mirror of
https://git.savannah.gnu.org/git/emacs.git
synced 2024-11-23 07:19:15 +00:00
135 lines
3.8 KiB
C
135 lines
3.8 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) 1995-1997, 1999-2001, 2005-2006, 2008-2024 Free Software
|
|
Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
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 Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995. */
|
|
|
|
#include <config.h>
|
|
|
|
/* Specification. */
|
|
#if HAVE_OPENSSL_MD5
|
|
# define GL_OPENSSL_INLINE _GL_EXTERN_INLINE
|
|
#endif
|
|
#include "md5.h"
|
|
|
|
#include <stdlib.h>
|
|
|
|
#if USE_UNLOCKED_IO
|
|
# include "unlocked-io.h"
|
|
#endif
|
|
|
|
#include "af_alg.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_stream __md5_stream
|
|
#endif
|
|
|
|
#define BLOCKSIZE 32768
|
|
#if BLOCKSIZE % 64 != 0
|
|
# error "invalid BLOCKSIZE"
|
|
#endif
|
|
|
|
/* 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 (FILE *stream, void *resblock)
|
|
{
|
|
switch (afalg_stream (stream, "md5", resblock, MD5_DIGEST_SIZE))
|
|
{
|
|
case 0: return 0;
|
|
case -EIO: return 1;
|
|
}
|
|
|
|
char *buffer = malloc (BLOCKSIZE + 72);
|
|
if (!buffer)
|
|
return 1;
|
|
|
|
struct md5_ctx ctx;
|
|
md5_init_ctx (&ctx);
|
|
size_t sum;
|
|
|
|
/* 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. */
|
|
while (1)
|
|
{
|
|
/* Either process a partial fread() from this loop,
|
|
or the fread() in afalg_stream may have gotten EOF.
|
|
We need to avoid a subsequent fread() as EOF may
|
|
not be sticky. For details of such systems, see:
|
|
https://sourceware.org/bugzilla/show_bug.cgi?id=1190 */
|
|
if (feof (stream))
|
|
goto process_partial_block;
|
|
|
|
n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
|
|
|
|
sum += n;
|
|
|
|
if (sum == BLOCKSIZE)
|
|
break;
|
|
|
|
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))
|
|
{
|
|
free (buffer);
|
|
return 1;
|
|
}
|
|
goto process_partial_block;
|
|
}
|
|
}
|
|
|
|
/* Process buffer with BLOCKSIZE bytes. Note that
|
|
BLOCKSIZE % 64 == 0
|
|
*/
|
|
md5_process_block (buffer, BLOCKSIZE, &ctx);
|
|
}
|
|
|
|
process_partial_block:
|
|
|
|
/* Process any remaining bytes. */
|
|
if (sum > 0)
|
|
md5_process_bytes (buffer, sum, &ctx);
|
|
|
|
/* Construct result in desired memory. */
|
|
md5_finish_ctx (&ctx, resblock);
|
|
free (buffer);
|
|
return 0;
|
|
}
|