1 /*
2 * MD5 hash implementation and interface functions
3 * Copyright (c) 2003-2005, Jouni Malinen <j@w1.fi>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * Alternatively, this software may be distributed under the terms of BSD
10 * license.
11 *
12 * See README and COPYING for more details.
13 */
14
15 #include "includes.h"
16
17 #include "common.h"
18 #include "md5.h"
19 #include "crypto.h"
20
21
22 /**
23 * hmac_md5_vector - HMAC-MD5 over data vector (RFC 2104)
24 * @key: Key for HMAC operations
25 * @key_len: Length of the key in bytes
26 * @num_elem: Number of elements in the data vector
27 * @addr: Pointers to the data areas
28 * @len: Lengths of the data blocks
29 * @mac: Buffer for the hash (16 bytes)
30 */
hmac_md5_vector(const u8 * key,size_t key_len,size_t num_elem,const u8 * addr[],const size_t * len,u8 * mac)31 void hmac_md5_vector(const u8 *key, size_t key_len, size_t num_elem,
32 const u8 *addr[], const size_t *len, u8 *mac)
33 {
34 u8 k_pad[64]; /* padding - key XORd with ipad/opad */
35 u8 tk[16];
36 const u8 *_addr[6];
37 size_t i, _len[6];
38
39 if (num_elem > 5) {
40 /*
41 * Fixed limit on the number of fragments to avoid having to
42 * allocate memory (which could fail).
43 */
44 return;
45 }
46
47 /* if key is longer than 64 bytes reset it to key = MD5(key) */
48 if (key_len > 64) {
49 md5_vector(1, &key, &key_len, tk);
50 key = tk;
51 key_len = 16;
52 }
53
54 /* the HMAC_MD5 transform looks like:
55 *
56 * MD5(K XOR opad, MD5(K XOR ipad, text))
57 *
58 * where K is an n byte key
59 * ipad is the byte 0x36 repeated 64 times
60 * opad is the byte 0x5c repeated 64 times
61 * and text is the data being protected */
62
63 /* start out by storing key in ipad */
64 os_memset(k_pad, 0, sizeof(k_pad));
65 os_memcpy(k_pad, key, key_len);
66
67 /* XOR key with ipad values */
68 for (i = 0; i < 64; i++)
69 k_pad[i] ^= 0x36;
70
71 /* perform inner MD5 */
72 _addr[0] = k_pad;
73 _len[0] = 64;
74 for (i = 0; i < num_elem; i++) {
75 _addr[i + 1] = addr[i];
76 _len[i + 1] = len[i];
77 }
78 md5_vector(1 + num_elem, _addr, _len, mac);
79
80 os_memset(k_pad, 0, sizeof(k_pad));
81 os_memcpy(k_pad, key, key_len);
82 /* XOR key with opad values */
83 for (i = 0; i < 64; i++)
84 k_pad[i] ^= 0x5c;
85
86 /* perform outer MD5 */
87 _addr[0] = k_pad;
88 _len[0] = 64;
89 _addr[1] = mac;
90 _len[1] = MD5_MAC_LEN;
91 md5_vector(2, _addr, _len, mac);
92 }
93
94
95 /**
96 * hmac_md5 - HMAC-MD5 over data buffer (RFC 2104)
97 * @key: Key for HMAC operations
98 * @key_len: Length of the key in bytes
99 * @data: Pointers to the data area
100 * @data_len: Length of the data area
101 * @mac: Buffer for the hash (16 bytes)
102 */
hmac_md5(const u8 * key,size_t key_len,const u8 * data,size_t data_len,u8 * mac)103 void hmac_md5(const u8 *key, size_t key_len, const u8 *data, size_t data_len,
104 u8 *mac)
105 {
106 hmac_md5_vector(key, key_len, 1, &data, &data_len, mac);
107 }
108
109
110 #ifdef INTERNAL_MD5
111
112 struct MD5Context {
113 u32 buf[4];
114 u32 bits[2];
115 u8 in[64];
116 };
117
118 #ifndef CONFIG_CRYPTO_INTERNAL
119 static void MD5Init(struct MD5Context *context);
120 static void MD5Update(struct MD5Context *context, unsigned char const *buf,
121 unsigned len);
122 static void MD5Final(unsigned char digest[16], struct MD5Context *context);
123 #endif /* CONFIG_CRYPTO_INTERNAL */
124 static void MD5Transform(u32 buf[4], u32 const in[16]);
125
126
127 typedef struct MD5Context MD5_CTX;
128
129
130 /**
131 * md5_vector - MD5 hash for data vector
132 * @num_elem: Number of elements in the data vector
133 * @addr: Pointers to the data areas
134 * @len: Lengths of the data blocks
135 * @mac: Buffer for the hash
136 */
md5_vector(size_t num_elem,const u8 * addr[],const size_t * len,u8 * mac)137 void md5_vector(size_t num_elem, const u8 *addr[], const size_t *len, u8 *mac)
138 {
139 MD5_CTX ctx;
140 size_t i;
141
142 MD5Init(&ctx);
143 for (i = 0; i < num_elem; i++)
144 MD5Update(&ctx, addr[i], len[i]);
145 MD5Final(mac, &ctx);
146 }
147
148
149 /* ===== start - public domain MD5 implementation ===== */
150 /*
151 * This code implements the MD5 message-digest algorithm.
152 * The algorithm is due to Ron Rivest. This code was
153 * written by Colin Plumb in 1993, no copyright is claimed.
154 * This code is in the public domain; do with it what you wish.
155 *
156 * Equivalent code is available from RSA Data Security, Inc.
157 * This code has been tested against that, and is equivalent,
158 * except that you don't need to include two pages of legalese
159 * with every copy.
160 *
161 * To compute the message digest of a chunk of bytes, declare an
162 * MD5Context structure, pass it to MD5Init, call MD5Update as
163 * needed on buffers full of bytes, and then call MD5Final, which
164 * will fill a supplied 16-byte array with the digest.
165 */
166
167 #ifndef WORDS_BIGENDIAN
168 #define byteReverse(buf, len) /* Nothing */
169 #else
170 /*
171 * Note: this code is harmless on little-endian machines.
172 */
byteReverse(unsigned char * buf,unsigned longs)173 static void byteReverse(unsigned char *buf, unsigned longs)
174 {
175 u32 t;
176 do {
177 t = (u32) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
178 ((unsigned) buf[1] << 8 | buf[0]);
179 *(u32 *) buf = t;
180 buf += 4;
181 } while (--longs);
182 }
183 #endif
184
185 /*
186 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
187 * initialization constants.
188 */
MD5Init(struct MD5Context * ctx)189 void MD5Init(struct MD5Context *ctx)
190 {
191 ctx->buf[0] = 0x67452301;
192 ctx->buf[1] = 0xefcdab89;
193 ctx->buf[2] = 0x98badcfe;
194 ctx->buf[3] = 0x10325476;
195
196 ctx->bits[0] = 0;
197 ctx->bits[1] = 0;
198 }
199
200 /*
201 * Update context to reflect the concatenation of another buffer full
202 * of bytes.
203 */
MD5Update(struct MD5Context * ctx,unsigned char const * buf,unsigned len)204 void MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len)
205 {
206 u32 t;
207
208 /* Update bitcount */
209
210 t = ctx->bits[0];
211 if ((ctx->bits[0] = t + ((u32) len << 3)) < t)
212 ctx->bits[1]++; /* Carry from low to high */
213 ctx->bits[1] += len >> 29;
214
215 t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
216
217 /* Handle any leading odd-sized chunks */
218
219 if (t) {
220 unsigned char *p = (unsigned char *) ctx->in + t;
221
222 t = 64 - t;
223 if (len < t) {
224 os_memcpy(p, buf, len);
225 return;
226 }
227 os_memcpy(p, buf, t);
228 byteReverse(ctx->in, 16);
229 MD5Transform(ctx->buf, (u32 *) ctx->in);
230 buf += t;
231 len -= t;
232 }
233 /* Process data in 64-byte chunks */
234
235 while (len >= 64) {
236 os_memcpy(ctx->in, buf, 64);
237 byteReverse(ctx->in, 16);
238 MD5Transform(ctx->buf, (u32 *) ctx->in);
239 buf += 64;
240 len -= 64;
241 }
242
243 /* Handle any remaining bytes of data. */
244
245 os_memcpy(ctx->in, buf, len);
246 }
247
248 /*
249 * Final wrapup - pad to 64-byte boundary with the bit pattern
250 * 1 0* (64-bit count of bits processed, MSB-first)
251 */
MD5Final(unsigned char digest[16],struct MD5Context * ctx)252 void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
253 {
254 unsigned count;
255 unsigned char *p;
256
257 /* Compute number of bytes mod 64 */
258 count = (ctx->bits[0] >> 3) & 0x3F;
259
260 /* Set the first char of padding to 0x80. This is safe since there is
261 always at least one byte free */
262 p = ctx->in + count;
263 *p++ = 0x80;
264
265 /* Bytes of padding needed to make 64 bytes */
266 count = 64 - 1 - count;
267
268 /* Pad out to 56 mod 64 */
269 if (count < 8) {
270 /* Two lots of padding: Pad the first block to 64 bytes */
271 os_memset(p, 0, count);
272 byteReverse(ctx->in, 16);
273 MD5Transform(ctx->buf, (u32 *) ctx->in);
274
275 /* Now fill the next block with 56 bytes */
276 os_memset(ctx->in, 0, 56);
277 } else {
278 /* Pad block to 56 bytes */
279 os_memset(p, 0, count - 8);
280 }
281 byteReverse(ctx->in, 14);
282
283 /* Append length in bits and transform */
284 ((u32 *) ctx->in)[14] = ctx->bits[0];
285 ((u32 *) ctx->in)[15] = ctx->bits[1];
286
287 MD5Transform(ctx->buf, (u32 *) ctx->in);
288 byteReverse((unsigned char *) ctx->buf, 4);
289 os_memcpy(digest, ctx->buf, 16);
290 os_memset(ctx, 0, sizeof(ctx)); /* In case it's sensitive */
291 }
292
293 /* The four core functions - F1 is optimized somewhat */
294
295 /* #define F1(x, y, z) (x & y | ~x & z) */
296 #define F1(x, y, z) (z ^ (x & (y ^ z)))
297 #define F2(x, y, z) F1(z, x, y)
298 #define F3(x, y, z) (x ^ y ^ z)
299 #define F4(x, y, z) (y ^ (x | ~z))
300
301 /* This is the central step in the MD5 algorithm. */
302 #define MD5STEP(f, w, x, y, z, data, s) \
303 ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
304
305 /*
306 * The core of the MD5 algorithm, this alters an existing MD5 hash to
307 * reflect the addition of 16 longwords of new data. MD5Update blocks
308 * the data and converts bytes into longwords for this routine.
309 */
MD5Transform(u32 buf[4],u32 const in[16])310 static void MD5Transform(u32 buf[4], u32 const in[16])
311 {
312 register u32 a, b, c, d;
313
314 a = buf[0];
315 b = buf[1];
316 c = buf[2];
317 d = buf[3];
318
319 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
320 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
321 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
322 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
323 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
324 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
325 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
326 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
327 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
328 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
329 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
330 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
331 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
332 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
333 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
334 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
335
336 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
337 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
338 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
339 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
340 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
341 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
342 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
343 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
344 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
345 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
346 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
347 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
348 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
349 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
350 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
351 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
352
353 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
354 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
355 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
356 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
357 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
358 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
359 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
360 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
361 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
362 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
363 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
364 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
365 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
366 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
367 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
368 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
369
370 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
371 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
372 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
373 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
374 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
375 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
376 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
377 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
378 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
379 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
380 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
381 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
382 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
383 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
384 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
385 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
386
387 buf[0] += a;
388 buf[1] += b;
389 buf[2] += c;
390 buf[3] += d;
391 }
392 /* ===== end - public domain MD5 implementation ===== */
393
394 #endif /* INTERNAL_MD5 */
395