/* 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 ocb_ntz.c OCB implementation, internal function, by Tom St Denis */ #include "tomcrypt.h" #ifdef LTC_OCB_MODE /** Returns the number of leading zero bits [from lsb up] @param x The 32-bit value to observe @return The number of bits [from the lsb up] that are zero */ int ocb_ntz(unsigned long x) { int c; x &= 0xFFFFFFFFUL; c = 0; while ((x & 1) == 0) { ++c; x >>= 1; } return c; } #endif /* ref: HEAD -> master, tag: v1.18.2 */ /* git commit: 7e7eb695d581782f04b24dc444cbfde86af59853 */ /* commit time: 2018-07-01 22:49:01 +0200 */