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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Herbert Xu06ace7a2005-10-30 21:25:15 +110027#include <linux/types.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#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
66/* XXX: this stuff can be optimized */
67static 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
75static 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
83static 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
149static inline void md4_transform_helper(struct md4_ctx *ctx)
150{
151 le32_to_cpu_array(ctx->block, sizeof(ctx->block) / sizeof(u32));
152 md4_transform(ctx->hash, ctx->block);
153}
154
155static void md4_init(void *ctx)
156{
157 struct md4_ctx *mctx = ctx;
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
166static void md4_update(void *ctx, const u8 *data, unsigned int len)
167{
168 struct md4_ctx *mctx = ctx;
169 const u32 avail = sizeof(mctx->block) - (mctx->byte_count & 0x3f);
170
171 mctx->byte_count += len;
172
173 if (avail > len) {
174 memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
175 data, len);
176 return;
177 }
178
179 memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
180 data, avail);
181
182 md4_transform_helper(mctx);
183 data += avail;
184 len -= avail;
185
186 while (len >= sizeof(mctx->block)) {
187 memcpy(mctx->block, data, sizeof(mctx->block));
188 md4_transform_helper(mctx);
189 data += sizeof(mctx->block);
190 len -= sizeof(mctx->block);
191 }
192
193 memcpy(mctx->block, data, len);
194}
195
196static void md4_final(void *ctx, u8 *out)
197{
198 struct md4_ctx *mctx = ctx;
199 const unsigned int offset = mctx->byte_count & 0x3f;
200 char *p = (char *)mctx->block + offset;
201 int padding = 56 - (offset + 1);
202
203 *p++ = 0x80;
204 if (padding < 0) {
205 memset(p, 0x00, padding + sizeof (u64));
206 md4_transform_helper(mctx);
207 p = (char *)mctx->block;
208 padding = 56;
209 }
210
211 memset(p, 0, padding);
212 mctx->block[14] = mctx->byte_count << 3;
213 mctx->block[15] = mctx->byte_count >> 29;
214 le32_to_cpu_array(mctx->block, (sizeof(mctx->block) -
215 sizeof(u64)) / sizeof(u32));
216 md4_transform(mctx->hash, mctx->block);
217 cpu_to_le32_array(mctx->hash, sizeof(mctx->hash) / sizeof(u32));
218 memcpy(out, mctx->hash, sizeof(mctx->hash));
219 memset(mctx, 0, sizeof(*mctx));
220}
221
222static struct crypto_alg alg = {
223 .cra_name = "md4",
224 .cra_flags = CRYPTO_ALG_TYPE_DIGEST,
225 .cra_blocksize = MD4_HMAC_BLOCK_SIZE,
226 .cra_ctxsize = sizeof(struct md4_ctx),
227 .cra_module = THIS_MODULE,
228 .cra_list = LIST_HEAD_INIT(alg.cra_list),
229 .cra_u = { .digest = {
230 .dia_digestsize = MD4_DIGEST_SIZE,
231 .dia_init = md4_init,
232 .dia_update = md4_update,
233 .dia_final = md4_final } }
234};
235
236static int __init init(void)
237{
238 return crypto_register_alg(&alg);
239}
240
241static void __exit fini(void)
242{
243 crypto_unregister_alg(&alg);
244}
245
246module_init(init);
247module_exit(fini);
248
249MODULE_LICENSE("GPL");
250MODULE_DESCRIPTION("MD4 Message Digest Algorithm");
251