1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
3 * LibTomCrypt is a library that provides various cryptographic
4 * algorithms in a highly modular and flexible manner.
6 * The library is free for all purposes without any express
12 LTC_RC6 code by Tom St Denis
18 const struct ltc_cipher_descriptor rc6_desc =
29 NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
32 static const ulong32 stab[44] = {
33 0xb7e15163UL, 0x5618cb1cUL, 0xf45044d5UL, 0x9287be8eUL, 0x30bf3847UL, 0xcef6b200UL, 0x6d2e2bb9UL, 0x0b65a572UL,
34 0xa99d1f2bUL, 0x47d498e4UL, 0xe60c129dUL, 0x84438c56UL, 0x227b060fUL, 0xc0b27fc8UL, 0x5ee9f981UL, 0xfd21733aUL,
35 0x9b58ecf3UL, 0x399066acUL, 0xd7c7e065UL, 0x75ff5a1eUL, 0x1436d3d7UL, 0xb26e4d90UL, 0x50a5c749UL, 0xeedd4102UL,
36 0x8d14babbUL, 0x2b4c3474UL, 0xc983ae2dUL, 0x67bb27e6UL, 0x05f2a19fUL, 0xa42a1b58UL, 0x42619511UL, 0xe0990ecaUL,
37 0x7ed08883UL, 0x1d08023cUL, 0xbb3f7bf5UL, 0x5976f5aeUL, 0xf7ae6f67UL, 0x95e5e920UL, 0x341d62d9UL, 0xd254dc92UL,
38 0x708c564bUL, 0x0ec3d004UL, 0xacfb49bdUL, 0x4b32c376UL };
41 Initialize the LTC_RC6 block cipher
42 @param key The symmetric key you wish to pass
43 @param keylen The key length in bytes
44 @param num_rounds The number of rounds desired (0 for default)
45 @param skey The key in as scheduled by this function.
46 @return CRYPT_OK if successful
48 #ifdef LTC_CLEAN_STACK
49 static int _rc6_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey)
51 int rc6_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey)
54 ulong32 L[64], S[50], A, B, i, j, v, s, l;
56 LTC_ARGCHK(key != NULL);
57 LTC_ARGCHK(skey != NULL);
60 if (num_rounds != 0 && num_rounds != 20) {
61 return CRYPT_INVALID_ROUNDS;
64 /* key must be between 64 and 1024 bits */
65 if (keylen < 8 || keylen > 128) {
66 return CRYPT_INVALID_KEYSIZE;
69 /* copy the key into the L array */
70 for (A = i = j = 0; i < (ulong32)keylen; ) {
71 A = (A << 8) | ((ulong32)(key[i++] & 255));
78 /* handle odd sized keys */
80 A <<= (8 * (4 - (keylen&3)));
84 /* setup the S array */
85 XMEMCPY(S, stab, 44 * sizeof(stab[0]));
90 for (A = B = i = j = v = 0; v < s; v++) {
91 A = S[i] = ROLc(S[i] + A + B, 3);
92 B = L[j] = ROL(L[j] + A + B, (A+B));
93 if (++i == 44) { i = 0; }
94 if (++j == l) { j = 0; }
98 for (i = 0; i < 44; i++) {
99 skey->rc6.K[i] = S[i];
104 #ifdef LTC_CLEAN_STACK
105 int rc6_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey)
108 x = _rc6_setup(key, keylen, num_rounds, skey);
109 burn_stack(sizeof(ulong32) * 122);
115 Encrypts a block of text with LTC_RC6
116 @param pt The input plaintext (16 bytes)
117 @param ct The output ciphertext (16 bytes)
118 @param skey The key as scheduled
120 #ifdef LTC_CLEAN_STACK
121 static int _rc6_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey)
123 int rc6_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey)
126 ulong32 a,b,c,d,t,u, *K;
129 LTC_ARGCHK(skey != NULL);
130 LTC_ARGCHK(pt != NULL);
131 LTC_ARGCHK(ct != NULL);
132 LOAD32L(a,&pt[0]);LOAD32L(b,&pt[4]);LOAD32L(c,&pt[8]);LOAD32L(d,&pt[12]);
137 #define RND(a,b,c,d) \
138 t = (b * (b + b + 1)); t = ROLc(t, 5); \
139 u = (d * (d + d + 1)); u = ROLc(u, 5); \
140 a = ROL(a^t,u) + K[0]; \
141 c = ROL(c^u,t) + K[1]; K += 2;
144 for (r = 0; r < 20; r += 4) {
153 a += skey->rc6.K[42];
154 c += skey->rc6.K[43];
155 STORE32L(a,&ct[0]);STORE32L(b,&ct[4]);STORE32L(c,&ct[8]);STORE32L(d,&ct[12]);
159 #ifdef LTC_CLEAN_STACK
160 int rc6_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey)
162 int err = _rc6_ecb_encrypt(pt, ct, skey);
163 burn_stack(sizeof(ulong32) * 6 + sizeof(int));
169 Decrypts a block of text with LTC_RC6
170 @param ct The input ciphertext (16 bytes)
171 @param pt The output plaintext (16 bytes)
172 @param skey The key as scheduled
174 #ifdef LTC_CLEAN_STACK
175 static int _rc6_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *skey)
177 int rc6_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *skey)
180 ulong32 a,b,c,d,t,u, *K;
183 LTC_ARGCHK(skey != NULL);
184 LTC_ARGCHK(pt != NULL);
185 LTC_ARGCHK(ct != NULL);
187 LOAD32L(a,&ct[0]);LOAD32L(b,&ct[4]);LOAD32L(c,&ct[8]);LOAD32L(d,&ct[12]);
188 a -= skey->rc6.K[42];
189 c -= skey->rc6.K[43];
191 #define RND(a,b,c,d) \
192 t = (b * (b + b + 1)); t = ROLc(t, 5); \
193 u = (d * (d + d + 1)); u = ROLc(u, 5); \
194 c = ROR(c - K[1], t) ^ u; \
195 a = ROR(a - K[0], u) ^ t; K -= 2;
197 K = skey->rc6.K + 40;
199 for (r = 0; r < 20; r += 4) {
210 STORE32L(a,&pt[0]);STORE32L(b,&pt[4]);STORE32L(c,&pt[8]);STORE32L(d,&pt[12]);
215 #ifdef LTC_CLEAN_STACK
216 int rc6_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *skey)
218 int err = _rc6_ecb_decrypt(ct, pt, skey);
219 burn_stack(sizeof(ulong32) * 6 + sizeof(int));
225 Performs a self-test of the LTC_RC6 block cipher
226 @return CRYPT_OK if functional, CRYPT_NOP if self-test has been disabled
233 static const struct {
235 unsigned char key[32], pt[16], ct[16];
239 { 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef,
240 0x01, 0x12, 0x23, 0x34, 0x45, 0x56, 0x67, 0x78,
241 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
242 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
243 { 0x02, 0x13, 0x24, 0x35, 0x46, 0x57, 0x68, 0x79,
244 0x8a, 0x9b, 0xac, 0xbd, 0xce, 0xdf, 0xe0, 0xf1 },
245 { 0x52, 0x4e, 0x19, 0x2f, 0x47, 0x15, 0xc6, 0x23,
246 0x1f, 0x51, 0xf6, 0x36, 0x7e, 0xa4, 0x3f, 0x18 }
250 { 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef,
251 0x01, 0x12, 0x23, 0x34, 0x45, 0x56, 0x67, 0x78,
252 0x89, 0x9a, 0xab, 0xbc, 0xcd, 0xde, 0xef, 0xf0,
253 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
254 { 0x02, 0x13, 0x24, 0x35, 0x46, 0x57, 0x68, 0x79,
255 0x8a, 0x9b, 0xac, 0xbd, 0xce, 0xdf, 0xe0, 0xf1 },
256 { 0x68, 0x83, 0x29, 0xd0, 0x19, 0xe5, 0x05, 0x04,
257 0x1e, 0x52, 0xe9, 0x2a, 0xf9, 0x52, 0x91, 0xd4 }
261 { 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef,
262 0x01, 0x12, 0x23, 0x34, 0x45, 0x56, 0x67, 0x78,
263 0x89, 0x9a, 0xab, 0xbc, 0xcd, 0xde, 0xef, 0xf0,
264 0x10, 0x32, 0x54, 0x76, 0x98, 0xba, 0xdc, 0xfe },
265 { 0x02, 0x13, 0x24, 0x35, 0x46, 0x57, 0x68, 0x79,
266 0x8a, 0x9b, 0xac, 0xbd, 0xce, 0xdf, 0xe0, 0xf1 },
267 { 0xc8, 0x24, 0x18, 0x16, 0xf0, 0xd7, 0xe4, 0x89,
268 0x20, 0xad, 0x16, 0xa1, 0x67, 0x4e, 0x5d, 0x48 }
271 unsigned char tmp[2][16];
275 for (x = 0; x < (int)(sizeof(tests) / sizeof(tests[0])); x++) {
277 if ((err = rc6_setup(tests[x].key, tests[x].keylen, 0, &key)) != CRYPT_OK) {
281 /* encrypt and decrypt */
282 rc6_ecb_encrypt(tests[x].pt, tmp[0], &key);
283 rc6_ecb_decrypt(tmp[0], tmp[1], &key);
286 if (compare_testvector(tmp[0], 16, tests[x].ct, 16, "RC6 Encrypt", x) ||
287 compare_testvector(tmp[1], 16, tests[x].pt, 16, "RC6 Decrypt", x)) {
288 return CRYPT_FAIL_TESTVECTOR;
291 /* now see if we can encrypt all zero bytes 1000 times, decrypt and come back where we started */
292 for (y = 0; y < 16; y++) tmp[0][y] = 0;
293 for (y = 0; y < 1000; y++) rc6_ecb_encrypt(tmp[0], tmp[0], &key);
294 for (y = 0; y < 1000; y++) rc6_ecb_decrypt(tmp[0], tmp[0], &key);
295 for (y = 0; y < 16; y++) if (tmp[0][y] != 0) return CRYPT_FAIL_TESTVECTOR;
301 /** Terminate the context
302 @param skey The scheduled key
304 void rc6_done(symmetric_key *skey)
306 LTC_UNUSED_PARAM(skey);
310 Gets suitable key size
311 @param keysize [in/out] The length of the recommended key (in bytes). This function will store the suitable size back in this variable.
312 @return CRYPT_OK if the input key size is acceptable.
314 int rc6_keysize(int *keysize)
316 LTC_ARGCHK(keysize != NULL);
318 return CRYPT_INVALID_KEYSIZE;
319 } else if (*keysize > 128) {
329 /* ref: $Format:%D$ */
330 /* git commit: $Format:%H$ */
331 /* commit time: $Format:%ai$ */