[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: The canonical source of this file is maintained with the GNU C
   Library.  Bugs can be reported to bug-glibc@prep.ai.mit.edu.

   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., 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 "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 (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 (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 char *) buffer + add;
      len -= add;
    }

  /* Process available complete blocks.  */
  if (len > 64)
    {
      md5_process_block (buffer, len & ~63, ctx);
      buffer = (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 (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;
}
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.
	4	NOTE: The canonical source of this file is maintained with the GNU C
	5	Library. Bugs can be reported to bug-glibc@prep.ai.mit.edu.
	6
	7	This program is free software; you can redistribute it and/or modify it
	8	under the terms of the GNU General Public License as published by the
	9	Free Software Foundation; either version 2, or (at your option) any
	10	later version.
	11
	12	This program is distributed in the hope that it will be useful,
	13	but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	GNU General Public License for more details.
	16
	17	You should have received a copy of the GNU General Public License
	18	along with this program; if not, write to the Free Software Foundation,
	19	Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
	20
	21	/* Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995. */
	22
	23	#ifdef HAVE_CONFIG_H
	24	# include <config.h>
	25	#endif
	26
	27	#include <sys/types.h>
	28
	29	#if STDC_HEADERS \|\| defined _LIBC
	30	# include <stdlib.h>
	31	# include <string.h>
	32	#else
	33	# ifndef HAVE_MEMCPY
	34	# define memcpy(d, s, n) bcopy ((s), (d), (n))
	35	# endif
	36	#endif
	37
2ecd81ef	38	#include "ansidecl.h"
881c6935 JM	39	#include "md5.h"
	40
	41	#ifdef _LIBC
	42	# include <endian.h>
	43	# if __BYTE_ORDER == __BIG_ENDIAN
	44	# define WORDS_BIGENDIAN 1
	45	# endif
	46	#endif
	47
	48	#ifdef WORDS_BIGENDIAN
	49	# define SWAP(n) \
	50	(((n) << 24) \| (((n) & 0xff00) << 8) \| (((n) >> 8) & 0xff00) \| ((n) >> 24))
	51	#else
	52	# define SWAP(n) (n)
	53	#endif
	54
	55
	56	/* This array contains the bytes used to pad the buffer to the next
	57	64-byte boundary. (RFC 1321, 3.1: Step 1) */
	58	static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ };
	59
	60
	61	/* Initialize structure containing state of computation.
	62	(RFC 1321, 3.3: Step 3) */
	63	void
	64	md5_init_ctx (ctx)
	65	struct md5_ctx *ctx;
	66	{
	67	ctx->A = 0x67452301;
	68	ctx->B = 0xefcdab89;
	69	ctx->C = 0x98badcfe;
	70	ctx->D = 0x10325476;
	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 *
	82	md5_read_ctx (ctx, resbuf)
	83	const struct md5_ctx *ctx;
	84	void *resbuf;
	85	{
	86	((md5_uint32 *) resbuf)[0] = SWAP (ctx->A);
	87	((md5_uint32 *) resbuf)[1] = SWAP (ctx->B);
	88	((md5_uint32 *) resbuf)[2] = SWAP (ctx->C);
	89	((md5_uint32 *) resbuf)[3] = SWAP (ctx->D);
	90
	91	return resbuf;
	92	}
	93
	94	/* Process the remaining bytes in the internal buffer and the usual
	95	prolog according to the standard and write the result to RESBUF.
	96
	97	IMPORTANT: On some systems it is required that RESBUF is correctly
	98	aligned for a 32 bits value. */
	99	void *
	100	md5_finish_ctx (ctx, resbuf)
	101	struct md5_ctx *ctx;
	102	void *resbuf;
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
131	md5_stream (stream, resblock)
132	FILE *stream;
133	void *resblock;
134	{
135	/* Important: BLOCKSIZE must be a multiple of 64. */
136	#define BLOCKSIZE 4096
137	struct md5_ctx ctx;
138	char buffer[BLOCKSIZE + 72];
139	size_t sum;
140
141	/* Initialize the computation context. */
142	md5_init_ctx (&ctx);
143
144	/* Iterate over full file contents. */
145	while (1)
146	{
147	/* We read the file in blocks of BLOCKSIZE bytes. One call of the
148	computation function processes the whole buffer so that with the
149	next round of the loop another block can be read. */
150	size_t n;
151	sum = 0;
152
153	/* Read block. Take care for partial reads. */
154	do
155	{
156	n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
157
158	sum += n;
159	}
160	while (sum < BLOCKSIZE && n != 0);
161	if (n == 0 && ferror (stream))
162	return 1;
163
164	/* If end of file is reached, end the loop. */
165	if (n == 0)
166	break;
167
168	/* Process buffer with BLOCKSIZE bytes. Note that
169	BLOCKSIZE % 64 == 0
170	*/
171	md5_process_block (buffer, BLOCKSIZE, &ctx);
172	}
173
174	/* Add the last bytes if necessary. */
175	if (sum > 0)
176	md5_process_bytes (buffer, sum, &ctx);
177
178	/* Construct result in desired memory. */
179	md5_finish_ctx (&ctx, resblock);
180	return 0;
181	}
182
183	/* Compute MD5 message digest for LEN bytes beginning at BUFFER. The
184	result is always in little endian byte order, so that a byte-wise
185	output yields to the wanted ASCII representation of the message
186	digest. */
187	void *
188	md5_buffer (buffer, len, resblock)
189	const char *buffer;
190	size_t len;
191	void *resblock;
192	{
193	struct md5_ctx ctx;
194
195	/* Initialize the computation context. */
196	md5_init_ctx (&ctx);
197
198	/* Process whole buffer but last len % 64 bytes. */
199	md5_process_bytes (buffer, len, &ctx);
200
201	/* Put result in desired memory area. */
202	return md5_finish_ctx (&ctx, resblock);
203	}
204
205
206	void
207	md5_process_bytes (buffer, len, ctx)
208	const void *buffer;
209	size_t len;
210	struct md5_ctx *ctx;
211	{
212	/* When we already have some bits in our internal buffer concatenate
213	both inputs first. */
214	if (ctx->buflen != 0)
215	{
216	size_t left_over = ctx->buflen;
217	size_t add = 128 - left_over > len ? len : 128 - left_over;
218
219	memcpy (&ctx->buffer[left_over], buffer, add);
220	ctx->buflen += add;
221
222	if (left_over + add > 64)
223	{
224	md5_process_block (ctx->buffer, (left_over + add) & ~63, ctx);
225	/* The regions in the following copy operation cannot overlap. */
226	memcpy (ctx->buffer, &ctx->buffer[(left_over + add) & ~63],
227	(left_over + add) & 63);
228	ctx->buflen = (left_over + add) & 63;
229	}
230
231	buffer = (const char *) buffer + add;
232	len -= add;
233	}
234
235	/* Process available complete blocks. */
236	if (len > 64)
237	{
238	md5_process_block (buffer, len & ~63, ctx);
239	buffer = (const char *) buffer + (len & ~63);
240	len &= 63;
241	}
242
243	/* Move remaining bytes in internal buffer. */
244	if (len > 0)
245	{
246	memcpy (ctx->buffer, buffer, len);
247	ctx->buflen = len;
248	}
249	}
250
251
252	/* These are the four functions used in the four steps of the MD5 algorithm
253	and defined in the RFC 1321. The first function is a little bit optimized
254	(as found in Colin Plumbs public domain implementation). */
255	/* #define FF(b, c, d) ((b & c) \| (~b & d)) */
256	#define FF(b, c, d) (d ^ (b & (c ^ d)))
257	#define FG(b, c, d) FF (d, b, c)
258	#define FH(b, c, d) (b ^ c ^ d)
259	#define FI(b, c, d) (c ^ (b \| ~d))
260
261	/* Process LEN bytes of BUFFER, accumulating context into CTX.
262	It is assumed that LEN % 64 == 0. */
263
264	void
265	md5_process_block (buffer, len, ctx)
266	const void *buffer;
267	size_t len;
268	struct md5_ctx *ctx;
269	{
270	md5_uint32 correct_words[16];
271	const md5_uint32 *words = buffer;
272	size_t nwords = len / sizeof (md5_uint32);
273	const md5_uint32 *endp = words + nwords;
274	md5_uint32 A = ctx->A;
275	md5_uint32 B = ctx->B;
276	md5_uint32 C = ctx->C;
277	md5_uint32 D = ctx->D;
278
279	/* First increment the byte count. RFC 1321 specifies the possible
280	length of the file up to 2^64 bits. Here we only compute the
281	number of bytes. Do a double word increment. */
282	ctx->total[0] += len;
283	if (ctx->total[0] < len)
284	++ctx->total[1];
285
286	/* Process all bytes in the buffer with 64 bytes in each round of
287	the loop. */
288	while (words < endp)
289	{
290	md5_uint32 *cwp = correct_words;
291	md5_uint32 A_save = A;
292	md5_uint32 B_save = B;
293	md5_uint32 C_save = C;
294	md5_uint32 D_save = D;
295
296	/* First round: using the given function, the context and a constant
297	the next context is computed. Because the algorithms processing
298	unit is a 32-bit word and it is determined to work on words in
299	little endian byte order we perhaps have to change the byte order
300	before the computation. To reduce the work for the next steps
301	we store the swapped words in the array CORRECT_WORDS. */
302
303	#define OP(a, b, c, d, s, T) \
304	do \
305	{ \
306	a += FF (b, c, d) + (cwp++ = SWAP (words)) + T; \
307	++words; \
308	CYCLIC (a, s); \
309	a += b; \
310	} \
311	while (0)
312
313	/* It is unfortunate that C does not provide an operator for
314	cyclic rotation. Hope the C compiler is smart enough. */
315	#define CYCLIC(w, s) (w = (w << s) \| (w >> (32 - s)))
316
317	/* Before we start, one word to the strange constants.
318	They are defined in RFC 1321 as
319
320	T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64
321	*/
322
323	/* Round 1. */
324	OP (A, B, C, D, 7, 0xd76aa478);
325	OP (D, A, B, C, 12, 0xe8c7b756);
326	OP (C, D, A, B, 17, 0x242070db);
327	OP (B, C, D, A, 22, 0xc1bdceee);
328	OP (A, B, C, D, 7, 0xf57c0faf);
329	OP (D, A, B, C, 12, 0x4787c62a);
330	OP (C, D, A, B, 17, 0xa8304613);
331	OP (B, C, D, A, 22, 0xfd469501);
332	OP (A, B, C, D, 7, 0x698098d8);
333	OP (D, A, B, C, 12, 0x8b44f7af);
334	OP (C, D, A, B, 17, 0xffff5bb1);
335	OP (B, C, D, A, 22, 0x895cd7be);
336	OP (A, B, C, D, 7, 0x6b901122);
337	OP (D, A, B, C, 12, 0xfd987193);
338	OP (C, D, A, B, 17, 0xa679438e);
339	OP (B, C, D, A, 22, 0x49b40821);
340
341	/* For the second to fourth round we have the possibly swapped words
342	in CORRECT_WORDS. Redefine the macro to take an additional first
343	argument specifying the function to use. */
344	#undef OP
345	#define OP(f, a, b, c, d, k, s, T) \
346	do \
347	{ \
348	a += f (b, c, d) + correct_words[k] + T; \
349	CYCLIC (a, s); \
350	a += b; \
351	} \
352	while (0)
353
354	/* Round 2. */
355	OP (FG, A, B, C, D, 1, 5, 0xf61e2562);
356	OP (FG, D, A, B, C, 6, 9, 0xc040b340);
357	OP (FG, C, D, A, B, 11, 14, 0x265e5a51);
358	OP (FG, B, C, D, A, 0, 20, 0xe9b6c7aa);
359	OP (FG, A, B, C, D, 5, 5, 0xd62f105d);
360	OP (FG, D, A, B, C, 10, 9, 0x02441453);
361	OP (FG, C, D, A, B, 15, 14, 0xd8a1e681);
362	OP (FG, B, C, D, A, 4, 20, 0xe7d3fbc8);
363	OP (FG, A, B, C, D, 9, 5, 0x21e1cde6);
364	OP (FG, D, A, B, C, 14, 9, 0xc33707d6);
365	OP (FG, C, D, A, B, 3, 14, 0xf4d50d87);
366	OP (FG, B, C, D, A, 8, 20, 0x455a14ed);
367	OP (FG, A, B, C, D, 13, 5, 0xa9e3e905);
368	OP (FG, D, A, B, C, 2, 9, 0xfcefa3f8);
369	OP (FG, C, D, A, B, 7, 14, 0x676f02d9);
370	OP (FG, B, C, D, A, 12, 20, 0x8d2a4c8a);
371
372	/* Round 3. */
373	OP (FH, A, B, C, D, 5, 4, 0xfffa3942);
374	OP (FH, D, A, B, C, 8, 11, 0x8771f681);
375	OP (FH, C, D, A, B, 11, 16, 0x6d9d6122);
376	OP (FH, B, C, D, A, 14, 23, 0xfde5380c);
377	OP (FH, A, B, C, D, 1, 4, 0xa4beea44);
378	OP (FH, D, A, B, C, 4, 11, 0x4bdecfa9);
379	OP (FH, C, D, A, B, 7, 16, 0xf6bb4b60);
380	OP (FH, B, C, D, A, 10, 23, 0xbebfbc70);
381	OP (FH, A, B, C, D, 13, 4, 0x289b7ec6);
382	OP (FH, D, A, B, C, 0, 11, 0xeaa127fa);
383	OP (FH, C, D, A, B, 3, 16, 0xd4ef3085);
384	OP (FH, B, C, D, A, 6, 23, 0x04881d05);
385	OP (FH, A, B, C, D, 9, 4, 0xd9d4d039);
386	OP (FH, D, A, B, C, 12, 11, 0xe6db99e5);
387	OP (FH, C, D, A, B, 15, 16, 0x1fa27cf8);
388	OP (FH, B, C, D, A, 2, 23, 0xc4ac5665);
389
390	/* Round 4. */
391	OP (FI, A, B, C, D, 0, 6, 0xf4292244);
392	OP (FI, D, A, B, C, 7, 10, 0x432aff97);
393	OP (FI, C, D, A, B, 14, 15, 0xab9423a7);
394	OP (FI, B, C, D, A, 5, 21, 0xfc93a039);
395	OP (FI, A, B, C, D, 12, 6, 0x655b59c3);
396	OP (FI, D, A, B, C, 3, 10, 0x8f0ccc92);
397	OP (FI, C, D, A, B, 10, 15, 0xffeff47d);
398	OP (FI, B, C, D, A, 1, 21, 0x85845dd1);
399	OP (FI, A, B, C, D, 8, 6, 0x6fa87e4f);
400	OP (FI, D, A, B, C, 15, 10, 0xfe2ce6e0);
401	OP (FI, C, D, A, B, 6, 15, 0xa3014314);
402	OP (FI, B, C, D, A, 13, 21, 0x4e0811a1);
403	OP (FI, A, B, C, D, 4, 6, 0xf7537e82);
404	OP (FI, D, A, B, C, 11, 10, 0xbd3af235);
405	OP (FI, C, D, A, B, 2, 15, 0x2ad7d2bb);
406	OP (FI, B, C, D, A, 9, 21, 0xeb86d391);
407
408	/* Add the starting values of the context. */
409	A += A_save;
410	B += B_save;
411	C += C_save;
412	D += D_save;
413	}
414
415	/* Put checksum in context given as argument. */
416	ctx->A = A;
417	ctx->B = B;
418	ctx->C = C;
419	ctx->D = D;
420	}