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 Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 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 /* The following contortions are an attempt to use the C preprocessor
  31    to determine an unsigned integral type that is 32 bits wide.  An
  32    alternative approach is to use autoconf's AC_CHECK_SIZEOF macro, but
  33    doing that would require that the configure script compile and *run*
  34    the resulting executable.  Locally running cross-compiled executables
  35    is usually not possible.  */
  36
  37 #ifdef _LIBC
  38 # include <stdint.h>
  39 typedef uint32_t md5_uint32;
  40 typedef uintptr_t md5_uintptr;
  41 #else
  42 # if defined __STDC__ && __STDC__
  43 #  define UINT_MAX_32_BITS 4294967295U
  44 # else
  45 #  define UINT_MAX_32_BITS 0xFFFFFFFF
  46 # endif
  47
  48 /* If UINT_MAX isn't defined, assume it's a 32-bit type.
  49    This should be valid for all systems GNU cares about because
  50    that doesn't include 16-bit systems, and only modern systems
  51    (that certainly have <limits.h>) have 64+-bit integral types.  */
  52
  53 # ifndef UINT_MAX
  54 #  define UINT_MAX UINT_MAX_32_BITS
  55 # endif
  56
  57 # if UINT_MAX == UINT_MAX_32_BITS
  58    typedef unsigned int md5_uint32;
  59 # else
  60 #  if USHRT_MAX == UINT_MAX_32_BITS
  61     typedef unsigned short md5_uint32;
  62 #  else
  63 #   if ULONG_MAX == UINT_MAX_32_BITS
  64      typedef unsigned long md5_uint32;
  65 #   else
  66      /* The following line is intended to evoke an error.
  67         Using #error is not portable enough.  */
  68      "Cannot determine unsigned 32-bit data type."
  69 #   endif
  70 #  endif
  71 # endif
  72 /* We have to make a guess about the integer type equivalent in size
  73    to pointers which should always be correct.  */
  74 typedef unsigned long int md5_uintptr;
  75 #endif
  76
  77 /* Structure to save state of computation between the single steps.  */
  78 struct md5_ctx
  79 {
  80   md5_uint32 A;
  81   md5_uint32 B;
  82   md5_uint32 C;
  83   md5_uint32 D;
  84
  85   md5_uint32 total[2];
  86   md5_uint32 buflen;
  87   char buffer[128] __attribute__ ((__aligned__ (__alignof__ (md5_uint32))));
  88 };
  89
  90 /*
  91  * The following three functions are build up the low level used in
  92  * the functions `md5_stream' and `md5_buffer'.
  93  */
  94
  95 /* Initialize structure containing state of computation.
  96    (RFC 1321, 3.3: Step 3)  */
  97 extern void __md5_init_ctx (struct md5_ctx *ctx) __THROW;
  98
  99 /* Starting with the result of former calls of this function (or the
 100    initialization function update the context for the next LEN bytes
 101    starting at BUFFER.
 102    It is necessary that LEN is a multiple of 64!!! */
 103 extern void __md5_process_block (const void *buffer, size_t len,
 104                                  struct md5_ctx *ctx) __THROW;
 105
 106 /* Starting with the result of former calls of this function (or the
 107    initialization function update the context for the next LEN bytes
 108    starting at BUFFER.
 109    It is NOT required that LEN is a multiple of 64.  */
 110 extern void __md5_process_bytes (const void *buffer, size_t len,
 111                                  struct md5_ctx *ctx) __THROW;
 112
 113 /* Process the remaining bytes in the buffer and put result from CTX
 114    in first 16 bytes following RESBUF.  The result is always in little
 115    endian byte order, so that a byte-wise output yields to the wanted
 116    ASCII representation of the message digest.
 117
 118    IMPORTANT: On some systems it is required that RESBUF is correctly
 119    aligned for a 32 bits value.  */
 120 extern void *__md5_finish_ctx (struct md5_ctx *ctx, void *resbuf) __THROW;
 121
 122
 123 /* Put result from CTX in first 16 bytes following RESBUF.  The result is
 124    always in little endian byte order, so that a byte-wise output yields
 125    to the wanted ASCII representation of the message digest.
 126
 127    IMPORTANT: On some systems it is required that RESBUF is correctly
 128    aligned for a 32 bits value.  */
 129 extern void *__md5_read_ctx (const struct md5_ctx *ctx, void *resbuf) __THROW;
 130
 131
 132 /* Compute MD5 message digest for bytes read from STREAM.  The
 133    resulting message digest number will be written into the 16 bytes
 134    beginning at RESBLOCK.  */
 135 extern int __md5_stream (FILE *stream, void *resblock) __THROW;
 136
 137 /* Compute MD5 message digest for LEN bytes beginning at BUFFER.  The
 138    result is always in little endian byte order, so that a byte-wise
 139    output yields to the wanted ASCII representation of the message
 140    digest.  */
 141 extern void *__md5_buffer (const char *buffer, size_t len,
 142                            void *resblock) __THROW;
 143
 144 #endif /* md5.h */