Mercurial > dropbear
diff libtomcrypt/src/encauth/ocb3/ocb3_int_ntz.c @ 1471:6dba84798cd5
Update to libtomcrypt 1.18.1, merged with Dropbear changes
author | Matt Johnston <matt@ucc.asn.au> |
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date | Fri, 09 Feb 2018 21:44:05 +0800 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/libtomcrypt/src/encauth/ocb3/ocb3_int_ntz.c Fri Feb 09 21:44:05 2018 +0800 @@ -0,0 +1,39 @@ +/* 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 ocb3_int_ntz.c + OCB implementation, INTERNAL ONLY helper, by Tom St Denis +*/ +#include "tomcrypt.h" + +#ifdef LTC_OCB3_MODE + +/** + Returns the number of leading zero bits [from lsb up] (internal function) + @param x The 32-bit value to observe + @return The number of bits [from the lsb up] that are zero +*/ +int ocb3_int_ntz(unsigned long x) +{ + int c; + x &= 0xFFFFFFFFUL; + c = 0; + while ((x & 1) == 0) { + ++c; + x >>= 1; + } + return c; +} + +#endif + +/* ref: $Format:%D$ */ +/* git commit: $Format:%H$ */ +/* commit time: $Format:%ai$ */