Mercurial > dropbear

comparison rc6.c @ 3:7faae8f46238 libtomcrypt-orig

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Branch renaming
author Matt Johnston <matt@ucc.asn.au>
date Mon, 31 May 2004 18:25:41 +0000
parents
children 5d99163f7e32
comparison
equal deleted inserted replaced
-1:000000000000 3:7faae8f46238
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, [email protected], http://libtomcrypt.org
10 */
11
12 /* RC6 code by Tom St Denis */
13 #include "mycrypt.h"
14
15 #ifdef RC6
16
17 const struct _cipher_descriptor rc6_desc =
18 {
19 "rc6",
20 3,
21 8, 128, 16, 20,
22 &rc6_setup,
23 &rc6_ecb_encrypt,
24 &rc6_ecb_decrypt,
25 &rc6_test,
26 &rc6_keysize
27 };
28
29 static const ulong32 stab[44] = {
30 0xb7e15163UL, 0x5618cb1cUL, 0xf45044d5UL, 0x9287be8eUL, 0x30bf3847UL, 0xcef6b200UL, 0x6d2e2bb9UL, 0x0b65a572UL,
31 0xa99d1f2bUL, 0x47d498e4UL, 0xe60c129dUL, 0x84438c56UL, 0x227b060fUL, 0xc0b27fc8UL, 0x5ee9f981UL, 0xfd21733aUL,
32 0x9b58ecf3UL, 0x399066acUL, 0xd7c7e065UL, 0x75ff5a1eUL, 0x1436d3d7UL, 0xb26e4d90UL, 0x50a5c749UL, 0xeedd4102UL,
33 0x8d14babbUL, 0x2b4c3474UL, 0xc983ae2dUL, 0x67bb27e6UL, 0x05f2a19fUL, 0xa42a1b58UL, 0x42619511UL, 0xe0990ecaUL,
34 0x7ed08883UL, 0x1d08023cUL, 0xbb3f7bf5UL, 0x5976f5aeUL, 0xf7ae6f67UL, 0x95e5e920UL, 0x341d62d9UL, 0xd254dc92UL,
35 0x708c564bUL, 0x0ec3d004UL, 0xacfb49bdUL, 0x4b32c376UL };
36
37 #ifdef CLEAN_STACK
38 static int _rc6_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey)
39 #else
40 int rc6_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey)
41 #endif
42 {
43 ulong32 L[64], S[50], A, B, i, j, v, s, l;
44
45 _ARGCHK(key != NULL);
46 _ARGCHK(skey != NULL);
47
48 /* test parameters */
49 if (num_rounds != 0 && num_rounds != 20) {
50 return CRYPT_INVALID_ROUNDS;
51 }
52
53 /* key must be between 64 and 1024 bits */
54 if (keylen < 8 || keylen > 128) {
55 return CRYPT_INVALID_KEYSIZE;
56 }
57
58 /* copy the key into the L array */
59 for (A = i = j = 0; i < (ulong32)keylen; ) {
60 A = (A << 8) | ((ulong32)(key[i++] & 255));
61 if (!(i & 3)) {
62 L[j++] = BSWAP(A);
63 A = 0;
64 }
65 }
66
67 /* handle odd sized keys */
68 if (keylen & 3) {
69 A <<= (8 * (4 - (keylen&3)));
70 L[j++] = BSWAP(A);
71 }
72
73 /* setup the S array */
74 memcpy(S, stab, 44 * sizeof(stab[0]));
75
76 /* mix buffer */
77 s = 3 * MAX(44, j);
78 l = j;
79 for (A = B = i = j = v = 0; v < s; v++) {
80 A = S[i] = ROL(S[i] + A + B, 3);
81 B = L[j] = ROL(L[j] + A + B, (A+B));
82 if (++i == 44) { i = 0; }
83 if (++j == l) { j = 0; }
84 }
85
86 /* copy to key */
87 for (i = 0; i < 44; i++) {
88 skey->rc6.K[i] = S[i];
89 }
90 return CRYPT_OK;
91 }
92
93 #ifdef CLEAN_STACK
94 int rc6_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey)
95 {
96 int x;
97 x = _rc6_setup(key, keylen, num_rounds, skey);
98 burn_stack(sizeof(ulong32) * 122);
99 return x;
100 }
101 #endif
102
103 #ifdef CLEAN_STACK
104 static void _rc6_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *key)
105 #else
106 void rc6_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *key)
107 #endif
108 {
109 ulong32 a,b,c,d,t,u, *K;
110 int r;
111
112 _ARGCHK(key != NULL);
113 _ARGCHK(pt != NULL);
114 _ARGCHK(ct != NULL);
115 LOAD32L(a,&pt[0]);LOAD32L(b,&pt[4]);LOAD32L(c,&pt[8]);LOAD32L(d,&pt[12]);
116
117 b += key->rc6.K[0];
118 d += key->rc6.K[1];
119
120 #define RND(a,b,c,d) \
121 t = (b * (b + b + 1)); t = ROL(t, 5); \
122 u = (d * (d + d + 1)); u = ROL(u, 5); \
123 a = ROL(a^t,u) + K[0]; \
124 c = ROL(c^u,t) + K[1]; K += 2;
125
126 K = key->rc6.K + 2;
127 for (r = 0; r < 20; r += 4) {
128 RND(a,b,c,d);
129 RND(b,c,d,a);
130 RND(c,d,a,b);
131 RND(d,a,b,c);
132 }
133
134 #undef RND
135
136 a += key->rc6.K[42];
137 c += key->rc6.K[43];
138 STORE32L(a,&ct[0]);STORE32L(b,&ct[4]);STORE32L(c,&ct[8]);STORE32L(d,&ct[12]);
139 }
140
141 #ifdef CLEAN_STACK
142 void rc6_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *key)
143 {
144 _rc6_ecb_encrypt(pt, ct, key);
145 burn_stack(sizeof(ulong32) * 6 + sizeof(int));
146 }
147 #endif
148
149 #ifdef CLEAN_STACK
150 static void _rc6_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *key)
151 #else
152 void rc6_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *key)
153 #endif
154 {
155 ulong32 a,b,c,d,t,u, *K;
156 int r;
157
158 _ARGCHK(key != NULL);
159 _ARGCHK(pt != NULL);
160 _ARGCHK(ct != NULL);
161
162 LOAD32L(a,&ct[0]);LOAD32L(b,&ct[4]);LOAD32L(c,&ct[8]);LOAD32L(d,&ct[12]);
163 a -= key->rc6.K[42];
164 c -= key->rc6.K[43];
165
166 #define RND(a,b,c,d) \
167 t = (b * (b + b + 1)); t = ROL(t, 5); \
168 u = (d * (d + d + 1)); u = ROL(u, 5); \
169 c = ROR(c - K[1], t) ^ u; \
170 a = ROR(a - K[0], u) ^ t; K -= 2;
171
172 K = key->rc6.K + 40;
173
174 for (r = 0; r < 20; r += 4) {
175 RND(d,a,b,c);
176 RND(c,d,a,b);
177 RND(b,c,d,a);
178 RND(a,b,c,d);
179 }
180
181 #undef RND
182
183 b -= key->rc6.K[0];
184 d -= key->rc6.K[1];
185 STORE32L(a,&pt[0]);STORE32L(b,&pt[4]);STORE32L(c,&pt[8]);STORE32L(d,&pt[12]);
186 }
187
188 #ifdef CLEAN_STACK
189 void rc6_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *key)
190 {
191 _rc6_ecb_decrypt(ct, pt, key);
192 burn_stack(sizeof(ulong32) * 6 + sizeof(int));
193 }
194 #endif
195
196 int rc6_test(void)
197 {
198 #ifndef LTC_TEST
199 return CRYPT_NOP;
200 #else
201 static const struct {
202 int keylen;
203 unsigned char key[32], pt[16], ct[16];
204 } tests[] = {
205 {
206 16,
207 { 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef,
208 0x01, 0x12, 0x23, 0x34, 0x45, 0x56, 0x67, 0x78,
209 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
210 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
211 { 0x02, 0x13, 0x24, 0x35, 0x46, 0x57, 0x68, 0x79,
212 0x8a, 0x9b, 0xac, 0xbd, 0xce, 0xdf, 0xe0, 0xf1 },
213 { 0x52, 0x4e, 0x19, 0x2f, 0x47, 0x15, 0xc6, 0x23,
214 0x1f, 0x51, 0xf6, 0x36, 0x7e, 0xa4, 0x3f, 0x18 }
215 },
216 {
217 24,
218 { 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef,
219 0x01, 0x12, 0x23, 0x34, 0x45, 0x56, 0x67, 0x78,
220 0x89, 0x9a, 0xab, 0xbc, 0xcd, 0xde, 0xef, 0xf0,
221 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
222 { 0x02, 0x13, 0x24, 0x35, 0x46, 0x57, 0x68, 0x79,
223 0x8a, 0x9b, 0xac, 0xbd, 0xce, 0xdf, 0xe0, 0xf1 },
224 { 0x68, 0x83, 0x29, 0xd0, 0x19, 0xe5, 0x05, 0x04,
225 0x1e, 0x52, 0xe9, 0x2a, 0xf9, 0x52, 0x91, 0xd4 }
226 },
227 {
228 32,
229 { 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef,
230 0x01, 0x12, 0x23, 0x34, 0x45, 0x56, 0x67, 0x78,
231 0x89, 0x9a, 0xab, 0xbc, 0xcd, 0xde, 0xef, 0xf0,
232 0x10, 0x32, 0x54, 0x76, 0x98, 0xba, 0xdc, 0xfe },
233 { 0x02, 0x13, 0x24, 0x35, 0x46, 0x57, 0x68, 0x79,
234 0x8a, 0x9b, 0xac, 0xbd, 0xce, 0xdf, 0xe0, 0xf1 },
235 { 0xc8, 0x24, 0x18, 0x16, 0xf0, 0xd7, 0xe4, 0x89,
236 0x20, 0xad, 0x16, 0xa1, 0x67, 0x4e, 0x5d, 0x48 }
237 }
238 };
239 unsigned char tmp[2][16];
240 int x, y, err;
241 symmetric_key key;
242
243 for (x = 0; x < (int)(sizeof(tests) / sizeof(tests[0])); x++) {
244 /* setup key */
245 if ((err = rc6_setup(tests[x].key, tests[x].keylen, 0, &key)) != CRYPT_OK) {
246 return err;
247 }
248
249 /* encrypt and decrypt */
250 rc6_ecb_encrypt(tests[x].pt, tmp[0], &key);
251 rc6_ecb_decrypt(tmp[0], tmp[1], &key);
252
253 /* compare */
254 if (memcmp(tmp[0], tests[x].ct, 16) || memcmp(tmp[1], tests[x].pt, 16)) {
255 #if 0
256 printf("\n\nFailed test %d\n", x);
257 if (memcmp(tmp[0], tests[x].ct, 16)) {
258 printf("Ciphertext: ");
259 for (y = 0; y < 16; y++) printf("%02x ", tmp[0][y]);
260 printf("\nExpected : ");
261 for (y = 0; y < 16; y++) printf("%02x ", tests[x].ct[y]);
262 printf("\n");
263 }
264 if (memcmp(tmp[1], tests[x].pt, 16)) {
265 printf("Plaintext: ");
266 for (y = 0; y < 16; y++) printf("%02x ", tmp[0][y]);
267 printf("\nExpected : ");
268 for (y = 0; y < 16; y++) printf("%02x ", tests[x].pt[y]);
269 printf("\n");
270 }
271 #endif
272 return CRYPT_FAIL_TESTVECTOR;
273 }
274
275 /* now see if we can encrypt all zero bytes 1000 times, decrypt and come back where we started */
276 for (y = 0; y < 16; y++) tmp[0][y] = 0;
277 for (y = 0; y < 1000; y++) rc6_ecb_encrypt(tmp[0], tmp[0], &key);
278 for (y = 0; y < 1000; y++) rc6_ecb_decrypt(tmp[0], tmp[0], &key);
279 for (y = 0; y < 16; y++) if (tmp[0][y] != 0) return CRYPT_FAIL_TESTVECTOR;
280 }
281 return CRYPT_OK;
282 #endif
283 }
284
285 int rc6_keysize(int *desired_keysize)
286 {
287 _ARGCHK(desired_keysize != NULL);
288 if (*desired_keysize < 8) {
289 return CRYPT_INVALID_KEYSIZE;
290 } else if (*desired_keysize > 128) {
291 *desired_keysize = 128;
292 }
293 return CRYPT_OK;
294 }
295
296 #endif /*RC6*/
297
298