Mercurial > dropbear
diff libtomcrypt/src/encauth/ocb/ocb_ntz.c @ 389:5ff8218bcee9
propagate from branch 'au.asn.ucc.matt.ltm.dropbear' (head 2af95f00ebd5bb7a28b3817db1218442c935388e)
to branch 'au.asn.ucc.matt.dropbear' (head ecd779509ef23a8cdf64888904fc9b31d78aa933)
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Thu, 11 Jan 2007 03:14:55 +0000 |
parents | 0cbe8f6dbf9e |
children | f849a5ca2efc |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/libtomcrypt/src/encauth/ocb/ocb_ntz.c Thu Jan 11 03:14:55 2007 +0000 @@ -0,0 +1,42 @@ +/* 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, [email protected], http://libtomcrypt.com + */ + +/** + @file ocb_ntz.c + OCB implementation, internal function, by Tom St Denis +*/ + +#include "tomcrypt.h" + +#ifdef 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 + +/* $Source: /cvs/libtom/libtomcrypt/src/encauth/ocb/ocb_ntz.c,v $ */ +/* $Revision: 1.4 $ */ +/* $Date: 2006/03/31 14:15:35 $ */