include/md5.h

   1 /* md5.h - Declaration of functions and data types used for MD5 sum
   2    computing library functions.
   3    Copyright (C) 1995-2024 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 #ifdef USE_SYSTEM_MD5
  25 #include_next <md5.h>
  26 #else
  27
  28 #include <stdio.h>
  29
  30 #if defined HAVE_LIMITS_H || _LIBC
  31 # include <limits.h>
  32 #endif
  33
  34 #include "ansidecl.h"
  35
  36 /* The following contortions are an attempt to use the C preprocessor
  37    to determine an unsigned integral type that is 32 bits wide.  An
  38    alternative approach is to use autoconf's AC_CHECK_SIZEOF macro, but
  39    doing that would require that the configure script compile and *run*
  40    the resulting executable.  Locally running cross-compiled executables
  41    is usually not possible.  */
  42
  43 #ifdef _LIBC
  44 # include <sys/types.h>
  45 typedef u_int32_t md5_uint32;
  46 typedef uintptr_t md5_uintptr;
  47 #elif defined (HAVE_SYS_TYPES_H) && defined (HAVE_STDINT_H)
  48 #include <stdint.h>
  49 #include <sys/types.h>
  50 typedef uint32_t md5_uint32;
  51 typedef uintptr_t md5_uintptr;
  52 #else
  53 #  define INT_MAX_32_BITS 2147483647
  54
  55 /* If UINT_MAX isn't defined, assume it's a 32-bit type.
  56    This should be valid for all systems GNU cares about because
  57    that doesn't include 16-bit systems, and only modern systems
  58    (that certainly have <limits.h>) have 64+-bit integral types.  */
  59
  60 # ifndef INT_MAX
  61 #  define INT_MAX INT_MAX_32_BITS
  62 # endif
  63
  64 # if INT_MAX == INT_MAX_32_BITS
  65    typedef unsigned int md5_uint32;
  66 # else
  67 #  if SHRT_MAX == INT_MAX_32_BITS
  68     typedef unsigned short md5_uint32;
  69 #  else
  70 #   if LONG_MAX == INT_MAX_32_BITS
  71      typedef unsigned long md5_uint32;
  72 #   else
  73      /* The following line is intended to evoke an error.
  74         Using #error is not portable enough.  */
  75      "Cannot determine unsigned 32-bit data type."
  76 #   endif
  77 #  endif
  78 # endif
  79 /* We have to make a guess about the integer type equivalent in size
  80    to pointers which should always be correct.  */
  81 typedef unsigned long int md5_uintptr;
  82 #endif
  83
  84 #ifdef __cplusplus
  85 extern "C" {
  86 #endif
  87
  88 /* Structure to save state of computation between the single steps.  */
  89 struct md5_ctx
  90 {
  91   md5_uint32 A;
  92   md5_uint32 B;
  93   md5_uint32 C;
  94   md5_uint32 D;
  95
  96   md5_uint32 total[2];
  97   md5_uint32 buflen;
  98   char buffer[128] ATTRIBUTE_ALIGNED_ALIGNOF(md5_uint32);
  99 };
 100
 101 /*
 102  * The following three functions are build up the low level used in
 103  * the functions `md5_stream' and `md5_buffer'.
 104  */
 105
 106 /* Initialize structure containing state of computation.
 107    (RFC 1321, 3.3: Step 3)  */
 108 extern void md5_init_ctx (struct md5_ctx *ctx);
 109
 110 /* Starting with the result of former calls of this function (or the
 111    initialization function update the context for the next LEN bytes
 112    starting at BUFFER.
 113    It is necessary that LEN is a multiple of 64!!! */
 114 extern void md5_process_block (const void *buffer, size_t len,
 115                                struct md5_ctx *ctx);
 116
 117 /* Starting with the result of former calls of this function (or the
 118    initialization function update the context for the next LEN bytes
 119    starting at BUFFER.
 120    It is NOT required that LEN is a multiple of 64.  */
 121 extern void md5_process_bytes (const void *buffer, size_t len,
 122                                struct md5_ctx *ctx);
 123
 124 /* Process the remaining bytes in the buffer and put result from CTX
 125    in first 16 bytes following RESBUF.  The result is always in little
 126    endian byte order, so that a byte-wise output yields to the wanted
 127    ASCII representation of the message digest.
 128
 129    IMPORTANT: On some systems it is required that RESBUF is correctly
 130    aligned for a 32 bits value.  */
 131 extern void *md5_finish_ctx (struct md5_ctx *ctx, void *resbuf);
 132
 133
 134 /* Put result from CTX in first 16 bytes following RESBUF.  The result is
 135    always in little endian byte order, so that a byte-wise output yields
 136    to the wanted ASCII representation of the message digest.
 137
 138    IMPORTANT: On some systems it is required that RESBUF is correctly
 139    aligned for a 32 bits value.  */
 140 extern void *md5_read_ctx (const struct md5_ctx *ctx, void *resbuf);
 141
 142
 143 /* Compute MD5 message digest for bytes read from STREAM.  The
 144    resulting message digest number will be written into the 16 bytes
 145    beginning at RESBLOCK.  */
 146 extern int md5_stream (FILE *stream, void *resblock);
 147
 148 /* Compute MD5 message digest for LEN bytes beginning at BUFFER.  The
 149    result is always in little endian byte order, so that a byte-wise
 150    output yields to the wanted ASCII representation of the message
 151    digest.  */
 152 extern void *md5_buffer (const char *buffer, size_t len, void *resblock);
 153
 154 #ifdef __cplusplus
 155 }
 156 #endif
 157
 158 #endif // USE_SYSTEM_MD5
 159
 160 #endif