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 <linux/init.h>
24#include <linux/crypto.h>
25#include <linux/kernel.h>
26#include <linux/string.h>
27#include <linux/types.h>
28#include <asm/byteorder.h>
29
30#define MD4_DIGEST_SIZE		16
31#define MD4_HMAC_BLOCK_SIZE	64
32#define MD4_BLOCK_WORDS		16
33#define MD4_HASH_WORDS		4
34
35struct md4_ctx {
36	u32 hash[MD4_HASH_WORDS];
37	u32 block[MD4_BLOCK_WORDS];
38	u64 byte_count;
39};
40
41static inline u32 lshift(u32 x, unsigned int s)
42{
43	x &= 0xFFFFFFFF;
44	return ((x << s) & 0xFFFFFFFF) | (x >> (32 - s));
45}
46
47static inline u32 F(u32 x, u32 y, u32 z)
48{
49	return (x & y) | ((~x) & z);
50}
51
52static inline u32 G(u32 x, u32 y, u32 z)
53{
54	return (x & y) | (x & z) | (y & z);
55}
56
57static inline u32 H(u32 x, u32 y, u32 z)
58{
59	return x ^ y ^ z;
60}
61
62#define ROUND1(a,b,c,d,k,s) (a = lshift(a + F(b,c,d) + k, s))
63#define ROUND2(a,b,c,d,k,s) (a = lshift(a + G(b,c,d) + k + (u32)0x5A827999,s))
64#define ROUND3(a,b,c,d,k,s) (a = lshift(a + H(b,c,d) + k + (u32)0x6ED9EBA1,s))
65
66static inline void le32_to_cpu_array(u32 *buf, unsigned int words)
67{
68	while (words--) {
69		__le32_to_cpus(buf);
70		buf++;
71	}
72}
73
74static inline void cpu_to_le32_array(u32 *buf, unsigned int words)
75{
76	while (words--) {
77		__cpu_to_le32s(buf);
78		buf++;
79	}
80}
81
82static void md4_transform(u32 *hash, u32 const *in)
83{
84	u32 a, b, c, d;
85
86	a = hash[0];
87	b = hash[1];
88	c = hash[2];
89	d = hash[3];
90
91	ROUND1(a, b, c, d, in[0], 3);
92	ROUND1(d, a, b, c, in[1], 7);
93	ROUND1(c, d, a, b, in[2], 11);
94	ROUND1(b, c, d, a, in[3], 19);
95	ROUND1(a, b, c, d, in[4], 3);
96	ROUND1(d, a, b, c, in[5], 7);
97	ROUND1(c, d, a, b, in[6], 11);
98	ROUND1(b, c, d, a, in[7], 19);
99	ROUND1(a, b, c, d, in[8], 3);
100	ROUND1(d, a, b, c, in[9], 7);
101	ROUND1(c, d, a, b, in[10], 11);
102	ROUND1(b, c, d, a, in[11], 19);
103	ROUND1(a, b, c, d, in[12], 3);
104	ROUND1(d, a, b, c, in[13], 7);
105	ROUND1(c, d, a, b, in[14], 11);
106	ROUND1(b, c, d, a, in[15], 19);
107
108	ROUND2(a, b, c, d,in[ 0], 3);
109	ROUND2(d, a, b, c, in[4], 5);
110	ROUND2(c, d, a, b, in[8], 9);
111	ROUND2(b, c, d, a, in[12], 13);
112	ROUND2(a, b, c, d, in[1], 3);
113	ROUND2(d, a, b, c, in[5], 5);
114	ROUND2(c, d, a, b, in[9], 9);
115	ROUND2(b, c, d, a, in[13], 13);
116	ROUND2(a, b, c, d, in[2], 3);
117	ROUND2(d, a, b, c, in[6], 5);
118	ROUND2(c, d, a, b, in[10], 9);
119	ROUND2(b, c, d, a, in[14], 13);
120	ROUND2(a, b, c, d, in[3], 3);
121	ROUND2(d, a, b, c, in[7], 5);
122	ROUND2(c, d, a, b, in[11], 9);
123	ROUND2(b, c, d, a, in[15], 13);
124
125	ROUND3(a, b, c, d,in[ 0], 3);
126	ROUND3(d, a, b, c, in[8], 9);
127	ROUND3(c, d, a, b, in[4], 11);
128	ROUND3(b, c, d, a, in[12], 15);
129	ROUND3(a, b, c, d, in[2], 3);
130	ROUND3(d, a, b, c, in[10], 9);
131	ROUND3(c, d, a, b, in[6], 11);
132	ROUND3(b, c, d, a, in[14], 15);
133	ROUND3(a, b, c, d, in[1], 3);
134	ROUND3(d, a, b, c, in[9], 9);
135	ROUND3(c, d, a, b, in[5], 11);
136	ROUND3(b, c, d, a, in[13], 15);
137	ROUND3(a, b, c, d, in[3], 3);
138	ROUND3(d, a, b, c, in[11], 9);
139	ROUND3(c, d, a, b, in[7], 11);
140	ROUND3(b, c, d, a, in[15], 15);
141
142	hash[0] += a;
143	hash[1] += b;
144	hash[2] += c;
145	hash[3] += d;
146}
147
148static inline void md4_transform_helper(struct md4_ctx *ctx)
149{
150	le32_to_cpu_array(ctx->block, sizeof(ctx->block) / sizeof(u32));
151	md4_transform(ctx->hash, ctx->block);
152}
153
154static void md4_init(struct crypto_tfm *tfm)
155{
156	struct md4_ctx *mctx = crypto_tfm_ctx(tfm);
157
158	mctx->hash[0] = 0x67452301;
159	mctx->hash[1] = 0xefcdab89;
160	mctx->hash[2] = 0x98badcfe;
161	mctx->hash[3] = 0x10325476;
162	mctx->byte_count = 0;
163}
164
165static void md4_update(struct crypto_tfm *tfm, const u8 *data, unsigned int len)
166{
167	struct md4_ctx *mctx = crypto_tfm_ctx(tfm);
168	const u32 avail = sizeof(mctx->block) - (mctx->byte_count & 0x3f);
169
170	mctx->byte_count += len;
171
172	if (avail > len) {
173		memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
174		       data, len);
175		return;
176	}
177
178	memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
179	       data, avail);
180
181	md4_transform_helper(mctx);
182	data += avail;
183	len -= avail;
184
185	while (len >= sizeof(mctx->block)) {
186		memcpy(mctx->block, data, sizeof(mctx->block));
187		md4_transform_helper(mctx);
188		data += sizeof(mctx->block);
189		len -= sizeof(mctx->block);
190	}
191
192	memcpy(mctx->block, data, len);
193}
194
195static void md4_final(struct crypto_tfm *tfm, u8 *out)
196{
197	struct md4_ctx *mctx = crypto_tfm_ctx(tfm);
198	const unsigned int offset = mctx->byte_count & 0x3f;
199	char *p = (char *)mctx->block + offset;
200	int padding = 56 - (offset + 1);
201
202	*p++ = 0x80;
203	if (padding < 0) {
204		memset(p, 0x00, padding + sizeof (u64));
205		md4_transform_helper(mctx);
206		p = (char *)mctx->block;
207		padding = 56;
208	}
209
210	memset(p, 0, padding);
211	mctx->block[14] = mctx->byte_count << 3;
212	mctx->block[15] = mctx->byte_count >> 29;
213	le32_to_cpu_array(mctx->block, (sizeof(mctx->block) -
214	                  sizeof(u64)) / sizeof(u32));
215	md4_transform(mctx->hash, mctx->block);
216	cpu_to_le32_array(mctx->hash, sizeof(mctx->hash) / sizeof(u32));
217	memcpy(out, mctx->hash, sizeof(mctx->hash));
218	memset(mctx, 0, sizeof(*mctx));
219}
220
221static struct crypto_alg alg = {
222	.cra_name	=	"md4",
223	.cra_flags	=	CRYPTO_ALG_TYPE_DIGEST,
224	.cra_blocksize	=	MD4_HMAC_BLOCK_SIZE,
225	.cra_ctxsize	=	sizeof(struct md4_ctx),
226	.cra_module	=	THIS_MODULE,
227	.cra_list       =       LIST_HEAD_INIT(alg.cra_list),
228	.cra_u		=	{ .digest = {
229	.dia_digestsize	=	MD4_DIGEST_SIZE,
230	.dia_init   	= 	md4_init,
231	.dia_update 	=	md4_update,
232	.dia_final  	=	md4_final } }
233};
234
235static int __init init(void)
236{
237	return crypto_register_alg(&alg);
238}
239
240static void __exit fini(void)
241{
242	crypto_unregister_alg(&alg);
243}
244
245module_init(init);
246module_exit(fini);
247
248MODULE_LICENSE("GPL");
249MODULE_DESCRIPTION("MD4 Message Digest Algorithm");
250