include/md5.h

   1 /* md5.h - Declaration of functions and data types used for MD5 sum
   2    computing library functions.
   3    Copyright (C) 1995-2017 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 #elif defined (HAVE_SYS_TYPES_H) && defined (HAVE_STDINT_H)
  44 #include <stdint.h>
  45 #include <sys/types.h>
  46 typedef uint32_t md5_uint32;
  47 typedef uintptr_t md5_uintptr;
  48 #else
  49 #  define INT_MAX_32_BITS 2147483647
  50
  51 /* If UINT_MAX isn't defined, assume it's a 32-bit type.
  52    This should be valid for all systems GNU cares about because
  53    that doesn't include 16-bit systems, and only modern systems
  54    (that certainly have <limits.h>) have 64+-bit integral types.  */
  55
  56 # ifndef INT_MAX
  57 #  define INT_MAX INT_MAX_32_BITS
  58 # endif
  59
  60 # if INT_MAX == INT_MAX_32_BITS
  61    typedef unsigned int md5_uint32;
  62 # else
  63 #  if SHRT_MAX == INT_MAX_32_BITS
  64     typedef unsigned short md5_uint32;
  65 #  else
  66 #   if LONG_MAX == INT_MAX_32_BITS
  67      typedef unsigned long md5_uint32;
  68 #   else
  69      /* The following line is intended to evoke an error.
  70         Using #error is not portable enough.  */
  71      "Cannot determine unsigned 32-bit data type."
  72 #   endif
  73 #  endif
  74 # endif
  75 /* We have to make a guess about the integer type equivalent in size
  76    to pointers which should always be correct.  */
  77 typedef unsigned long int md5_uintptr;
  78 #endif
  79
  80 #ifdef __cplusplus
  81 extern "C" {
  82 #endif
  83
  84 /* Structure to save state of computation between the single steps.  */
  85 struct md5_ctx
  86 {
  87   md5_uint32 A;
  88   md5_uint32 B;
  89   md5_uint32 C;
  90   md5_uint32 D;
  91
  92   md5_uint32 total[2];
  93   md5_uint32 buflen;
  94   char buffer[128] ATTRIBUTE_ALIGNED_ALIGNOF(md5_uint32);
  95 };
  96
  97 /*
  98  * The following three functions are build up the low level used in
  99  * the functions `md5_stream' and `md5_buffer'.
 100  */
 101
 102 /* Initialize structure containing state of computation.
 103    (RFC 1321, 3.3: Step 3)  */
 104 extern void md5_init_ctx (struct md5_ctx *ctx);
 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 necessary that LEN is a multiple of 64!!! */
 110 extern void md5_process_block (const void *buffer, size_t len,
 111                                struct md5_ctx *ctx);
 112
 113 /* Starting with the result of former calls of this function (or the
 114    initialization function update the context for the next LEN bytes
 115    starting at BUFFER.
 116    It is NOT required that LEN is a multiple of 64.  */
 117 extern void md5_process_bytes (const void *buffer, size_t len,
 118                                struct md5_ctx *ctx);
 119
 120 /* Process the remaining bytes in the buffer and put result from CTX
 121    in first 16 bytes following RESBUF.  The result is always in little
 122    endian byte order, so that a byte-wise output yields to the wanted
 123    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_finish_ctx (struct md5_ctx *ctx, void *resbuf);
 128
 129
 130 /* Put result from CTX in first 16 bytes following RESBUF.  The result is
 131    always in little endian byte order, so that a byte-wise output yields
 132    to the wanted ASCII representation of the message digest.
 133
 134    IMPORTANT: On some systems it is required that RESBUF is correctly
 135    aligned for a 32 bits value.  */
 136 extern void *md5_read_ctx (const struct md5_ctx *ctx, void *resbuf);
 137
 138
 139 /* Compute MD5 message digest for bytes read from STREAM.  The
 140    resulting message digest number will be written into the 16 bytes
 141    beginning at RESBLOCK.  */
 142 extern int md5_stream (FILE *stream, void *resblock);
 143
 144 /* Compute MD5 message digest for LEN bytes beginning at BUFFER.  The
 145    result is always in little endian byte order, so that a byte-wise
 146    output yields to the wanted ASCII representation of the message
 147    digest.  */
 148 extern void *md5_buffer (const char *buffer, size_t len, void *resblock);
 149
 150 #ifdef __cplusplus
 151 }
 152 #endif
 153
 154 #endif