| // SPDX-License-Identifier: BSD-2-Clause |
| /* 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_private.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, const 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, const 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: $Format:%ai$ */ |