2 * Copyright (C) 2003-2006 Benny Prijono <benny@prijono.org>
3 * Copyright (C) 2012 C Elston, Katalix Systems Ltd <celston@katalix.com>
5 * Wireshark - Network traffic analyzer
6 * By Gerald Combs <gerald@wireshark.org>
7 * Copyright 1998 Gerald Combs
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 * 2012-08-21 - C Elston - Split md5_hmac function to allow incremental usage.
35 * This code implements the MD5 message-digest algorithm.
36 * The algorithm is due to Ron Rivest. This code was
37 * written by Colin Plumb in 1993, no copyright is claimed.
38 * This code is in the public domain; do with it what you wish.
40 * Equivalent code is available from RSA Data Security, Inc.
41 * This code has been tested against that, and is equivalent,
42 * except that you don't need to include two pages of legalese
45 * To compute the message digest of a chunk of bytes, declare an
46 * MD5Context structure, pass it to MD5Init, call MD5Update as
47 * needed on buffers full of bytes, and then call MD5Final, which
48 * will fill a supplied 16-byte array with the digest.
51 #if WORDS_BIGENDIAN == 1
56 #define byteReverse(buf, len) /* Nothing */
59 * Note: this code is harmless on little-endian machines.
61 static void byteReverse(guint32 *buf, unsigned int longs)
72 static void MD5Transform(guint32 buf[4], guint32 const in[16]);
76 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
77 * initialization constants.
79 void md5_init(md5_state_t *ctx)
81 ctx->buf[0] = 0x67452301;
82 ctx->buf[1] = 0xefcdab89;
83 ctx->buf[2] = 0x98badcfe;
84 ctx->buf[3] = 0x10325476;
91 * Update context to reflect the concatenation of another buffer full
94 void md5_append( md5_state_t *ctx, const guint8 *buf, size_t len)
101 if ((ctx->bits[0] = t + ((guint32) len << 3)) < t)
102 ctx->bits[1]++; /* Carry from low to high */
103 ctx->bits[1] += (guint32) len >> 29;
105 t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
107 /* Handle any leading odd-sized chunks */
110 guint8 *p = (guint8 *) ctx->in + t;
118 byteReverse(ctx->in, 16);
119 MD5Transform(ctx->buf, ctx->in);
123 /* Process data in 64-byte chunks */
126 memcpy(ctx->in, buf, 64);
127 byteReverse(ctx->in, 16);
128 MD5Transform(ctx->buf, ctx->in);
133 /* Handle any remaining bytes of data. */
135 memcpy(ctx->in, buf, len);
139 * Final wrapup - pad to 64-byte boundary with the bit pattern
140 * 1 0* (64-bit count of bits processed, MSB-first)
142 void md5_finish(md5_state_t *ctx, guint8 digest[16])
147 /* Compute number of bytes mod 64 */
148 count = (ctx->bits[0] >> 3) & 0x3F;
150 /* Set the first char of padding to 0x80. This is safe since there is
151 always at least one byte free */
152 p = (guint8 *) ctx->in + count;
155 /* Bytes of padding needed to make 64 bytes */
156 count = 64 - 1 - count;
158 /* Pad out to 56 mod 64 */
160 /* Two lots of padding: Pad the first block to 64 bytes */
162 byteReverse(ctx->in, 16);
163 MD5Transform(ctx->buf, ctx->in);
165 /* Now fill the next block with 56 bytes */
166 memset(ctx->in, 0, 56);
168 /* Pad block to 56 bytes */
169 memset(p, 0, count - 8);
171 byteReverse(ctx->in, 14);
173 /* Append length in bits and transform */
174 ctx->in[14] = ctx->bits[0];
175 ctx->in[15] = ctx->bits[1];
177 MD5Transform(ctx->buf, ctx->in);
178 byteReverse(ctx->buf, 4);
179 memcpy(digest, ctx->buf, 16);
180 memset(ctx, 0, sizeof(md5_state_t)); /* In case it's sensitive */
183 /* The four core functions - F1 is optimized somewhat */
185 /* #define F1(x, y, z) (x & y | ~x & z) */
186 #define F1(x, y, z) (z ^ (x & (y ^ z)))
187 #define F2(x, y, z) F1(z, x, y)
188 #define F3(x, y, z) (x ^ y ^ z)
189 #define F4(x, y, z) (y ^ (x | ~z))
191 /* This is the central step in the MD5 algorithm. */
192 #define MD5STEP(f, w, x, y, z, data, s) \
193 ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
196 * The core of the MD5 algorithm, this alters an existing MD5 hash to
197 * reflect the addition of 16 longwords of new data. MD5Update blocks
198 * the data and converts bytes into longwords for this routine.
200 static void MD5Transform(guint32 buf[4], guint32 const in[16])
202 register guint32 a, b, c, d;
209 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
210 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
211 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
212 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
213 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
214 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
215 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
216 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
217 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
218 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
219 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
220 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
221 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
222 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
223 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
224 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
226 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
227 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
228 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
229 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
230 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
231 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
232 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
233 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
234 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
235 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
236 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
237 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
238 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
239 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
240 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
241 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
243 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
244 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
245 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
246 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
247 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
248 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
249 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
250 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
251 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
252 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
253 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
254 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
255 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
256 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
257 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
258 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
260 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
261 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
262 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
263 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
264 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
265 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
266 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
267 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
268 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
269 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
270 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
271 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
272 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
273 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
274 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
275 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
283 /* from RFC 2104 HMAC Appendix -- Sample Code */
285 void md5_hmac_init(md5_hmac_state_t *hctx, const guint8* key, size_t key_len)
287 guint8 k_ipad[65]; /* inner padding - * key XORd with ipad */
291 /* if key is longer than 64 bytes reset it to key=MD5(key) */
296 md5_append(&tctx, key, key_len);
297 md5_finish(&tctx, tk);
304 * the HMAC_MD5 transform looks like:
306 * MD5(K XOR opad, MD5(K XOR ipad, text))
308 * where K is an n byte key
309 * ipad is the byte 0x36 repeated 64 times
310 * opad is the byte 0x5c repeated 64 times
311 * and text is the data being protected
314 /* start out by storing key in pads */
315 memset(k_ipad, 0, sizeof(k_ipad));
316 memset(hctx->k_opad, 0, sizeof(hctx->k_opad));
317 memcpy(k_ipad, key, key_len);
318 memcpy(hctx->k_opad, key, key_len);
320 /* XOR key with ipad and opad values */
321 for (i=0; i<64; i++) {
323 hctx->k_opad[i] ^= 0x5c;
329 md5_init(&hctx->ctx); /* init context for 1st pass */
330 md5_append(&hctx->ctx, k_ipad, 64); /* start with inner pad */
333 void md5_hmac_append(md5_hmac_state_t *hctx, const guint8* text, size_t text_len)
335 md5_append(&hctx->ctx, text, text_len);
338 void md5_hmac_finish(md5_hmac_state_t *hctx, guint8 digest[16])
342 md5_finish(&hctx->ctx, digest); /* finish up 1st pass */
347 md5_init(&context); /* init context for 2nd pass */
348 md5_append(&context, hctx->k_opad, 64); /* start with outer pad */
349 md5_append(&context, digest, 16); /* then results of 1st hash */
350 md5_finish(&context, digest); /* finish up 2nd pass */
353 void md5_hmac(const guint8* text, size_t text_len, const guint8* key, size_t key_len, guint8 digest[16])
355 md5_hmac_state_t hctx;
357 md5_hmac_init(&hctx, key, key_len);
358 md5_hmac_append(&hctx, text, text_len);
359 md5_hmac_finish(&hctx, digest);
363 * Editor modelines - http://www.wireshark.org/tools/modelines.html
368 * indent-tabs-mode: nil
371 * vi: set shiftwidth=4 tabstop=8 expandtab:
372 * :indentSize=4:tabSize=8:noTabs=true: