[deliverable/binutils-gdb.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: On some systems it is required that RESBUF is correctly
   aligned for a 32 bits value.  */
void *
md5_read_ctx (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 (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)
          {
            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 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
050823ca 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.
f6528837 DD	4
	5	NOTE: This source is derived from an old version taken from the GNU C
	6	Library (glibc).
050823ca 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,
979c05d3	20	Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */
050823ca 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
87263c36	39	#include "ansidecl.h"
050823ca 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
49b1fae4	65	md5_init_ctx (struct md5_ctx *ctx)
050823ca	66	{
b50c4073 DD	67	ctx->A = (md5_uint32) 0x67452301;
	68	ctx->B = (md5_uint32) 0xefcdab89;
	69	ctx->C = (md5_uint32) 0x98badcfe;
	70	ctx->D = (md5_uint32) 0x10325476;
050823ca 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
	79	IMPORTANT: On some systems it is required that RESBUF is correctly
	80	aligned for a 32 bits value. */
	81	void *
49b1fae4	82	md5_read_ctx (const struct md5_ctx ctx, void resbuf)
050823ca JM	83	{
	84	((md5_uint32 *) resbuf)[0] = SWAP (ctx->A);
	85	((md5_uint32 *) resbuf)[1] = SWAP (ctx->B);
	86	((md5_uint32 *) resbuf)[2] = SWAP (ctx->C);
	87	((md5_uint32 *) resbuf)[3] = SWAP (ctx->D);
	88
	89	return resbuf;
	90	}
	91
	92	/* Process the remaining bytes in the internal buffer and the usual
	93	prolog according to the standard and write the result to RESBUF.
	94
	95	IMPORTANT: On some systems it is required that RESBUF is correctly
	96	aligned for a 32 bits value. */
	97	void *
49b1fae4	98	md5_finish_ctx (struct md5_ctx ctx, void resbuf)
050823ca JM	99	{
	100	/* Take yet unprocessed bytes into account. */
	101	md5_uint32 bytes = ctx->buflen;
	102	size_t pad;
	103
	104	/* Now count remaining bytes. */
	105	ctx->total[0] += bytes;
	106	if (ctx->total[0] < bytes)
	107	++ctx->total[1];
	108
	109	pad = bytes >= 56 ? 64 + 56 - bytes : 56 - bytes;
	110	memcpy (&ctx->buffer[bytes], fillbuf, pad);
	111
	112	/* Put the 64-bit file length in bits at the end of the buffer. */
	113	(md5_uint32 ) &ctx->buffer[bytes + pad] = SWAP (ctx->total[0] << 3);
	114	(md5_uint32 ) &ctx->buffer[bytes + pad + 4] = SWAP ((ctx->total[1] << 3) \|
	115	(ctx->total[0] >> 29));
	116
	117	/* Process last bytes. */
	118	md5_process_block (ctx->buffer, bytes + pad + 8, ctx);
	119
	120	return md5_read_ctx (ctx, resbuf);
	121	}
	122
	123	/* Compute MD5 message digest for bytes read from STREAM. The
	124	resulting message digest number will be written into the 16 bytes
	125	beginning at RESBLOCK. */
	126	int
49b1fae4	127	md5_stream (FILE stream, void resblock)
050823ca JM	128	{
	129	/* Important: BLOCKSIZE must be a multiple of 64. */
	130	#define BLOCKSIZE 4096
	131	struct md5_ctx ctx;
	132	char buffer[BLOCKSIZE + 72];
	133	size_t sum;
	134
	135	/* Initialize the computation context. */
	136	md5_init_ctx (&ctx);
	137
	138	/* Iterate over full file contents. */
	139	while (1)
	140	{
	141	/* We read the file in blocks of BLOCKSIZE bytes. One call of the
	142	computation function processes the whole buffer so that with the
	143	next round of the loop another block can be read. */
	144	size_t n;
	145	sum = 0;
	146
	147	/* Read block. Take care for partial reads. */
	148	do
	149	{
	150	n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
	151
	152	sum += n;
	153	}
	154	while (sum < BLOCKSIZE && n != 0);
	155	if (n == 0 && ferror (stream))
	156	return 1;
	157
	158	/* If end of file is reached, end the loop. */
	159	if (n == 0)
	160	break;
	161
	162	/* Process buffer with BLOCKSIZE bytes. Note that
	163	BLOCKSIZE % 64 == 0
	164	*/
	165	md5_process_block (buffer, BLOCKSIZE, &ctx);
	166	}
	167
	168	/* Add the last bytes if necessary. */
	169	if (sum > 0)
	170	md5_process_bytes (buffer, sum, &ctx);
	171
	172	/* Construct result in desired memory. */
	173	md5_finish_ctx (&ctx, resblock);
	174	return 0;
	175	}
	176
	177	/* Compute MD5 message digest for LEN bytes beginning at BUFFER. The
	178	result is always in little endian byte order, so that a byte-wise
	179	output yields to the wanted ASCII representation of the message
	180	digest. */
	181	void *
49b1fae4	182	md5_buffer (const char buffer, size_t len, void resblock)
050823ca JM	183	{
	184	struct md5_ctx ctx;
	185
	186	/* Initialize the computation context. */
	187	md5_init_ctx (&ctx);
	188
	189	/* Process whole buffer but last len % 64 bytes. */
	190	md5_process_bytes (buffer, len, &ctx);
	191
	192	/* Put result in desired memory area. */
	193	return md5_finish_ctx (&ctx, resblock);
	194	}
	195
	196
	197	void
49b1fae4	198	md5_process_bytes (const void buffer, size_t len, struct md5_ctx ctx)
050823ca JM	199	{
	200	/* When we already have some bits in our internal buffer concatenate
	201	both inputs first. */
	202	if (ctx->buflen != 0)
	203	{
	204	size_t left_over = ctx->buflen;
	205	size_t add = 128 - left_over > len ? len : 128 - left_over;
	206
	207	memcpy (&ctx->buffer[left_over], buffer, add);
	208	ctx->buflen += add;
	209
	210	if (left_over + add > 64)
	211	{
	212	md5_process_block (ctx->buffer, (left_over + add) & ~63, ctx);
	213	/* The regions in the following copy operation cannot overlap. */
	214	memcpy (ctx->buffer, &ctx->buffer[(left_over + add) & ~63],
	215	(left_over + add) & 63);
	216	ctx->buflen = (left_over + add) & 63;
	217	}
	218
585cc78f	219	buffer = (const void ) ((const char ) buffer + add);
050823ca JM	220	len -= add;
	221	}
	222
	223	/* Process available complete blocks. */
	224	if (len > 64)
	225	{
6ba85b8c DD	226	#if !_STRING_ARCH_unaligned
	227	/* To check alignment gcc has an appropriate operator. Other
	228	compilers don't. */
	229	# if __GNUC__ >= 2
	230	# define UNALIGNED_P(p) (((md5_uintptr) p) % __alignof__ (md5_uint32) != 0)
	231	# else
	232	# define UNALIGNED_P(p) (((md5_uintptr) p) % sizeof (md5_uint32) != 0)
	233	# endif
	234	if (UNALIGNED_P (buffer))
	235	while (len > 64)
	236	{
	237	md5_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx);
	238	buffer = (const char *) buffer + 64;
	239	len -= 64;
	240	}
	241	else
	242	#endif
050823ca	243	md5_process_block (buffer, len & ~63, ctx);
585cc78f	244	buffer = (const void ) ((const char ) buffer + (len & ~63));
050823ca JM	245	len &= 63;
	246	}
	247
	248	/* Move remaining bytes in internal buffer. */
	249	if (len > 0)
	250	{
	251	memcpy (ctx->buffer, buffer, len);
	252	ctx->buflen = len;
	253	}
	254	}
	255
	256
	257	/* These are the four functions used in the four steps of the MD5 algorithm
	258	and defined in the RFC 1321. The first function is a little bit optimized
	259	(as found in Colin Plumbs public domain implementation). */
	260	/* #define FF(b, c, d) ((b & c) \| (~b & d)) */
	261	#define FF(b, c, d) (d ^ (b & (c ^ d)))
	262	#define FG(b, c, d) FF (d, b, c)
	263	#define FH(b, c, d) (b ^ c ^ d)
	264	#define FI(b, c, d) (c ^ (b \| ~d))
	265
	266	/* Process LEN bytes of BUFFER, accumulating context into CTX.
	267	It is assumed that LEN % 64 == 0. */
	268
	269	void
49b1fae4	270	md5_process_block (const void buffer, size_t len, struct md5_ctx ctx)
050823ca JM	271	{
050823ca JM	272	md5_uint32 correct_words[16];
585cc78f	273	const md5_uint32 words = (const md5_uint32 ) buffer;
050823ca JM	274	size_t nwords = len / sizeof (md5_uint32);
	275	const md5_uint32 *endp = words + nwords;
	276	md5_uint32 A = ctx->A;
	277	md5_uint32 B = ctx->B;
	278	md5_uint32 C = ctx->C;
	279	md5_uint32 D = ctx->D;
	280
	281	/* First increment the byte count. RFC 1321 specifies the possible
	282	length of the file up to 2^64 bits. Here we only compute the
	283	number of bytes. Do a double word increment. */
	284	ctx->total[0] += len;
	285	if (ctx->total[0] < len)
	286	++ctx->total[1];
	287
	288	/* Process all bytes in the buffer with 64 bytes in each round of
	289	the loop. */
	290	while (words < endp)
	291	{
	292	md5_uint32 *cwp = correct_words;
	293	md5_uint32 A_save = A;
	294	md5_uint32 B_save = B;
	295	md5_uint32 C_save = C;
	296	md5_uint32 D_save = D;
	297
	298	/* First round: using the given function, the context and a constant
	299	the next context is computed. Because the algorithms processing
	300	unit is a 32-bit word and it is determined to work on words in
	301	little endian byte order we perhaps have to change the byte order
	302	before the computation. To reduce the work for the next steps
	303	we store the swapped words in the array CORRECT_WORDS. */
	304
	305	#define OP(a, b, c, d, s, T) \
	306	do \
	307	{ \
	308	a += FF (b, c, d) + (cwp++ = SWAP (words)) + T; \
	309	++words; \
	310	CYCLIC (a, s); \
	311	a += b; \
	312	} \
	313	while (0)
	314
	315	/* It is unfortunate that C does not provide an operator for
	316	cyclic rotation. Hope the C compiler is smart enough. */
	317	#define CYCLIC(w, s) (w = (w << s) \| (w >> (32 - s)))
	318
	319	/* Before we start, one word to the strange constants.
	320	They are defined in RFC 1321 as
	321
	322	T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64
	323	*/
	324
	325	/* Round 1. */
b50c4073 DD	326	OP (A, B, C, D, 7, (md5_uint32) 0xd76aa478);
	327	OP (D, A, B, C, 12, (md5_uint32) 0xe8c7b756);
	328	OP (C, D, A, B, 17, (md5_uint32) 0x242070db);
	329	OP (B, C, D, A, 22, (md5_uint32) 0xc1bdceee);
	330	OP (A, B, C, D, 7, (md5_uint32) 0xf57c0faf);
	331	OP (D, A, B, C, 12, (md5_uint32) 0x4787c62a);
	332	OP (C, D, A, B, 17, (md5_uint32) 0xa8304613);
	333	OP (B, C, D, A, 22, (md5_uint32) 0xfd469501);
	334	OP (A, B, C, D, 7, (md5_uint32) 0x698098d8);
	335	OP (D, A, B, C, 12, (md5_uint32) 0x8b44f7af);
	336	OP (C, D, A, B, 17, (md5_uint32) 0xffff5bb1);
	337	OP (B, C, D, A, 22, (md5_uint32) 0x895cd7be);
	338	OP (A, B, C, D, 7, (md5_uint32) 0x6b901122);
	339	OP (D, A, B, C, 12, (md5_uint32) 0xfd987193);
	340	OP (C, D, A, B, 17, (md5_uint32) 0xa679438e);
	341	OP (B, C, D, A, 22, (md5_uint32) 0x49b40821);
050823ca JM	342
	343	/* For the second to fourth round we have the possibly swapped words
	344	in CORRECT_WORDS. Redefine the macro to take an additional first
	345	argument specifying the function to use. */
	346	#undef OP
768b20d8	347	#define OP(a, b, c, d, k, s, T) \
050823ca JM	348	do \
050823ca JM	349	{ \
768b20d8	350	a += FX (b, c, d) + correct_words[k] + T; \
050823ca JM	351	CYCLIC (a, s); \
	352	a += b; \
	353	} \
	354	while (0)
	355
768b20d8 JJ	356	#define FX(b, c, d) FG (b, c, d)
768b20d8 JJ	357
050823ca	358	/* Round 2. */
768b20d8 JJ	359	OP (A, B, C, D, 1, 5, (md5_uint32) 0xf61e2562);
	360	OP (D, A, B, C, 6, 9, (md5_uint32) 0xc040b340);
	361	OP (C, D, A, B, 11, 14, (md5_uint32) 0x265e5a51);
	362	OP (B, C, D, A, 0, 20, (md5_uint32) 0xe9b6c7aa);
	363	OP (A, B, C, D, 5, 5, (md5_uint32) 0xd62f105d);
	364	OP (D, A, B, C, 10, 9, (md5_uint32) 0x02441453);
	365	OP (C, D, A, B, 15, 14, (md5_uint32) 0xd8a1e681);
	366	OP (B, C, D, A, 4, 20, (md5_uint32) 0xe7d3fbc8);
	367	OP (A, B, C, D, 9, 5, (md5_uint32) 0x21e1cde6);
	368	OP (D, A, B, C, 14, 9, (md5_uint32) 0xc33707d6);
	369	OP (C, D, A, B, 3, 14, (md5_uint32) 0xf4d50d87);
	370	OP (B, C, D, A, 8, 20, (md5_uint32) 0x455a14ed);
	371	OP (A, B, C, D, 13, 5, (md5_uint32) 0xa9e3e905);
	372	OP (D, A, B, C, 2, 9, (md5_uint32) 0xfcefa3f8);
	373	OP (C, D, A, B, 7, 14, (md5_uint32) 0x676f02d9);
	374	OP (B, C, D, A, 12, 20, (md5_uint32) 0x8d2a4c8a);
	375
	376	#undef FX
	377	#define FX(b, c, d) FH (b, c, d)
050823ca JM	378
050823ca JM	379	/* Round 3. */
768b20d8 JJ	380	OP (A, B, C, D, 5, 4, (md5_uint32) 0xfffa3942);
	381	OP (D, A, B, C, 8, 11, (md5_uint32) 0x8771f681);
	382	OP (C, D, A, B, 11, 16, (md5_uint32) 0x6d9d6122);
	383	OP (B, C, D, A, 14, 23, (md5_uint32) 0xfde5380c);
	384	OP (A, B, C, D, 1, 4, (md5_uint32) 0xa4beea44);
	385	OP (D, A, B, C, 4, 11, (md5_uint32) 0x4bdecfa9);
	386	OP (C, D, A, B, 7, 16, (md5_uint32) 0xf6bb4b60);
	387	OP (B, C, D, A, 10, 23, (md5_uint32) 0xbebfbc70);
	388	OP (A, B, C, D, 13, 4, (md5_uint32) 0x289b7ec6);
	389	OP (D, A, B, C, 0, 11, (md5_uint32) 0xeaa127fa);
	390	OP (C, D, A, B, 3, 16, (md5_uint32) 0xd4ef3085);
	391	OP (B, C, D, A, 6, 23, (md5_uint32) 0x04881d05);
	392	OP (A, B, C, D, 9, 4, (md5_uint32) 0xd9d4d039);
	393	OP (D, A, B, C, 12, 11, (md5_uint32) 0xe6db99e5);
	394	OP (C, D, A, B, 15, 16, (md5_uint32) 0x1fa27cf8);
	395	OP (B, C, D, A, 2, 23, (md5_uint32) 0xc4ac5665);
	396
	397	#undef FX
	398	#define FX(b, c, d) FI (b, c, d)
050823ca JM	399
050823ca JM	400	/* Round 4. */
768b20d8 JJ	401	OP (A, B, C, D, 0, 6, (md5_uint32) 0xf4292244);
	402	OP (D, A, B, C, 7, 10, (md5_uint32) 0x432aff97);
	403	OP (C, D, A, B, 14, 15, (md5_uint32) 0xab9423a7);
	404	OP (B, C, D, A, 5, 21, (md5_uint32) 0xfc93a039);
	405	OP (A, B, C, D, 12, 6, (md5_uint32) 0x655b59c3);
	406	OP (D, A, B, C, 3, 10, (md5_uint32) 0x8f0ccc92);
	407	OP (C, D, A, B, 10, 15, (md5_uint32) 0xffeff47d);
	408	OP (B, C, D, A, 1, 21, (md5_uint32) 0x85845dd1);
	409	OP (A, B, C, D, 8, 6, (md5_uint32) 0x6fa87e4f);
	410	OP (D, A, B, C, 15, 10, (md5_uint32) 0xfe2ce6e0);
	411	OP (C, D, A, B, 6, 15, (md5_uint32) 0xa3014314);
	412	OP (B, C, D, A, 13, 21, (md5_uint32) 0x4e0811a1);
	413	OP (A, B, C, D, 4, 6, (md5_uint32) 0xf7537e82);
	414	OP (D, A, B, C, 11, 10, (md5_uint32) 0xbd3af235);
	415	OP (C, D, A, B, 2, 15, (md5_uint32) 0x2ad7d2bb);
	416	OP (B, C, D, A, 9, 21, (md5_uint32) 0xeb86d391);
050823ca JM	417
	418	/* Add the starting values of the context. */
	419	A += A_save;
	420	B += B_save;
	421	C += C_save;
	422	D += D_save;
	423	}
	424
	425	/* Put checksum in context given as argument. */
	426	ctx->A = A;
	427	ctx->B = B;
	428	ctx->C = C;
	429	ctx->D = D;
	430	}