1/*
2 * Cryptographic API.
3 *
4 * MD4 Message Digest Algorithm (RFC1320).
5 *
6 * Implementation derived from Andrew Tridgell and Steve French's
7 * CIFS MD4 implementation, and the cryptoapi implementation
8 * originally based on the public domain implementation written
9 * by Colin Plumb in 1993.
10 *
11 * Copyright (c) Andrew Tridgell 1997-1998.
12 * Modified by Steve French (sfrench@us.ibm.com) 2002
13 * Copyright (c) Cryptoapi developers.
14 * Copyright (c) 2002 David S. Miller (davem@redhat.com)
15 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
16 *
17 * This program is free software; you can redistribute it and/or modify
18 * it under the terms of the GNU General Public License as published by
19 * the Free Software Foundation; either version 2 of the License, or
20 * (at your option) any later version.
21 *
22 */
23#include <crypto/internal/hash.h>
24#include <linux/init.h>
25#include <linux/kernel.h>
26#include <linux/module.h>
27#include <linux/string.h>
28#include <linux/types.h>
29#include <asm/byteorder.h>
30
31#define MD4_DIGEST_SIZE		16
32#define MD4_HMAC_BLOCK_SIZE	64
33#define MD4_BLOCK_WORDS		16
34#define MD4_HASH_WORDS		4
35
36struct md4_ctx {
37	u32 hash[MD4_HASH_WORDS];
38	u32 block[MD4_BLOCK_WORDS];
39	u64 byte_count;
40};
41
42static inline u32 lshift(u32 x, unsigned int s)
43{
44	x &= 0xFFFFFFFF;
45	return ((x << s) & 0xFFFFFFFF) | (x >> (32 - s));
46}
47
48static inline u32 F(u32 x, u32 y, u32 z)
49{
50	return (x & y) | ((~x) & z);
51}
52
53static inline u32 G(u32 x, u32 y, u32 z)
54{
55	return (x & y) | (x & z) | (y & z);
56}
57
58static inline u32 H(u32 x, u32 y, u32 z)
59{
60	return x ^ y ^ z;
61}
62
63#define ROUND1(a,b,c,d,k,s) (a = lshift(a + F(b,c,d) + k, s))
64#define ROUND2(a,b,c,d,k,s) (a = lshift(a + G(b,c,d) + k + (u32)0x5A827999,s))
65#define ROUND3(a,b,c,d,k,s) (a = lshift(a + H(b,c,d) + k + (u32)0x6ED9EBA1,s))
66
67static void md4_transform(u32 *hash, u32 const *in)
68{
69	u32 a, b, c, d;
70
71	a = hash[0];
72	b = hash[1];
73	c = hash[2];
74	d = hash[3];
75
76	ROUND1(a, b, c, d, in[0], 3);
77	ROUND1(d, a, b, c, in[1], 7);
78	ROUND1(c, d, a, b, in[2], 11);
79	ROUND1(b, c, d, a, in[3], 19);
80	ROUND1(a, b, c, d, in[4], 3);
81	ROUND1(d, a, b, c, in[5], 7);
82	ROUND1(c, d, a, b, in[6], 11);
83	ROUND1(b, c, d, a, in[7], 19);
84	ROUND1(a, b, c, d, in[8], 3);
85	ROUND1(d, a, b, c, in[9], 7);
86	ROUND1(c, d, a, b, in[10], 11);
87	ROUND1(b, c, d, a, in[11], 19);
88	ROUND1(a, b, c, d, in[12], 3);
89	ROUND1(d, a, b, c, in[13], 7);
90	ROUND1(c, d, a, b, in[14], 11);
91	ROUND1(b, c, d, a, in[15], 19);
92
93	ROUND2(a, b, c, d,in[ 0], 3);
94	ROUND2(d, a, b, c, in[4], 5);
95	ROUND2(c, d, a, b, in[8], 9);
96	ROUND2(b, c, d, a, in[12], 13);
97	ROUND2(a, b, c, d, in[1], 3);
98	ROUND2(d, a, b, c, in[5], 5);
99	ROUND2(c, d, a, b, in[9], 9);
100	ROUND2(b, c, d, a, in[13], 13);
101	ROUND2(a, b, c, d, in[2], 3);
102	ROUND2(d, a, b, c, in[6], 5);
103	ROUND2(c, d, a, b, in[10], 9);
104	ROUND2(b, c, d, a, in[14], 13);
105	ROUND2(a, b, c, d, in[3], 3);
106	ROUND2(d, a, b, c, in[7], 5);
107	ROUND2(c, d, a, b, in[11], 9);
108	ROUND2(b, c, d, a, in[15], 13);
109
110	ROUND3(a, b, c, d,in[ 0], 3);
111	ROUND3(d, a, b, c, in[8], 9);
112	ROUND3(c, d, a, b, in[4], 11);
113	ROUND3(b, c, d, a, in[12], 15);
114	ROUND3(a, b, c, d, in[2], 3);
115	ROUND3(d, a, b, c, in[10], 9);
116	ROUND3(c, d, a, b, in[6], 11);
117	ROUND3(b, c, d, a, in[14], 15);
118	ROUND3(a, b, c, d, in[1], 3);
119	ROUND3(d, a, b, c, in[9], 9);
120	ROUND3(c, d, a, b, in[5], 11);
121	ROUND3(b, c, d, a, in[13], 15);
122	ROUND3(a, b, c, d, in[3], 3);
123	ROUND3(d, a, b, c, in[11], 9);
124	ROUND3(c, d, a, b, in[7], 11);
125	ROUND3(b, c, d, a, in[15], 15);
126
127	hash[0] += a;
128	hash[1] += b;
129	hash[2] += c;
130	hash[3] += d;
131}
132
133static inline void md4_transform_helper(struct md4_ctx *ctx)
134{
135	le32_to_cpu_array(ctx->block, ARRAY_SIZE(ctx->block));
136	md4_transform(ctx->hash, ctx->block);
137}
138
139static int md4_init(struct shash_desc *desc)
140{
141	struct md4_ctx *mctx = shash_desc_ctx(desc);
142
143	mctx->hash[0] = 0x67452301;
144	mctx->hash[1] = 0xefcdab89;
145	mctx->hash[2] = 0x98badcfe;
146	mctx->hash[3] = 0x10325476;
147	mctx->byte_count = 0;
148
149	return 0;
150}
151
152static int md4_update(struct shash_desc *desc, const u8 *data, unsigned int len)
153{
154	struct md4_ctx *mctx = shash_desc_ctx(desc);
155	const u32 avail = sizeof(mctx->block) - (mctx->byte_count & 0x3f);
156
157	mctx->byte_count += len;
158
159	if (avail > len) {
160		memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
161		       data, len);
162		return 0;
163	}
164
165	memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
166	       data, avail);
167
168	md4_transform_helper(mctx);
169	data += avail;
170	len -= avail;
171
172	while (len >= sizeof(mctx->block)) {
173		memcpy(mctx->block, data, sizeof(mctx->block));
174		md4_transform_helper(mctx);
175		data += sizeof(mctx->block);
176		len -= sizeof(mctx->block);
177	}
178
179	memcpy(mctx->block, data, len);
180
181	return 0;
182}
183
184static int md4_final(struct shash_desc *desc, u8 *out)
185{
186	struct md4_ctx *mctx = shash_desc_ctx(desc);
187	const unsigned int offset = mctx->byte_count & 0x3f;
188	char *p = (char *)mctx->block + offset;
189	int padding = 56 - (offset + 1);
190
191	*p++ = 0x80;
192	if (padding < 0) {
193		memset(p, 0x00, padding + sizeof (u64));
194		md4_transform_helper(mctx);
195		p = (char *)mctx->block;
196		padding = 56;
197	}
198
199	memset(p, 0, padding);
200	mctx->block[14] = mctx->byte_count << 3;
201	mctx->block[15] = mctx->byte_count >> 29;
202	le32_to_cpu_array(mctx->block, (sizeof(mctx->block) -
203	                  sizeof(u64)) / sizeof(u32));
204	md4_transform(mctx->hash, mctx->block);
205	cpu_to_le32_array(mctx->hash, ARRAY_SIZE(mctx->hash));
206	memcpy(out, mctx->hash, sizeof(mctx->hash));
207	memset(mctx, 0, sizeof(*mctx));
208
209	return 0;
210}
211
212static struct shash_alg alg = {
213	.digestsize	=	MD4_DIGEST_SIZE,
214	.init		=	md4_init,
215	.update		=	md4_update,
216	.final		=	md4_final,
217	.descsize	=	sizeof(struct md4_ctx),
218	.base		=	{
219		.cra_name	 =	"md4",
220		.cra_driver_name =	"md4-generic",
221		.cra_blocksize	 =	MD4_HMAC_BLOCK_SIZE,
222		.cra_module	 =	THIS_MODULE,
223	}
224};
225
226static int __init md4_mod_init(void)
227{
228	return crypto_register_shash(&alg);
229}
230
231static void __exit md4_mod_fini(void)
232{
233	crypto_unregister_shash(&alg);
234}
235
236subsys_initcall(md4_mod_init);
237module_exit(md4_mod_fini);
238
239MODULE_LICENSE("GPL");
240MODULE_DESCRIPTION("MD4 Message Digest Algorithm");
241MODULE_ALIAS_CRYPTO("md4");
242