1/*
2 * Cryptographic API.
3 *
4 * MD5 Message Digest Algorithm (RFC1321).
5 *
6 * Derived from cryptoapi implementation, originally based on the
7 * public domain implementation written by Colin Plumb in 1993.
8 *
9 * Copyright (c) Cryptoapi developers.
10 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
11 *
12 * This program is free software; you can redistribute it and/or modify it
13 * under the terms of the GNU General Public License as published by the Free
14 * Software Foundation; either version 2 of the License, or (at your option)
15 * any later version.
16 *
17 */
18#include <crypto/internal/hash.h>
19#include <crypto/md5.h>
20#include <linux/init.h>
21#include <linux/module.h>
22#include <linux/string.h>
23#include <linux/types.h>
24#include <asm/byteorder.h>
25
26const u8 md5_zero_message_hash[MD5_DIGEST_SIZE] = {
27	0xd4, 0x1d, 0x8c, 0xd9, 0x8f, 0x00, 0xb2, 0x04,
28	0xe9, 0x80, 0x09, 0x98, 0xec, 0xf8, 0x42, 0x7e,
29};
30EXPORT_SYMBOL_GPL(md5_zero_message_hash);
31
32#define F1(x, y, z)	(z ^ (x & (y ^ z)))
33#define F2(x, y, z)	F1(z, x, y)
34#define F3(x, y, z)	(x ^ y ^ z)
35#define F4(x, y, z)	(y ^ (x | ~z))
36
37#define MD5STEP(f, w, x, y, z, in, s) \
38	(w += f(x, y, z) + in, w = (w<<s | w>>(32-s)) + x)
39
40static void md5_transform(__u32 *hash, __u32 const *in)
41{
42	u32 a, b, c, d;
43
44	a = hash[0];
45	b = hash[1];
46	c = hash[2];
47	d = hash[3];
48
49	MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
50	MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
51	MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
52	MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
53	MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
54	MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
55	MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
56	MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
57	MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
58	MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
59	MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
60	MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
61	MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
62	MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
63	MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
64	MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
65
66	MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
67	MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
68	MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
69	MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
70	MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
71	MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
72	MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
73	MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
74	MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
75	MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
76	MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
77	MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
78	MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
79	MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
80	MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
81	MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
82
83	MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
84	MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
85	MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
86	MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
87	MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
88	MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
89	MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
90	MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
91	MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
92	MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
93	MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
94	MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
95	MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
96	MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
97	MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
98	MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
99
100	MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
101	MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
102	MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
103	MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
104	MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
105	MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
106	MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
107	MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
108	MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
109	MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
110	MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
111	MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
112	MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
113	MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
114	MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
115	MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
116
117	hash[0] += a;
118	hash[1] += b;
119	hash[2] += c;
120	hash[3] += d;
121}
122
123static inline void md5_transform_helper(struct md5_state *ctx)
124{
125	le32_to_cpu_array(ctx->block, sizeof(ctx->block) / sizeof(u32));
126	md5_transform(ctx->hash, ctx->block);
127}
128
129static int md5_init(struct shash_desc *desc)
130{
131	struct md5_state *mctx = shash_desc_ctx(desc);
132
133	mctx->hash[0] = MD5_H0;
134	mctx->hash[1] = MD5_H1;
135	mctx->hash[2] = MD5_H2;
136	mctx->hash[3] = MD5_H3;
137	mctx->byte_count = 0;
138
139	return 0;
140}
141
142static int md5_update(struct shash_desc *desc, const u8 *data, unsigned int len)
143{
144	struct md5_state *mctx = shash_desc_ctx(desc);
145	const u32 avail = sizeof(mctx->block) - (mctx->byte_count & 0x3f);
146
147	mctx->byte_count += len;
148
149	if (avail > len) {
150		memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
151		       data, len);
152		return 0;
153	}
154
155	memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
156	       data, avail);
157
158	md5_transform_helper(mctx);
159	data += avail;
160	len -= avail;
161
162	while (len >= sizeof(mctx->block)) {
163		memcpy(mctx->block, data, sizeof(mctx->block));
164		md5_transform_helper(mctx);
165		data += sizeof(mctx->block);
166		len -= sizeof(mctx->block);
167	}
168
169	memcpy(mctx->block, data, len);
170
171	return 0;
172}
173
174static int md5_final(struct shash_desc *desc, u8 *out)
175{
176	struct md5_state *mctx = shash_desc_ctx(desc);
177	const unsigned int offset = mctx->byte_count & 0x3f;
178	char *p = (char *)mctx->block + offset;
179	int padding = 56 - (offset + 1);
180
181	*p++ = 0x80;
182	if (padding < 0) {
183		memset(p, 0x00, padding + sizeof (u64));
184		md5_transform_helper(mctx);
185		p = (char *)mctx->block;
186		padding = 56;
187	}
188
189	memset(p, 0, padding);
190	mctx->block[14] = mctx->byte_count << 3;
191	mctx->block[15] = mctx->byte_count >> 29;
192	le32_to_cpu_array(mctx->block, (sizeof(mctx->block) -
193	                  sizeof(u64)) / sizeof(u32));
194	md5_transform(mctx->hash, mctx->block);
195	cpu_to_le32_array(mctx->hash, sizeof(mctx->hash) / sizeof(u32));
196	memcpy(out, mctx->hash, sizeof(mctx->hash));
197	memset(mctx, 0, sizeof(*mctx));
198
199	return 0;
200}
201
202static int md5_export(struct shash_desc *desc, void *out)
203{
204	struct md5_state *ctx = shash_desc_ctx(desc);
205
206	memcpy(out, ctx, sizeof(*ctx));
207	return 0;
208}
209
210static int md5_import(struct shash_desc *desc, const void *in)
211{
212	struct md5_state *ctx = shash_desc_ctx(desc);
213
214	memcpy(ctx, in, sizeof(*ctx));
215	return 0;
216}
217
218static struct shash_alg alg = {
219	.digestsize	=	MD5_DIGEST_SIZE,
220	.init		=	md5_init,
221	.update		=	md5_update,
222	.final		=	md5_final,
223	.export		=	md5_export,
224	.import		=	md5_import,
225	.descsize	=	sizeof(struct md5_state),
226	.statesize	=	sizeof(struct md5_state),
227	.base		=	{
228		.cra_name	 =	"md5",
229		.cra_driver_name =	"md5-generic",
230		.cra_blocksize	 =	MD5_HMAC_BLOCK_SIZE,
231		.cra_module	 =	THIS_MODULE,
232	}
233};
234
235static int __init md5_mod_init(void)
236{
237	return crypto_register_shash(&alg);
238}
239
240static void __exit md5_mod_fini(void)
241{
242	crypto_unregister_shash(&alg);
243}
244
245subsys_initcall(md5_mod_init);
246module_exit(md5_mod_fini);
247
248MODULE_LICENSE("GPL");
249MODULE_DESCRIPTION("MD5 Message Digest Algorithm");
250MODULE_ALIAS_CRYPTO("md5");
251