include/md5.h

   1 /* md5.h - Declaration of functions and data types used for MD5 sum
   2    computing library functions.
   3    Copyright 1995, 1996, 2000 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., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.  */
  20
  21 #ifndef _MD5_H
  22 #define _MD5_H 1
  23
  24 #include <stdio.h>
  25
  26 #if defined HAVE_LIMITS_H || _LIBC
  27 # include <limits.h>
  28 #endif
  29
  30 #include "ansidecl.h"
  31
  32 /* The following contortions are an attempt to use the C preprocessor
  33    to determine an unsigned integral type that is 32 bits wide.  An
  34    alternative approach is to use autoconf's AC_CHECK_SIZEOF macro, but
  35    doing that would require that the configure script compile and *run*
  36    the resulting executable.  Locally running cross-compiled executables
  37    is usually not possible.  */
  38
  39 #ifdef _LIBC
  40 # include <sys/types.h>
  41 typedef u_int32_t md5_uint32;
  42 typedef uintptr_t md5_uintptr;
  43 #else
  44 #  define INT_MAX_32_BITS 2147483647
  45
  46 /* If UINT_MAX isn't defined, assume it's a 32-bit type.
  47    This should be valid for all systems GNU cares about because
  48    that doesn't include 16-bit systems, and only modern systems
  49    (that certainly have <limits.h>) have 64+-bit integral types.  */
  50
  51 # ifndef INT_MAX
  52 #  define INT_MAX INT_MAX_32_BITS
  53 # endif
  54
  55 # if INT_MAX == INT_MAX_32_BITS
  56    typedef unsigned int md5_uint32;
  57 # else
  58 #  if SHRT_MAX == INT_MAX_32_BITS
  59     typedef unsigned short md5_uint32;
  60 #  else
  61 #   if LONG_MAX == INT_MAX_32_BITS
  62      typedef unsigned long md5_uint32;
  63 #   else
  64      /* The following line is intended to evoke an error.
  65         Using #error is not portable enough.  */
  66      "Cannot determine unsigned 32-bit data type."
  67 #   endif
  68 #  endif
  69 # endif
  70 /* We have to make a guess about the integer type equivalent in size
  71    to pointers which should always be correct.  */
  72 typedef unsigned long int md5_uintptr;
  73 #endif
  74
  75 /* Structure to save state of computation between the single steps.  */
  76 struct md5_ctx
  77 {
  78   md5_uint32 A;
  79   md5_uint32 B;
  80   md5_uint32 C;
  81   md5_uint32 D;
  82
  83   md5_uint32 total[2];
  84   md5_uint32 buflen;
  85   char buffer[128] ATTRIBUTE_ALIGNED_ALIGNOF(md5_uint32);
  86 };
  87
  88 /*
  89  * The following three functions are build up the low level used in
  90  * the functions `md5_stream' and `md5_buffer'.
  91  */
  92
  93 /* Initialize structure containing state of computation.
  94    (RFC 1321, 3.3: Step 3)  */
  95 extern void md5_init_ctx (struct md5_ctx *ctx);
  96
  97 /* Starting with the result of former calls of this function (or the
  98    initialization function update the context for the next LEN bytes
  99    starting at BUFFER.
 100    It is necessary that LEN is a multiple of 64!!! */
 101 extern void md5_process_block (const void *buffer, size_t len,
 102                                struct md5_ctx *ctx);
 103
 104 /* Starting with the result of former calls of this function (or the
 105    initialization function update the context for the next LEN bytes
 106    starting at BUFFER.
 107    It is NOT required that LEN is a multiple of 64.  */
 108 extern void md5_process_bytes (const void *buffer, size_t len,
 109                                struct md5_ctx *ctx);
 110
 111 /* Process the remaining bytes in the buffer and put result from CTX
 112    in first 16 bytes following RESBUF.  The result is always in little
 113    endian byte order, so that a byte-wise output yields to the wanted
 114    ASCII representation of the message digest.
 115
 116    IMPORTANT: On some systems it is required that RESBUF is correctly
 117    aligned for a 32 bits value.  */
 118 extern void *md5_finish_ctx (struct md5_ctx *ctx, void *resbuf);
 119
 120
 121 /* Put result from CTX in first 16 bytes following RESBUF.  The result is
 122    always in little endian byte order, so that a byte-wise output yields
 123    to the wanted ASCII representation of the message digest.
 124
 125    IMPORTANT: On some systems it is required that RESBUF is correctly
 126    aligned for a 32 bits value.  */
 127 extern void *md5_read_ctx (const struct md5_ctx *ctx, void *resbuf);
 128
 129
 130 /* Compute MD5 message digest for bytes read from STREAM.  The
 131    resulting message digest number will be written into the 16 bytes
 132    beginning at RESBLOCK.  */
 133 extern int md5_stream (FILE *stream, void *resblock);
 134
 135 /* Compute MD5 message digest for LEN bytes beginning at BUFFER.  The
 136    result is always in little endian byte order, so that a byte-wise
 137    output yields to the wanted ASCII representation of the message
 138    digest.  */
 139 extern void *md5_buffer (const char *buffer, size_t len, void *resblock);
 140
 141 #endif