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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/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 
35 struct md4_ctx {
36 	u32 hash[MD4_HASH_WORDS];
37 	u32 block[MD4_BLOCK_WORDS];
38 	u64 byte_count;
39 };
40 
lshift(u32 x,unsigned int s)41 static inline u32 lshift(u32 x, unsigned int s)
42 {
43 	x &= 0xFFFFFFFF;
44 	return ((x << s) & 0xFFFFFFFF) | (x >> (32 - s));
45 }
46 
F(u32 x,u32 y,u32 z)47 static inline u32 F(u32 x, u32 y, u32 z)
48 {
49 	return (x & y) | ((~x) & z);
50 }
51 
G(u32 x,u32 y,u32 z)52 static inline u32 G(u32 x, u32 y, u32 z)
53 {
54 	return (x & y) | (x & z) | (y & z);
55 }
56 
H(u32 x,u32 y,u32 z)57 static 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 
66 /* XXX: this stuff can be optimized */
le32_to_cpu_array(u32 * buf,unsigned int words)67 static inline void le32_to_cpu_array(u32 *buf, unsigned int words)
68 {
69 	while (words--) {
70 		__le32_to_cpus(buf);
71 		buf++;
72 	}
73 }
74 
cpu_to_le32_array(u32 * buf,unsigned int words)75 static inline void cpu_to_le32_array(u32 *buf, unsigned int words)
76 {
77 	while (words--) {
78 		__cpu_to_le32s(buf);
79 		buf++;
80 	}
81 }
82 
md4_transform(u32 * hash,u32 const * in)83 static void md4_transform(u32 *hash, u32 const *in)
84 {
85 	u32 a, b, c, d;
86 
87 	a = hash[0];
88 	b = hash[1];
89 	c = hash[2];
90 	d = hash[3];
91 
92 	ROUND1(a, b, c, d, in[0], 3);
93 	ROUND1(d, a, b, c, in[1], 7);
94 	ROUND1(c, d, a, b, in[2], 11);
95 	ROUND1(b, c, d, a, in[3], 19);
96 	ROUND1(a, b, c, d, in[4], 3);
97 	ROUND1(d, a, b, c, in[5], 7);
98 	ROUND1(c, d, a, b, in[6], 11);
99 	ROUND1(b, c, d, a, in[7], 19);
100 	ROUND1(a, b, c, d, in[8], 3);
101 	ROUND1(d, a, b, c, in[9], 7);
102 	ROUND1(c, d, a, b, in[10], 11);
103 	ROUND1(b, c, d, a, in[11], 19);
104 	ROUND1(a, b, c, d, in[12], 3);
105 	ROUND1(d, a, b, c, in[13], 7);
106 	ROUND1(c, d, a, b, in[14], 11);
107 	ROUND1(b, c, d, a, in[15], 19);
108 
109 	ROUND2(a, b, c, d,in[ 0], 3);
110 	ROUND2(d, a, b, c, in[4], 5);
111 	ROUND2(c, d, a, b, in[8], 9);
112 	ROUND2(b, c, d, a, in[12], 13);
113 	ROUND2(a, b, c, d, in[1], 3);
114 	ROUND2(d, a, b, c, in[5], 5);
115 	ROUND2(c, d, a, b, in[9], 9);
116 	ROUND2(b, c, d, a, in[13], 13);
117 	ROUND2(a, b, c, d, in[2], 3);
118 	ROUND2(d, a, b, c, in[6], 5);
119 	ROUND2(c, d, a, b, in[10], 9);
120 	ROUND2(b, c, d, a, in[14], 13);
121 	ROUND2(a, b, c, d, in[3], 3);
122 	ROUND2(d, a, b, c, in[7], 5);
123 	ROUND2(c, d, a, b, in[11], 9);
124 	ROUND2(b, c, d, a, in[15], 13);
125 
126 	ROUND3(a, b, c, d,in[ 0], 3);
127 	ROUND3(d, a, b, c, in[8], 9);
128 	ROUND3(c, d, a, b, in[4], 11);
129 	ROUND3(b, c, d, a, in[12], 15);
130 	ROUND3(a, b, c, d, in[2], 3);
131 	ROUND3(d, a, b, c, in[10], 9);
132 	ROUND3(c, d, a, b, in[6], 11);
133 	ROUND3(b, c, d, a, in[14], 15);
134 	ROUND3(a, b, c, d, in[1], 3);
135 	ROUND3(d, a, b, c, in[9], 9);
136 	ROUND3(c, d, a, b, in[5], 11);
137 	ROUND3(b, c, d, a, in[13], 15);
138 	ROUND3(a, b, c, d, in[3], 3);
139 	ROUND3(d, a, b, c, in[11], 9);
140 	ROUND3(c, d, a, b, in[7], 11);
141 	ROUND3(b, c, d, a, in[15], 15);
142 
143 	hash[0] += a;
144 	hash[1] += b;
145 	hash[2] += c;
146 	hash[3] += d;
147 }
148 
md4_transform_helper(struct md4_ctx * ctx)149 static inline void md4_transform_helper(struct md4_ctx *ctx)
150 {
151 	le32_to_cpu_array(ctx->block, ARRAY_SIZE(ctx->block));
152 	md4_transform(ctx->hash, ctx->block);
153 }
154 
md4_init(struct shash_desc * desc)155 static int md4_init(struct shash_desc *desc)
156 {
157 	struct md4_ctx *mctx = shash_desc_ctx(desc);
158 
159 	mctx->hash[0] = 0x67452301;
160 	mctx->hash[1] = 0xefcdab89;
161 	mctx->hash[2] = 0x98badcfe;
162 	mctx->hash[3] = 0x10325476;
163 	mctx->byte_count = 0;
164 
165 	return 0;
166 }
167 
md4_update(struct shash_desc * desc,const u8 * data,unsigned int len)168 static int md4_update(struct shash_desc *desc, const u8 *data, unsigned int len)
169 {
170 	struct md4_ctx *mctx = shash_desc_ctx(desc);
171 	const u32 avail = sizeof(mctx->block) - (mctx->byte_count & 0x3f);
172 
173 	mctx->byte_count += len;
174 
175 	if (avail > len) {
176 		memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
177 		       data, len);
178 		return 0;
179 	}
180 
181 	memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
182 	       data, avail);
183 
184 	md4_transform_helper(mctx);
185 	data += avail;
186 	len -= avail;
187 
188 	while (len >= sizeof(mctx->block)) {
189 		memcpy(mctx->block, data, sizeof(mctx->block));
190 		md4_transform_helper(mctx);
191 		data += sizeof(mctx->block);
192 		len -= sizeof(mctx->block);
193 	}
194 
195 	memcpy(mctx->block, data, len);
196 
197 	return 0;
198 }
199 
md4_final(struct shash_desc * desc,u8 * out)200 static int md4_final(struct shash_desc *desc, u8 *out)
201 {
202 	struct md4_ctx *mctx = shash_desc_ctx(desc);
203 	const unsigned int offset = mctx->byte_count & 0x3f;
204 	char *p = (char *)mctx->block + offset;
205 	int padding = 56 - (offset + 1);
206 
207 	*p++ = 0x80;
208 	if (padding < 0) {
209 		memset(p, 0x00, padding + sizeof (u64));
210 		md4_transform_helper(mctx);
211 		p = (char *)mctx->block;
212 		padding = 56;
213 	}
214 
215 	memset(p, 0, padding);
216 	mctx->block[14] = mctx->byte_count << 3;
217 	mctx->block[15] = mctx->byte_count >> 29;
218 	le32_to_cpu_array(mctx->block, (sizeof(mctx->block) -
219 	                  sizeof(u64)) / sizeof(u32));
220 	md4_transform(mctx->hash, mctx->block);
221 	cpu_to_le32_array(mctx->hash, ARRAY_SIZE(mctx->hash));
222 	memcpy(out, mctx->hash, sizeof(mctx->hash));
223 	memset(mctx, 0, sizeof(*mctx));
224 
225 	return 0;
226 }
227 
228 static struct shash_alg alg = {
229 	.digestsize	=	MD4_DIGEST_SIZE,
230 	.init		=	md4_init,
231 	.update		=	md4_update,
232 	.final		=	md4_final,
233 	.descsize	=	sizeof(struct md4_ctx),
234 	.base		=	{
235 		.cra_name	=	"md4",
236 		.cra_flags	=	CRYPTO_ALG_TYPE_SHASH,
237 		.cra_blocksize	=	MD4_HMAC_BLOCK_SIZE,
238 		.cra_module	=	THIS_MODULE,
239 	}
240 };
241 
md4_mod_init(void)242 static int __init md4_mod_init(void)
243 {
244 	return crypto_register_shash(&alg);
245 }
246 
md4_mod_fini(void)247 static void __exit md4_mod_fini(void)
248 {
249 	crypto_unregister_shash(&alg);
250 }
251 
252 module_init(md4_mod_init);
253 module_exit(md4_mod_fini);
254 
255 MODULE_LICENSE("GPL");
256 MODULE_DESCRIPTION("MD4 Message Digest Algorithm");
257 
258