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