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 
36 struct md4_ctx {
37 	u32 hash[MD4_HASH_WORDS];
38 	u32 block[MD4_BLOCK_WORDS];
39 	u64 byte_count;
40 };
41 
lshift(u32 x,unsigned int s)42 static inline u32 lshift(u32 x, unsigned int s)
43 {
44 	x &= 0xFFFFFFFF;
45 	return ((x << s) & 0xFFFFFFFF) | (x >> (32 - s));
46 }
47 
F(u32 x,u32 y,u32 z)48 static inline u32 F(u32 x, u32 y, u32 z)
49 {
50 	return (x & y) | ((~x) & z);
51 }
52 
G(u32 x,u32 y,u32 z)53 static inline u32 G(u32 x, u32 y, u32 z)
54 {
55 	return (x & y) | (x & z) | (y & z);
56 }
57 
H(u32 x,u32 y,u32 z)58 static 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 
md4_transform(u32 * hash,u32 const * in)67 static 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 
md4_transform_helper(struct md4_ctx * ctx)133 static 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 
md4_init(struct shash_desc * desc)139 static 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 
md4_update(struct shash_desc * desc,const u8 * data,unsigned int len)152 static 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 
md4_final(struct shash_desc * desc,u8 * out)184 static 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 
212 static 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 
md4_mod_init(void)226 static int __init md4_mod_init(void)
227 {
228 	return crypto_register_shash(&alg);
229 }
230 
md4_mod_fini(void)231 static void __exit md4_mod_fini(void)
232 {
233 	crypto_unregister_shash(&alg);
234 }
235 
236 subsys_initcall(md4_mod_init);
237 module_exit(md4_mod_fini);
238 
239 MODULE_LICENSE("GPL");
240 MODULE_DESCRIPTION("MD4 Message Digest Algorithm");
241 MODULE_ALIAS_CRYPTO("md4");
242