aboutsummaryrefslogtreecommitdiffstats
path: root/wsutil/md5.c
blob: 55dcd4c0cd35c279f66b18b823c4c39dfcf186a2 (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
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
/*
 * Copyright (C) 2003-2006 Benny Prijono <benny@prijono.org>
 * Copyright (C) 2012      C Elston, Katalix Systems Ltd <celston@katalix.com>
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 *
 *  2012-08-21 - C Elston - Split md5_hmac function to allow incremental usage.
 *
 */


#include "config.h"

#include <string.h>

#include "pint.h"
#include "md5.h"
/*
 * This code implements the MD5 message-digest algorithm.
 * The algorithm is due to Ron Rivest.  This code was
 * written by Colin Plumb in 1993, no copyright is claimed.
 * This code is in the public domain; do with it what you wish.
 *
 * Equivalent code is available from RSA Data Security, Inc.
 * This code has been tested against that, and is equivalent,
 * except that you don't need to include two pages of legalese
 * with every copy.
 *
 * To compute the message digest of a chunk of bytes, declare an
 * MD5Context structure, pass it to MD5Init, call MD5Update as
 * needed on buffers full of bytes, and then call MD5Final, which
 * will fill a supplied 16-byte array with the digest.
 */

#if WORDS_BIGENDIAN == 1
#define HIGHFIRST 1
#endif

#ifndef HIGHFIRST
#define byteReverse(buf, len)    /* Nothing */
#else
/*
 * Note: this code is harmless on little-endian machines.
 */
static void byteReverse(guint32 *buf, unsigned int longs)
{
    guint32 t;
    do {
        t = pletoh32(buf);
        *buf = t;
        buf++;
    } while (--longs);
}
#endif

static void MD5Transform(guint32 buf[4], guint32 const in[16]);


/*
 * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
 * initialization constants.
 */
void md5_init(md5_state_t *ctx)
{
    ctx->buf[0] = 0x67452301;
    ctx->buf[1] = 0xefcdab89;
    ctx->buf[2] = 0x98badcfe;
    ctx->buf[3] = 0x10325476;

    ctx->bits[0] = 0;
    ctx->bits[1] = 0;
}

/*
 * Update context to reflect the concatenation of another buffer full
 * of bytes.
 */
void md5_append( md5_state_t *ctx, const guint8 *buf, size_t len)
{
    guint32 t;

    /* Update bitcount */

    t = ctx->bits[0];
    if ((ctx->bits[0] = t + ((guint32) len << 3)) < t)
        ctx->bits[1]++;         /* Carry from low to high */
    ctx->bits[1] += (guint32) len >> 29;

    t = (t >> 3) & 0x3f;        /* Bytes already in shsInfo->data */

    /* Handle any leading odd-sized chunks */

    if (t) {
        guint8 *p = (guint8 *) ctx->in + t;

        t = 64 - t;
        if (len < t) {
            memcpy(p, buf, len);
            return;
        }
        memcpy(p, buf, t);
        byteReverse(ctx->in, 16);
        MD5Transform(ctx->buf, ctx->in);
        buf += t;
        len -= t;
    }
    /* Process data in 64-byte chunks */

    while (len >= 64) {
        memcpy(ctx->in, buf, 64);
        byteReverse(ctx->in, 16);
        MD5Transform(ctx->buf, ctx->in);
        buf += 64;
        len -= 64;
    }

    /* Handle any remaining bytes of data. */

    memcpy(ctx->in, buf, len);
}

/*
 * Final wrapup - pad to 64-byte boundary with the bit pattern
 * 1 0* (64-bit count of bits processed, MSB-first)
 */
void md5_finish(md5_state_t *ctx, guint8 digest[16])
{
    guint count;
    guint8 *p;

    /* Compute number of bytes mod 64 */
    count = (ctx->bits[0] >> 3) & 0x3F;

    /* Set the first char of padding to 0x80.  This is safe since there is
       always at least one byte free */
    p = (guint8 *) ctx->in + count;
    *p++ = 0x80;

    /* Bytes of padding needed to make 64 bytes */
    count = 64 - 1 - count;

    /* Pad out to 56 mod 64 */
    if (count < 8) {
        /* Two lots of padding:  Pad the first block to 64 bytes */
        memset(p, 0, count);
        byteReverse(ctx->in, 16);
        MD5Transform(ctx->buf, ctx->in);

        /* Now fill the next block with 56 bytes */
        memset(ctx->in, 0, 56);
    } else {
        /* Pad block to 56 bytes */
        memset(p, 0, count - 8);
    }
    byteReverse(ctx->in, 14);

    /* Append length in bits and transform */
    ctx->in[14] = ctx->bits[0];
    ctx->in[15] = ctx->bits[1];

    MD5Transform(ctx->buf, ctx->in);
    byteReverse(ctx->buf, 4);
    memcpy(digest, ctx->buf, 16);
    memset(ctx, 0, sizeof(md5_state_t));    /* In case it's sensitive */
}

/* The four core functions - F1 is optimized somewhat */

/* #define F1(x, y, z) (x & y | ~x & z) */
#define F1(x, y, z) (z ^ (x & (y ^ z)))
#define F2(x, y, z) F1(z, x, y)
#define F3(x, y, z) (x ^ y ^ z)
#define F4(x, y, z) (y ^ (x | ~z))

/* This is the central step in the MD5 algorithm. */
#define MD5STEP(f, w, x, y, z, data, s) \
    ( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )

/*
 * The core of the MD5 algorithm, this alters an existing MD5 hash to
 * reflect the addition of 16 longwords of new data.  MD5Update blocks
 * the data and converts bytes into longwords for this routine.
 */
static void MD5Transform(guint32 buf[4], guint32 const in[16])
{
    register guint32 a, b, c, d;

    a = buf[0];
    b = buf[1];
    c = buf[2];
    d = buf[3];

    MD5STEP(F1, a, b, c, d, in[0]  + 0xd76aa478,  7);
    MD5STEP(F1, d, a, b, c, in[1]  + 0xe8c7b756, 12);
    MD5STEP(F1, c, d, a, b, in[2]  + 0x242070db, 17);
    MD5STEP(F1, b, c, d, a, in[3]  + 0xc1bdceee, 22);
    MD5STEP(F1, a, b, c, d, in[4]  + 0xf57c0faf,  7);
    MD5STEP(F1, d, a, b, c, in[5]  + 0x4787c62a, 12);
    MD5STEP(F1, c, d, a, b, in[6]  + 0xa8304613, 17);
    MD5STEP(F1, b, c, d, a, in[7]  + 0xfd469501, 22);
    MD5STEP(F1, a, b, c, d, in[8]  + 0x698098d8,  7);
    MD5STEP(F1, d, a, b, c, in[9]  + 0x8b44f7af, 12);
    MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
    MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
    MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122,  7);
    MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
    MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
    MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);

    MD5STEP(F2, a, b, c, d, in[1]  + 0xf61e2562,  5);
    MD5STEP(F2, d, a, b, c, in[6]  + 0xc040b340,  9);
    MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
    MD5STEP(F2, b, c, d, a, in[0]  + 0xe9b6c7aa, 20);
    MD5STEP(F2, a, b, c, d, in[5]  + 0xd62f105d,  5);
    MD5STEP(F2, d, a, b, c, in[10] + 0x02441453,  9);
    MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
    MD5STEP(F2, b, c, d, a, in[4]  + 0xe7d3fbc8, 20);
    MD5STEP(F2, a, b, c, d, in[9]  + 0x21e1cde6,  5);
    MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6,  9);
    MD5STEP(F2, c, d, a, b, in[3]  + 0xf4d50d87, 14);
    MD5STEP(F2, b, c, d, a, in[8]  + 0x455a14ed, 20);
    MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905,  5);
    MD5STEP(F2, d, a, b, c, in[2]  + 0xfcefa3f8,  9);
    MD5STEP(F2, c, d, a, b, in[7]  + 0x676f02d9, 14);
    MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);

    MD5STEP(F3, a, b, c, d, in[5]  + 0xfffa3942,  4);
    MD5STEP(F3, d, a, b, c, in[8]  + 0x8771f681, 11);
    MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
    MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
    MD5STEP(F3, a, b, c, d, in[1]  + 0xa4beea44,  4);
    MD5STEP(F3, d, a, b, c, in[4]  + 0x4bdecfa9, 11);
    MD5STEP(F3, c, d, a, b, in[7]  + 0xf6bb4b60, 16);
    MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
    MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6,  4);
    MD5STEP(F3, d, a, b, c, in[0]  + 0xeaa127fa, 11);
    MD5STEP(F3, c, d, a, b, in[3]  + 0xd4ef3085, 16);
    MD5STEP(F3, b, c, d, a, in[6]  + 0x04881d05, 23);
    MD5STEP(F3, a, b, c, d, in[9]  + 0xd9d4d039,  4);
    MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
    MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
    MD5STEP(F3, b, c, d, a, in[2]  + 0xc4ac5665, 23);

    MD5STEP(F4, a, b, c, d, in[0]  + 0xf4292244,  6);
    MD5STEP(F4, d, a, b, c, in[7]  + 0x432aff97, 10);
    MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
    MD5STEP(F4, b, c, d, a, in[5]  + 0xfc93a039, 21);
    MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3,  6);
    MD5STEP(F4, d, a, b, c, in[3]  + 0x8f0ccc92, 10);
    MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
    MD5STEP(F4, b, c, d, a, in[1]  + 0x85845dd1, 21);
    MD5STEP(F4, a, b, c, d, in[8]  + 0x6fa87e4f,  6);
    MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
    MD5STEP(F4, c, d, a, b, in[6]  + 0xa3014314, 15);
    MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
    MD5STEP(F4, a, b, c, d, in[4]  + 0xf7537e82,  6);
    MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
    MD5STEP(F4, c, d, a, b, in[2]  + 0x2ad7d2bb, 15);
    MD5STEP(F4, b, c, d, a, in[9]  + 0xeb86d391, 21);

    buf[0] += a;
    buf[1] += b;
    buf[2] += c;
    buf[3] += d;
}

/* from RFC 2104 HMAC  Appendix -- Sample Code */

void md5_hmac_init(md5_hmac_state_t *hctx, const guint8* key, size_t key_len)
{
    guint8 k_ipad[65];    /* inner padding - * key XORd with ipad */
    guint8 tk[16];
    int i;

    /* if key is longer than 64 bytes reset it to key=MD5(key) */
    if (key_len > 64) {
        md5_state_t tctx;

        md5_init(&tctx);
        md5_append(&tctx, key, key_len);
        md5_finish(&tctx, tk);

        key = tk;
        key_len = 16;
    }

    /*
     * the HMAC_MD5 transform looks like:
     *
     * MD5(K XOR opad, MD5(K XOR ipad, text))
     *
     * where K is an n byte key
     * ipad is the byte 0x36 repeated 64 times
     * opad is the byte 0x5c repeated 64 times
     * and text is the data being protected
     */

    /* start out by storing key in pads */
    memset(k_ipad, 0, sizeof(k_ipad));
    memset(hctx->k_opad, 0, sizeof(hctx->k_opad));
    memcpy(k_ipad, key, key_len);
    memcpy(hctx->k_opad, key, key_len);

    /* XOR key with ipad and opad values */
    for (i=0; i<64; i++) {
        k_ipad[i] ^= 0x36;
        hctx->k_opad[i] ^= 0x5c;
    }

    /*
     * perform inner MD5
     */
    md5_init(&hctx->ctx);                   /* init context for 1st  pass */
    md5_append(&hctx->ctx, k_ipad, 64);     /* start with inner pad */
}

void md5_hmac_append(md5_hmac_state_t *hctx, const guint8* text, size_t text_len)
{
    md5_append(&hctx->ctx, text, text_len);
}

void md5_hmac_finish(md5_hmac_state_t *hctx, guint8 digest[16])
{
    md5_state_t context;

    md5_finish(&hctx->ctx, digest);          /* finish up 1st pass */

    /*
     * perform outer MD5
     */
    md5_init(&context);                     /* init context for 2nd pass */
    md5_append(&context, hctx->k_opad, 64); /* start with outer pad */
    md5_append(&context, digest, 16);       /* then results of 1st hash */
    md5_finish(&context, digest);           /* finish up 2nd pass */
}

void md5_hmac(const guint8* text, size_t text_len, const guint8* key, size_t key_len, guint8 digest[16])
{
    md5_hmac_state_t hctx;

    md5_hmac_init(&hctx, key, key_len);
    md5_hmac_append(&hctx, text, text_len);
    md5_hmac_finish(&hctx, digest);
}

/*
 * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
 *
 * Local variables:
 * c-basic-offset: 4
 * tab-width: 8
 * indent-tabs-mode: nil
 * End:
 *
 * vi: set shiftwidth=4 tabstop=8 expandtab:
 * :indentSize=4:tabSize=8:noTabs=true:
 */