1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
2 *
3 * LibTomCrypt is a library that provides various cryptographic
4 * algorithms in a highly modular and flexible manner.
5 *
6 * The library is free for all purposes without any express
7 * guarantee it works.
8 *
9 * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.com
10 */
11 #include "tomcrypt.h"
12
13 /**
14 @param md2.c
15 MD2 (RFC 1319) hash function implementation by Tom St Denis
16 */
17
18 #ifdef MD2
19
20 const struct ltc_hash_descriptor md2_desc =
21 {
22 "md2",
23 7,
24 16,
25 16,
26
27 /* OID */
28 { 1, 2, 840, 113549, 2, 2, },
29 6,
30
31 &md2_init,
32 &md2_process,
33 &md2_done,
34 &md2_test,
35 NULL
36 };
37
38 static const unsigned char PI_SUBST[256] = {
39 41, 46, 67, 201, 162, 216, 124, 1, 61, 54, 84, 161, 236, 240, 6,
40 19, 98, 167, 5, 243, 192, 199, 115, 140, 152, 147, 43, 217, 188,
41 76, 130, 202, 30, 155, 87, 60, 253, 212, 224, 22, 103, 66, 111, 24,
42 138, 23, 229, 18, 190, 78, 196, 214, 218, 158, 222, 73, 160, 251,
43 245, 142, 187, 47, 238, 122, 169, 104, 121, 145, 21, 178, 7, 63,
44 148, 194, 16, 137, 11, 34, 95, 33, 128, 127, 93, 154, 90, 144, 50,
45 39, 53, 62, 204, 231, 191, 247, 151, 3, 255, 25, 48, 179, 72, 165,
46 181, 209, 215, 94, 146, 42, 172, 86, 170, 198, 79, 184, 56, 210,
47 150, 164, 125, 182, 118, 252, 107, 226, 156, 116, 4, 241, 69, 157,
48 112, 89, 100, 113, 135, 32, 134, 91, 207, 101, 230, 45, 168, 2, 27,
49 96, 37, 173, 174, 176, 185, 246, 28, 70, 97, 105, 52, 64, 126, 15,
50 85, 71, 163, 35, 221, 81, 175, 58, 195, 92, 249, 206, 186, 197,
51 234, 38, 44, 83, 13, 110, 133, 40, 132, 9, 211, 223, 205, 244, 65,
52 129, 77, 82, 106, 220, 55, 200, 108, 193, 171, 250, 36, 225, 123,
53 8, 12, 189, 177, 74, 120, 136, 149, 139, 227, 99, 232, 109, 233,
54 203, 213, 254, 59, 0, 29, 57, 242, 239, 183, 14, 102, 88, 208, 228,
55 166, 119, 114, 248, 235, 117, 75, 10, 49, 68, 80, 180, 143, 237,
56 31, 26, 219, 153, 141, 51, 159, 17, 131, 20
57 };
58
59 /* adds 16 bytes to the checksum */
md2_update_chksum(hash_state * md)60 static void md2_update_chksum(hash_state *md)
61 {
62 int j;
63 unsigned char L;
64 L = md->md2.chksum[15];
65 for (j = 0; j < 16; j++) {
66
67 /* caution, the RFC says its "C[j] = S[M[i*16+j] xor L]" but the reference source code [and test vectors] say
68 otherwise.
69 */
70 L = (md->md2.chksum[j] ^= PI_SUBST[(int)(md->md2.buf[j] ^ L)] & 255);
71 }
72 }
73
md2_compress(hash_state * md)74 static void md2_compress(hash_state *md)
75 {
76 int j, k;
77 unsigned char t;
78
79 /* copy block */
80 for (j = 0; j < 16; j++) {
81 md->md2.X[16+j] = md->md2.buf[j];
82 md->md2.X[32+j] = md->md2.X[j] ^ md->md2.X[16+j];
83 }
84
85 t = (unsigned char)0;
86
87 /* do 18 rounds */
88 for (j = 0; j < 18; j++) {
89 for (k = 0; k < 48; k++) {
90 t = (md->md2.X[k] ^= PI_SUBST[(int)(t & 255)]);
91 }
92 t = (t + (unsigned char)j) & 255;
93 }
94 }
95
96 /**
97 Initialize the hash state
98 @param md The hash state you wish to initialize
99 @return CRYPT_OK if successful
100 */
md2_init(hash_state * md)101 int md2_init(hash_state *md)
102 {
103 LTC_ARGCHK(md != NULL);
104
105 /* MD2 uses a zero'ed state... */
106 zeromem(md->md2.X, sizeof(md->md2.X));
107 zeromem(md->md2.chksum, sizeof(md->md2.chksum));
108 zeromem(md->md2.buf, sizeof(md->md2.buf));
109 md->md2.curlen = 0;
110 return CRYPT_OK;
111 }
112
113 /**
114 Process a block of memory though the hash
115 @param md The hash state
116 @param in The data to hash
117 @param inlen The length of the data (octets)
118 @return CRYPT_OK if successful
119 */
md2_process(hash_state * md,const unsigned char * in,unsigned long inlen)120 int md2_process(hash_state *md, const unsigned char *in, unsigned long inlen)
121 {
122 unsigned long n;
123 LTC_ARGCHK(md != NULL);
124 LTC_ARGCHK(in != NULL);
125 if (md-> md2 .curlen > sizeof(md-> md2 .buf)) {
126 return CRYPT_INVALID_ARG;
127 }
128 while (inlen > 0) {
129 n = MIN(inlen, (16 - md->md2.curlen));
130 XMEMCPY(md->md2.buf + md->md2.curlen, in, (size_t)n);
131 md->md2.curlen += n;
132 in += n;
133 inlen -= n;
134
135 /* is 16 bytes full? */
136 if (md->md2.curlen == 16) {
137 md2_compress(md);
138 md2_update_chksum(md);
139 md->md2.curlen = 0;
140 }
141 }
142 return CRYPT_OK;
143 }
144
145 /**
146 Terminate the hash to get the digest
147 @param md The hash state
148 @param out [out] The destination of the hash (16 bytes)
149 @return CRYPT_OK if successful
150 */
md2_done(hash_state * md,unsigned char * out)151 int md2_done(hash_state * md, unsigned char *out)
152 {
153 unsigned long i, k;
154
155 LTC_ARGCHK(md != NULL);
156 LTC_ARGCHK(out != NULL);
157
158 if (md->md2.curlen >= sizeof(md->md2.buf)) {
159 return CRYPT_INVALID_ARG;
160 }
161
162
163 /* pad the message */
164 k = 16 - md->md2.curlen;
165 for (i = md->md2.curlen; i < 16; i++) {
166 md->md2.buf[i] = (unsigned char)k;
167 }
168
169 /* hash and update */
170 md2_compress(md);
171 md2_update_chksum(md);
172
173 /* hash checksum */
174 XMEMCPY(md->md2.buf, md->md2.chksum, 16);
175 md2_compress(md);
176
177 /* output is lower 16 bytes of X */
178 XMEMCPY(out, md->md2.X, 16);
179
180 #ifdef LTC_CLEAN_STACK
181 zeromem(md, sizeof(hash_state));
182 #endif
183 return CRYPT_OK;
184 }
185
186 /**
187 Self-test the hash
188 @return CRYPT_OK if successful, CRYPT_NOP if self-tests have been disabled
189 */
md2_test(void)190 int md2_test(void)
191 {
192 #ifndef LTC_TEST
193 return CRYPT_NOP;
194 #else
195 static const struct {
196 char *msg;
197 unsigned char md[16];
198 } tests[] = {
199 { "",
200 {0x83,0x50,0xe5,0xa3,0xe2,0x4c,0x15,0x3d,
201 0xf2,0x27,0x5c,0x9f,0x80,0x69,0x27,0x73
202 }
203 },
204 { "a",
205 {0x32,0xec,0x01,0xec,0x4a,0x6d,0xac,0x72,
206 0xc0,0xab,0x96,0xfb,0x34,0xc0,0xb5,0xd1
207 }
208 },
209 { "message digest",
210 {0xab,0x4f,0x49,0x6b,0xfb,0x2a,0x53,0x0b,
211 0x21,0x9f,0xf3,0x30,0x31,0xfe,0x06,0xb0
212 }
213 },
214 { "abcdefghijklmnopqrstuvwxyz",
215 {0x4e,0x8d,0xdf,0xf3,0x65,0x02,0x92,0xab,
216 0x5a,0x41,0x08,0xc3,0xaa,0x47,0x94,0x0b
217 }
218 },
219 { "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789",
220 {0xda,0x33,0xde,0xf2,0xa4,0x2d,0xf1,0x39,
221 0x75,0x35,0x28,0x46,0xc3,0x03,0x38,0xcd
222 }
223 },
224 { "12345678901234567890123456789012345678901234567890123456789012345678901234567890",
225 {0xd5,0x97,0x6f,0x79,0xd8,0x3d,0x3a,0x0d,
226 0xc9,0x80,0x6c,0x3c,0x66,0xf3,0xef,0xd8
227 }
228 }
229 };
230 int i;
231 hash_state md;
232 unsigned char buf[16];
233
234 for (i = 0; i < (int)(sizeof(tests) / sizeof(tests[0])); i++) {
235 md2_init(&md);
236 md2_process(&md, (unsigned char*)tests[i].msg, (unsigned long)strlen(tests[i].msg));
237 md2_done(&md, buf);
238 if (XMEMCMP(buf, tests[i].md, 16) != 0) {
239 return CRYPT_FAIL_TESTVECTOR;
240 }
241 }
242 return CRYPT_OK;
243 #endif
244 }
245
246 #endif
247
248
249 /* $Source: /cvs/libtom/libtomcrypt/src/hashes/md2.c,v $ */
250 /* $Revision: 1.8 $ */
251 /* $Date: 2006/11/01 09:28:17 $ */
252