[thirdparty/gcc.git] / libiberty / md5.c

/* md5.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 Free Software Foundation, Inc.

   NOTE: This source is derived from an old version taken from the GNU C
   Library (glibc).

   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., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, 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 "ansidecl.h"
#include "md5.h"

#ifdef _LIBC
# include <endian.h>
# if __BYTE_ORDER == __BIG_ENDIAN
#  define WORDS_BIGENDIAN 1
# endif
#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 (struct md5_ctx *ctx)
{
  ctx->A = (md5_uint32) 0x67452301;
  ctx->B = (md5_uint32) 0xefcdab89;
  ctx->C = (md5_uint32) 0x98badcfe;
  ctx->D = (md5_uint32) 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: RESBUF may not be aligned as strongly as MD5_UNIT32 so we
   put things in a local (aligned) buffer first, then memcpy into RESBUF.  */
void *
md5_read_ctx (const struct md5_ctx *ctx, void *resbuf)
{
  md5_uint32 buffer[4];

  buffer[0] = SWAP (ctx->A);
  buffer[1] = SWAP (ctx->B);
  buffer[2] = SWAP (ctx->C);
  buffer[3] = SWAP (ctx->D);

  memcpy (resbuf, buffer, 16);

  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 (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 (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 (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 (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 (left_over + add > 64)
	{
	  md5_process_block (ctx->buffer, (left_over + add) & ~63, ctx);
	  /* The regions in the following copy operation cannot overlap.  */
	  memcpy (ctx->buffer, &ctx->buffer[(left_over + add) & ~63],
		  (left_over + add) & 63);
	  ctx->buflen = (left_over + add) & 63;
	}

      buffer = (const void *) ((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)
          {
	    memcpy (ctx->buffer, buffer, 64);
            md5_process_block (ctx->buffer, 64, ctx);
            buffer = (const char *) buffer + 64;
            len -= 64;
          }
      else
#endif
      md5_process_block (buffer, len & ~63, ctx);
      buffer = (const void *) ((const char *) buffer + (len & ~63));
      len &= 63;
    }

  /* Move remaining bytes in internal buffer.  */
  if (len > 0)
    {
      memcpy (ctx->buffer, buffer, len);
      ctx->buflen = len;
    }
}


/* 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 (const void *buffer, size_t len, struct md5_ctx *ctx)
{
  md5_uint32 correct_words[16];
  const md5_uint32 *words = (const md5_uint32 *) 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, (md5_uint32) 0xd76aa478);
      OP (D, A, B, C, 12, (md5_uint32) 0xe8c7b756);
      OP (C, D, A, B, 17, (md5_uint32) 0x242070db);
      OP (B, C, D, A, 22, (md5_uint32) 0xc1bdceee);
      OP (A, B, C, D,  7, (md5_uint32) 0xf57c0faf);
      OP (D, A, B, C, 12, (md5_uint32) 0x4787c62a);
      OP (C, D, A, B, 17, (md5_uint32) 0xa8304613);
      OP (B, C, D, A, 22, (md5_uint32) 0xfd469501);
      OP (A, B, C, D,  7, (md5_uint32) 0x698098d8);
      OP (D, A, B, C, 12, (md5_uint32) 0x8b44f7af);
      OP (C, D, A, B, 17, (md5_uint32) 0xffff5bb1);
      OP (B, C, D, A, 22, (md5_uint32) 0x895cd7be);
      OP (A, B, C, D,  7, (md5_uint32) 0x6b901122);
      OP (D, A, B, C, 12, (md5_uint32) 0xfd987193);
      OP (C, D, A, B, 17, (md5_uint32) 0xa679438e);
      OP (B, C, D, A, 22, (md5_uint32) 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(a, b, c, d, k, s, T)						\
      do 								\
	{								\
	  a += FX (b, c, d) + correct_words[k] + T;			\
	  CYCLIC (a, s);						\
	  a += b;							\
	}								\
      while (0)

#define FX(b, c, d) FG (b, c, d)

      /* Round 2.  */
      OP (A, B, C, D,  1,  5, (md5_uint32) 0xf61e2562);
      OP (D, A, B, C,  6,  9, (md5_uint32) 0xc040b340);
      OP (C, D, A, B, 11, 14, (md5_uint32) 0x265e5a51);
      OP (B, C, D, A,  0, 20, (md5_uint32) 0xe9b6c7aa);
      OP (A, B, C, D,  5,  5, (md5_uint32) 0xd62f105d);
      OP (D, A, B, C, 10,  9, (md5_uint32) 0x02441453);
      OP (C, D, A, B, 15, 14, (md5_uint32) 0xd8a1e681);
      OP (B, C, D, A,  4, 20, (md5_uint32) 0xe7d3fbc8);
      OP (A, B, C, D,  9,  5, (md5_uint32) 0x21e1cde6);
      OP (D, A, B, C, 14,  9, (md5_uint32) 0xc33707d6);
      OP (C, D, A, B,  3, 14, (md5_uint32) 0xf4d50d87);
      OP (B, C, D, A,  8, 20, (md5_uint32) 0x455a14ed);
      OP (A, B, C, D, 13,  5, (md5_uint32) 0xa9e3e905);
      OP (D, A, B, C,  2,  9, (md5_uint32) 0xfcefa3f8);
      OP (C, D, A, B,  7, 14, (md5_uint32) 0x676f02d9);
      OP (B, C, D, A, 12, 20, (md5_uint32) 0x8d2a4c8a);

#undef FX
#define FX(b, c, d) FH (b, c, d)

      /* Round 3.  */
      OP (A, B, C, D,  5,  4, (md5_uint32) 0xfffa3942);
      OP (D, A, B, C,  8, 11, (md5_uint32) 0x8771f681);
      OP (C, D, A, B, 11, 16, (md5_uint32) 0x6d9d6122);
      OP (B, C, D, A, 14, 23, (md5_uint32) 0xfde5380c);
      OP (A, B, C, D,  1,  4, (md5_uint32) 0xa4beea44);
      OP (D, A, B, C,  4, 11, (md5_uint32) 0x4bdecfa9);
      OP (C, D, A, B,  7, 16, (md5_uint32) 0xf6bb4b60);
      OP (B, C, D, A, 10, 23, (md5_uint32) 0xbebfbc70);
      OP (A, B, C, D, 13,  4, (md5_uint32) 0x289b7ec6);
      OP (D, A, B, C,  0, 11, (md5_uint32) 0xeaa127fa);
      OP (C, D, A, B,  3, 16, (md5_uint32) 0xd4ef3085);
      OP (B, C, D, A,  6, 23, (md5_uint32) 0x04881d05);
      OP (A, B, C, D,  9,  4, (md5_uint32) 0xd9d4d039);
      OP (D, A, B, C, 12, 11, (md5_uint32) 0xe6db99e5);
      OP (C, D, A, B, 15, 16, (md5_uint32) 0x1fa27cf8);
      OP (B, C, D, A,  2, 23, (md5_uint32) 0xc4ac5665);

#undef FX
#define FX(b, c, d) FI (b, c, d)

      /* Round 4.  */
      OP (A, B, C, D,  0,  6, (md5_uint32) 0xf4292244);
      OP (D, A, B, C,  7, 10, (md5_uint32) 0x432aff97);
      OP (C, D, A, B, 14, 15, (md5_uint32) 0xab9423a7);
      OP (B, C, D, A,  5, 21, (md5_uint32) 0xfc93a039);
      OP (A, B, C, D, 12,  6, (md5_uint32) 0x655b59c3);
      OP (D, A, B, C,  3, 10, (md5_uint32) 0x8f0ccc92);
      OP (C, D, A, B, 10, 15, (md5_uint32) 0xffeff47d);
      OP (B, C, D, A,  1, 21, (md5_uint32) 0x85845dd1);
      OP (A, B, C, D,  8,  6, (md5_uint32) 0x6fa87e4f);
      OP (D, A, B, C, 15, 10, (md5_uint32) 0xfe2ce6e0);
      OP (C, D, A, B,  6, 15, (md5_uint32) 0xa3014314);
      OP (B, C, D, A, 13, 21, (md5_uint32) 0x4e0811a1);
      OP (A, B, C, D,  4,  6, (md5_uint32) 0xf7537e82);
      OP (D, A, B, C, 11, 10, (md5_uint32) 0xbd3af235);
      OP (C, D, A, B,  2, 15, (md5_uint32) 0x2ad7d2bb);
      OP (B, C, D, A,  9, 21, (md5_uint32) 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;
}
Commit	Line	Data
881c6935 JM	1	/* md5.c - Functions to compute MD5 message digest of files or memory blocks
	2	according to the definition of MD5 in RFC 1321 from April 1992.
	3	Copyright (C) 1995, 1996 Free Software Foundation, Inc.
584932e9 DD	4
	5	NOTE: This source is derived from an old version taken from the GNU C
	6	Library (glibc).
881c6935 JM	7
	8	This program is free software; you can redistribute it and/or modify it
	9	under the terms of the GNU General Public License as published by the
	10	Free Software Foundation; either version 2, or (at your option) any
	11	later version.
	12
	13	This program is distributed in the hope that it will be useful,
	14	but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	GNU General Public License for more details.
	17
	18	You should have received a copy of the GNU General Public License
	19	along with this program; if not, write to the Free Software Foundation,
ee58dffd	20	Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */
881c6935 JM	21
	22	/* Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995. */
	23
	24	#ifdef HAVE_CONFIG_H
	25	# include <config.h>
	26	#endif
	27
	28	#include <sys/types.h>
	29
	30	#if STDC_HEADERS \|\| defined _LIBC
	31	# include <stdlib.h>
	32	# include <string.h>
	33	#else
	34	# ifndef HAVE_MEMCPY
	35	# define memcpy(d, s, n) bcopy ((s), (d), (n))
	36	# endif
	37	#endif
	38
2ecd81ef	39	#include "ansidecl.h"
881c6935 JM	40	#include "md5.h"
	41
	42	#ifdef _LIBC
	43	# include <endian.h>
	44	# if __BYTE_ORDER == __BIG_ENDIAN
	45	# define WORDS_BIGENDIAN 1
	46	# endif
	47	#endif
	48
	49	#ifdef WORDS_BIGENDIAN
	50	# define SWAP(n) \
	51	(((n) << 24) \| (((n) & 0xff00) << 8) \| (((n) >> 8) & 0xff00) \| ((n) >> 24))
	52	#else
	53	# define SWAP(n) (n)
	54	#endif
	55
	56
	57	/* This array contains the bytes used to pad the buffer to the next
	58	64-byte boundary. (RFC 1321, 3.1: Step 1) */
	59	static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ };
	60
	61
	62	/* Initialize structure containing state of computation.
	63	(RFC 1321, 3.3: Step 3) */
	64	void
6da879de	65	md5_init_ctx (struct md5_ctx *ctx)
881c6935	66	{
8a153288 TS	67	ctx->A = (md5_uint32) 0x67452301;
	68	ctx->B = (md5_uint32) 0xefcdab89;
	69	ctx->C = (md5_uint32) 0x98badcfe;
	70	ctx->D = (md5_uint32) 0x10325476;
881c6935 JM	71
	72	ctx->total[0] = ctx->total[1] = 0;
	73	ctx->buflen = 0;
	74	}
	75
	76	/* Put result from CTX in first 16 bytes following RESBUF. The result
	77	must be in little endian byte order.
	78
c49b1a29 SE	79	IMPORTANT: RESBUF may not be aligned as strongly as MD5_UNIT32 so we
c49b1a29 SE	80	put things in a local (aligned) buffer first, then memcpy into RESBUF. */
881c6935	81	void *
6da879de	82	md5_read_ctx (const struct md5_ctx ctx, void resbuf)
881c6935	83	{
c49b1a29 SE	84	md5_uint32 buffer[4];
	85
	86	buffer[0] = SWAP (ctx->A);
	87	buffer[1] = SWAP (ctx->B);
	88	buffer[2] = SWAP (ctx->C);
	89	buffer[3] = SWAP (ctx->D);
	90
	91	memcpy (resbuf, buffer, 16);
881c6935 JM	92
	93	return resbuf;
	94	}
	95
	96	/* Process the remaining bytes in the internal buffer and the usual
	97	prolog according to the standard and write the result to RESBUF.
	98
	99	IMPORTANT: On some systems it is required that RESBUF is correctly
	100	aligned for a 32 bits value. */
	101	void *
6da879de	102	md5_finish_ctx (struct md5_ctx ctx, void resbuf)
881c6935 JM	103	{
	104	/* Take yet unprocessed bytes into account. */
	105	md5_uint32 bytes = ctx->buflen;
	106	size_t pad;
	107
	108	/* Now count remaining bytes. */
	109	ctx->total[0] += bytes;
	110	if (ctx->total[0] < bytes)
	111	++ctx->total[1];
	112
	113	pad = bytes >= 56 ? 64 + 56 - bytes : 56 - bytes;
	114	memcpy (&ctx->buffer[bytes], fillbuf, pad);
	115
	116	/* Put the 64-bit file length in bits at the end of the buffer. */
	117	(md5_uint32 ) &ctx->buffer[bytes + pad] = SWAP (ctx->total[0] << 3);
	118	(md5_uint32 ) &ctx->buffer[bytes + pad + 4] = SWAP ((ctx->total[1] << 3) \|
	119	(ctx->total[0] >> 29));
	120
	121	/* Process last bytes. */
	122	md5_process_block (ctx->buffer, bytes + pad + 8, ctx);
	123
	124	return md5_read_ctx (ctx, resbuf);
	125	}
	126
	127	/* Compute MD5 message digest for bytes read from STREAM. The
	128	resulting message digest number will be written into the 16 bytes
	129	beginning at RESBLOCK. */
	130	int
6da879de	131	md5_stream (FILE stream, void resblock)
881c6935 JM	132	{
	133	/* Important: BLOCKSIZE must be a multiple of 64. */
	134	#define BLOCKSIZE 4096
	135	struct md5_ctx ctx;
	136	char buffer[BLOCKSIZE + 72];
	137	size_t sum;
	138
	139	/* Initialize the computation context. */
	140	md5_init_ctx (&ctx);
	141
	142	/* Iterate over full file contents. */
	143	while (1)
	144	{
	145	/* We read the file in blocks of BLOCKSIZE bytes. One call of the
	146	computation function processes the whole buffer so that with the
	147	next round of the loop another block can be read. */
	148	size_t n;
	149	sum = 0;
	150
	151	/* Read block. Take care for partial reads. */
	152	do
	153	{
	154	n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
	155
	156	sum += n;
	157	}
	158	while (sum < BLOCKSIZE && n != 0);
	159	if (n == 0 && ferror (stream))
	160	return 1;
	161
	162	/* If end of file is reached, end the loop. */
	163	if (n == 0)
	164	break;
	165
	166	/* Process buffer with BLOCKSIZE bytes. Note that
	167	BLOCKSIZE % 64 == 0
	168	*/
	169	md5_process_block (buffer, BLOCKSIZE, &ctx);
	170	}
	171
	172	/* Add the last bytes if necessary. */
	173	if (sum > 0)
	174	md5_process_bytes (buffer, sum, &ctx);
	175
	176	/* Construct result in desired memory. */
	177	md5_finish_ctx (&ctx, resblock);
	178	return 0;
	179	}
	180
	181	/* Compute MD5 message digest for LEN bytes beginning at BUFFER. The
	182	result is always in little endian byte order, so that a byte-wise
	183	output yields to the wanted ASCII representation of the message
	184	digest. */
	185	void *
6da879de	186	md5_buffer (const char buffer, size_t len, void resblock)
881c6935 JM	187	{
	188	struct md5_ctx ctx;
	189
	190	/* Initialize the computation context. */
	191	md5_init_ctx (&ctx);
	192
	193	/* Process whole buffer but last len % 64 bytes. */
	194	md5_process_bytes (buffer, len, &ctx);
	195
	196	/* Put result in desired memory area. */
	197	return md5_finish_ctx (&ctx, resblock);
	198	}
	199
	200
	201	void
6da879de	202	md5_process_bytes (const void buffer, size_t len, struct md5_ctx ctx)
881c6935 JM	203	{
	204	/* When we already have some bits in our internal buffer concatenate
	205	both inputs first. */
	206	if (ctx->buflen != 0)
	207	{
	208	size_t left_over = ctx->buflen;
	209	size_t add = 128 - left_over > len ? len : 128 - left_over;
	210
	211	memcpy (&ctx->buffer[left_over], buffer, add);
	212	ctx->buflen += add;
	213
	214	if (left_over + add > 64)
	215	{
	216	md5_process_block (ctx->buffer, (left_over + add) & ~63, ctx);
	217	/* The regions in the following copy operation cannot overlap. */
	218	memcpy (ctx->buffer, &ctx->buffer[(left_over + add) & ~63],
	219	(left_over + add) & 63);
	220	ctx->buflen = (left_over + add) & 63;
	221	}
	222
f08b7eee	223	buffer = (const void ) ((const char ) buffer + add);
881c6935 JM	224	len -= add;
	225	}
	226
	227	/* Process available complete blocks. */
	228	if (len > 64)
	229	{
6cbfa10e SE	230	#if !_STRING_ARCH_unaligned
	231	/* To check alignment gcc has an appropriate operator. Other
	232	compilers don't. */
	233	# if __GNUC__ >= 2
	234	# define UNALIGNED_P(p) (((md5_uintptr) p) % __alignof__ (md5_uint32) != 0)
	235	# else
	236	# define UNALIGNED_P(p) (((md5_uintptr) p) % sizeof (md5_uint32) != 0)
	237	# endif
	238	if (UNALIGNED_P (buffer))
	239	while (len > 64)
	240	{
73b38fce NC	241	memcpy (ctx->buffer, buffer, 64);
73b38fce NC	242	md5_process_block (ctx->buffer, 64, ctx);
6cbfa10e SE	243	buffer = (const char *) buffer + 64;
	244	len -= 64;
	245	}
	246	else
	247	#endif
881c6935	248	md5_process_block (buffer, len & ~63, ctx);
f08b7eee	249	buffer = (const void ) ((const char ) buffer + (len & ~63));
881c6935 JM	250	len &= 63;
	251	}
	252
	253	/* Move remaining bytes in internal buffer. */
	254	if (len > 0)
	255	{
	256	memcpy (ctx->buffer, buffer, len);
	257	ctx->buflen = len;
	258	}
	259	}
	260
	261
	262	/* These are the four functions used in the four steps of the MD5 algorithm
	263	and defined in the RFC 1321. The first function is a little bit optimized
	264	(as found in Colin Plumbs public domain implementation). */
	265	/* #define FF(b, c, d) ((b & c) \| (~b & d)) */
	266	#define FF(b, c, d) (d ^ (b & (c ^ d)))
	267	#define FG(b, c, d) FF (d, b, c)
	268	#define FH(b, c, d) (b ^ c ^ d)
	269	#define FI(b, c, d) (c ^ (b \| ~d))
	270
	271	/* Process LEN bytes of BUFFER, accumulating context into CTX.
	272	It is assumed that LEN % 64 == 0. */
	273
	274	void
6da879de	275	md5_process_block (const void buffer, size_t len, struct md5_ctx ctx)
881c6935 JM	276	{
881c6935 JM	277	md5_uint32 correct_words[16];
f08b7eee	278	const md5_uint32 words = (const md5_uint32 ) buffer;
881c6935 JM	279	size_t nwords = len / sizeof (md5_uint32);
	280	const md5_uint32 *endp = words + nwords;
	281	md5_uint32 A = ctx->A;
	282	md5_uint32 B = ctx->B;
	283	md5_uint32 C = ctx->C;
	284	md5_uint32 D = ctx->D;
	285
	286	/* First increment the byte count. RFC 1321 specifies the possible
	287	length of the file up to 2^64 bits. Here we only compute the
	288	number of bytes. Do a double word increment. */
	289	ctx->total[0] += len;
	290	if (ctx->total[0] < len)
	291	++ctx->total[1];
	292
	293	/* Process all bytes in the buffer with 64 bytes in each round of
	294	the loop. */
	295	while (words < endp)
	296	{
	297	md5_uint32 *cwp = correct_words;
	298	md5_uint32 A_save = A;
	299	md5_uint32 B_save = B;
	300	md5_uint32 C_save = C;
	301	md5_uint32 D_save = D;
	302
	303	/* First round: using the given function, the context and a constant
	304	the next context is computed. Because the algorithms processing
	305	unit is a 32-bit word and it is determined to work on words in
	306	little endian byte order we perhaps have to change the byte order
	307	before the computation. To reduce the work for the next steps
	308	we store the swapped words in the array CORRECT_WORDS. */
	309
	310	#define OP(a, b, c, d, s, T) \
	311	do \
	312	{ \
	313	a += FF (b, c, d) + (cwp++ = SWAP (words)) + T; \
	314	++words; \
	315	CYCLIC (a, s); \
	316	a += b; \
	317	} \
	318	while (0)
	319
	320	/* It is unfortunate that C does not provide an operator for
	321	cyclic rotation. Hope the C compiler is smart enough. */
	322	#define CYCLIC(w, s) (w = (w << s) \| (w >> (32 - s)))
	323
	324	/* Before we start, one word to the strange constants.
	325	They are defined in RFC 1321 as
	326
	327	T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64
	328	*/
	329
	330	/* Round 1. */
8a153288 TS	331	OP (A, B, C, D, 7, (md5_uint32) 0xd76aa478);
	332	OP (D, A, B, C, 12, (md5_uint32) 0xe8c7b756);
	333	OP (C, D, A, B, 17, (md5_uint32) 0x242070db);
	334	OP (B, C, D, A, 22, (md5_uint32) 0xc1bdceee);
	335	OP (A, B, C, D, 7, (md5_uint32) 0xf57c0faf);
	336	OP (D, A, B, C, 12, (md5_uint32) 0x4787c62a);
	337	OP (C, D, A, B, 17, (md5_uint32) 0xa8304613);
	338	OP (B, C, D, A, 22, (md5_uint32) 0xfd469501);
	339	OP (A, B, C, D, 7, (md5_uint32) 0x698098d8);
	340	OP (D, A, B, C, 12, (md5_uint32) 0x8b44f7af);
	341	OP (C, D, A, B, 17, (md5_uint32) 0xffff5bb1);
	342	OP (B, C, D, A, 22, (md5_uint32) 0x895cd7be);
	343	OP (A, B, C, D, 7, (md5_uint32) 0x6b901122);
	344	OP (D, A, B, C, 12, (md5_uint32) 0xfd987193);
	345	OP (C, D, A, B, 17, (md5_uint32) 0xa679438e);
	346	OP (B, C, D, A, 22, (md5_uint32) 0x49b40821);
881c6935 JM	347
	348	/* For the second to fourth round we have the possibly swapped words
	349	in CORRECT_WORDS. Redefine the macro to take an additional first
	350	argument specifying the function to use. */
	351	#undef OP
783080ab	352	#define OP(a, b, c, d, k, s, T) \
881c6935 JM	353	do \
881c6935 JM	354	{ \
783080ab	355	a += FX (b, c, d) + correct_words[k] + T; \
881c6935 JM	356	CYCLIC (a, s); \
	357	a += b; \
	358	} \
	359	while (0)
	360
783080ab JJ	361	#define FX(b, c, d) FG (b, c, d)
783080ab JJ	362
881c6935	363	/* Round 2. */
783080ab JJ	364	OP (A, B, C, D, 1, 5, (md5_uint32) 0xf61e2562);
	365	OP (D, A, B, C, 6, 9, (md5_uint32) 0xc040b340);
	366	OP (C, D, A, B, 11, 14, (md5_uint32) 0x265e5a51);
	367	OP (B, C, D, A, 0, 20, (md5_uint32) 0xe9b6c7aa);
	368	OP (A, B, C, D, 5, 5, (md5_uint32) 0xd62f105d);
	369	OP (D, A, B, C, 10, 9, (md5_uint32) 0x02441453);
	370	OP (C, D, A, B, 15, 14, (md5_uint32) 0xd8a1e681);
	371	OP (B, C, D, A, 4, 20, (md5_uint32) 0xe7d3fbc8);
	372	OP (A, B, C, D, 9, 5, (md5_uint32) 0x21e1cde6);
	373	OP (D, A, B, C, 14, 9, (md5_uint32) 0xc33707d6);
	374	OP (C, D, A, B, 3, 14, (md5_uint32) 0xf4d50d87);
	375	OP (B, C, D, A, 8, 20, (md5_uint32) 0x455a14ed);
	376	OP (A, B, C, D, 13, 5, (md5_uint32) 0xa9e3e905);
	377	OP (D, A, B, C, 2, 9, (md5_uint32) 0xfcefa3f8);
	378	OP (C, D, A, B, 7, 14, (md5_uint32) 0x676f02d9);
	379	OP (B, C, D, A, 12, 20, (md5_uint32) 0x8d2a4c8a);
	380
	381	#undef FX
	382	#define FX(b, c, d) FH (b, c, d)
881c6935 JM	383
881c6935 JM	384	/* Round 3. */
783080ab JJ	385	OP (A, B, C, D, 5, 4, (md5_uint32) 0xfffa3942);
	386	OP (D, A, B, C, 8, 11, (md5_uint32) 0x8771f681);
	387	OP (C, D, A, B, 11, 16, (md5_uint32) 0x6d9d6122);
	388	OP (B, C, D, A, 14, 23, (md5_uint32) 0xfde5380c);
	389	OP (A, B, C, D, 1, 4, (md5_uint32) 0xa4beea44);
	390	OP (D, A, B, C, 4, 11, (md5_uint32) 0x4bdecfa9);
	391	OP (C, D, A, B, 7, 16, (md5_uint32) 0xf6bb4b60);
	392	OP (B, C, D, A, 10, 23, (md5_uint32) 0xbebfbc70);
	393	OP (A, B, C, D, 13, 4, (md5_uint32) 0x289b7ec6);
	394	OP (D, A, B, C, 0, 11, (md5_uint32) 0xeaa127fa);
	395	OP (C, D, A, B, 3, 16, (md5_uint32) 0xd4ef3085);
	396	OP (B, C, D, A, 6, 23, (md5_uint32) 0x04881d05);
	397	OP (A, B, C, D, 9, 4, (md5_uint32) 0xd9d4d039);
	398	OP (D, A, B, C, 12, 11, (md5_uint32) 0xe6db99e5);
	399	OP (C, D, A, B, 15, 16, (md5_uint32) 0x1fa27cf8);
	400	OP (B, C, D, A, 2, 23, (md5_uint32) 0xc4ac5665);
	401
	402	#undef FX
	403	#define FX(b, c, d) FI (b, c, d)
881c6935 JM	404
881c6935 JM	405	/* Round 4. */
783080ab JJ	406	OP (A, B, C, D, 0, 6, (md5_uint32) 0xf4292244);
	407	OP (D, A, B, C, 7, 10, (md5_uint32) 0x432aff97);
	408	OP (C, D, A, B, 14, 15, (md5_uint32) 0xab9423a7);
	409	OP (B, C, D, A, 5, 21, (md5_uint32) 0xfc93a039);
	410	OP (A, B, C, D, 12, 6, (md5_uint32) 0x655b59c3);
	411	OP (D, A, B, C, 3, 10, (md5_uint32) 0x8f0ccc92);
	412	OP (C, D, A, B, 10, 15, (md5_uint32) 0xffeff47d);
	413	OP (B, C, D, A, 1, 21, (md5_uint32) 0x85845dd1);
	414	OP (A, B, C, D, 8, 6, (md5_uint32) 0x6fa87e4f);
	415	OP (D, A, B, C, 15, 10, (md5_uint32) 0xfe2ce6e0);
	416	OP (C, D, A, B, 6, 15, (md5_uint32) 0xa3014314);
	417	OP (B, C, D, A, 13, 21, (md5_uint32) 0x4e0811a1);
	418	OP (A, B, C, D, 4, 6, (md5_uint32) 0xf7537e82);
	419	OP (D, A, B, C, 11, 10, (md5_uint32) 0xbd3af235);
	420	OP (C, D, A, B, 2, 15, (md5_uint32) 0x2ad7d2bb);
	421	OP (B, C, D, A, 9, 21, (md5_uint32) 0xeb86d391);
881c6935 JM	422
	423	/* Add the starting values of the context. */
	424	A += A_save;
	425	B += B_save;
	426	C += C_save;
	427	D += D_save;
	428	}
	429
	430	/* Put checksum in context given as argument. */
	431	ctx->A = A;
	432	ctx->B = B;
	433	ctx->C = C;
	434	ctx->D = D;
	435	}