md5-internal.c revision 8d520ff1dc2da35cdca849e982051b86468016d8 
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 "md5_i.h"
20#include "crypto.h"
21
22
23static void MD5Transform(u32 buf[4], u32 const in[16]);
24
25
26typedef struct MD5Context MD5_CTX;
27
28
29/**
30 * md5_vector - MD5 hash for data vector
31 * @num_elem: Number of elements in the data vector
32 * @addr: Pointers to the data areas
33 * @len: Lengths of the data blocks
34 * @mac: Buffer for the hash
35 * Returns: 0 on success, -1 of failure
36 */
37int md5_vector(size_t num_elem, const u8 *addr[], const size_t *len, u8 *mac)
38{
39	MD5_CTX ctx;
40	size_t i;
41
42	MD5Init(&ctx);
43	for (i = 0; i < num_elem; i++)
44		MD5Update(&ctx, addr[i], len[i]);
45	MD5Final(mac, &ctx);
46	return 0;
47}
48
49
50/* ===== start - public domain MD5 implementation ===== */
51/*
52 * This code implements the MD5 message-digest algorithm.
53 * The algorithm is due to Ron Rivest.  This code was
54 * written by Colin Plumb in 1993, no copyright is claimed.
55 * This code is in the public domain; do with it what you wish.
56 *
57 * Equivalent code is available from RSA Data Security, Inc.
58 * This code has been tested against that, and is equivalent,
59 * except that you don't need to include two pages of legalese
60 * with every copy.
61 *
62 * To compute the message digest of a chunk of bytes, declare an
63 * MD5Context structure, pass it to MD5Init, call MD5Update as
64 * needed on buffers full of bytes, and then call MD5Final, which
65 * will fill a supplied 16-byte array with the digest.
66 */
67
68#ifndef WORDS_BIGENDIAN
69#define byteReverse(buf, len)	/* Nothing */
70#else
71/*
72 * Note: this code is harmless on little-endian machines.
73 */
74static void byteReverse(unsigned char *buf, unsigned longs)
75{
76    u32 t;
77    do {
78	t = (u32) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
79	    ((unsigned) buf[1] << 8 | buf[0]);
80	*(u32 *) buf = t;
81	buf += 4;
82    } while (--longs);
83}
84#endif
85
86/*
87 * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
88 * initialization constants.
89 */
90void MD5Init(struct MD5Context *ctx)
91{
92    ctx->buf[0] = 0x67452301;
93    ctx->buf[1] = 0xefcdab89;
94    ctx->buf[2] = 0x98badcfe;
95    ctx->buf[3] = 0x10325476;
96
97    ctx->bits[0] = 0;
98    ctx->bits[1] = 0;
99}
100
101/*
102 * Update context to reflect the concatenation of another buffer full
103 * of bytes.
104 */
105void MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len)
106{
107    u32 t;
108
109    /* Update bitcount */
110
111    t = ctx->bits[0];
112    if ((ctx->bits[0] = t + ((u32) len << 3)) < t)
113	ctx->bits[1]++;		/* Carry from low to high */
114    ctx->bits[1] += len >> 29;
115
116    t = (t >> 3) & 0x3f;	/* Bytes already in shsInfo->data */
117
118    /* Handle any leading odd-sized chunks */
119
120    if (t) {
121	unsigned char *p = (unsigned char *) ctx->in + t;
122
123	t = 64 - t;
124	if (len < t) {
125	    os_memcpy(p, buf, len);
126	    return;
127	}
128	os_memcpy(p, buf, t);
129	byteReverse(ctx->in, 16);
130	MD5Transform(ctx->buf, (u32 *) ctx->in);
131	buf += t;
132	len -= t;
133    }
134    /* Process data in 64-byte chunks */
135
136    while (len >= 64) {
137	os_memcpy(ctx->in, buf, 64);
138	byteReverse(ctx->in, 16);
139	MD5Transform(ctx->buf, (u32 *) ctx->in);
140	buf += 64;
141	len -= 64;
142    }
143
144    /* Handle any remaining bytes of data. */
145
146    os_memcpy(ctx->in, buf, len);
147}
148
149/*
150 * Final wrapup - pad to 64-byte boundary with the bit pattern
151 * 1 0* (64-bit count of bits processed, MSB-first)
152 */
153void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
154{
155    unsigned count;
156    unsigned char *p;
157
158    /* Compute number of bytes mod 64 */
159    count = (ctx->bits[0] >> 3) & 0x3F;
160
161    /* Set the first char of padding to 0x80.  This is safe since there is
162       always at least one byte free */
163    p = ctx->in + count;
164    *p++ = 0x80;
165
166    /* Bytes of padding needed to make 64 bytes */
167    count = 64 - 1 - count;
168
169    /* Pad out to 56 mod 64 */
170    if (count < 8) {
171	/* Two lots of padding:  Pad the first block to 64 bytes */
172	os_memset(p, 0, count);
173	byteReverse(ctx->in, 16);
174	MD5Transform(ctx->buf, (u32 *) ctx->in);
175
176	/* Now fill the next block with 56 bytes */
177	os_memset(ctx->in, 0, 56);
178    } else {
179	/* Pad block to 56 bytes */
180	os_memset(p, 0, count - 8);
181    }
182    byteReverse(ctx->in, 14);
183
184    /* Append length in bits and transform */
185    ((u32 *) ctx->in)[14] = ctx->bits[0];
186    ((u32 *) ctx->in)[15] = ctx->bits[1];
187
188    MD5Transform(ctx->buf, (u32 *) ctx->in);
189    byteReverse((unsigned char *) ctx->buf, 4);
190    os_memcpy(digest, ctx->buf, 16);
191    os_memset(ctx, 0, sizeof(ctx));	/* In case it's sensitive */
192}
193
194/* The four core functions - F1 is optimized somewhat */
195
196/* #define F1(x, y, z) (x & y | ~x & z) */
197#define F1(x, y, z) (z ^ (x & (y ^ z)))
198#define F2(x, y, z) F1(z, x, y)
199#define F3(x, y, z) (x ^ y ^ z)
200#define F4(x, y, z) (y ^ (x | ~z))
201
202/* This is the central step in the MD5 algorithm. */
203#define MD5STEP(f, w, x, y, z, data, s) \
204	( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )
205
206/*
207 * The core of the MD5 algorithm, this alters an existing MD5 hash to
208 * reflect the addition of 16 longwords of new data.  MD5Update blocks
209 * the data and converts bytes into longwords for this routine.
210 */
211static void MD5Transform(u32 buf[4], u32 const in[16])
212{
213    register u32 a, b, c, d;
214
215    a = buf[0];
216    b = buf[1];
217    c = buf[2];
218    d = buf[3];
219
220    MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
221    MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
222    MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
223    MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
224    MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
225    MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
226    MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
227    MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
228    MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
229    MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
230    MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
231    MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
232    MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
233    MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
234    MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
235    MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
236
237    MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
238    MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
239    MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
240    MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
241    MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
242    MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
243    MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
244    MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
245    MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
246    MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
247    MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
248    MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
249    MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
250    MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
251    MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
252    MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
253
254    MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
255    MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
256    MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
257    MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
258    MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
259    MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
260    MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
261    MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
262    MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
263    MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
264    MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
265    MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
266    MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
267    MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
268    MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
269    MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
270
271    MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
272    MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
273    MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
274    MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
275    MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
276    MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
277    MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
278    MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
279    MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
280    MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
281    MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
282    MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
283    MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
284    MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
285    MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
286    MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
287
288    buf[0] += a;
289    buf[1] += b;
290    buf[2] += c;
291    buf[3] += d;
292}
293/* ===== end - public domain MD5 implementation ===== */
294