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Linux/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 
 36 struct md4_ctx {
 37         u32 hash[MD4_HASH_WORDS];
 38         u32 block[MD4_BLOCK_WORDS];
 39         u64 byte_count;
 40 };
 41 
 42 static inline u32 lshift(u32 x, unsigned int s)
 43 {
 44         x &= 0xFFFFFFFF;
 45         return ((x << s) & 0xFFFFFFFF) | (x >> (32 - s));
 46 }
 47 
 48 static inline u32 F(u32 x, u32 y, u32 z)
 49 {
 50         return (x & y) | ((~x) & z);
 51 }
 52 
 53 static inline u32 G(u32 x, u32 y, u32 z)
 54 {
 55         return (x & y) | (x & z) | (y & z);
 56 }
 57 
 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 
 67 /* XXX: this stuff can be optimized */
 68 static 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 
 76 static 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 
 84 static 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 
150 static 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 
156 static 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 
169 static 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 
201 static 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 
229 static 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 
243 static int __init md4_mod_init(void)
244 {
245         return crypto_register_shash(&alg);
246 }
247 
248 static void __exit md4_mod_fini(void)
249 {
250         crypto_unregister_shash(&alg);
251 }
252 
253 module_init(md4_mod_init);
254 module_exit(md4_mod_fini);
255 
256 MODULE_LICENSE("GPL");
257 MODULE_DESCRIPTION("MD4 Message Digest Algorithm");
258 MODULE_ALIAS_CRYPTO("md4");
259 

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