1/*
2 * This is an OpenSSL-compatible implementation of the RSA Data Security, Inc.
3 * MD5 Message-Digest Algorithm (RFC 1321).
4 *
5 * Homepage:
6 * http://openwall.info/wiki/people/solar/software/public-domain-source-code/md5
7 *
8 * Author:
9 * Alexander Peslyak, better known as Solar Designer <solar at openwall.com>
10 *
11 * This software was written by Alexander Peslyak in 2001.  No copyright is
12 * claimed, and the software is hereby placed in the public domain.
13 * In case this attempt to disclaim copyright and place the software in the
14 * public domain is deemed null and void, then the software is
15 * Copyright (c) 2001 Alexander Peslyak and it is hereby released to the
16 * general public under the following terms:
17 *
18 * Redistribution and use in source and binary forms, with or without
19 * modification, are permitted.
20 *
21 * There's ABSOLUTELY NO WARRANTY, express or implied.
22 *
23 * (This is a heavily cut-down "BSD license".)
24 *
25 * This differs from Colin Plumb's older public domain implementation in that
26 * no exactly 32-bit integer data type is required (any 32-bit or wider
27 * unsigned integer data type will do), there's no compile-time endianness
28 * configuration, and the function prototypes match OpenSSL's.  No code from
29 * Colin Plumb's implementation has been reused; this comment merely compares
30 * the properties of the two independent implementations.
31 *
32 * The primary goals of this implementation are portability and ease of use.
33 * It is meant to be fast, but not as fast as possible.  Some known
34 * optimizations are not included to reduce source code size and avoid
35 * compile-time configuration.
36 */
37
38
39#include "md5.h"
40
41#include <string.h>
42
43
44/*
45 * The basic MD5 functions.
46 *
47 * F and G are optimized compared to their RFC 1321 definitions for
48 * architectures that lack an AND-NOT instruction, just like in Colin Plumb's
49 * implementation.
50 */
51#define F(x, y, z)			((z) ^ ((x) & ((y) ^ (z))))
52#define G(x, y, z)			((y) ^ ((z) & ((x) ^ (y))))
53#define H(x, y, z)			((x) ^ (y) ^ (z))
54#define I(x, y, z)			((y) ^ ((x) | ~(z)))
55
56/*
57 * The MD5 transformation for all four rounds.
58 */
59#define STEP(f, a, b, c, d, x, t, s) \
60	(a) += f((b), (c), (d)) + (x) + (t); \
61	(a) = (((a) << (s)) | (((a) & 0xffffffff) >> (32 - (s)))); \
62	(a) += (b);
63
64/*
65 * SET reads 4 input bytes in little-endian byte order and stores them
66 * in a properly aligned word in host byte order.
67 *
68 * The check for little-endian architectures that tolerate unaligned
69 * memory accesses is just an optimization.  Nothing will break if it
70 * doesn't work.
71 */
72#if defined(__i386__) || defined(__x86_64__) || defined(__vax__)
73#define SET(n) \
74	(*(MD5_u32plus *)&ptr[(n) * 4])
75#define GET(n) \
76	SET(n)
77#else
78#define SET(n) \
79	(ctx->block[(n)] = \
80	(MD5_u32plus)ptr[(n) * 4] | \
81	((MD5_u32plus)ptr[(n) * 4 + 1] << 8) | \
82	((MD5_u32plus)ptr[(n) * 4 + 2] << 16) | \
83	((MD5_u32plus)ptr[(n) * 4 + 3] << 24))
84#define GET(n) \
85	(ctx->block[(n)])
86#endif
87
88/*
89 * This processes one or more 64-byte data blocks, but does NOT update
90 * the bit counters.  There are no alignment requirements.
91 */
92static void *body(MD5_CTX *ctx, void *data, unsigned long size)
93{
94	unsigned char *ptr;
95	MD5_u32plus a, b, c, d;
96	MD5_u32plus saved_a, saved_b, saved_c, saved_d;
97
98	ptr = data;
99
100	a = ctx->a;
101	b = ctx->b;
102	c = ctx->c;
103	d = ctx->d;
104
105	do {
106		saved_a = a;
107		saved_b = b;
108		saved_c = c;
109		saved_d = d;
110
111/* Round 1 */
112		STEP(F, a, b, c, d, SET(0), 0xd76aa478, 7)
113		STEP(F, d, a, b, c, SET(1), 0xe8c7b756, 12)
114		STEP(F, c, d, a, b, SET(2), 0x242070db, 17)
115		STEP(F, b, c, d, a, SET(3), 0xc1bdceee, 22)
116		STEP(F, a, b, c, d, SET(4), 0xf57c0faf, 7)
117		STEP(F, d, a, b, c, SET(5), 0x4787c62a, 12)
118		STEP(F, c, d, a, b, SET(6), 0xa8304613, 17)
119		STEP(F, b, c, d, a, SET(7), 0xfd469501, 22)
120		STEP(F, a, b, c, d, SET(8), 0x698098d8, 7)
121		STEP(F, d, a, b, c, SET(9), 0x8b44f7af, 12)
122		STEP(F, c, d, a, b, SET(10), 0xffff5bb1, 17)
123		STEP(F, b, c, d, a, SET(11), 0x895cd7be, 22)
124		STEP(F, a, b, c, d, SET(12), 0x6b901122, 7)
125		STEP(F, d, a, b, c, SET(13), 0xfd987193, 12)
126		STEP(F, c, d, a, b, SET(14), 0xa679438e, 17)
127		STEP(F, b, c, d, a, SET(15), 0x49b40821, 22)
128
129/* Round 2 */
130		STEP(G, a, b, c, d, GET(1), 0xf61e2562, 5)
131		STEP(G, d, a, b, c, GET(6), 0xc040b340, 9)
132		STEP(G, c, d, a, b, GET(11), 0x265e5a51, 14)
133		STEP(G, b, c, d, a, GET(0), 0xe9b6c7aa, 20)
134		STEP(G, a, b, c, d, GET(5), 0xd62f105d, 5)
135		STEP(G, d, a, b, c, GET(10), 0x02441453, 9)
136		STEP(G, c, d, a, b, GET(15), 0xd8a1e681, 14)
137		STEP(G, b, c, d, a, GET(4), 0xe7d3fbc8, 20)
138		STEP(G, a, b, c, d, GET(9), 0x21e1cde6, 5)
139		STEP(G, d, a, b, c, GET(14), 0xc33707d6, 9)
140		STEP(G, c, d, a, b, GET(3), 0xf4d50d87, 14)
141		STEP(G, b, c, d, a, GET(8), 0x455a14ed, 20)
142		STEP(G, a, b, c, d, GET(13), 0xa9e3e905, 5)
143		STEP(G, d, a, b, c, GET(2), 0xfcefa3f8, 9)
144		STEP(G, c, d, a, b, GET(7), 0x676f02d9, 14)
145		STEP(G, b, c, d, a, GET(12), 0x8d2a4c8a, 20)
146
147/* Round 3 */
148		STEP(H, a, b, c, d, GET(5), 0xfffa3942, 4)
149		STEP(H, d, a, b, c, GET(8), 0x8771f681, 11)
150		STEP(H, c, d, a, b, GET(11), 0x6d9d6122, 16)
151		STEP(H, b, c, d, a, GET(14), 0xfde5380c, 23)
152		STEP(H, a, b, c, d, GET(1), 0xa4beea44, 4)
153		STEP(H, d, a, b, c, GET(4), 0x4bdecfa9, 11)
154		STEP(H, c, d, a, b, GET(7), 0xf6bb4b60, 16)
155		STEP(H, b, c, d, a, GET(10), 0xbebfbc70, 23)
156		STEP(H, a, b, c, d, GET(13), 0x289b7ec6, 4)
157		STEP(H, d, a, b, c, GET(0), 0xeaa127fa, 11)
158		STEP(H, c, d, a, b, GET(3), 0xd4ef3085, 16)
159		STEP(H, b, c, d, a, GET(6), 0x04881d05, 23)
160		STEP(H, a, b, c, d, GET(9), 0xd9d4d039, 4)
161		STEP(H, d, a, b, c, GET(12), 0xe6db99e5, 11)
162		STEP(H, c, d, a, b, GET(15), 0x1fa27cf8, 16)
163		STEP(H, b, c, d, a, GET(2), 0xc4ac5665, 23)
164
165/* Round 4 */
166		STEP(I, a, b, c, d, GET(0), 0xf4292244, 6)
167		STEP(I, d, a, b, c, GET(7), 0x432aff97, 10)
168		STEP(I, c, d, a, b, GET(14), 0xab9423a7, 15)
169		STEP(I, b, c, d, a, GET(5), 0xfc93a039, 21)
170		STEP(I, a, b, c, d, GET(12), 0x655b59c3, 6)
171		STEP(I, d, a, b, c, GET(3), 0x8f0ccc92, 10)
172		STEP(I, c, d, a, b, GET(10), 0xffeff47d, 15)
173		STEP(I, b, c, d, a, GET(1), 0x85845dd1, 21)
174		STEP(I, a, b, c, d, GET(8), 0x6fa87e4f, 6)
175		STEP(I, d, a, b, c, GET(15), 0xfe2ce6e0, 10)
176		STEP(I, c, d, a, b, GET(6), 0xa3014314, 15)
177		STEP(I, b, c, d, a, GET(13), 0x4e0811a1, 21)
178		STEP(I, a, b, c, d, GET(4), 0xf7537e82, 6)
179		STEP(I, d, a, b, c, GET(11), 0xbd3af235, 10)
180		STEP(I, c, d, a, b, GET(2), 0x2ad7d2bb, 15)
181		STEP(I, b, c, d, a, GET(9), 0xeb86d391, 21)
182
183		a += saved_a;
184		b += saved_b;
185		c += saved_c;
186		d += saved_d;
187
188		ptr += 64;
189	} while (size -= 64);
190
191	ctx->a = a;
192	ctx->b = b;
193	ctx->c = c;
194	ctx->d = d;
195
196	return ptr;
197}
198
199void MD5_Init(MD5_CTX *ctx)
200{
201	ctx->a = 0x67452301;
202	ctx->b = 0xefcdab89;
203	ctx->c = 0x98badcfe;
204	ctx->d = 0x10325476;
205
206	ctx->lo = 0;
207	ctx->hi = 0;
208}
209
210void MD5_Update(MD5_CTX *ctx, void *data, unsigned long size)
211{
212	MD5_u32plus saved_lo;
213	unsigned long used, free;
214
215	saved_lo = ctx->lo;
216	if ((ctx->lo = (saved_lo + size) & 0x1fffffff) < saved_lo)
217		ctx->hi++;
218	ctx->hi += size >> 29;
219
220	used = saved_lo & 0x3f;
221
222	if (used) {
223		free = 64 - used;
224
225		if (size < free) {
226			memcpy(&ctx->buffer[used], data, size);
227			return;
228		}
229
230		memcpy(&ctx->buffer[used], data, free);
231		data = (unsigned char *)data + free;
232		size -= free;
233		body(ctx, ctx->buffer, 64);
234	}
235
236	if (size >= 64) {
237		data = body(ctx, data, size & ~(unsigned long)0x3f);
238		size &= 0x3f;
239	}
240
241	memcpy(ctx->buffer, data, size);
242}
243
244void MD5_Final(unsigned char *result, MD5_CTX *ctx)
245{
246	unsigned long used, free;
247
248	used = ctx->lo & 0x3f;
249
250	ctx->buffer[used++] = 0x80;
251
252	free = 64 - used;
253
254	if (free < 8) {
255		memset(&ctx->buffer[used], 0, free);
256		body(ctx, ctx->buffer, 64);
257		used = 0;
258		free = 64;
259	}
260
261	memset(&ctx->buffer[used], 0, free - 8);
262
263	ctx->lo <<= 3;
264	ctx->buffer[56] = ctx->lo;
265	ctx->buffer[57] = ctx->lo >> 8;
266	ctx->buffer[58] = ctx->lo >> 16;
267	ctx->buffer[59] = ctx->lo >> 24;
268	ctx->buffer[60] = ctx->hi;
269	ctx->buffer[61] = ctx->hi >> 8;
270	ctx->buffer[62] = ctx->hi >> 16;
271	ctx->buffer[63] = ctx->hi >> 24;
272
273	body(ctx, ctx->buffer, 64);
274
275	result[0] = ctx->a;
276	result[1] = ctx->a >> 8;
277	result[2] = ctx->a >> 16;
278	result[3] = ctx->a >> 24;
279	result[4] = ctx->b;
280	result[5] = ctx->b >> 8;
281	result[6] = ctx->b >> 16;
282	result[7] = ctx->b >> 24;
283	result[8] = ctx->c;
284	result[9] = ctx->c >> 8;
285	result[10] = ctx->c >> 16;
286	result[11] = ctx->c >> 24;
287	result[12] = ctx->d;
288	result[13] = ctx->d >> 8;
289	result[14] = ctx->d >> 16;
290	result[15] = ctx->d >> 24;
291
292	memset(ctx, 0, sizeof(*ctx));
293}
294