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emacs/lib/sha1.c
Paul Eggert 3add626f14 Update from Gnulib by running admin/merge-gnulib
2024-01-20 11:45:38 -08:00

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/* sha1.c - Functions to compute SHA1 message digest of files or
memory blocks according to the NIST specification FIPS-180-1.
Copyright (C) 2000-2001, 2003-2006, 2008-2024 Free Software Foundation, Inc.
This file is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of the
License, or (at your option) any later version.
This file 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 Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>. */
/* Written by Scott G. Miller
Credits:
Robert Klep <robert@ilse.nl> -- Expansion function fix
*/
#include <config.h>
/* Specification. */
#if HAVE_OPENSSL_SHA1
# define GL_OPENSSL_INLINE _GL_EXTERN_INLINE
#endif
#include "sha1.h"
#include <stdint.h>
#include <string.h>
#include <byteswap.h>
#ifdef WORDS_BIGENDIAN
# define SWAP(n) (n)
#else
# define SWAP(n) bswap_32 (n)
#endif
#if ! HAVE_OPENSSL_SHA1
/* 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, ... */ };
/* 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;
ctx->total[0] = ctx->total[1] = 0;
ctx->buflen = 0;
}
/* Copy the 4 byte value from v into the memory location pointed to by *cp,
If your architecture allows unaligned access this is equivalent to
* (uint32_t *) cp = v */
static void
set_uint32 (char *cp, uint32_t v)
{
memcpy (cp, &v, sizeof v);
}
/* Put result from CTX in first 20 bytes following RESBUF. The result
must be in little endian byte order. */
void *
sha1_read_ctx (const struct sha1_ctx *ctx, void *resbuf)
{
char *r = resbuf;
set_uint32 (r + 0 * sizeof ctx->A, SWAP (ctx->A));
set_uint32 (r + 1 * sizeof ctx->B, SWAP (ctx->B));
set_uint32 (r + 2 * sizeof ctx->C, SWAP (ctx->C));
set_uint32 (r + 3 * sizeof ctx->D, SWAP (ctx->D));
set_uint32 (r + 4 * sizeof ctx->E, SWAP (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. */
void *
sha1_finish_ctx (struct sha1_ctx *ctx, void *resbuf)
{
/* Take yet unprocessed bytes into account. */
uint32_t bytes = ctx->buflen;
size_t size = (bytes < 56) ? 64 / 4 : 64 * 2 / 4;
/* Now count remaining bytes. */
ctx->total[0] += bytes;
if (ctx->total[0] < bytes)
++ctx->total[1];
/* 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);
memcpy (&((char *) ctx->buffer)[bytes], fillbuf, (size - 2) * 4 - bytes);
/* Process last bytes. */
sha1_process_block (ctx->buffer, size * 4, ctx);
return sha1_read_ctx (ctx, resbuf);
}
/* 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;
/* Initialize the computation context. */
sha1_init_ctx (&ctx);
/* Process whole buffer but last len % 64 bytes. */
sha1_process_bytes (buffer, len, &ctx);
/* Put result in desired memory area. */
return sha1_finish_ctx (&ctx, resblock);
}
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;
memcpy (&((char *) ctx->buffer)[left_over], buffer, add);
ctx->buflen += add;
if (ctx->buflen > 64)
{
sha1_process_block (ctx->buffer, ctx->buflen & ~63, ctx);
ctx->buflen &= 63;
/* The regions in the following copy operation cannot overlap,
because ctx->buflen < 64 ≤ (left_over + add) & ~63. */
memcpy (ctx->buffer,
&((char *) 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 || _STRING_INLINE_unaligned)
# define UNALIGNED_P(p) ((uintptr_t) (p) % alignof (uint32_t) != 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;
}
}
/* Move remaining bytes in internal buffer. */
if (len > 0)
{
size_t left_over = ctx->buflen;
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;
/* The regions in the following copy operation cannot overlap,
because left_over ≤ 64. */
memcpy (ctx->buffer, &ctx->buffer[16], left_over);
}
ctx->buflen = left_over;
}
}
/* --- Code below is the primary difference between md5.c and sha1.c --- */
/* SHA1 round constants */
#define K1 0x5a827999
#define K2 0x6ed9eba1
#define K3 0x8f1bbcdc
#define K4 0xca62c1d6
/* 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. */
void
sha1_process_block (const void *buffer, size_t len, struct sha1_ctx *ctx)
{
const uint32_t *words = buffer;
size_t nwords = len / sizeof (uint32_t);
const uint32_t *endp = words + nwords;
uint32_t x[16];
uint32_t a = ctx->A;
uint32_t b = ctx->B;
uint32_t c = ctx->C;
uint32_t d = ctx->D;
uint32_t e = ctx->E;
uint32_t lolen = len;
/* 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] += lolen;
ctx->total[1] += (len >> 31 >> 1) + (ctx->total[0] < lolen);
#define rol(x, n) (((x) << (n)) | ((uint32_t) (x) >> (32 - (n))))
#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)
{
uint32_t tm;
int t;
for (t = 0; t < 16; t++)
{
x[t] = SWAP (*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;
}
}
#endif
/*
* Hey Emacs!
* Local Variables:
* coding: utf-8
* End:
*/
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