--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/md5.c	Mon Aug 13 11:28:15 2007 +0200
@@ -0,0 +1,618 @@
+/* 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.  */
+
+/* XEmacs frontend written by Ben Wing, Jareth Hein and Hrvoje Niksic.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <sys/types.h>
+#include <string.h>
+#include <stdio.h>
+
+#if defined HAVE_LIMITS_H || _LIBC
+# include <limits.h>
+#endif
+
+/* The following contortions are an attempt to use the C preprocessor
+   to determine an unsigned integral type that is 32 bits wide.  An
+   alternative approach is to use autoconf's AC_CHECK_SIZEOF macro, but
+   doing that would require that the configure script compile and *run*
+   the resulting executable.  Locally running cross-compiled executables
+   is usually not possible.  */
+
+#ifdef _LIBC
+# include <sys/types.h>
+typedef u_int32_t md5_uint32;
+#else
+# if defined __STDC__ && __STDC__
+#  define UINT_MAX_32_BITS 4294967295U
+# else
+#  define UINT_MAX_32_BITS 0xFFFFFFFF
+# endif
+
+/* If UINT_MAX isn't defined, assume it's a 32-bit type.
+   This should be valid for all systems GNU cares about because
+   that doesn't include 16-bit systems, and only modern systems
+   (that certainly have <limits.h>) have 64+-bit integral types.  */
+
+# ifndef UINT_MAX
+#  define UINT_MAX UINT_MAX_32_BITS
+# endif
+
+# if UINT_MAX == UINT_MAX_32_BITS
+   typedef unsigned int md5_uint32;
+# else
+#  if USHRT_MAX == UINT_MAX_32_BITS
+    typedef unsigned short md5_uint32;
+#  else
+#   if ULONG_MAX == UINT_MAX_32_BITS
+     typedef unsigned long md5_uint32;
+#   else
+     /* The following line is intended to evoke an error.
+        Using #error is not portable enough.  */
+     "Cannot determine unsigned 32-bit data type."
+#   endif
+#  endif
+# endif
+#endif
+
+#include "lisp.h"
+#include "buffer.h"
+#include "lstream.h"
+#ifdef FILE_CODING
+# include "file-coding.h"
+#endif
+
+/* Structure to save state of computation between the single steps.  */
+struct md5_ctx
+{
+  md5_uint32 A;
+  md5_uint32 B;
+  md5_uint32 C;
+  md5_uint32 D;
+
+  md5_uint32 total[2];
+  md5_uint32 buflen;
+  char buffer[128];
+};
+
+#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, ...  */ };
+
+
+static void md5_process_block (CONST void *, size_t, struct md5_ctx *);
+
+
+/* Initialize structure containing state of computation.
+   (RFC 1321, 3.3: Step 3)  */
+static void
+md5_init_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.  */
+static 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.  */
+static 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);
+}
+
+#ifndef emacs			/* unused in Emacs */
+/* 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);
+}
+#endif /* not emacs */
+
+
+static 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 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.  */
+
+static 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, 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;
+}
+
+
+#ifdef emacs
+#ifdef FILE_CODING
+/* Find out what format the buffer will be saved in, so we can make
+   the digest based on what it will look like on disk.  */
+static Lisp_Object
+md5_coding_system (Lisp_Object object, Lisp_Object coding, Lisp_Object istream,
+		   int error_me_not)
+{
+  Lisp_Object coding_system;
+
+  if (NILP (coding))
+    {
+      if (BUFFERP (object))
+	{
+	  /* Use the file coding for this buffer by default.  */
+	  coding_system = XBUFFER (object)->buffer_file_coding_system;
+	}
+      else
+	{
+	  /* Attempt to autodetect the coding of the string.  This is
+             VERY hit-and-miss.  */
+	  enum eol_type eol = EOL_AUTODETECT;
+	  coding_system = Fget_coding_system (Qundecided);
+	  determine_real_coding_system (XLSTREAM (istream),
+					&coding_system, &eol);
+	}
+      if (NILP (coding_system)) 
+	coding_system = Fget_coding_system (Qbinary);
+      else
+	{
+	  coding_system = Ffind_coding_system (coding_system);
+	  if (NILP (coding_system))
+	    coding_system = Fget_coding_system (Qbinary);
+	}
+    }
+  else
+    {
+      coding_system = Ffind_coding_system (coding);
+      if (NILP (coding_system))
+	{
+	  if (error_me_not)
+	    /* Default to binary.  */
+	    coding_system = Fget_coding_system (Qbinary);
+	  else
+	    signal_simple_error ("No such coding system", coding);
+	}
+    }
+  return coding_system;
+}
+#endif /* FILE_CODING */
+
+
+DEFUN ("md5", Fmd5, 1, 5, 0, /*
+Return the MD5 message digest of OBJECT, a buffer or string.
+
+Optional arguments START and END denote positions for computing the
+digest of a portion of OBJECT.
+
+The optional CODING argument specifies the coding system the text is to be
+represented in while computing the digest.  If unspecified, it defaults
+to the current format of the data, or is guessed.
+
+If NOERROR is non-nil, silently assume binary coding if the guesswork
+fails.  Normally, an error is signaled in such case.
+
+CODING and NOERROR arguments are meaningful only in XEmacsen with
+file-coding or Mule support.  Otherwise, they are ignored.
+*/
+       (object, start, end, coding, noerror))
+{
+  /* This function can GC */
+  /* Can this really GC?  How?  */
+  struct md5_ctx ctx;
+  unsigned char digest[16];
+  unsigned char thehash[33];
+  int i;
+
+  Lisp_Object instream;
+  struct gcpro gcpro1;
+#ifdef FILE_CODING
+  Lisp_Object raw_instream;
+  struct gcpro ngcpro1;
+#endif
+
+  /* Set up the input stream.  */
+  if (BUFFERP (object))
+    {
+      struct buffer *b;
+      Bufpos begv, endv;
+      CHECK_LIVE_BUFFER (object);
+      b = XBUFFER (object);
+      /* Figure out where we need to get info from */
+      get_buffer_range_char (b, start, end, &begv, &endv, GB_ALLOW_NIL);
+
+      instream = make_lisp_buffer_input_stream (b, begv, endv, 0);
+    }
+  else
+    {
+      Bytecount bstart, bend;
+      CHECK_STRING (object);
+      get_string_range_byte (object, start, end, &bstart, &bend,
+			     GB_HISTORICAL_STRING_BEHAVIOR);
+      instream = make_lisp_string_input_stream (object, bstart, bend - bstart);
+    }
+  GCPRO1 (instream);
+
+#ifdef FILE_CODING
+  /* Determine the coding and set up the conversion stream.  */
+  coding = md5_coding_system (object, coding, instream, !NILP (noerror));
+  raw_instream = instream;
+  instream = make_encoding_input_stream (XLSTREAM (instream), coding);
+  NGCPRO1 (raw_instream);
+#endif
+
+  /* Initialize MD5 context.  */
+  md5_init_ctx (&ctx);
+
+  /* Get the data while doing the conversion.  */
+  while (1)
+    {
+      Bufbyte tempbuf[1024];	/* some random amount */
+      ssize_t size_in_bytes =
+	Lstream_read (XLSTREAM (instream), tempbuf, sizeof (tempbuf));
+      if (!size_in_bytes)
+	break;
+
+      /* Process the bytes.  */
+      md5_process_bytes (tempbuf, size_in_bytes, &ctx);
+    }
+  Lstream_delete (XLSTREAM (instream));
+#ifdef FILE_CODING
+  Lstream_delete (XLSTREAM (raw_instream));
+  NUNGCPRO;
+#endif
+  UNGCPRO;
+
+  md5_finish_ctx (&ctx, digest);
+  for (i = 0; i < 16; i++)
+    sprintf ((char *) (thehash + (i * 2)), "%02x", digest[i]);
+
+  return make_string (thehash, 32);
+}
+
+void
+syms_of_md5 (void)
+{
+  DEFSUBR (Fmd5);
+}
+
+void
+vars_of_md5 (void)
+{
+  Fprovide (intern ("md5"));
+}
+#endif /* emacs */