crypt/md5.h

   1 /* Declaration of functions and data types used for MD5 sum computing
   2    library functions.
   3    Copyright (C) 1995-1997,1999,2000,2001,2004,2005,2011
   4       Free Software Foundation, Inc.
   5    This file is part of the GNU C Library.
   6
   7    The GNU C Library is free software; you can redistribute it and/or
   8    modify it under the terms of the GNU Lesser General Public
   9    License as published by the Free Software Foundation; either
  10    version 2.1 of the License, or (at your option) any later version.
  11
  12    The GNU C Library 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 GNU
  15    Lesser General Public License for more details.
  16
  17    You should have received a copy of the GNU Lesser General Public
  18    License along with the GNU C Library; if not, write to the Free
  19    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  20    02111-1307 USA.  */
  21
  22 #ifndef _MD5_H
  23 #define _MD5_H 1
  24
  25 #include <stdio.h>
  26
  27 #if defined HAVE_LIMITS_H || _LIBC
  28 # include <limits.h>
  29 #endif
  30
  31 #define MD5_DIGEST_SIZE 16
  32 #define MD5_BLOCK_SIZE 64
  33
  34 /* The following contortions are an attempt to use the C preprocessor
  35    to determine an unsigned integral type that is 32 bits wide.  An
  36    alternative approach is to use autoconf's AC_CHECK_SIZEOF macro, but
  37    doing that would require that the configure script compile and *run*
  38    the resulting executable.  Locally running cross-compiled executables
  39    is usually not possible.  */
  40
  41 #ifdef _LIBC
  42 # include <stdint.h>
  43 typedef uint32_t md5_uint32;
  44 typedef uintptr_t md5_uintptr;
  45 #else
  46 # if defined __STDC__ && __STDC__
  47 #  define UINT_MAX_32_BITS 4294967295U
  48 # else
  49 #  define UINT_MAX_32_BITS 0xFFFFFFFF
  50 # endif
  51
  52 /* If UINT_MAX isn't defined, assume it's a 32-bit type.
  53    This should be valid for all systems GNU cares about because
  54    that doesn't include 16-bit systems, and only modern systems
  55    (that certainly have <limits.h>) have 64+-bit integral types.  */
  56
  57 # ifndef UINT_MAX
  58 #  define UINT_MAX UINT_MAX_32_BITS
  59 # endif
  60
  61 # if UINT_MAX == UINT_MAX_32_BITS
  62    typedef unsigned int md5_uint32;
  63 # else
  64 #  if USHRT_MAX == UINT_MAX_32_BITS
  65     typedef unsigned short md5_uint32;
  66 #  else
  67 #   if ULONG_MAX == UINT_MAX_32_BITS
  68      typedef unsigned long md5_uint32;
  69 #   else
  70      /* The following line is intended to evoke an error.
  71         Using #error is not portable enough.  */
  72      "Cannot determine unsigned 32-bit data type."
  73 #   endif
  74 #  endif
  75 # endif
  76 /* We have to make a guess about the integer type equivalent in size
  77    to pointers which should always be correct.  */
  78 typedef unsigned long int md5_uintptr;
  79 #endif
  80
  81 /* Structure to save state of computation between the single steps.  */
  82 struct md5_ctx
  83 {
  84   md5_uint32 A;
  85   md5_uint32 B;
  86   md5_uint32 C;
  87   md5_uint32 D;
  88
  89   md5_uint32 total[2];
  90   md5_uint32 buflen;
  91   union
  92   {
  93     char buffer[128];
  94     md5_uint32 buffer32[32];
  95   };
  96 };
  97
  98 /*
  99  * The following three functions are build up the low level used in
 100  * the functions `md5_stream' and `md5_buffer'.
 101  */
 102
 103 /* Initialize structure containing state of computation.
 104    (RFC 1321, 3.3: Step 3)  */
 105 extern void __md5_init_ctx (struct md5_ctx *ctx) __THROW;
 106
 107 /* Starting with the result of former calls of this function (or the
 108    initialization function update the context for the next LEN bytes
 109    starting at BUFFER.
 110    It is necessary that LEN is a multiple of 64!!! */
 111 extern void __md5_process_block (const void *buffer, size_t len,
 112                                  struct md5_ctx *ctx) __THROW;
 113
 114 /* Starting with the result of former calls of this function (or the
 115    initialization function update the context for the next LEN bytes
 116    starting at BUFFER.
 117    It is NOT required that LEN is a multiple of 64.  */
 118 extern void __md5_process_bytes (const void *buffer, size_t len,
 119                                  struct md5_ctx *ctx) __THROW;
 120
 121 /* Process the remaining bytes in the buffer and put result from CTX
 122    in first 16 bytes following RESBUF.  The result is always in little
 123    endian byte order, so that a byte-wise output yields to the wanted
 124    ASCII representation of the message digest.
 125
 126    IMPORTANT: On some systems it is required that RESBUF is correctly
 127    aligned for a 32 bits value.  */
 128 extern void *__md5_finish_ctx (struct md5_ctx *ctx, void *resbuf) __THROW;
 129
 130
 131 /* Put result from CTX in first 16 bytes following RESBUF.  The result is
 132    always in little endian byte order, so that a byte-wise output yields
 133    to the wanted ASCII representation of the message digest.
 134
 135    IMPORTANT: On some systems it is required that RESBUF is correctly
 136    aligned for a 32 bits value.  */
 137 extern void *__md5_read_ctx (const struct md5_ctx *ctx, void *resbuf) __THROW;
 138
 139
 140 /* Compute MD5 message digest for bytes read from STREAM.  The
 141    resulting message digest number will be written into the 16 bytes
 142    beginning at RESBLOCK.  */
 143 extern int __md5_stream (FILE *stream, void *resblock) __THROW;
 144
 145 /* Compute MD5 message digest for LEN bytes beginning at BUFFER.  The
 146    result is always in little endian byte order, so that a byte-wise
 147    output yields to the wanted ASCII representation of the message
 148    digest.  */
 149 extern void *__md5_buffer (const char *buffer, size_t len,
 150                            void *resblock) __THROW;
 151
 152 #endif /* md5.h */