| // 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. |
| */ |
| #include "tomcrypt_private.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: $Format:%ai$ */ |