aboutsummaryrefslogtreecommitdiffhomepage
path: root/libvo/md5sum.h
blob: 3c5c2b71de86dea71216e3581404b01007ece919 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
#ifndef AUTH_MD5_H
#define AUTH_MD5_H
/* ========================================================================== **
 *
 *                                    MD5.h
 *
 * Copyright:
 *  Copyright (C) 2003, 2004 by Christopher R. Hertel
 *
 * Email: crh@ubiqx.mn.org
 *
 * Modified for use with MPlayer, detailed CVS changelog at
 * http://www.mplayerhq.hu/cgi-bin/cvsweb.cgi/main/
 * $Id$
 *
 * -------------------------------------------------------------------------- **
 *
 * Description:
 *  Implements the MD5 hash algorithm, as described in RFC 1321.
 *
 * -------------------------------------------------------------------------- **
 *
 * License:
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 *
 * -------------------------------------------------------------------------- **
 *
 * Notes:
 *
 *  None of this will make any sense unless you're studying RFC 1321 as you
 *  read the code.
 *
 *  MD5 is described in RFC 1321.
 *  The MD*4* algorithm is described in RFC 1320 (that's 1321 - 1).
 *  MD5 is very similar to MD4, but not quite similar enough to justify
 *  putting the two into a single module.  Besides, I wanted to add a few
 *  extra functions to this one to expand its usability.
 *
 *  There are three primary motivations for this particular implementation.
 *  1) Programmer's pride.  I wanted to be able to say I'd done it, and I
 *     wanted to learn from the experience.
 *  2) Portability.  I wanted an implementation that I knew to be portable
 *     to a reasonable number platforms.  In particular, the algorithm is
 *     designed with little-endian platforms in mind, but I wanted an
 *     endian-agnostic implementation.
 *  3) Compactness.  While not an overriding goal, I thought it worth-while
 *     to see if I could reduce the overall size of the result.  This is in
 *     keeping with my hopes that this library will be suitable for use in
 *     some embedded environments.
 *  Beyond that, cleanliness and clarity are always worth pursuing.
 *
 *  As mentioned above, the code really only makes sense if you are familiar
 *  with the MD5 algorithm or are using RFC 1321 as a guide.  This code is
 *  quirky, however, so you'll want to be reading carefully.
 *
 *  Yeah...most of the comments are cut-and-paste from my MD4 implementation.
 *
 * -------------------------------------------------------------------------- **
 *
 * References:
 *  IETF RFC 1321: The MD5 Message-Digest Algorithm
 *       Ron Rivest. IETF, April, 1992
 *
 * ========================================================================== **
 */

/* #include "auth_common.h"   This was in the original. */

#include <inttypes.h> /* This was not... */

/* -------------------------------------------------------------------------- **
 * Typedefs:
 */

typedef unsigned char uchar; /* Added uchar typedef to keep as close to the
                                original as possible. */

typedef struct
  {
  uint32_t len;
  uint32_t ABCD[4];
  int      b_used;
  uchar    block[64];
  } auth_md5Ctx;


/* -------------------------------------------------------------------------- **
 * Functions:
 */

auth_md5Ctx *auth_md5InitCtx( auth_md5Ctx *ctx );
  /* ------------------------------------------------------------------------ **
   * Initialize an MD5 context.
   *
   *  Input:  ctx - A pointer to the MD5 context structure to be initialized.
   *                Contexts are typically created thusly:
   *                  ctx = (auth_md5Ctx *)malloc( sizeof(auth_md5Ctx) );
   *
   *  Output: A pointer to the initialized context (same as <ctx>).
   *
   *  Notes:  The purpose of the context is to make it possible to generate
   *          an MD5 Message Digest in stages, rather than having to pass a
   *          single large block to a single MD5 function.  The context
   *          structure keeps track of various bits of state information.
   *
   *          Once the context is initialized, the blocks of message data
   *          are passed to the <auth_md5SumCtx()> function.  Once the
   *          final bit of data has been handed to <auth_md5SumCtx()> the
   *          context can be closed out by calling <auth_md5CloseCtx()>,
   *          which also calculates the final MD5 result.
   *
   *          Don't forget to free an allocated context structure when
   *          you've finished using it.
   *
   *  See Also:  <auth_md5SumCtx()>, <auth_md5CloseCtx()>
   *
   * ------------------------------------------------------------------------ **
   */


auth_md5Ctx *auth_md5SumCtx( auth_md5Ctx *ctx,
                             const uchar *src,
                             const int    len );
  /* ------------------------------------------------------------------------ **
   * Build an MD5 Message Digest within the given context.
   *
   *  Input:  ctx - Pointer to the context in which the MD5 sum is being
   *                built.
   *          src - A chunk of source data.  This will be used to drive
   *                the MD5 algorithm.
   *          len - The number of bytes in <src>.
   *
   *  Output: A pointer to the updated context (same as <ctx>).
   *
   *  See Also:  <auth_md5InitCtx()>, <auth_md5CloseCtx()>, <auth_md5Sum()>
   *
   * ------------------------------------------------------------------------ **
   */


auth_md5Ctx *auth_md5CloseCtx( auth_md5Ctx *ctx, uchar *dst );
  /* ------------------------------------------------------------------------ **
   * Close an MD5 Message Digest context and generate the final MD5 sum.
   *
   *  Input:  ctx - Pointer to the context in which the MD5 sum is being
   *                built.
   *          dst - A pointer to at least 16 bytes of memory, which will
   *                receive the finished MD5 sum.
   *
   *  Output: A pointer to the closed context (same as <ctx>).
   *          You might use this to free a malloc'd context structure.  :)
   *
   *  Notes:  The context (<ctx>) is returned in an undefined state.
   *          It must be re-initialized before re-use.
   *
   *  See Also:  <auth_md5InitCtx()>, <auth_md5SumCtx()>
   *
   * ------------------------------------------------------------------------ **
   */


uchar *auth_md5Sum( uchar *dst, const uchar *src, const int len );
  /* ------------------------------------------------------------------------ **
   * Compute an MD5 message digest.
   *
   *  Input:  dst - Destination buffer into which the result will be written.
   *                Must be 16 bytes, minimum.
   *          src - Source data block to be MD5'd.
   *          len - The length, in bytes, of the source block.
   *                (Note that the length is given in bytes, not bits.)
   *
   *  Output: A pointer to <dst>, which will contain the calculated 16-byte
   *          MD5 message digest.
   *
   *  Notes:  This function is a shortcut.  It takes a single input block.
   *          For more drawn-out operations, see <auth_md5InitCtx()>.
   *
   *          This function is interface-compatible with the
   *          <auth_md4Sum()> function in the MD4 module.
   *
   *          The MD5 algorithm is designed to work on data with an
   *          arbitrary *bit* length.  Most implementations, this one
   *          included, handle the input data in byte-sized chunks.
   *
   *          The MD5 algorithm does much of its work using four-byte
   *          words, and so can be tuned for speed based on the endian-ness
   *          of the host.  This implementation is intended to be
   *          endian-neutral, which may make it a teeny bit slower than
   *          others.  ...maybe.
   *
   *  See Also:  <auth_md5InitCtx()>
   *
   * ------------------------------------------------------------------------ **
   */


/* ========================================================================== */
#endif /* AUTH_MD5_H */