Mercurial > dropbear
view libtomcrypt/src/ciphers/rc6.c @ 959:f92394f3f332
Merge pull request #2 from iquaba/patch-1
Try without identifying current user
author | Matt Johnston <matt@ucc.asn.au> |
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date | Wed, 06 Aug 2014 22:04:49 +0800 |
parents | 0cbe8f6dbf9e |
children | f849a5ca2efc |
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/* LibTomCrypt, modular cryptographic library -- Tom St Denis * * LibTomCrypt is a library that provides various cryptographic * algorithms in a highly modular and flexible manner. * * The library is free for all purposes without any express * guarantee it works. * * Tom St Denis, [email protected], http://libtomcrypt.com */ /** @file rc6.c RC6 code by Tom St Denis */ #include "tomcrypt.h" #ifdef RC6 const struct ltc_cipher_descriptor rc6_desc = { "rc6", 3, 8, 128, 16, 20, &rc6_setup, &rc6_ecb_encrypt, &rc6_ecb_decrypt, &rc6_test, &rc6_done, &rc6_keysize, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL }; static const ulong32 stab[44] = { 0xb7e15163UL, 0x5618cb1cUL, 0xf45044d5UL, 0x9287be8eUL, 0x30bf3847UL, 0xcef6b200UL, 0x6d2e2bb9UL, 0x0b65a572UL, 0xa99d1f2bUL, 0x47d498e4UL, 0xe60c129dUL, 0x84438c56UL, 0x227b060fUL, 0xc0b27fc8UL, 0x5ee9f981UL, 0xfd21733aUL, 0x9b58ecf3UL, 0x399066acUL, 0xd7c7e065UL, 0x75ff5a1eUL, 0x1436d3d7UL, 0xb26e4d90UL, 0x50a5c749UL, 0xeedd4102UL, 0x8d14babbUL, 0x2b4c3474UL, 0xc983ae2dUL, 0x67bb27e6UL, 0x05f2a19fUL, 0xa42a1b58UL, 0x42619511UL, 0xe0990ecaUL, 0x7ed08883UL, 0x1d08023cUL, 0xbb3f7bf5UL, 0x5976f5aeUL, 0xf7ae6f67UL, 0x95e5e920UL, 0x341d62d9UL, 0xd254dc92UL, 0x708c564bUL, 0x0ec3d004UL, 0xacfb49bdUL, 0x4b32c376UL }; /** Initialize the RC6 block cipher @param key The symmetric key you wish to pass @param keylen The key length in bytes @param num_rounds The number of rounds desired (0 for default) @param skey The key in as scheduled by this function. @return CRYPT_OK if successful */ #ifdef LTC_CLEAN_STACK static int _rc6_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey) #else int rc6_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey) #endif { ulong32 L[64], S[50], A, B, i, j, v, s, l; LTC_ARGCHK(key != NULL); LTC_ARGCHK(skey != NULL); /* test parameters */ if (num_rounds != 0 && num_rounds != 20) { return CRYPT_INVALID_ROUNDS; } /* key must be between 64 and 1024 bits */ if (keylen < 8 || keylen > 128) { return CRYPT_INVALID_KEYSIZE; } /* copy the key into the L array */ for (A = i = j = 0; i < (ulong32)keylen; ) { A = (A << 8) | ((ulong32)(key[i++] & 255)); if (!(i & 3)) { L[j++] = BSWAP(A); A = 0; } } /* handle odd sized keys */ if (keylen & 3) { A <<= (8 * (4 - (keylen&3))); L[j++] = BSWAP(A); } /* setup the S array */ XMEMCPY(S, stab, 44 * sizeof(stab[0])); /* mix buffer */ s = 3 * MAX(44, j); l = j; for (A = B = i = j = v = 0; v < s; v++) { A = S[i] = ROLc(S[i] + A + B, 3); B = L[j] = ROL(L[j] + A + B, (A+B)); if (++i == 44) { i = 0; } if (++j == l) { j = 0; } } /* copy to key */ for (i = 0; i < 44; i++) { skey->rc6.K[i] = S[i]; } return CRYPT_OK; } #ifdef LTC_CLEAN_STACK int rc6_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey) { int x; x = _rc6_setup(key, keylen, num_rounds, skey); burn_stack(sizeof(ulong32) * 122); return x; } #endif /** Encrypts a block of text with RC6 @param pt The input plaintext (16 bytes) @param ct The output ciphertext (16 bytes) @param skey The key as scheduled */ #ifdef LTC_CLEAN_STACK static int _rc6_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey) #else int rc6_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey) #endif { ulong32 a,b,c,d,t,u, *K; int r; LTC_ARGCHK(skey != NULL); LTC_ARGCHK(pt != NULL); LTC_ARGCHK(ct != NULL); LOAD32L(a,&pt[0]);LOAD32L(b,&pt[4]);LOAD32L(c,&pt[8]);LOAD32L(d,&pt[12]); b += skey->rc6.K[0]; d += skey->rc6.K[1]; #define RND(a,b,c,d) \ t = (b * (b + b + 1)); t = ROLc(t, 5); \ u = (d * (d + d + 1)); u = ROLc(u, 5); \ a = ROL(a^t,u) + K[0]; \ c = ROL(c^u,t) + K[1]; K += 2; K = skey->rc6.K + 2; for (r = 0; r < 20; r += 4) { RND(a,b,c,d); RND(b,c,d,a); RND(c,d,a,b); RND(d,a,b,c); } #undef RND a += skey->rc6.K[42]; c += skey->rc6.K[43]; STORE32L(a,&ct[0]);STORE32L(b,&ct[4]);STORE32L(c,&ct[8]);STORE32L(d,&ct[12]); return CRYPT_OK; } #ifdef LTC_CLEAN_STACK int rc6_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey) { int err = _rc6_ecb_encrypt(pt, ct, skey); burn_stack(sizeof(ulong32) * 6 + sizeof(int)); return err; } #endif /** Decrypts a block of text with RC6 @param ct The input ciphertext (16 bytes) @param pt The output plaintext (16 bytes) @param skey The key as scheduled */ #ifdef LTC_CLEAN_STACK static int _rc6_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *skey) #else int rc6_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *skey) #endif { ulong32 a,b,c,d,t,u, *K; int r; LTC_ARGCHK(skey != NULL); LTC_ARGCHK(pt != NULL); LTC_ARGCHK(ct != NULL); LOAD32L(a,&ct[0]);LOAD32L(b,&ct[4]);LOAD32L(c,&ct[8]);LOAD32L(d,&ct[12]); a -= skey->rc6.K[42]; c -= skey->rc6.K[43]; #define RND(a,b,c,d) \ t = (b * (b + b + 1)); t = ROLc(t, 5); \ u = (d * (d + d + 1)); u = ROLc(u, 5); \ c = ROR(c - K[1], t) ^ u; \ a = ROR(a - K[0], u) ^ t; K -= 2; K = skey->rc6.K + 40; for (r = 0; r < 20; r += 4) { RND(d,a,b,c); RND(c,d,a,b); RND(b,c,d,a); RND(a,b,c,d); } #undef RND b -= skey->rc6.K[0]; d -= skey->rc6.K[1]; STORE32L(a,&pt[0]);STORE32L(b,&pt[4]);STORE32L(c,&pt[8]);STORE32L(d,&pt[12]); return CRYPT_OK; } #ifdef LTC_CLEAN_STACK int rc6_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *skey) { int err = _rc6_ecb_decrypt(ct, pt, skey); burn_stack(sizeof(ulong32) * 6 + sizeof(int)); return err; } #endif /** Performs a self-test of the RC6 block cipher @return CRYPT_OK if functional, CRYPT_NOP if self-test has been disabled */ int rc6_test(void) { #ifndef LTC_TEST return CRYPT_NOP; #else static const struct { int keylen; unsigned char key[32], pt[16], ct[16]; } tests[] = { { 16, { 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0x01, 0x12, 0x23, 0x34, 0x45, 0x56, 0x67, 0x78, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, { 0x02, 0x13, 0x24, 0x35, 0x46, 0x57, 0x68, 0x79, 0x8a, 0x9b, 0xac, 0xbd, 0xce, 0xdf, 0xe0, 0xf1 }, { 0x52, 0x4e, 0x19, 0x2f, 0x47, 0x15, 0xc6, 0x23, 0x1f, 0x51, 0xf6, 0x36, 0x7e, 0xa4, 0x3f, 0x18 } }, { 24, { 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0x01, 0x12, 0x23, 0x34, 0x45, 0x56, 0x67, 0x78, 0x89, 0x9a, 0xab, 0xbc, 0xcd, 0xde, 0xef, 0xf0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, { 0x02, 0x13, 0x24, 0x35, 0x46, 0x57, 0x68, 0x79, 0x8a, 0x9b, 0xac, 0xbd, 0xce, 0xdf, 0xe0, 0xf1 }, { 0x68, 0x83, 0x29, 0xd0, 0x19, 0xe5, 0x05, 0x04, 0x1e, 0x52, 0xe9, 0x2a, 0xf9, 0x52, 0x91, 0xd4 } }, { 32, { 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0x01, 0x12, 0x23, 0x34, 0x45, 0x56, 0x67, 0x78, 0x89, 0x9a, 0xab, 0xbc, 0xcd, 0xde, 0xef, 0xf0, 0x10, 0x32, 0x54, 0x76, 0x98, 0xba, 0xdc, 0xfe }, { 0x02, 0x13, 0x24, 0x35, 0x46, 0x57, 0x68, 0x79, 0x8a, 0x9b, 0xac, 0xbd, 0xce, 0xdf, 0xe0, 0xf1 }, { 0xc8, 0x24, 0x18, 0x16, 0xf0, 0xd7, 0xe4, 0x89, 0x20, 0xad, 0x16, 0xa1, 0x67, 0x4e, 0x5d, 0x48 } } }; unsigned char tmp[2][16]; int x, y, err; symmetric_key key; for (x = 0; x < (int)(sizeof(tests) / sizeof(tests[0])); x++) { /* setup key */ if ((err = rc6_setup(tests[x].key, tests[x].keylen, 0, &key)) != CRYPT_OK) { return err; } /* encrypt and decrypt */ rc6_ecb_encrypt(tests[x].pt, tmp[0], &key); rc6_ecb_decrypt(tmp[0], tmp[1], &key); /* compare */ if (XMEMCMP(tmp[0], tests[x].ct, 16) || XMEMCMP(tmp[1], tests[x].pt, 16)) { #if 0 printf("\n\nFailed test %d\n", x); if (XMEMCMP(tmp[0], tests[x].ct, 16)) { printf("Ciphertext: "); for (y = 0; y < 16; y++) printf("%02x ", tmp[0][y]); printf("\nExpected : "); for (y = 0; y < 16; y++) printf("%02x ", tests[x].ct[y]); printf("\n"); } if (XMEMCMP(tmp[1], tests[x].pt, 16)) { printf("Plaintext: "); for (y = 0; y < 16; y++) printf("%02x ", tmp[0][y]); printf("\nExpected : "); for (y = 0; y < 16; y++) printf("%02x ", tests[x].pt[y]); printf("\n"); } #endif return CRYPT_FAIL_TESTVECTOR; } /* now see if we can encrypt all zero bytes 1000 times, decrypt and come back where we started */ for (y = 0; y < 16; y++) tmp[0][y] = 0; for (y = 0; y < 1000; y++) rc6_ecb_encrypt(tmp[0], tmp[0], &key); for (y = 0; y < 1000; y++) rc6_ecb_decrypt(tmp[0], tmp[0], &key); for (y = 0; y < 16; y++) if (tmp[0][y] != 0) return CRYPT_FAIL_TESTVECTOR; } return CRYPT_OK; #endif } /** Terminate the context @param skey The scheduled key */ void rc6_done(symmetric_key *skey) { } /** Gets suitable key size @param keysize [in/out] The length of the recommended key (in bytes). This function will store the suitable size back in this variable. @return CRYPT_OK if the input key size is acceptable. */ int rc6_keysize(int *keysize) { LTC_ARGCHK(keysize != NULL); if (*keysize < 8) { return CRYPT_INVALID_KEYSIZE; } else if (*keysize > 128) { *keysize = 128; } return CRYPT_OK; } #endif /*RC6*/ /* $Source: /cvs/libtom/libtomcrypt/src/ciphers/rc6.c,v $ */ /* $Revision: 1.12 $ */ /* $Date: 2006/11/08 23:01:06 $ */