/* 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. */ #include "tomcrypt.h" /** Source donated by Elliptic Semiconductor Inc (www.ellipticsemi.com) to the LibTom Projects */ #ifdef LTC_XTS_MODE /** multiply by x @param I The value to multiply by x (LFSR shift) */ void xts_mult_x(unsigned char *I) { int x; unsigned char t, tt; for (x = t = 0; x < 16; x++) { tt = I[x] >> 7; I[x] = ((I[x] << 1) | t) & 0xFF; t = tt; } if (tt) { I[0] ^= 0x87; } } #endif /* ref: $Format:%D$ */ /* git commit: $Format:%H$ */ /* commit time: $Format:%ai$ */