1 /*
2 * Cryptographic API.
3 *
4 * MD5 Message Digest Algorithm (RFC1321).
5 *
6 * Derived from cryptoapi implementation, originally based on the
7 * public domain implementation written by Colin Plumb in 1993.
8 *
9 * Copyright (c) Cryptoapi developers.
10 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
11 *
12 * This program is free software; you can redistribute it and/or modify it
13 * under the terms of the GNU General Public License as published by the Free
14 * Software Foundation; either version 2 of the License, or (at your option)
15 * any later version.
16 *
17 */
18 #include <crypto/internal/hash.h>
19 #include <crypto/md5.h>
20 #include <linux/init.h>
21 #include <linux/module.h>
22 #include <linux/string.h>
23 #include <linux/types.h>
24 #include <asm/byteorder.h>
25
26 #define MD5_DIGEST_WORDS 4
27 #define MD5_MESSAGE_BYTES 64
28
29 const u8 md5_zero_message_hash[MD5_DIGEST_SIZE] = {
30 0xd4, 0x1d, 0x8c, 0xd9, 0x8f, 0x00, 0xb2, 0x04,
31 0xe9, 0x80, 0x09, 0x98, 0xec, 0xf8, 0x42, 0x7e,
32 };
33 EXPORT_SYMBOL_GPL(md5_zero_message_hash);
34
35 #define F1(x, y, z) (z ^ (x & (y ^ z)))
36 #define F2(x, y, z) F1(z, x, y)
37 #define F3(x, y, z) (x ^ y ^ z)
38 #define F4(x, y, z) (y ^ (x | ~z))
39
40 #define MD5STEP(f, w, x, y, z, in, s) \
41 (w += f(x, y, z) + in, w = (w<<s | w>>(32-s)) + x)
42
md5_transform(__u32 * hash,__u32 const * in)43 static void md5_transform(__u32 *hash, __u32 const *in)
44 {
45 u32 a, b, c, d;
46
47 a = hash[0];
48 b = hash[1];
49 c = hash[2];
50 d = hash[3];
51
52 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
53 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
54 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
55 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
56 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
57 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
58 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
59 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
60 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
61 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
62 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
63 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
64 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
65 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
66 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
67 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
68
69 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
70 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
71 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
72 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
73 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
74 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
75 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
76 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
77 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
78 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
79 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
80 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
81 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
82 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
83 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
84 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
85
86 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
87 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
88 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
89 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
90 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
91 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
92 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
93 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
94 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
95 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
96 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
97 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
98 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
99 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
100 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
101 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
102
103 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
104 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
105 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
106 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
107 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
108 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
109 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
110 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
111 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
112 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
113 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
114 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
115 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
116 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
117 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
118 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
119
120 hash[0] += a;
121 hash[1] += b;
122 hash[2] += c;
123 hash[3] += d;
124 }
125
md5_transform_helper(struct md5_state * ctx)126 static inline void md5_transform_helper(struct md5_state *ctx)
127 {
128 le32_to_cpu_array(ctx->block, sizeof(ctx->block) / sizeof(u32));
129 md5_transform(ctx->hash, ctx->block);
130 }
131
md5_init(struct shash_desc * desc)132 static int md5_init(struct shash_desc *desc)
133 {
134 struct md5_state *mctx = shash_desc_ctx(desc);
135
136 mctx->hash[0] = MD5_H0;
137 mctx->hash[1] = MD5_H1;
138 mctx->hash[2] = MD5_H2;
139 mctx->hash[3] = MD5_H3;
140 mctx->byte_count = 0;
141
142 return 0;
143 }
144
md5_update(struct shash_desc * desc,const u8 * data,unsigned int len)145 static int md5_update(struct shash_desc *desc, const u8 *data, unsigned int len)
146 {
147 struct md5_state *mctx = shash_desc_ctx(desc);
148 const u32 avail = sizeof(mctx->block) - (mctx->byte_count & 0x3f);
149
150 mctx->byte_count += len;
151
152 if (avail > len) {
153 memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
154 data, len);
155 return 0;
156 }
157
158 memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
159 data, avail);
160
161 md5_transform_helper(mctx);
162 data += avail;
163 len -= avail;
164
165 while (len >= sizeof(mctx->block)) {
166 memcpy(mctx->block, data, sizeof(mctx->block));
167 md5_transform_helper(mctx);
168 data += sizeof(mctx->block);
169 len -= sizeof(mctx->block);
170 }
171
172 memcpy(mctx->block, data, len);
173
174 return 0;
175 }
176
md5_final(struct shash_desc * desc,u8 * out)177 static int md5_final(struct shash_desc *desc, u8 *out)
178 {
179 struct md5_state *mctx = shash_desc_ctx(desc);
180 const unsigned int offset = mctx->byte_count & 0x3f;
181 char *p = (char *)mctx->block + offset;
182 int padding = 56 - (offset + 1);
183
184 *p++ = 0x80;
185 if (padding < 0) {
186 memset(p, 0x00, padding + sizeof (u64));
187 md5_transform_helper(mctx);
188 p = (char *)mctx->block;
189 padding = 56;
190 }
191
192 memset(p, 0, padding);
193 mctx->block[14] = mctx->byte_count << 3;
194 mctx->block[15] = mctx->byte_count >> 29;
195 le32_to_cpu_array(mctx->block, (sizeof(mctx->block) -
196 sizeof(u64)) / sizeof(u32));
197 md5_transform(mctx->hash, mctx->block);
198 cpu_to_le32_array(mctx->hash, sizeof(mctx->hash) / sizeof(u32));
199 memcpy(out, mctx->hash, sizeof(mctx->hash));
200 memset(mctx, 0, sizeof(*mctx));
201
202 return 0;
203 }
204
md5_export(struct shash_desc * desc,void * out)205 static int md5_export(struct shash_desc *desc, void *out)
206 {
207 struct md5_state *ctx = shash_desc_ctx(desc);
208
209 memcpy(out, ctx, sizeof(*ctx));
210 return 0;
211 }
212
md5_import(struct shash_desc * desc,const void * in)213 static int md5_import(struct shash_desc *desc, const void *in)
214 {
215 struct md5_state *ctx = shash_desc_ctx(desc);
216
217 memcpy(ctx, in, sizeof(*ctx));
218 return 0;
219 }
220
221 static struct shash_alg alg = {
222 .digestsize = MD5_DIGEST_SIZE,
223 .init = md5_init,
224 .update = md5_update,
225 .final = md5_final,
226 .export = md5_export,
227 .import = md5_import,
228 .descsize = sizeof(struct md5_state),
229 .statesize = sizeof(struct md5_state),
230 .base = {
231 .cra_name = "md5",
232 .cra_driver_name = "md5-generic",
233 .cra_blocksize = MD5_HMAC_BLOCK_SIZE,
234 .cra_module = THIS_MODULE,
235 }
236 };
237
md5_mod_init(void)238 static int __init md5_mod_init(void)
239 {
240 return crypto_register_shash(&alg);
241 }
242
md5_mod_fini(void)243 static void __exit md5_mod_fini(void)
244 {
245 crypto_unregister_shash(&alg);
246 }
247
248 subsys_initcall(md5_mod_init);
249 module_exit(md5_mod_fini);
250
251 MODULE_LICENSE("GPL");
252 MODULE_DESCRIPTION("MD5 Message Digest Algorithm");
253 MODULE_ALIAS_CRYPTO("md5");
254