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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
29const 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};
33EXPORT_SYMBOL_GPL(md5_zero_message_hash);
34
35
36static inline void le32_to_cpu_array(u32 *buf, unsigned int words)
37{
38 while (words--) {
39 __le32_to_cpus(buf);
40 buf++;
41 }
42}
43
44static inline void cpu_to_le32_array(u32 *buf, unsigned int words)
45{
46 while (words--) {
47 __cpu_to_le32s(buf);
48 buf++;
49 }
50}
51
52#define F1(x, y, z) (z ^ (x & (y ^ z)))
53#define F2(x, y, z) F1(z, x, y)
54#define F3(x, y, z) (x ^ y ^ z)
55#define F4(x, y, z) (y ^ (x | ~z))
56
57#define MD5STEP(f, w, x, y, z, in, s) \
58 (w += f(x, y, z) + in, w = (w<<s | w>>(32-s)) + x)
59
60static void md5_transform(__u32 *hash, __u32 const *in)
61{
62 u32 a, b, c, d;
63
64 a = hash[0];
65 b = hash[1];
66 c = hash[2];
67 d = hash[3];
68
69 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
70 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
71 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
72 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
73 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
74 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
75 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
76 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
77 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
78 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
79 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
80 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
81 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
82 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
83 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
84 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
85
86 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
87 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
88 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
89 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
90 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
91 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
92 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
93 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
94 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
95 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
96 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
97 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
98 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
99 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
100 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
101 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
102
103 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
104 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
105 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
106 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
107 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
108 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
109 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
110 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
111 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
112 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
113 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
114 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
115 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
116 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
117 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
118 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
119
120 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
121 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
122 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
123 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
124 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
125 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
126 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
127 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
128 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
129 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
130 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
131 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
132 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
133 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
134 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
135 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
136
137 hash[0] += a;
138 hash[1] += b;
139 hash[2] += c;
140 hash[3] += d;
141}
142
143static inline void md5_transform_helper(struct md5_state *ctx)
144{
145 le32_to_cpu_array(ctx->block, sizeof(ctx->block) / sizeof(u32));
146 md5_transform(ctx->hash, ctx->block);
147}
148
149static int md5_init(struct shash_desc *desc)
150{
151 struct md5_state *mctx = shash_desc_ctx(desc);
152
153 mctx->hash[0] = MD5_H0;
154 mctx->hash[1] = MD5_H1;
155 mctx->hash[2] = MD5_H2;
156 mctx->hash[3] = MD5_H3;
157 mctx->byte_count = 0;
158
159 return 0;
160}
161
162static int md5_update(struct shash_desc *desc, const u8 *data, unsigned int len)
163{
164 struct md5_state *mctx = shash_desc_ctx(desc);
165 const u32 avail = sizeof(mctx->block) - (mctx->byte_count & 0x3f);
166
167 mctx->byte_count += len;
168
169 if (avail > len) {
170 memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
171 data, len);
172 return 0;
173 }
174
175 memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
176 data, avail);
177
178 md5_transform_helper(mctx);
179 data += avail;
180 len -= avail;
181
182 while (len >= sizeof(mctx->block)) {
183 memcpy(mctx->block, data, sizeof(mctx->block));
184 md5_transform_helper(mctx);
185 data += sizeof(mctx->block);
186 len -= sizeof(mctx->block);
187 }
188
189 memcpy(mctx->block, data, len);
190
191 return 0;
192}
193
194static int md5_final(struct shash_desc *desc, u8 *out)
195{
196 struct md5_state *mctx = shash_desc_ctx(desc);
197 const unsigned int offset = mctx->byte_count & 0x3f;
198 char *p = (char *)mctx->block + offset;
199 int padding = 56 - (offset + 1);
200
201 *p++ = 0x80;
202 if (padding < 0) {
203 memset(p, 0x00, padding + sizeof (u64));
204 md5_transform_helper(mctx);
205 p = (char *)mctx->block;
206 padding = 56;
207 }
208
209 memset(p, 0, padding);
210 mctx->block[14] = mctx->byte_count << 3;
211 mctx->block[15] = mctx->byte_count >> 29;
212 le32_to_cpu_array(mctx->block, (sizeof(mctx->block) -
213 sizeof(u64)) / sizeof(u32));
214 md5_transform(mctx->hash, mctx->block);
215 cpu_to_le32_array(mctx->hash, sizeof(mctx->hash) / sizeof(u32));
216 memcpy(out, mctx->hash, sizeof(mctx->hash));
217 memset(mctx, 0, sizeof(*mctx));
218
219 return 0;
220}
221
222static int md5_export(struct shash_desc *desc, void *out)
223{
224 struct md5_state *ctx = shash_desc_ctx(desc);
225
226 memcpy(out, ctx, sizeof(*ctx));
227 return 0;
228}
229
230static int md5_import(struct shash_desc *desc, const void *in)
231{
232 struct md5_state *ctx = shash_desc_ctx(desc);
233
234 memcpy(ctx, in, sizeof(*ctx));
235 return 0;
236}
237
238static struct shash_alg alg = {
239 .digestsize = MD5_DIGEST_SIZE,
240 .init = md5_init,
241 .update = md5_update,
242 .final = md5_final,
243 .export = md5_export,
244 .import = md5_import,
245 .descsize = sizeof(struct md5_state),
246 .statesize = sizeof(struct md5_state),
247 .base = {
248 .cra_name = "md5",
249 .cra_flags = CRYPTO_ALG_TYPE_SHASH,
250 .cra_blocksize = MD5_HMAC_BLOCK_SIZE,
251 .cra_module = THIS_MODULE,
252 }
253};
254
255static int __init md5_mod_init(void)
256{
257 return crypto_register_shash(&alg);
258}
259
260static void __exit md5_mod_fini(void)
261{
262 crypto_unregister_shash(&alg);
263}
264
265module_init(md5_mod_init);
266module_exit(md5_mod_fini);
267
268MODULE_LICENSE("GPL");
269MODULE_DESCRIPTION("MD5 Message Digest Algorithm");
270MODULE_ALIAS_CRYPTO("md5");
271
