[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, 2011 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;
  md5_uint32 swap_bytes;
  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.
     Use memcpy to avoid aliasing problems.  On most systems, this
     will be optimized away to the same code.  */
  swap_bytes = SWAP (ctx->total[0] << 3);
  memcpy (&ctx->buffer[bytes + pad], &swap_bytes, sizeof (swap_bytes));
  swap_bytes = SWAP ((ctx->total[1] << 3) | (ctx->total[0] >> 29));
  memcpy (&ctx->buffer[bytes + pad + 4], &swap_bytes, sizeof (swap_bytes));

  /* 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;
  ctx->total[1] += ((len >> 31) >> 1) + (ctx->total[0] < len);

  /* 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
050823ca JM	2	according to the definition of MD5 in RFC 1321 from April 1992.
634e4f4f	3	Copyright (C) 1995, 1996, 2011 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
091c2a96 DD	79	IMPORTANT: RESBUF may not be aligned as strongly as MD5_UNIT32 so we
091c2a96 DD	80	put things in a local (aligned) buffer first, then memcpy into RESBUF. */
050823ca	81	void *
49b1fae4	82	md5_read_ctx (const struct md5_ctx ctx, void resbuf)
050823ca	83	{
091c2a96 DD	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);
050823ca 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 *
49b1fae4	102	md5_finish_ctx (struct md5_ctx ctx, void resbuf)
050823ca JM	103	{
	104	/* Take yet unprocessed bytes into account. */
	105	md5_uint32 bytes = ctx->buflen;
902e4335	106	md5_uint32 swap_bytes;
050823ca JM	107	size_t pad;
	108
	109	/* Now count remaining bytes. */
	110	ctx->total[0] += bytes;
	111	if (ctx->total[0] < bytes)
	112	++ctx->total[1];
	113
	114	pad = bytes >= 56 ? 64 + 56 - bytes : 56 - bytes;
	115	memcpy (&ctx->buffer[bytes], fillbuf, pad);
	116
902e4335 MF	117	/* Put the 64-bit file length in bits at the end of the buffer.
	118	Use memcpy to avoid aliasing problems. On most systems, this
	119	will be optimized away to the same code. */
	120	swap_bytes = SWAP (ctx->total[0] << 3);
	121	memcpy (&ctx->buffer[bytes + pad], &swap_bytes, sizeof (swap_bytes));
	122	swap_bytes = SWAP ((ctx->total[1] << 3) \| (ctx->total[0] >> 29));
	123	memcpy (&ctx->buffer[bytes + pad + 4], &swap_bytes, sizeof (swap_bytes));
050823ca JM	124
	125	/* Process last bytes. */
	126	md5_process_block (ctx->buffer, bytes + pad + 8, ctx);
	127
	128	return md5_read_ctx (ctx, resbuf);
	129	}
	130
	131	/* Compute MD5 message digest for bytes read from STREAM. The
	132	resulting message digest number will be written into the 16 bytes
	133	beginning at RESBLOCK. */
	134	int
49b1fae4	135	md5_stream (FILE stream, void resblock)
050823ca JM	136	{
	137	/* Important: BLOCKSIZE must be a multiple of 64. */
	138	#define BLOCKSIZE 4096
	139	struct md5_ctx ctx;
	140	char buffer[BLOCKSIZE + 72];
	141	size_t sum;
	142
	143	/* Initialize the computation context. */
	144	md5_init_ctx (&ctx);
	145
	146	/* Iterate over full file contents. */
	147	while (1)
	148	{
	149	/* We read the file in blocks of BLOCKSIZE bytes. One call of the
	150	computation function processes the whole buffer so that with the
	151	next round of the loop another block can be read. */
	152	size_t n;
	153	sum = 0;
	154
	155	/* Read block. Take care for partial reads. */
	156	do
	157	{
	158	n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
	159
	160	sum += n;
	161	}
	162	while (sum < BLOCKSIZE && n != 0);
	163	if (n == 0 && ferror (stream))
	164	return 1;
	165
	166	/* If end of file is reached, end the loop. */
	167	if (n == 0)
	168	break;
	169
	170	/* Process buffer with BLOCKSIZE bytes. Note that
	171	BLOCKSIZE % 64 == 0
	172	*/
	173	md5_process_block (buffer, BLOCKSIZE, &ctx);
	174	}
	175
	176	/* Add the last bytes if necessary. */
	177	if (sum > 0)
	178	md5_process_bytes (buffer, sum, &ctx);
	179
	180	/* Construct result in desired memory. */
	181	md5_finish_ctx (&ctx, resblock);
	182	return 0;
	183	}
	184
	185	/* Compute MD5 message digest for LEN bytes beginning at BUFFER. The
	186	result is always in little endian byte order, so that a byte-wise
	187	output yields to the wanted ASCII representation of the message
	188	digest. */
	189	void *
49b1fae4	190	md5_buffer (const char buffer, size_t len, void resblock)
050823ca JM	191	{
	192	struct md5_ctx ctx;
	193
	194	/* Initialize the computation context. */
	195	md5_init_ctx (&ctx);
	196
	197	/* Process whole buffer but last len % 64 bytes. */
	198	md5_process_bytes (buffer, len, &ctx);
	199
	200	/* Put result in desired memory area. */
	201	return md5_finish_ctx (&ctx, resblock);
	202	}
	203
	204
	205	void
49b1fae4	206	md5_process_bytes (const void buffer, size_t len, struct md5_ctx ctx)
050823ca JM	207	{
	208	/* When we already have some bits in our internal buffer concatenate
	209	both inputs first. */
	210	if (ctx->buflen != 0)
	211	{
	212	size_t left_over = ctx->buflen;
	213	size_t add = 128 - left_over > len ? len : 128 - left_over;
	214
	215	memcpy (&ctx->buffer[left_over], buffer, add);
	216	ctx->buflen += add;
	217
	218	if (left_over + add > 64)
	219	{
	220	md5_process_block (ctx->buffer, (left_over + add) & ~63, ctx);
	221	/* The regions in the following copy operation cannot overlap. */
	222	memcpy (ctx->buffer, &ctx->buffer[(left_over + add) & ~63],
	223	(left_over + add) & 63);
	224	ctx->buflen = (left_over + add) & 63;
	225	}
	226
585cc78f	227	buffer = (const void ) ((const char ) buffer + add);
050823ca JM	228	len -= add;
	229	}
	230
	231	/* Process available complete blocks. */
	232	if (len > 64)
	233	{
6ba85b8c DD	234	#if !_STRING_ARCH_unaligned
	235	/* To check alignment gcc has an appropriate operator. Other
	236	compilers don't. */
	237	# if __GNUC__ >= 2
	238	# define UNALIGNED_P(p) (((md5_uintptr) p) % __alignof__ (md5_uint32) != 0)
	239	# else
	240	# define UNALIGNED_P(p) (((md5_uintptr) p) % sizeof (md5_uint32) != 0)
	241	# endif
	242	if (UNALIGNED_P (buffer))
	243	while (len > 64)
	244	{
3f69c6bf DD	245	memcpy (ctx->buffer, buffer, 64);
3f69c6bf DD	246	md5_process_block (ctx->buffer, 64, ctx);
6ba85b8c DD	247	buffer = (const char *) buffer + 64;
	248	len -= 64;
	249	}
	250	else
	251	#endif
634e4f4f DD	252	{
	253	md5_process_block (buffer, len & ~63, ctx);
	254	buffer = (const void ) ((const char ) buffer + (len & ~63));
	255	len &= 63;
	256	}
050823ca JM	257	}
	258
	259	/* Move remaining bytes in internal buffer. */
	260	if (len > 0)
	261	{
	262	memcpy (ctx->buffer, buffer, len);
	263	ctx->buflen = len;
	264	}
	265	}
	266
	267
	268	/* These are the four functions used in the four steps of the MD5 algorithm
	269	and defined in the RFC 1321. The first function is a little bit optimized
	270	(as found in Colin Plumbs public domain implementation). */
	271	/* #define FF(b, c, d) ((b & c) \| (~b & d)) */
	272	#define FF(b, c, d) (d ^ (b & (c ^ d)))
	273	#define FG(b, c, d) FF (d, b, c)
	274	#define FH(b, c, d) (b ^ c ^ d)
	275	#define FI(b, c, d) (c ^ (b \| ~d))
	276
	277	/* Process LEN bytes of BUFFER, accumulating context into CTX.
	278	It is assumed that LEN % 64 == 0. */
	279
	280	void
49b1fae4	281	md5_process_block (const void buffer, size_t len, struct md5_ctx ctx)
050823ca JM	282	{
050823ca JM	283	md5_uint32 correct_words[16];
585cc78f	284	const md5_uint32 words = (const md5_uint32 ) buffer;
050823ca JM	285	size_t nwords = len / sizeof (md5_uint32);
	286	const md5_uint32 *endp = words + nwords;
	287	md5_uint32 A = ctx->A;
	288	md5_uint32 B = ctx->B;
	289	md5_uint32 C = ctx->C;
	290	md5_uint32 D = ctx->D;
	291
	292	/* First increment the byte count. RFC 1321 specifies the possible
	293	length of the file up to 2^64 bits. Here we only compute the
	294	number of bytes. Do a double word increment. */
	295	ctx->total[0] += len;
fe4b0b46	296	ctx->total[1] += ((len >> 31) >> 1) + (ctx->total[0] < len);
050823ca JM	297
	298	/* Process all bytes in the buffer with 64 bytes in each round of
	299	the loop. */
	300	while (words < endp)
	301	{
	302	md5_uint32 *cwp = correct_words;
	303	md5_uint32 A_save = A;
	304	md5_uint32 B_save = B;
	305	md5_uint32 C_save = C;
	306	md5_uint32 D_save = D;
	307
	308	/* First round: using the given function, the context and a constant
	309	the next context is computed. Because the algorithms processing
	310	unit is a 32-bit word and it is determined to work on words in
	311	little endian byte order we perhaps have to change the byte order
	312	before the computation. To reduce the work for the next steps
	313	we store the swapped words in the array CORRECT_WORDS. */
	314
	315	#define OP(a, b, c, d, s, T) \
	316	do \
	317	{ \
	318	a += FF (b, c, d) + (cwp++ = SWAP (words)) + T; \
	319	++words; \
	320	CYCLIC (a, s); \
	321	a += b; \
	322	} \
	323	while (0)
	324
	325	/* It is unfortunate that C does not provide an operator for
	326	cyclic rotation. Hope the C compiler is smart enough. */
	327	#define CYCLIC(w, s) (w = (w << s) \| (w >> (32 - s)))
	328
	329	/* Before we start, one word to the strange constants.
	330	They are defined in RFC 1321 as
	331
	332	T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64
	333	*/
	334
	335	/* Round 1. */
b50c4073 DD	336	OP (A, B, C, D, 7, (md5_uint32) 0xd76aa478);
	337	OP (D, A, B, C, 12, (md5_uint32) 0xe8c7b756);
	338	OP (C, D, A, B, 17, (md5_uint32) 0x242070db);
	339	OP (B, C, D, A, 22, (md5_uint32) 0xc1bdceee);
	340	OP (A, B, C, D, 7, (md5_uint32) 0xf57c0faf);
	341	OP (D, A, B, C, 12, (md5_uint32) 0x4787c62a);
	342	OP (C, D, A, B, 17, (md5_uint32) 0xa8304613);
	343	OP (B, C, D, A, 22, (md5_uint32) 0xfd469501);
	344	OP (A, B, C, D, 7, (md5_uint32) 0x698098d8);
	345	OP (D, A, B, C, 12, (md5_uint32) 0x8b44f7af);
	346	OP (C, D, A, B, 17, (md5_uint32) 0xffff5bb1);
	347	OP (B, C, D, A, 22, (md5_uint32) 0x895cd7be);
	348	OP (A, B, C, D, 7, (md5_uint32) 0x6b901122);
	349	OP (D, A, B, C, 12, (md5_uint32) 0xfd987193);
	350	OP (C, D, A, B, 17, (md5_uint32) 0xa679438e);
	351	OP (B, C, D, A, 22, (md5_uint32) 0x49b40821);
050823ca JM	352
	353	/* For the second to fourth round we have the possibly swapped words
	354	in CORRECT_WORDS. Redefine the macro to take an additional first
	355	argument specifying the function to use. */
	356	#undef OP
768b20d8	357	#define OP(a, b, c, d, k, s, T) \
050823ca JM	358	do \
050823ca JM	359	{ \
768b20d8	360	a += FX (b, c, d) + correct_words[k] + T; \
050823ca JM	361	CYCLIC (a, s); \
	362	a += b; \
	363	} \
	364	while (0)
	365
768b20d8 JJ	366	#define FX(b, c, d) FG (b, c, d)
768b20d8 JJ	367
050823ca	368	/* Round 2. */
768b20d8 JJ	369	OP (A, B, C, D, 1, 5, (md5_uint32) 0xf61e2562);
	370	OP (D, A, B, C, 6, 9, (md5_uint32) 0xc040b340);
	371	OP (C, D, A, B, 11, 14, (md5_uint32) 0x265e5a51);
	372	OP (B, C, D, A, 0, 20, (md5_uint32) 0xe9b6c7aa);
	373	OP (A, B, C, D, 5, 5, (md5_uint32) 0xd62f105d);
	374	OP (D, A, B, C, 10, 9, (md5_uint32) 0x02441453);
	375	OP (C, D, A, B, 15, 14, (md5_uint32) 0xd8a1e681);
	376	OP (B, C, D, A, 4, 20, (md5_uint32) 0xe7d3fbc8);
	377	OP (A, B, C, D, 9, 5, (md5_uint32) 0x21e1cde6);
	378	OP (D, A, B, C, 14, 9, (md5_uint32) 0xc33707d6);
	379	OP (C, D, A, B, 3, 14, (md5_uint32) 0xf4d50d87);
	380	OP (B, C, D, A, 8, 20, (md5_uint32) 0x455a14ed);
	381	OP (A, B, C, D, 13, 5, (md5_uint32) 0xa9e3e905);
	382	OP (D, A, B, C, 2, 9, (md5_uint32) 0xfcefa3f8);
	383	OP (C, D, A, B, 7, 14, (md5_uint32) 0x676f02d9);
	384	OP (B, C, D, A, 12, 20, (md5_uint32) 0x8d2a4c8a);
	385
	386	#undef FX
	387	#define FX(b, c, d) FH (b, c, d)
050823ca JM	388
050823ca JM	389	/* Round 3. */
768b20d8 JJ	390	OP (A, B, C, D, 5, 4, (md5_uint32) 0xfffa3942);
	391	OP (D, A, B, C, 8, 11, (md5_uint32) 0x8771f681);
	392	OP (C, D, A, B, 11, 16, (md5_uint32) 0x6d9d6122);
	393	OP (B, C, D, A, 14, 23, (md5_uint32) 0xfde5380c);
	394	OP (A, B, C, D, 1, 4, (md5_uint32) 0xa4beea44);
	395	OP (D, A, B, C, 4, 11, (md5_uint32) 0x4bdecfa9);
	396	OP (C, D, A, B, 7, 16, (md5_uint32) 0xf6bb4b60);
	397	OP (B, C, D, A, 10, 23, (md5_uint32) 0xbebfbc70);
	398	OP (A, B, C, D, 13, 4, (md5_uint32) 0x289b7ec6);
	399	OP (D, A, B, C, 0, 11, (md5_uint32) 0xeaa127fa);
	400	OP (C, D, A, B, 3, 16, (md5_uint32) 0xd4ef3085);
	401	OP (B, C, D, A, 6, 23, (md5_uint32) 0x04881d05);
	402	OP (A, B, C, D, 9, 4, (md5_uint32) 0xd9d4d039);
	403	OP (D, A, B, C, 12, 11, (md5_uint32) 0xe6db99e5);
	404	OP (C, D, A, B, 15, 16, (md5_uint32) 0x1fa27cf8);
	405	OP (B, C, D, A, 2, 23, (md5_uint32) 0xc4ac5665);
	406
	407	#undef FX
	408	#define FX(b, c, d) FI (b, c, d)
050823ca JM	409
050823ca JM	410	/* Round 4. */
768b20d8 JJ	411	OP (A, B, C, D, 0, 6, (md5_uint32) 0xf4292244);
	412	OP (D, A, B, C, 7, 10, (md5_uint32) 0x432aff97);
	413	OP (C, D, A, B, 14, 15, (md5_uint32) 0xab9423a7);
	414	OP (B, C, D, A, 5, 21, (md5_uint32) 0xfc93a039);
	415	OP (A, B, C, D, 12, 6, (md5_uint32) 0x655b59c3);
	416	OP (D, A, B, C, 3, 10, (md5_uint32) 0x8f0ccc92);
	417	OP (C, D, A, B, 10, 15, (md5_uint32) 0xffeff47d);
	418	OP (B, C, D, A, 1, 21, (md5_uint32) 0x85845dd1);
	419	OP (A, B, C, D, 8, 6, (md5_uint32) 0x6fa87e4f);
	420	OP (D, A, B, C, 15, 10, (md5_uint32) 0xfe2ce6e0);
	421	OP (C, D, A, B, 6, 15, (md5_uint32) 0xa3014314);
	422	OP (B, C, D, A, 13, 21, (md5_uint32) 0x4e0811a1);
	423	OP (A, B, C, D, 4, 6, (md5_uint32) 0xf7537e82);
	424	OP (D, A, B, C, 11, 10, (md5_uint32) 0xbd3af235);
	425	OP (C, D, A, B, 2, 15, (md5_uint32) 0x2ad7d2bb);
	426	OP (B, C, D, A, 9, 21, (md5_uint32) 0xeb86d391);
050823ca JM	427
	428	/* Add the starting values of the context. */
	429	A += A_save;
	430	B += B_save;
	431	C += C_save;
	432	D += D_save;
	433	}
	434
	435	/* Put checksum in context given as argument. */
	436	ctx->A = A;
	437	ctx->B = B;
	438	ctx->C = C;
	439	ctx->D = D;
	440	}