ctx (struct sha_ctx *ctx)
{
ctx->A = 0x67452301;
ctx->B = 0xefcdab89;
ctx->C = 0x98badcfe;
ctx->D = 0x10325476;
ctx->E = 0xc3d2e1f0;
ctx->total[0] = ctx->total[1] = 0;
ctx->buflen = 0;
}
/* Put result from CTX in first 20 bytes following RESBUF. The result
must be in little endian byte order.
IMPORTANT: On some systems it is required that RESBUF is correctly
aligned for a 32 bits value. */
static void *
sha_read_ctx (const struct sha_ctx *ctx, void *resbuf)
{
((sha_uint32 *) resbuf)[0] = NOTSWAP (ctx->A);
((sha_uint32 *) resbuf)[1] = NOTSWAP (ctx->B);
((sha_uint32 *) resbuf)[2] = NOTSWAP (ctx->C);
((sha_uint32 *) resbuf)[3] = NOTSWAP (ctx->D);
((sha_uint32 *) resbuf)[4] = NOTSWAP (ctx->E);
return resbuf;
}
/* Process the remaining bytes in the internal buffer and the usual
prolog according to the standard and write the result to RESBUF.
IMPORTANT: On some systems it is required that RESBUF is correctly
aligned for a 32 bits value. */
static void *
sha_finish_ctx (struct sha_ctx *ctx, void *resbuf)
{
/* Take yet unprocessed bytes into account. */
sha_uint32 bytes = ctx->buflen;
size_t pad;
/* Now count remaining bytes. */
ctx->total[0] += bytes;
if (ctx->total[0] < bytes)
++ctx->total[1];
pad = bytes >= 56 ? 64 + 56 - bytes : 56 - bytes;
memcpy (&ctx->buffer[bytes], fillbuf, pad);
/* Put the 64-bit file length in *bits* at the end of the buffer. */
*(sha_uint32 *) &ctx->buffer[bytes + pad + 4] = NOTSWAP (ctx->total[0] << 3);
*(sha_uint32 *) &ctx->buffer[bytes + pad] = NOTSWAP ((ctx->total[1] << 3) |
(ctx->total[0] >> 29));
/* Process last bytes. */
sha_process_block (ctx->buffer, bytes + pad + 8, ctx);
return sha_read_ctx (ctx, resbuf);
}
static void
sha_process_bytes (const void *buffer, size_t len, struct sha_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;
memcpy (&ctx->buffer[left_over], buffer, add);
ctx->buflen += add;
if (ctx->buflen > 64)
{
sha_process_block (ctx->buffer, ctx->buflen & ~63, ctx);
ctx->buflen &= 63;
/* The regions in the following copy operation cannot overlap. */
memcpy (ctx->buffer, &ctx->buffer[(left_over + add) & ~63],
ctx->buflen);
}
buffer = (const char *) buffer + add;
len -= add;
}
/* Process available complete blocks. */
if (len >= 64)
{
#if !_STRING_ARCH_unaligned
/* To check alignment gcc has an appropriate operator. Other
compilers don't. */
# if __GNUC__ >= 2
# define UNALIGNED_P(p) (((sha_uintptr) p) % __alignof__ (sha_uint32) != 0)
# else
# define UNALIGNED_P(p) (((sha_uintptr) p) % sizeof (sha_uint32) != 0)
# endif
if (UNALIGNED_P (buffer))
while (len > 64)
{
sha_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx);
buffer = (const char *) buffer + 64;
len -= 64;
}
else
#endif
{
sha_process_block (buffer, len & ~63, ctx);
buffer = (const char *) buffer + (len & ~63);
len &= 63;
}
}
/* Move remaining bytes in internal buffer. */
if (len > 0)
{
size_t left_over = ctx->buflen;
memcpy (&ctx->buffer[left_over], buffer, len);
left_over += len;
if (left_over >= 64)
{
sha_process_block (ctx->buffer, 64, ctx);
left_over -= 64;
memcpy (ctx->buffer, &ctx->buffer[64], left_over);
}
ctx->buflen = left_over;
}
}
/* --- Code below is the primary difference between md5.c and sha.c --- */
/* SHA1 round constants */
#define K1 0x5a827999L
#define K2 0x6ed9eba1L
#define K3 0x8f1bbcdcL
#define K4 0xca62c1d6L
/* 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)
/* 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. */
static void
sha_process_block (const void *buffer, size_t len, struct sha_ctx *ctx)
{
const sha_uint32 *words = buffer;
size_t nwords = len / sizeof (sha_uint32);
const sha_uint32 *endp = words + nwords;
sha_uint32 x[16];
sha_uint32 a = ctx->A;
sha_uint32 b = ctx->B;
sha_uint32 c = ctx->C;
sha_uint32 d = ctx->D;
sha_uint32 e = ctx->E;
/* 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;
if (ctx->total[0] < len)
++ctx->total[1];
#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)) )
#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)
while (words < endp)
{
sha_uint32 tm;
int t;
/* FIXME: see sha1.c for a better implementation. */
for (t = 0; t < 16; t++)
{
x[t] = NOTSWAP (*words);
words++;
}
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) );
a = ctx->A += a;
b = ctx->B += b;
c = ctx->C += c;
d = ctx->D += d;
e = ctx->E += e;
}
}
/* Copyright (C) 1990-2, RSA Data Security, Inc. Created 1990. All
rights reserved.
RSA Data Security, Inc. makes no representations concerning either
the merchantability of this software or the suitability of this
software for any particular purpose. It is provided "as is"
without express or implied warranty of any kind.
These notices must be retained in any copies of any part of this
documentation and/or software.
*/
char* _alpm_SHAFile(char *filename) {
FILE *file;
struct sha_ctx context;
int len, i;
unsigned char buffer[1024], digest[20];
char *ret;
if((file = fopen(filename, "rb")) == NULL) {
fprintf(stderr, _("%s can't be opened\n"), filename);
} else {
sha_init_ctx(&context);
while((len = fread(buffer, 1, 1024, file))) {
sha_process_bytes(buffer, len, &context);
}
sha_finish_ctx(&context, digest);
fclose(file);
#ifdef DEBUG
SHAPrint(digest);
#endif
ret = (char*)malloc(41);
ret[0] = '\0';
for(i = 0; i < 20; i++) {
sprintf(ret, "%s%02x", ret, digest[i]);
}
return(ret);
}
return(NULL);
}