lib/md5.h

   1 /* Declaration of functions and data types used for MD5 sum computing
   2    library functions.
   3    Copyright (C) 1995-1997, 1999-2001, 2004-2006, 2008-2011 Free Software
   4    Foundation, Inc.
   5    This file is part of the GNU C Library.
   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 3, 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 #define MD5_DIGEST_SIZE 16
  27 #define MD5_BLOCK_SIZE 64
  28
  29 #ifndef __GNUC_PREREQ
  30 # if defined __GNUC__ && defined __GNUC_MINOR__
  31 #  define __GNUC_PREREQ(maj, min)                                       \
  32   ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
  33 # else
  34 #  define __GNUC_PREREQ(maj, min) 0
  35 # endif
  36 #endif
  37
  38 #ifndef __THROW
  39 # if defined __cplusplus && __GNUC_PREREQ (2,8)
  40 #  define __THROW       throw ()
  41 # else
  42 #  define __THROW
  43 # endif
  44 #endif
  45
  46 #ifndef _LIBC
  47 # define __md5_buffer md5_buffer
  48 # define __md5_finish_ctx md5_finish_ctx
  49 # define __md5_init_ctx md5_init_ctx
  50 # define __md5_process_block md5_process_block
  51 # define __md5_process_bytes md5_process_bytes
  52 # define __md5_read_ctx md5_read_ctx
  53 # define __md5_stream md5_stream
  54 #endif
  55
  56 # ifdef __cplusplus
  57 extern "C" {
  58 # endif
  59
  60 /* The following contortions are an attempt to use the C preprocessor
  61    to determine an unsigned integral type that is 32 bits wide.  An
  62    alternative approach is to use autoconf's AC_CHECK_SIZEOF macro, but
  63    doing that would require that the configure script compile and *run*
  64    the resulting executable.  Locally running cross-compiled executables
  65    is usually not possible.  */
  66
  67 #if defined _LIBC
  68 # include <stdint.h>
  69 typedef uint32_t md5_uint32;
  70 #else
  71 # if defined __STDC__ && __STDC__
  72 #  define UINT_MAX_32_BITS 4294967295U
  73 # else
  74 #  define UINT_MAX_32_BITS 0xFFFFFFFF
  75 # endif
  76
  77 # include <limits.h>
  78
  79 # if UINT_MAX == UINT_MAX_32_BITS
  80    typedef unsigned int md5_uint32;
  81 # else
  82 #  if USHRT_MAX == UINT_MAX_32_BITS
  83     typedef unsigned short md5_uint32;
  84 #  else
  85 #   if ULONG_MAX == UINT_MAX_32_BITS
  86      typedef unsigned long md5_uint32;
  87 #   else
  88      /* A machine this weird should have <stdint.h>.  */
  89 #    include <stdint.h>
  90      typedef uint32_t md5_uint32;
  91 #   endif
  92 #  endif
  93 # endif
  94 #endif
  95
  96 /* Structure to save state of computation between the single steps.  */
  97 struct md5_ctx
  98 {
  99   md5_uint32 A;
 100   md5_uint32 B;
 101   md5_uint32 C;
 102   md5_uint32 D;
 103
 104   md5_uint32 total[2];
 105   md5_uint32 buflen;
 106   md5_uint32 buffer[32];
 107 };
 108
 109 /*
 110  * The following three functions are build up the low level used in
 111  * the functions `md5_stream' and `md5_buffer'.
 112  */
 113
 114 /* Initialize structure containing state of computation.
 115    (RFC 1321, 3.3: Step 3)  */
 116 extern void __md5_init_ctx (struct md5_ctx *ctx) __THROW;
 117
 118 /* Starting with the result of former calls of this function (or the
 119    initialization function update the context for the next LEN bytes
 120    starting at BUFFER.
 121    It is necessary that LEN is a multiple of 64!!! */
 122 extern void __md5_process_block (const void *buffer, size_t len,
 123                                  struct md5_ctx *ctx) __THROW;
 124
 125 /* Starting with the result of former calls of this function (or the
 126    initialization function update the context for the next LEN bytes
 127    starting at BUFFER.
 128    It is NOT required that LEN is a multiple of 64.  */
 129 extern void __md5_process_bytes (const void *buffer, size_t len,
 130                                  struct md5_ctx *ctx) __THROW;
 131
 132 /* Process the remaining bytes in the buffer and put result from CTX
 133    in first 16 bytes following RESBUF.  The result is always in little
 134    endian byte order, so that a byte-wise output yields to the wanted
 135    ASCII representation of the message digest.  */
 136 extern void *__md5_finish_ctx (struct md5_ctx *ctx, void *resbuf) __THROW;
 137
 138
 139 /* Put result from CTX in first 16 bytes following RESBUF.  The result is
 140    always in little endian byte order, so that a byte-wise output yields
 141    to the wanted ASCII representation of the message digest.  */
 142 extern void *__md5_read_ctx (const struct md5_ctx *ctx, void *resbuf) __THROW;
 143
 144
 145 /* Compute MD5 message digest for bytes read from STREAM.  The
 146    resulting message digest number will be written into the 16 bytes
 147    beginning at RESBLOCK.  */
 148 extern int __md5_stream (FILE *stream, void *resblock) __THROW;
 149
 150 /* Compute MD5 message digest for LEN bytes beginning at BUFFER.  The
 151    result is always in little endian byte order, so that a byte-wise
 152    output yields to the wanted ASCII representation of the message
 153    digest.  */
 154 extern void *__md5_buffer (const char *buffer, size_t len,
 155                            void *resblock) __THROW;
 156
 157 # ifdef __cplusplus
 158 }
 159 # endif
 160
 161 #endif /* md5.h */