md5.h

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00001 /* md5.h - Declaration of functions and data types used for MD5 sum
00002    computing library functions.
00003    Copyright (C) 1995, 1996 Free Software Foundation, Inc.
00004    NOTE: The canonical source of this file is maintained with the GNU C
00005    Library.  Bugs can be reported to bug-glibc@prep.ai.mit.edu.
00006 
00007    This program is free software; you can redistribute it and/or modify it
00008    under the terms of the GNU General Public License as published by the
00009    Free Software Foundation; either version 2, or (at your option) any
00010    later version.
00011 
00012    This program is distributed in the hope that it will be useful,
00013    but WITHOUT ANY WARRANTY; without even the implied warranty of
00014    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00015    GNU General Public License for more details.
00016 
00017    You should have received a copy of the GNU General Public License
00018    along with this program; if not, write to the Free Software Foundation,
00019    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
00020 
00021 #ifndef _MD5_H
00022 #define _MD5_H 1
00023 
00024 #include <config.h>
00025 
00026 #include <stdio.h>
00027 
00028 #if defined HAVE_LIMITS_H || _LIBC
00029 #include <limits.h>
00030 #endif
00031 
00032 /* The following contortions are an attempt to use the C preprocessor
00033    to determine an unsigned integral type that is 32 bits wide.  An
00034    alternative approach is to use autoconf's AC_CHECK_SIZEOF macro, but
00035    doing that would require that the configure script compile and *run*
00036    the resulting executable.  Locally running cross-compiled executables
00037    is usually not possible.  */
00038 
00039 #ifdef _LIBC
00040 # include <sys/types.h>
00041 typedef u_int32_t md5_uint32;
00042 #else
00043 # if defined __STDC__ && __STDC__
00044 #  define UINT_MAX_32_BITS 4294967295U
00045 # else
00046 #  define UINT_MAX_32_BITS 0xFFFFFFFF
00047 # endif
00048 
00049 /* If UINT_MAX isn't defined, assume it's a 32-bit type.
00050    This should be valid for all systems GNU cares about because
00051    that doesn't include 16-bit systems, and only modern systems
00052    (that certainly have <limits.h>) have 64+-bit integral types.  */
00053 
00054 # ifndef UINT_MAX
00055 #  define UINT_MAX UINT_MAX_32_BITS
00056 # endif
00057 
00058 # if UINT_MAX == UINT_MAX_32_BITS
00059    typedef unsigned int md5_uint32;
00060 # else
00061 #  if USHRT_MAX == UINT_MAX_32_BITS
00062     typedef unsigned short md5_uint32;
00063 #  else
00064 #   if ULONG_MAX == UINT_MAX_32_BITS
00065      typedef unsigned long md5_uint32;
00066 #   else
00067      /* The following line is intended to evoke an error.
00068         Using #error is not portable enough.  */
00069      "Cannot determine unsigned 32-bit data type."
00070 #   endif
00071 #  endif
00072 # endif
00073 #endif
00074 
00075 #undef __P
00076 #if defined (__STDC__) && __STDC__
00077 #define __P(x) x
00078 #else
00079 #define __P(x) ()
00080 #endif
00081 
00082 /* Structure to save state of computation between the single steps.  */
00083 struct md5_ctx
00084 {
00085   md5_uint32 A;
00086   md5_uint32 B;
00087   md5_uint32 C;
00088   md5_uint32 D;
00089 
00090   md5_uint32 total[2];
00091   md5_uint32 buflen;
00092   char buffer[128];
00093 };
00094 
00095 /*
00096  * The following three functions are build up the low level used in
00097  * the functions `md5_stream' and `md5_buffer'.
00098  */
00099 
00100 /* Initialize structure containing state of computation.
00101    (RFC 1321, 3.3: Step 3)  */
00102 extern void md5_init_ctx __P ((struct md5_ctx *ctx));
00103 
00104 /* Starting with the result of former calls of this function (or the
00105    initialization function update the context for the next LEN bytes
00106    starting at BUFFER.
00107    It is necessary that LEN is a multiple of 64!!! */
00108 extern void md5_process_block __P ((const void *buffer, size_t len,
00109                     struct md5_ctx *ctx));
00110 
00111 /* Starting with the result of former calls of this function (or the
00112    initialization function update the context for the next LEN bytes
00113    starting at BUFFER.
00114    It is NOT required that LEN is a multiple of 64.  */
00115 extern void md5_process_bytes __P ((const void *buffer, size_t len,
00116                     struct md5_ctx *ctx));
00117 
00118 /* Process the remaining bytes in the buffer and put result from CTX
00119    in first 16 bytes following RESBUF.  The result is always in little
00120    endian byte order, so that a byte-wise output yields to the wanted
00121    ASCII representation of the message digest.
00122 
00123    IMPORTANT: On some systems it is required that RESBUF is correctly
00124    aligned for a 32 bits value.  */
00125 extern void *md5_finish_ctx __P ((struct md5_ctx *ctx, void *resbuf));
00126 
00127 
00128 /* Put result from CTX in first 16 bytes following RESBUF.  The result is
00129    always in little endian byte order, so that a byte-wise output yields
00130    to the wanted ASCII representation of the message digest.
00131 
00132    IMPORTANT: On some systems it is required that RESBUF is correctly
00133    aligned for a 32 bits value.  */
00134 extern void *md5_read_ctx __P ((const struct md5_ctx *ctx, void *resbuf));
00135 
00136 
00137 /* Compute MD5 message digest for bytes read from STREAM.  The
00138    resulting message digest number will be written into the 16 bytes
00139    beginning at RESBLOCK.  */
00140 extern int md5_stream __P ((FILE *stream, void *resblock));
00141 
00142 /* Compute MD5 message digest for LEN bytes beginning at BUFFER.  The
00143    result is always in little endian byte order, so that a byte-wise
00144    output yields to the wanted ASCII representation of the message
00145    digest.  */
00146 extern void *md5_buffer __P ((const char *buffer, size_t len, void *resblock));
00147 
00148 #endif