Root/crypto/md4.c

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
67/* XXX: this stuff can be optimized */
68static inline void le32_to_cpu_array(u32 *buf, unsigned int words)
69{
70    while (words--) {
71        __le32_to_cpus(buf);
72        buf++;
73    }
74}
75
76static inline void cpu_to_le32_array(u32 *buf, unsigned int words)
77{
78    while (words--) {
79        __cpu_to_le32s(buf);
80        buf++;
81    }
82}
83
84static void md4_transform(u32 *hash, u32 const *in)
85{
86    u32 a, b, c, d;
87
88    a = hash[0];
89    b = hash[1];
90    c = hash[2];
91    d = hash[3];
92
93    ROUND1(a, b, c, d, in[0], 3);
94    ROUND1(d, a, b, c, in[1], 7);
95    ROUND1(c, d, a, b, in[2], 11);
96    ROUND1(b, c, d, a, in[3], 19);
97    ROUND1(a, b, c, d, in[4], 3);
98    ROUND1(d, a, b, c, in[5], 7);
99    ROUND1(c, d, a, b, in[6], 11);
100    ROUND1(b, c, d, a, in[7], 19);
101    ROUND1(a, b, c, d, in[8], 3);
102    ROUND1(d, a, b, c, in[9], 7);
103    ROUND1(c, d, a, b, in[10], 11);
104    ROUND1(b, c, d, a, in[11], 19);
105    ROUND1(a, b, c, d, in[12], 3);
106    ROUND1(d, a, b, c, in[13], 7);
107    ROUND1(c, d, a, b, in[14], 11);
108    ROUND1(b, c, d, a, in[15], 19);
109
110    ROUND2(a, b, c, d,in[ 0], 3);
111    ROUND2(d, a, b, c, in[4], 5);
112    ROUND2(c, d, a, b, in[8], 9);
113    ROUND2(b, c, d, a, in[12], 13);
114    ROUND2(a, b, c, d, in[1], 3);
115    ROUND2(d, a, b, c, in[5], 5);
116    ROUND2(c, d, a, b, in[9], 9);
117    ROUND2(b, c, d, a, in[13], 13);
118    ROUND2(a, b, c, d, in[2], 3);
119    ROUND2(d, a, b, c, in[6], 5);
120    ROUND2(c, d, a, b, in[10], 9);
121    ROUND2(b, c, d, a, in[14], 13);
122    ROUND2(a, b, c, d, in[3], 3);
123    ROUND2(d, a, b, c, in[7], 5);
124    ROUND2(c, d, a, b, in[11], 9);
125    ROUND2(b, c, d, a, in[15], 13);
126
127    ROUND3(a, b, c, d,in[ 0], 3);
128    ROUND3(d, a, b, c, in[8], 9);
129    ROUND3(c, d, a, b, in[4], 11);
130    ROUND3(b, c, d, a, in[12], 15);
131    ROUND3(a, b, c, d, in[2], 3);
132    ROUND3(d, a, b, c, in[10], 9);
133    ROUND3(c, d, a, b, in[6], 11);
134    ROUND3(b, c, d, a, in[14], 15);
135    ROUND3(a, b, c, d, in[1], 3);
136    ROUND3(d, a, b, c, in[9], 9);
137    ROUND3(c, d, a, b, in[5], 11);
138    ROUND3(b, c, d, a, in[13], 15);
139    ROUND3(a, b, c, d, in[3], 3);
140    ROUND3(d, a, b, c, in[11], 9);
141    ROUND3(c, d, a, b, in[7], 11);
142    ROUND3(b, c, d, a, in[15], 15);
143
144    hash[0] += a;
145    hash[1] += b;
146    hash[2] += c;
147    hash[3] += d;
148}
149
150static inline void md4_transform_helper(struct md4_ctx *ctx)
151{
152    le32_to_cpu_array(ctx->block, ARRAY_SIZE(ctx->block));
153    md4_transform(ctx->hash, ctx->block);
154}
155
156static int md4_init(struct shash_desc *desc)
157{
158    struct md4_ctx *mctx = shash_desc_ctx(desc);
159
160    mctx->hash[0] = 0x67452301;
161    mctx->hash[1] = 0xefcdab89;
162    mctx->hash[2] = 0x98badcfe;
163    mctx->hash[3] = 0x10325476;
164    mctx->byte_count = 0;
165
166    return 0;
167}
168
169static int md4_update(struct shash_desc *desc, const u8 *data, unsigned int len)
170{
171    struct md4_ctx *mctx = shash_desc_ctx(desc);
172    const u32 avail = sizeof(mctx->block) - (mctx->byte_count & 0x3f);
173
174    mctx->byte_count += len;
175
176    if (avail > len) {
177        memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
178               data, len);
179        return 0;
180    }
181
182    memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
183           data, avail);
184
185    md4_transform_helper(mctx);
186    data += avail;
187    len -= avail;
188
189    while (len >= sizeof(mctx->block)) {
190        memcpy(mctx->block, data, sizeof(mctx->block));
191        md4_transform_helper(mctx);
192        data += sizeof(mctx->block);
193        len -= sizeof(mctx->block);
194    }
195
196    memcpy(mctx->block, data, len);
197
198    return 0;
199}
200
201static int md4_final(struct shash_desc *desc, u8 *out)
202{
203    struct md4_ctx *mctx = shash_desc_ctx(desc);
204    const unsigned int offset = mctx->byte_count & 0x3f;
205    char *p = (char *)mctx->block + offset;
206    int padding = 56 - (offset + 1);
207
208    *p++ = 0x80;
209    if (padding < 0) {
210        memset(p, 0x00, padding + sizeof (u64));
211        md4_transform_helper(mctx);
212        p = (char *)mctx->block;
213        padding = 56;
214    }
215
216    memset(p, 0, padding);
217    mctx->block[14] = mctx->byte_count << 3;
218    mctx->block[15] = mctx->byte_count >> 29;
219    le32_to_cpu_array(mctx->block, (sizeof(mctx->block) -
220                      sizeof(u64)) / sizeof(u32));
221    md4_transform(mctx->hash, mctx->block);
222    cpu_to_le32_array(mctx->hash, ARRAY_SIZE(mctx->hash));
223    memcpy(out, mctx->hash, sizeof(mctx->hash));
224    memset(mctx, 0, sizeof(*mctx));
225
226    return 0;
227}
228
229static struct shash_alg alg = {
230    .digestsize = MD4_DIGEST_SIZE,
231    .init = md4_init,
232    .update = md4_update,
233    .final = md4_final,
234    .descsize = sizeof(struct md4_ctx),
235    .base = {
236        .cra_name = "md4",
237        .cra_flags = CRYPTO_ALG_TYPE_SHASH,
238        .cra_blocksize = MD4_HMAC_BLOCK_SIZE,
239        .cra_module = THIS_MODULE,
240    }
241};
242
243static int __init md4_mod_init(void)
244{
245    return crypto_register_shash(&alg);
246}
247
248static void __exit md4_mod_fini(void)
249{
250    crypto_unregister_shash(&alg);
251}
252
253module_init(md4_mod_init);
254module_exit(md4_mod_fini);
255
256MODULE_LICENSE("GPL");
257MODULE_DESCRIPTION("MD4 Message Digest Algorithm");
258
259

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