mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-23 03:10:05 +00:00
0838e0b926
2001-12-13 Ulrich Drepper <drepper@redhat.com> * crypt/md5.c (md5_process_bytes): Correct handling of alignment. Patch by Eric Sharkey <sharkey@netrics.com>. * crypt/md5test.c (main): Add test for multiple calls to __md5_process_bytes to itererate over input string.
458 lines
14 KiB
C
458 lines
14 KiB
C
/* Functions to compute MD5 message digest of files or memory blocks.
|
|
according to the definition of MD5 in RFC 1321 from April 1992.
|
|
Copyright (C) 1995,1996,1997,1999,2000,2001 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library 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.
|
|
|
|
The GNU C Library 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 the GNU C Library; if not, write to the Free
|
|
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
|
02111-1307 USA. */
|
|
|
|
/* Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995. */
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
# include <config.h>
|
|
#endif
|
|
|
|
#include <sys/types.h>
|
|
|
|
#if STDC_HEADERS || defined _LIBC
|
|
# include <stdlib.h>
|
|
# include <string.h>
|
|
#else
|
|
# ifndef HAVE_MEMCPY
|
|
# define memcpy(d, s, n) bcopy ((s), (d), (n))
|
|
# endif
|
|
#endif
|
|
|
|
#include "md5.h"
|
|
|
|
#ifdef _LIBC
|
|
# include <endian.h>
|
|
# if __BYTE_ORDER == __BIG_ENDIAN
|
|
# define WORDS_BIGENDIAN 1
|
|
# endif
|
|
/* We need to keep the namespace clean so define the MD5 function
|
|
protected using leading __ . */
|
|
# define md5_init_ctx __md5_init_ctx
|
|
# define md5_process_block __md5_process_block
|
|
# define md5_process_bytes __md5_process_bytes
|
|
# define md5_finish_ctx __md5_finish_ctx
|
|
# define md5_read_ctx __md5_read_ctx
|
|
# define md5_stream __md5_stream
|
|
# define md5_buffer __md5_buffer
|
|
#endif
|
|
|
|
#ifdef WORDS_BIGENDIAN
|
|
# define SWAP(n) \
|
|
(((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
|
|
#else
|
|
# define SWAP(n) (n)
|
|
#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, ... */ };
|
|
|
|
|
|
/* Initialize structure containing state of computation.
|
|
(RFC 1321, 3.3: Step 3) */
|
|
void
|
|
md5_init_ctx (ctx)
|
|
struct md5_ctx *ctx;
|
|
{
|
|
ctx->A = 0x67452301;
|
|
ctx->B = 0xefcdab89;
|
|
ctx->C = 0x98badcfe;
|
|
ctx->D = 0x10325476;
|
|
|
|
ctx->total[0] = ctx->total[1] = 0;
|
|
ctx->buflen = 0;
|
|
}
|
|
|
|
/* Put result from CTX in first 16 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. */
|
|
void *
|
|
md5_read_ctx (ctx, resbuf)
|
|
const struct md5_ctx *ctx;
|
|
void *resbuf;
|
|
{
|
|
((md5_uint32 *) resbuf)[0] = SWAP (ctx->A);
|
|
((md5_uint32 *) resbuf)[1] = SWAP (ctx->B);
|
|
((md5_uint32 *) resbuf)[2] = SWAP (ctx->C);
|
|
((md5_uint32 *) resbuf)[3] = SWAP (ctx->D);
|
|
|
|
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. */
|
|
void *
|
|
md5_finish_ctx (ctx, resbuf)
|
|
struct md5_ctx *ctx;
|
|
void *resbuf;
|
|
{
|
|
/* Take yet unprocessed bytes into account. */
|
|
md5_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. */
|
|
*(md5_uint32 *) &ctx->buffer[bytes + pad] = SWAP (ctx->total[0] << 3);
|
|
*(md5_uint32 *) &ctx->buffer[bytes + pad + 4] = SWAP ((ctx->total[1] << 3) |
|
|
(ctx->total[0] >> 29));
|
|
|
|
/* Process last bytes. */
|
|
md5_process_block (ctx->buffer, bytes + pad + 8, ctx);
|
|
|
|
return md5_read_ctx (ctx, resbuf);
|
|
}
|
|
|
|
/* Compute MD5 message digest for bytes read from STREAM. The
|
|
resulting message digest number will be written into the 16 bytes
|
|
beginning at RESBLOCK. */
|
|
int
|
|
md5_stream (stream, resblock)
|
|
FILE *stream;
|
|
void *resblock;
|
|
{
|
|
/* Important: BLOCKSIZE must be a multiple of 64. */
|
|
#define BLOCKSIZE 4096
|
|
struct md5_ctx ctx;
|
|
char buffer[BLOCKSIZE + 72];
|
|
size_t sum;
|
|
|
|
/* Initialize the computation context. */
|
|
md5_init_ctx (&ctx);
|
|
|
|
/* 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;
|
|
|
|
/* Read block. Take care for partial reads. */
|
|
do
|
|
{
|
|
n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
|
|
|
|
sum += n;
|
|
}
|
|
while (sum < BLOCKSIZE && n != 0);
|
|
if (n == 0 && ferror (stream))
|
|
return 1;
|
|
|
|
/* If end of file is reached, end the loop. */
|
|
if (n == 0)
|
|
break;
|
|
|
|
/* Process buffer with BLOCKSIZE bytes. Note that
|
|
BLOCKSIZE % 64 == 0
|
|
*/
|
|
md5_process_block (buffer, BLOCKSIZE, &ctx);
|
|
}
|
|
|
|
/* Add the last bytes if necessary. */
|
|
if (sum > 0)
|
|
md5_process_bytes (buffer, sum, &ctx);
|
|
|
|
/* Construct result in desired memory. */
|
|
md5_finish_ctx (&ctx, resblock);
|
|
return 0;
|
|
}
|
|
|
|
/* Compute MD5 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 *
|
|
md5_buffer (buffer, len, resblock)
|
|
const char *buffer;
|
|
size_t len;
|
|
void *resblock;
|
|
{
|
|
struct md5_ctx ctx;
|
|
|
|
/* Initialize the computation context. */
|
|
md5_init_ctx (&ctx);
|
|
|
|
/* Process whole buffer but last len % 64 bytes. */
|
|
md5_process_bytes (buffer, len, &ctx);
|
|
|
|
/* Put result in desired memory area. */
|
|
return md5_finish_ctx (&ctx, resblock);
|
|
}
|
|
|
|
|
|
void
|
|
md5_process_bytes (buffer, len, ctx)
|
|
const void *buffer;
|
|
size_t len;
|
|
struct md5_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)
|
|
{
|
|
md5_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) (((md5_uintptr) p) % __alignof__ (md5_uint32) != 0)
|
|
# else
|
|
# define UNALIGNED_P(p) (((md5_uintptr) p) % sizeof (md5_uint32) != 0)
|
|
# endif
|
|
if (UNALIGNED_P (buffer))
|
|
while (len > 64)
|
|
{
|
|
md5_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx);
|
|
buffer = (const char *) buffer + 64;
|
|
len -= 64;
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
md5_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)
|
|
{
|
|
md5_process_block (ctx->buffer, 64, ctx);
|
|
left_over -= 64;
|
|
memcpy (ctx->buffer, &ctx->buffer[64], left_over);
|
|
}
|
|
ctx->buflen = left_over;
|
|
}
|
|
}
|
|
|
|
|
|
/* These are the four functions used in the four steps of the MD5 algorithm
|
|
and defined in the RFC 1321. The first function is a little bit optimized
|
|
(as found in Colin Plumbs public domain implementation). */
|
|
/* #define FF(b, c, d) ((b & c) | (~b & d)) */
|
|
#define FF(b, c, d) (d ^ (b & (c ^ d)))
|
|
#define FG(b, c, d) FF (d, b, c)
|
|
#define FH(b, c, d) (b ^ c ^ d)
|
|
#define FI(b, c, d) (c ^ (b | ~d))
|
|
|
|
/* Process LEN bytes of BUFFER, accumulating context into CTX.
|
|
It is assumed that LEN % 64 == 0. */
|
|
|
|
void
|
|
md5_process_block (buffer, len, ctx)
|
|
const void *buffer;
|
|
size_t len;
|
|
struct md5_ctx *ctx;
|
|
{
|
|
md5_uint32 correct_words[16];
|
|
const md5_uint32 *words = buffer;
|
|
size_t nwords = len / sizeof (md5_uint32);
|
|
const md5_uint32 *endp = words + nwords;
|
|
md5_uint32 A = ctx->A;
|
|
md5_uint32 B = ctx->B;
|
|
md5_uint32 C = ctx->C;
|
|
md5_uint32 D = ctx->D;
|
|
|
|
/* 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];
|
|
|
|
/* Process all bytes in the buffer with 64 bytes in each round of
|
|
the loop. */
|
|
while (words < endp)
|
|
{
|
|
md5_uint32 *cwp = correct_words;
|
|
md5_uint32 A_save = A;
|
|
md5_uint32 B_save = B;
|
|
md5_uint32 C_save = C;
|
|
md5_uint32 D_save = D;
|
|
|
|
/* First round: using the given function, the context and a constant
|
|
the next context is computed. Because the algorithms processing
|
|
unit is a 32-bit word and it is determined to work on words in
|
|
little endian byte order we perhaps have to change the byte order
|
|
before the computation. To reduce the work for the next steps
|
|
we store the swapped words in the array CORRECT_WORDS. */
|
|
|
|
#define OP(a, b, c, d, s, T) \
|
|
do \
|
|
{ \
|
|
a += FF (b, c, d) + (*cwp++ = SWAP (*words)) + T; \
|
|
++words; \
|
|
CYCLIC (a, s); \
|
|
a += b; \
|
|
} \
|
|
while (0)
|
|
|
|
/* It is unfortunate that C does not provide an operator for
|
|
cyclic rotation. Hope the C compiler is smart enough. */
|
|
#define CYCLIC(w, s) (w = (w << s) | (w >> (32 - s)))
|
|
|
|
/* Before we start, one word to the strange constants.
|
|
They are defined in RFC 1321 as
|
|
|
|
T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64
|
|
*/
|
|
|
|
/* Round 1. */
|
|
OP (A, B, C, D, 7, 0xd76aa478);
|
|
OP (D, A, B, C, 12, 0xe8c7b756);
|
|
OP (C, D, A, B, 17, 0x242070db);
|
|
OP (B, C, D, A, 22, 0xc1bdceee);
|
|
OP (A, B, C, D, 7, 0xf57c0faf);
|
|
OP (D, A, B, C, 12, 0x4787c62a);
|
|
OP (C, D, A, B, 17, 0xa8304613);
|
|
OP (B, C, D, A, 22, 0xfd469501);
|
|
OP (A, B, C, D, 7, 0x698098d8);
|
|
OP (D, A, B, C, 12, 0x8b44f7af);
|
|
OP (C, D, A, B, 17, 0xffff5bb1);
|
|
OP (B, C, D, A, 22, 0x895cd7be);
|
|
OP (A, B, C, D, 7, 0x6b901122);
|
|
OP (D, A, B, C, 12, 0xfd987193);
|
|
OP (C, D, A, B, 17, 0xa679438e);
|
|
OP (B, C, D, A, 22, 0x49b40821);
|
|
|
|
/* For the second to fourth round we have the possibly swapped words
|
|
in CORRECT_WORDS. Redefine the macro to take an additional first
|
|
argument specifying the function to use. */
|
|
#undef OP
|
|
#define OP(f, a, b, c, d, k, s, T) \
|
|
do \
|
|
{ \
|
|
a += f (b, c, d) + correct_words[k] + T; \
|
|
CYCLIC (a, s); \
|
|
a += b; \
|
|
} \
|
|
while (0)
|
|
|
|
/* Round 2. */
|
|
OP (FG, A, B, C, D, 1, 5, 0xf61e2562);
|
|
OP (FG, D, A, B, C, 6, 9, 0xc040b340);
|
|
OP (FG, C, D, A, B, 11, 14, 0x265e5a51);
|
|
OP (FG, B, C, D, A, 0, 20, 0xe9b6c7aa);
|
|
OP (FG, A, B, C, D, 5, 5, 0xd62f105d);
|
|
OP (FG, D, A, B, C, 10, 9, 0x02441453);
|
|
OP (FG, C, D, A, B, 15, 14, 0xd8a1e681);
|
|
OP (FG, B, C, D, A, 4, 20, 0xe7d3fbc8);
|
|
OP (FG, A, B, C, D, 9, 5, 0x21e1cde6);
|
|
OP (FG, D, A, B, C, 14, 9, 0xc33707d6);
|
|
OP (FG, C, D, A, B, 3, 14, 0xf4d50d87);
|
|
OP (FG, B, C, D, A, 8, 20, 0x455a14ed);
|
|
OP (FG, A, B, C, D, 13, 5, 0xa9e3e905);
|
|
OP (FG, D, A, B, C, 2, 9, 0xfcefa3f8);
|
|
OP (FG, C, D, A, B, 7, 14, 0x676f02d9);
|
|
OP (FG, B, C, D, A, 12, 20, 0x8d2a4c8a);
|
|
|
|
/* Round 3. */
|
|
OP (FH, A, B, C, D, 5, 4, 0xfffa3942);
|
|
OP (FH, D, A, B, C, 8, 11, 0x8771f681);
|
|
OP (FH, C, D, A, B, 11, 16, 0x6d9d6122);
|
|
OP (FH, B, C, D, A, 14, 23, 0xfde5380c);
|
|
OP (FH, A, B, C, D, 1, 4, 0xa4beea44);
|
|
OP (FH, D, A, B, C, 4, 11, 0x4bdecfa9);
|
|
OP (FH, C, D, A, B, 7, 16, 0xf6bb4b60);
|
|
OP (FH, B, C, D, A, 10, 23, 0xbebfbc70);
|
|
OP (FH, A, B, C, D, 13, 4, 0x289b7ec6);
|
|
OP (FH, D, A, B, C, 0, 11, 0xeaa127fa);
|
|
OP (FH, C, D, A, B, 3, 16, 0xd4ef3085);
|
|
OP (FH, B, C, D, A, 6, 23, 0x04881d05);
|
|
OP (FH, A, B, C, D, 9, 4, 0xd9d4d039);
|
|
OP (FH, D, A, B, C, 12, 11, 0xe6db99e5);
|
|
OP (FH, C, D, A, B, 15, 16, 0x1fa27cf8);
|
|
OP (FH, B, C, D, A, 2, 23, 0xc4ac5665);
|
|
|
|
/* Round 4. */
|
|
OP (FI, A, B, C, D, 0, 6, 0xf4292244);
|
|
OP (FI, D, A, B, C, 7, 10, 0x432aff97);
|
|
OP (FI, C, D, A, B, 14, 15, 0xab9423a7);
|
|
OP (FI, B, C, D, A, 5, 21, 0xfc93a039);
|
|
OP (FI, A, B, C, D, 12, 6, 0x655b59c3);
|
|
OP (FI, D, A, B, C, 3, 10, 0x8f0ccc92);
|
|
OP (FI, C, D, A, B, 10, 15, 0xffeff47d);
|
|
OP (FI, B, C, D, A, 1, 21, 0x85845dd1);
|
|
OP (FI, A, B, C, D, 8, 6, 0x6fa87e4f);
|
|
OP (FI, D, A, B, C, 15, 10, 0xfe2ce6e0);
|
|
OP (FI, C, D, A, B, 6, 15, 0xa3014314);
|
|
OP (FI, B, C, D, A, 13, 21, 0x4e0811a1);
|
|
OP (FI, A, B, C, D, 4, 6, 0xf7537e82);
|
|
OP (FI, D, A, B, C, 11, 10, 0xbd3af235);
|
|
OP (FI, C, D, A, B, 2, 15, 0x2ad7d2bb);
|
|
OP (FI, B, C, D, A, 9, 21, 0xeb86d391);
|
|
|
|
/* Add the starting values of the context. */
|
|
A += A_save;
|
|
B += B_save;
|
|
C += C_save;
|
|
D += D_save;
|
|
}
|
|
|
|
/* Put checksum in context given as argument. */
|
|
ctx->A = A;
|
|
ctx->B = B;
|
|
ctx->C = C;
|
|
ctx->D = D;
|
|
}
|