/* 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, tomstdenis@gmail.com, http://libtom.org */ #include "tomcrypt.h" /** Source donated by Elliptic Semiconductor Inc (www.ellipticsemi.com) to the LibTom Projects */ #ifdef LTC_XTS_MODE /** Start XTS mode @param cipher The index of the cipher to use @param key1 The encrypt key @param key2 The tweak encrypt key @param keylen The length of the keys (each) in octets @param num_rounds The number of rounds for the cipher (0 == default) @param xts [out] XTS structure Returns CRYPT_OK upon success. */ int xts_start( int cipher, const unsigned char *key1, const unsigned char *key2, unsigned long keylen, int num_rounds, symmetric_xts *xts) { int err; /* check inputs */ LTC_ARGCHK(key1 != NULL); LTC_ARGCHK(key2 != NULL); LTC_ARGCHK(xts != NULL); /* check if valid */ if ((err = cipher_is_valid(cipher)) != CRYPT_OK) { return err; } if (cipher_descriptor[cipher].block_length != 16) { return CRYPT_INVALID_ARG; } /* schedule the two ciphers */ if ((err = cipher_descriptor[cipher].setup(key1, keylen, num_rounds, &xts->key1)) != CRYPT_OK) { return err; } if ((err = cipher_descriptor[cipher].setup(key2, keylen, num_rounds, &xts->key2)) != CRYPT_OK) { return err; } xts->cipher = cipher; return err; } #endif /* $Source$ */ /* $Revision$ */ /* $Date$ */