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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
36struct md4_ctx {
37 u32 hash[MD4_HASH_WORDS];
38 u32 block[MD4_BLOCK_WORDS];
39 u64 byte_count;
40};
41
42static inline u32 lshift(u32 x, unsigned int s)
43{
44 x &= 0xFFFFFFFF;
45 return ((x << s) & 0xFFFFFFFF) | (x >> (32 - s));
46}
47
48static inline u32 F(u32 x, u32 y, u32 z)
49{
50 return (x & y) | ((~x) & z);
51}
52
53static inline u32 G(u32 x, u32 y, u32 z)
54{
55 return (x & y) | (x & z) | (y & z);
56}
57
58static 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
68static 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
76static 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
84static 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
150static 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
156static 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
169static 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
201static 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
229static 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
243static int __init md4_mod_init(void)
244{
245 return crypto_register_shash(&alg);
246}
247
248static void __exit md4_mod_fini(void)
249{
250 crypto_unregister_shash(&alg);
251}
252
253module_init(md4_mod_init);
254module_exit(md4_mod_fini);
255
256MODULE_LICENSE("GPL");
257MODULE_DESCRIPTION("MD4 Message Digest Algorithm");
258MODULE_ALIAS_CRYPTO("md4");
259
