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/kernel.h>
21 #include <linux/module.h>
22 #include <linux/string.h>
23
24 const u8 md5_zero_message_hash[MD5_DIGEST_SIZE] = {
25 0xd4, 0x1d, 0x8c, 0xd9, 0x8f, 0x00, 0xb2, 0x04,
26 0xe9, 0x80, 0x09, 0x98, 0xec, 0xf8, 0x42, 0x7e,
27 };
28 EXPORT_SYMBOL_GPL(md5_zero_message_hash);
29
30 #define F1(x, y, z) (z ^ (x & (y ^ z)))
31 #define F2(x, y, z) F1(z, x, y)
32 #define F3(x, y, z) (x ^ y ^ z)
33 #define F4(x, y, z) (y ^ (x | ~z))
34
35 #define MD5STEP(f, w, x, y, z, in, s) \
36 (w += f(x, y, z) + in, w = (w<<s | w>>(32-s)) + x)
37
md5_transform(__u32 * hash,__u32 const * in)38 static void md5_transform(__u32 *hash, __u32 const *in)
39 {
40 u32 a, b, c, d;
41
42 a = hash[0];
43 b = hash[1];
44 c = hash[2];
45 d = hash[3];
46
47 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
48 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
49 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
50 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
51 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
52 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
53 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
54 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
55 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
56 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
57 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
58 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
59 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
60 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
61 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
62 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
63
64 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
65 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
66 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
67 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
68 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
69 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
70 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
71 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
72 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
73 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
74 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
75 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
76 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
77 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
78 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
79 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
80
81 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
82 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
83 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
84 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
85 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
86 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
87 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
88 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
89 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
90 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
91 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
92 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
93 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
94 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
95 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
96 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
97
98 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
99 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
100 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
101 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
102 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
103 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
104 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
105 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
106 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
107 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
108 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
109 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
110 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
111 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
112 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
113 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
114
115 hash[0] += a;
116 hash[1] += b;
117 hash[2] += c;
118 hash[3] += d;
119 }
120
md5_transform_helper(struct md5_state * ctx,u32 block[MD5_BLOCK_WORDS])121 static inline void md5_transform_helper(struct md5_state *ctx,
122 u32 block[MD5_BLOCK_WORDS])
123 {
124 le32_to_cpu_array(block, MD5_BLOCK_WORDS);
125 md5_transform(ctx->hash, block);
126 }
127
md5_init(struct shash_desc * desc)128 static int md5_init(struct shash_desc *desc)
129 {
130 struct md5_state *mctx = shash_desc_ctx(desc);
131
132 mctx->hash[0] = MD5_H0;
133 mctx->hash[1] = MD5_H1;
134 mctx->hash[2] = MD5_H2;
135 mctx->hash[3] = MD5_H3;
136 mctx->byte_count = 0;
137
138 return 0;
139 }
140
md5_update(struct shash_desc * desc,const u8 * data,unsigned int len)141 static int md5_update(struct shash_desc *desc, const u8 *data, unsigned int len)
142 {
143 struct md5_state *mctx = shash_desc_ctx(desc);
144 u32 block[MD5_BLOCK_WORDS];
145
146 mctx->byte_count += len;
147 do {
148 memcpy(block, data, sizeof(block));
149 md5_transform_helper(mctx, block);
150 data += sizeof(block);
151 len -= sizeof(block);
152 } while (len >= sizeof(block));
153 memzero_explicit(block, sizeof(block));
154 mctx->byte_count -= len;
155 return len;
156 }
157
md5_finup(struct shash_desc * desc,const u8 * data,unsigned int len,u8 * out)158 static int md5_finup(struct shash_desc *desc, const u8 *data, unsigned int len,
159 u8 *out)
160 {
161 struct md5_state *mctx = shash_desc_ctx(desc);
162 u32 block[MD5_BLOCK_WORDS];
163 unsigned int offset;
164 int padding;
165 char *p;
166
167 memcpy(block, data, len);
168
169 offset = len;
170 p = (char *)block + offset;
171 padding = 56 - (offset + 1);
172
173 *p++ = 0x80;
174 if (padding < 0) {
175 memset(p, 0x00, padding + sizeof (u64));
176 md5_transform_helper(mctx, block);
177 p = (char *)block;
178 padding = 56;
179 }
180
181 memset(p, 0, padding);
182 mctx->byte_count += len;
183 block[14] = mctx->byte_count << 3;
184 block[15] = mctx->byte_count >> 29;
185 le32_to_cpu_array(block, (sizeof(block) - sizeof(u64)) / sizeof(u32));
186 md5_transform(mctx->hash, block);
187 memzero_explicit(block, sizeof(block));
188 cpu_to_le32_array(mctx->hash, sizeof(mctx->hash) / sizeof(u32));
189 memcpy(out, mctx->hash, sizeof(mctx->hash));
190
191 return 0;
192 }
193
194 static struct shash_alg alg = {
195 .digestsize = MD5_DIGEST_SIZE,
196 .init = md5_init,
197 .update = md5_update,
198 .finup = md5_finup,
199 .descsize = MD5_STATE_SIZE,
200 .base = {
201 .cra_name = "md5",
202 .cra_driver_name = "md5-generic",
203 .cra_flags = CRYPTO_AHASH_ALG_BLOCK_ONLY,
204 .cra_blocksize = MD5_HMAC_BLOCK_SIZE,
205 .cra_module = THIS_MODULE,
206 }
207 };
208
md5_mod_init(void)209 static int __init md5_mod_init(void)
210 {
211 return crypto_register_shash(&alg);
212 }
213
md5_mod_fini(void)214 static void __exit md5_mod_fini(void)
215 {
216 crypto_unregister_shash(&alg);
217 }
218
219 module_init(md5_mod_init);
220 module_exit(md5_mod_fini);
221
222 MODULE_LICENSE("GPL");
223 MODULE_DESCRIPTION("MD5 Message Digest Algorithm");
224 MODULE_ALIAS_CRYPTO("md5");
225