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23#include <crypto/internal/hash.h>
24#include <linux/init.h>
25#include <linux/kernel.h>
26#include <linux/string.h>
27#include <linux/types.h>
28#include <asm/byteorder.h>
29
30#define MD4_DIGEST_SIZE 16
31#define MD4_HMAC_BLOCK_SIZE 64
32#define MD4_BLOCK_WORDS 16
33#define MD4_HASH_WORDS 4
34
35struct md4_ctx {
36 u32 hash[MD4_HASH_WORDS];
37 u32 block[MD4_BLOCK_WORDS];
38 u64 byte_count;
39};
40
41static inline u32 lshift(u32 x, unsigned int s)
42{
43 x &= 0xFFFFFFFF;
44 return ((x << s) & 0xFFFFFFFF) | (x >> (32 - s));
45}
46
47static inline u32 F(u32 x, u32 y, u32 z)
48{
49 return (x & y) | ((~x) & z);
50}
51
52static inline u32 G(u32 x, u32 y, u32 z)
53{
54 return (x & y) | (x & z) | (y & z);
55}
56
57static inline u32 H(u32 x, u32 y, u32 z)
58{
59 return x ^ y ^ z;
60}
61
62#define ROUND1(a,b,c,d,k,s) (a = lshift(a + F(b,c,d) + k, s))
63#define ROUND2(a,b,c,d,k,s) (a = lshift(a + G(b,c,d) + k + (u32)0x5A827999,s))
64#define ROUND3(a,b,c,d,k,s) (a = lshift(a + H(b,c,d) + k + (u32)0x6ED9EBA1,s))
65
66
67static inline void le32_to_cpu_array(u32 *buf, unsigned int words)
68{
69 while (words--) {
70 __le32_to_cpus(buf);
71 buf++;
72 }
73}
74
75static inline void cpu_to_le32_array(u32 *buf, unsigned int words)
76{
77 while (words--) {
78 __cpu_to_le32s(buf);
79 buf++;
80 }
81}
82
83static void md4_transform(u32 *hash, u32 const *in)
84{
85 u32 a, b, c, d;
86
87 a = hash[0];
88 b = hash[1];
89 c = hash[2];
90 d = hash[3];
91
92 ROUND1(a, b, c, d, in[0], 3);
93 ROUND1(d, a, b, c, in[1], 7);
94 ROUND1(c, d, a, b, in[2], 11);
95 ROUND1(b, c, d, a, in[3], 19);
96 ROUND1(a, b, c, d, in[4], 3);
97 ROUND1(d, a, b, c, in[5], 7);
98 ROUND1(c, d, a, b, in[6], 11);
99 ROUND1(b, c, d, a, in[7], 19);
100 ROUND1(a, b, c, d, in[8], 3);
101 ROUND1(d, a, b, c, in[9], 7);
102 ROUND1(c, d, a, b, in[10], 11);
103 ROUND1(b, c, d, a, in[11], 19);
104 ROUND1(a, b, c, d, in[12], 3);
105 ROUND1(d, a, b, c, in[13], 7);
106 ROUND1(c, d, a, b, in[14], 11);
107 ROUND1(b, c, d, a, in[15], 19);
108
109 ROUND2(a, b, c, d,in[ 0], 3);
110 ROUND2(d, a, b, c, in[4], 5);
111 ROUND2(c, d, a, b, in[8], 9);
112 ROUND2(b, c, d, a, in[12], 13);
113 ROUND2(a, b, c, d, in[1], 3);
114 ROUND2(d, a, b, c, in[5], 5);
115 ROUND2(c, d, a, b, in[9], 9);
116 ROUND2(b, c, d, a, in[13], 13);
117 ROUND2(a, b, c, d, in[2], 3);
118 ROUND2(d, a, b, c, in[6], 5);
119 ROUND2(c, d, a, b, in[10], 9);
120 ROUND2(b, c, d, a, in[14], 13);
121 ROUND2(a, b, c, d, in[3], 3);
122 ROUND2(d, a, b, c, in[7], 5);
123 ROUND2(c, d, a, b, in[11], 9);
124 ROUND2(b, c, d, a, in[15], 13);
125
126 ROUND3(a, b, c, d,in[ 0], 3);
127 ROUND3(d, a, b, c, in[8], 9);
128 ROUND3(c, d, a, b, in[4], 11);
129 ROUND3(b, c, d, a, in[12], 15);
130 ROUND3(a, b, c, d, in[2], 3);
131 ROUND3(d, a, b, c, in[10], 9);
132 ROUND3(c, d, a, b, in[6], 11);
133 ROUND3(b, c, d, a, in[14], 15);
134 ROUND3(a, b, c, d, in[1], 3);
135 ROUND3(d, a, b, c, in[9], 9);
136 ROUND3(c, d, a, b, in[5], 11);
137 ROUND3(b, c, d, a, in[13], 15);
138 ROUND3(a, b, c, d, in[3], 3);
139 ROUND3(d, a, b, c, in[11], 9);
140 ROUND3(c, d, a, b, in[7], 11);
141 ROUND3(b, c, d, a, in[15], 15);
142
143 hash[0] += a;
144 hash[1] += b;
145 hash[2] += c;
146 hash[3] += d;
147}
148
149static inline void md4_transform_helper(struct md4_ctx *ctx)
150{
151 le32_to_cpu_array(ctx->block, ARRAY_SIZE(ctx->block));
152 md4_transform(ctx->hash, ctx->block);
153}
154
155static int md4_init(struct shash_desc *desc)
156{
157 struct md4_ctx *mctx = shash_desc_ctx(desc);
158
159 mctx->hash[0] = 0x67452301;
160 mctx->hash[1] = 0xefcdab89;
161 mctx->hash[2] = 0x98badcfe;
162 mctx->hash[3] = 0x10325476;
163 mctx->byte_count = 0;
164
165 return 0;
166}
167
168static int md4_update(struct shash_desc *desc, const u8 *data, unsigned int len)
169{
170 struct md4_ctx *mctx = shash_desc_ctx(desc);
171 const u32 avail = sizeof(mctx->block) - (mctx->byte_count & 0x3f);
172
173 mctx->byte_count += len;
174
175 if (avail > len) {
176 memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
177 data, len);
178 return 0;
179 }
180
181 memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
182 data, avail);
183
184 md4_transform_helper(mctx);
185 data += avail;
186 len -= avail;
187
188 while (len >= sizeof(mctx->block)) {
189 memcpy(mctx->block, data, sizeof(mctx->block));
190 md4_transform_helper(mctx);
191 data += sizeof(mctx->block);
192 len -= sizeof(mctx->block);
193 }
194
195 memcpy(mctx->block, data, len);
196
197 return 0;
198}
199
200static int md4_final(struct shash_desc *desc, u8 *out)
201{
202 struct md4_ctx *mctx = shash_desc_ctx(desc);
203 const unsigned int offset = mctx->byte_count & 0x3f;
204 char *p = (char *)mctx->block + offset;
205 int padding = 56 - (offset + 1);
206
207 *p++ = 0x80;
208 if (padding < 0) {
209 memset(p, 0x00, padding + sizeof (u64));
210 md4_transform_helper(mctx);
211 p = (char *)mctx->block;
212 padding = 56;
213 }
214
215 memset(p, 0, padding);
216 mctx->block[14] = mctx->byte_count << 3;
217 mctx->block[15] = mctx->byte_count >> 29;
218 le32_to_cpu_array(mctx->block, (sizeof(mctx->block) -
219 sizeof(u64)) / sizeof(u32));
220 md4_transform(mctx->hash, mctx->block);
221 cpu_to_le32_array(mctx->hash, ARRAY_SIZE(mctx->hash));
222 memcpy(out, mctx->hash, sizeof(mctx->hash));
223 memset(mctx, 0, sizeof(*mctx));
224
225 return 0;
226}
227
228static struct shash_alg alg = {
229 .digestsize = MD4_DIGEST_SIZE,
230 .init = md4_init,
231 .update = md4_update,
232 .final = md4_final,
233 .descsize = sizeof(struct md4_ctx),
234 .base = {
235 .cra_name = "md4",
236 .cra_flags = CRYPTO_ALG_TYPE_SHASH,
237 .cra_blocksize = MD4_HMAC_BLOCK_SIZE,
238 .cra_module = THIS_MODULE,
239 }
240};
241
242static int __init md4_mod_init(void)
243{
244 return crypto_register_shash(&alg);
245}
246
247static void __exit md4_mod_fini(void)
248{
249 crypto_unregister_shash(&alg);
250}
251
252module_init(md4_mod_init);
253module_exit(md4_mod_fini);
254
255MODULE_LICENSE("GPL");
256MODULE_DESCRIPTION("MD4 Message Digest Algorithm");
257
258
