Mercurial > dropbear
view libtomcrypt/src/ciphers/xtea.c @ 1686:83d48276885b
fix typo
author | Matt Johnston <matt@ucc.asn.au> |
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date | Tue, 26 May 2020 20:15:00 +0800 |
parents | 6dba84798cd5 |
children |
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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. */ /** @file xtea.c Implementation of LTC_XTEA, Tom St Denis */ #include "tomcrypt.h" #ifdef LTC_XTEA const struct ltc_cipher_descriptor xtea_desc = { "xtea", 1, 16, 16, 8, 32, &xtea_setup, &xtea_ecb_encrypt, &xtea_ecb_decrypt, &xtea_test, &xtea_done, &xtea_keysize, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL }; int xtea_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey) { ulong32 x, sum, K[4]; LTC_ARGCHK(key != NULL); LTC_ARGCHK(skey != NULL); /* check arguments */ if (keylen != 16) { return CRYPT_INVALID_KEYSIZE; } if (num_rounds != 0 && num_rounds != 32) { return CRYPT_INVALID_ROUNDS; } /* load key */ LOAD32H(K[0], key+0); LOAD32H(K[1], key+4); LOAD32H(K[2], key+8); LOAD32H(K[3], key+12); for (x = sum = 0; x < 32; x++) { skey->xtea.A[x] = (sum + K[sum&3]) & 0xFFFFFFFFUL; sum = (sum + 0x9E3779B9UL) & 0xFFFFFFFFUL; skey->xtea.B[x] = (sum + K[(sum>>11)&3]) & 0xFFFFFFFFUL; } #ifdef LTC_CLEAN_STACK zeromem(&K, sizeof(K)); #endif return CRYPT_OK; } /** Encrypts a block of text with LTC_XTEA @param pt The input plaintext (8 bytes) @param ct The output ciphertext (8 bytes) @param skey The key as scheduled @return CRYPT_OK if successful */ int xtea_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey) { ulong32 y, z; int r; LTC_ARGCHK(pt != NULL); LTC_ARGCHK(ct != NULL); LTC_ARGCHK(skey != NULL); LOAD32H(y, &pt[0]); LOAD32H(z, &pt[4]); for (r = 0; r < 32; r += 4) { y = (y + ((((z<<4)^(z>>5)) + z) ^ skey->xtea.A[r])) & 0xFFFFFFFFUL; z = (z + ((((y<<4)^(y>>5)) + y) ^ skey->xtea.B[r])) & 0xFFFFFFFFUL; y = (y + ((((z<<4)^(z>>5)) + z) ^ skey->xtea.A[r+1])) & 0xFFFFFFFFUL; z = (z + ((((y<<4)^(y>>5)) + y) ^ skey->xtea.B[r+1])) & 0xFFFFFFFFUL; y = (y + ((((z<<4)^(z>>5)) + z) ^ skey->xtea.A[r+2])) & 0xFFFFFFFFUL; z = (z + ((((y<<4)^(y>>5)) + y) ^ skey->xtea.B[r+2])) & 0xFFFFFFFFUL; y = (y + ((((z<<4)^(z>>5)) + z) ^ skey->xtea.A[r+3])) & 0xFFFFFFFFUL; z = (z + ((((y<<4)^(y>>5)) + y) ^ skey->xtea.B[r+3])) & 0xFFFFFFFFUL; } STORE32H(y, &ct[0]); STORE32H(z, &ct[4]); return CRYPT_OK; } /** Decrypts a block of text with LTC_XTEA @param ct The input ciphertext (8 bytes) @param pt The output plaintext (8 bytes) @param skey The key as scheduled @return CRYPT_OK if successful */ int xtea_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *skey) { ulong32 y, z; int r; LTC_ARGCHK(pt != NULL); LTC_ARGCHK(ct != NULL); LTC_ARGCHK(skey != NULL); LOAD32H(y, &ct[0]); LOAD32H(z, &ct[4]); for (r = 31; r >= 0; r -= 4) { z = (z - ((((y<<4)^(y>>5)) + y) ^ skey->xtea.B[r])) & 0xFFFFFFFFUL; y = (y - ((((z<<4)^(z>>5)) + z) ^ skey->xtea.A[r])) & 0xFFFFFFFFUL; z = (z - ((((y<<4)^(y>>5)) + y) ^ skey->xtea.B[r-1])) & 0xFFFFFFFFUL; y = (y - ((((z<<4)^(z>>5)) + z) ^ skey->xtea.A[r-1])) & 0xFFFFFFFFUL; z = (z - ((((y<<4)^(y>>5)) + y) ^ skey->xtea.B[r-2])) & 0xFFFFFFFFUL; y = (y - ((((z<<4)^(z>>5)) + z) ^ skey->xtea.A[r-2])) & 0xFFFFFFFFUL; z = (z - ((((y<<4)^(y>>5)) + y) ^ skey->xtea.B[r-3])) & 0xFFFFFFFFUL; y = (y - ((((z<<4)^(z>>5)) + z) ^ skey->xtea.A[r-3])) & 0xFFFFFFFFUL; } STORE32H(y, &pt[0]); STORE32H(z, &pt[4]); return CRYPT_OK; } /** Performs a self-test of the LTC_XTEA block cipher @return CRYPT_OK if functional, CRYPT_NOP if self-test has been disabled */ int xtea_test(void) { #ifndef LTC_TEST return CRYPT_NOP; #else static const struct { unsigned char key[16], pt[8], ct[8]; } tests[] = { { { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, { 0xde, 0xe9, 0xd4, 0xd8, 0xf7, 0x13, 0x1e, 0xd9 } }, { { 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x04 }, { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, { 0xa5, 0x97, 0xab, 0x41, 0x76, 0x01, 0x4d, 0x72 } }, { { 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00, 0x06 }, { 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x02 }, { 0xb1, 0xfd, 0x5d, 0xa9, 0xcc, 0x6d, 0xc9, 0xdc } }, { { 0x78, 0x69, 0x5a, 0x4b, 0x3c, 0x2d, 0x1e, 0x0f, 0xf0, 0xe1, 0xd2, 0xc3, 0xb4, 0xa5, 0x96, 0x87 }, { 0xf0, 0xe1, 0xd2, 0xc3, 0xb4, 0xa5, 0x96, 0x87 }, { 0x70, 0x4b, 0x31, 0x34, 0x47, 0x44, 0xdf, 0xab } }, { { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f }, { 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48 }, { 0x49, 0x7d, 0xf3, 0xd0, 0x72, 0x61, 0x2c, 0xb5 } }, { { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f }, { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 }, { 0xe7, 0x8f, 0x2d, 0x13, 0x74, 0x43, 0x41, 0xd8 } }, { { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f }, { 0x5a, 0x5b, 0x6e, 0x27, 0x89, 0x48, 0xd7, 0x7f }, { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 } }, { { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, { 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48 }, { 0xa0, 0x39, 0x05, 0x89, 0xf8, 0xb8, 0xef, 0xa5 } }, { { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 }, { 0xed, 0x23, 0x37, 0x5a, 0x82, 0x1a, 0x8c, 0x2d } }, { { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, { 0x70, 0xe1, 0x22, 0x5d, 0x6e, 0x4e, 0x76, 0x55 }, { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 } } }; unsigned char tmp[2][8]; symmetric_key skey; int i, err, y; for (i = 0; i < (int)(sizeof(tests)/sizeof(tests[0])); i++) { zeromem(&skey, sizeof(skey)); if ((err = xtea_setup(tests[i].key, 16, 0, &skey)) != CRYPT_OK) { return err; } xtea_ecb_encrypt(tests[i].pt, tmp[0], &skey); xtea_ecb_decrypt(tmp[0], tmp[1], &skey); if (compare_testvector(tmp[0], 8, tests[i].ct, 8, "XTEA Encrypt", i) != 0 || compare_testvector(tmp[1], 8, tests[i].pt, 8, "XTEA Decrypt", i) != 0) { 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 < 8; y++) tmp[0][y] = 0; for (y = 0; y < 1000; y++) xtea_ecb_encrypt(tmp[0], tmp[0], &skey); for (y = 0; y < 1000; y++) xtea_ecb_decrypt(tmp[0], tmp[0], &skey); for (y = 0; y < 8; y++) if (tmp[0][y] != 0) return CRYPT_FAIL_TESTVECTOR; } /* for */ return CRYPT_OK; #endif } /** Terminate the context @param skey The scheduled key */ void xtea_done(symmetric_key *skey) { LTC_UNUSED_PARAM(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 xtea_keysize(int *keysize) { LTC_ARGCHK(keysize != NULL); if (*keysize < 16) { return CRYPT_INVALID_KEYSIZE; } *keysize = 16; return CRYPT_OK; } #endif /* ref: $Format:%D$ */ /* git commit: $Format:%H$ */ /* commit time: $Format:%ai$ */