libvo/md5sum.h

   1 #ifndef AUTH_MD5_H
   2 #define AUTH_MD5_H
   3 /* ========================================================================== **
   4  *
   5  *                                    MD5.h
   6  *
   7  * Copyright:
   8  *  Copyright (C) 2003, 2004 by Christopher R. Hertel
   9  *
  10  * Email: crh@ubiqx.mn.org
  11  *
  12  * Modified for use with MPlayer, detailed CVS changelog at
  13  * http://www.mplayerhq.hu/cgi-bin/cvsweb.cgi/main/
  14  * $Id$
  15  *
  16  * -------------------------------------------------------------------------- **
  17  *
  18  * Description:
  19  *  Implements the MD5 hash algorithm, as described in RFC 1321.
  20  *
  21  * -------------------------------------------------------------------------- **
  22  *
  23  * License:
  24  *
  25  *  This library is free software; you can redistribute it and/or
  26  *  modify it under the terms of the GNU Lesser General Public
  27  *  License as published by the Free Software Foundation; either
  28  *  version 2.1 of the License, or (at your option) any later version.
  29  *
  30  *  This library is distributed in the hope that it will be useful,
  31  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  32  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  33  *  Lesser General Public License for more details.
  34  *
  35  *  You should have received a copy of the GNU Lesser General Public
  36  *  License along with this library; if not, write to the Free Software
  37  *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  38  *
  39  * -------------------------------------------------------------------------- **
  40  *
  41  * Notes:
  42  *
  43  *  None of this will make any sense unless you're studying RFC 1321 as you
  44  *  read the code.
  45  *
  46  *  MD5 is described in RFC 1321.
  47  *  The MD*4* algorithm is described in RFC 1320 (that's 1321 - 1).
  48  *  MD5 is very similar to MD4, but not quite similar enough to justify
  49  *  putting the two into a single module.  Besides, I wanted to add a few
  50  *  extra functions to this one to expand its usability.
  51  *
  52  *  There are three primary motivations for this particular implementation.
  53  *  1) Programmer's pride.  I wanted to be able to say I'd done it, and I
  54  *     wanted to learn from the experience.
  55  *  2) Portability.  I wanted an implementation that I knew to be portable
  56  *     to a reasonable number platforms.  In particular, the algorithm is
  57  *     designed with little-endian platforms in mind, but I wanted an
  58  *     endian-agnostic implementation.
  59  *  3) Compactness.  While not an overriding goal, I thought it worth-while
  60  *     to see if I could reduce the overall size of the result.  This is in
  61  *     keeping with my hopes that this library will be suitable for use in
  62  *     some embedded environments.
  63  *  Beyond that, cleanliness and clarity are always worth pursuing.
  64  *
  65  *  As mentioned above, the code really only makes sense if you are familiar
  66  *  with the MD5 algorithm or are using RFC 1321 as a guide.  This code is
  67  *  quirky, however, so you'll want to be reading carefully.
  68  *
  69  *  Yeah...most of the comments are cut-and-paste from my MD4 implementation.
  70  *
  71  * -------------------------------------------------------------------------- **
  72  *
  73  * References:
  74  *  IETF RFC 1321: The MD5 Message-Digest Algorithm
  75  *       Ron Rivest. IETF, April, 1992
  76  *
  77  * ========================================================================== **
  78  */
  79
  80 /* #include "auth_common.h"   This was in the original. */
  81
  82 #include <inttypes.h> /* This was not... */
  83
  84 /* -------------------------------------------------------------------------- **
  85  * Typedefs:
  86  */
  87
  88 typedef unsigned char uchar; /* Added uchar typedef to keep as close to the
  89                                 original as possible. */
  90
  91 typedef struct
  92   {
  93   uint32_t len;
  94   uint32_t ABCD[4];
  95   int      b_used;
  96   uchar    block[64];
  97   } auth_md5Ctx;
  98
  99
 100 /* -------------------------------------------------------------------------- **
 101  * Functions:
 102  */
 103
 104 auth_md5Ctx *auth_md5InitCtx( auth_md5Ctx *ctx );
 105   /* ------------------------------------------------------------------------ **
 106    * Initialize an MD5 context.
 107    *
 108    *  Input:  ctx - A pointer to the MD5 context structure to be initialized.
 109    *                Contexts are typically created thusly:
 110    *                  ctx = (auth_md5Ctx *)malloc( sizeof(auth_md5Ctx) );
 111    *
 112    *  Output: A pointer to the initialized context (same as <ctx>).
 113    *
 114    *  Notes:  The purpose of the context is to make it possible to generate
 115    *          an MD5 Message Digest in stages, rather than having to pass a
 116    *          single large block to a single MD5 function.  The context
 117    *          structure keeps track of various bits of state information.
 118    *
 119    *          Once the context is initialized, the blocks of message data
 120    *          are passed to the <auth_md5SumCtx()> function.  Once the
 121    *          final bit of data has been handed to <auth_md5SumCtx()> the
 122    *          context can be closed out by calling <auth_md5CloseCtx()>,
 123    *          which also calculates the final MD5 result.
 124    *
 125    *          Don't forget to free an allocated context structure when
 126    *          you've finished using it.
 127    *
 128    *  See Also:  <auth_md5SumCtx()>, <auth_md5CloseCtx()>
 129    *
 130    * ------------------------------------------------------------------------ **
 131    */
 132
 133
 134 auth_md5Ctx *auth_md5SumCtx( auth_md5Ctx *ctx,
 135                              const uchar *src,
 136                              const int    len );
 137   /* ------------------------------------------------------------------------ **
 138    * Build an MD5 Message Digest within the given context.
 139    *
 140    *  Input:  ctx - Pointer to the context in which the MD5 sum is being
 141    *                built.
 142    *          src - A chunk of source data.  This will be used to drive
 143    *                the MD5 algorithm.
 144    *          len - The number of bytes in <src>.
 145    *
 146    *  Output: A pointer to the updated context (same as <ctx>).
 147    *
 148    *  See Also:  <auth_md5InitCtx()>, <auth_md5CloseCtx()>, <auth_md5Sum()>
 149    *
 150    * ------------------------------------------------------------------------ **
 151    */
 152
 153
 154 auth_md5Ctx *auth_md5CloseCtx( auth_md5Ctx *ctx, uchar *dst );
 155   /* ------------------------------------------------------------------------ **
 156    * Close an MD5 Message Digest context and generate the final MD5 sum.
 157    *
 158    *  Input:  ctx - Pointer to the context in which the MD5 sum is being
 159    *                built.
 160    *          dst - A pointer to at least 16 bytes of memory, which will
 161    *                receive the finished MD5 sum.
 162    *
 163    *  Output: A pointer to the closed context (same as <ctx>).
 164    *          You might use this to free a malloc'd context structure.  :)
 165    *
 166    *  Notes:  The context (<ctx>) is returned in an undefined state.
 167    *          It must be re-initialized before re-use.
 168    *
 169    *  See Also:  <auth_md5InitCtx()>, <auth_md5SumCtx()>
 170    *
 171    * ------------------------------------------------------------------------ **
 172    */
 173
 174
 175 uchar *auth_md5Sum( uchar *dst, const uchar *src, const int len );
 176   /* ------------------------------------------------------------------------ **
 177    * Compute an MD5 message digest.
 178    *
 179    *  Input:  dst - Destination buffer into which the result will be written.
 180    *                Must be 16 bytes, minimum.
 181    *          src - Source data block to be MD5'd.
 182    *          len - The length, in bytes, of the source block.
 183    *                (Note that the length is given in bytes, not bits.)
 184    *
 185    *  Output: A pointer to <dst>, which will contain the calculated 16-byte
 186    *          MD5 message digest.
 187    *
 188    *  Notes:  This function is a shortcut.  It takes a single input block.
 189    *          For more drawn-out operations, see <auth_md5InitCtx()>.
 190    *
 191    *          This function is interface-compatible with the
 192    *          <auth_md4Sum()> function in the MD4 module.
 193    *
 194    *          The MD5 algorithm is designed to work on data with an
 195    *          arbitrary *bit* length.  Most implementations, this one
 196    *          included, handle the input data in byte-sized chunks.
 197    *
 198    *          The MD5 algorithm does much of its work using four-byte
 199    *          words, and so can be tuned for speed based on the endian-ness
 200    *          of the host.  This implementation is intended to be
 201    *          endian-neutral, which may make it a teeny bit slower than
 202    *          others.  ...maybe.
 203    *
 204    *  See Also:  <auth_md5InitCtx()>
 205    *
 206    * ------------------------------------------------------------------------ **
 207    */
 208
 209
 210 /* ========================================================================== */
 211 #endif /* AUTH_MD5_H */