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