X-Git-Url: https://git.pterodactylus.net/?p=fms.git;a=blobdiff_plain;f=libs%2Flibtommath%2Fbn_mp_reduce_is_2k_l.c;fp=libs%2Flibtommath%2Fbn_mp_reduce_is_2k_l.c;h=c4b42c9c4404f8d747a1a341ff2160953a31e4ed;hp=0000000000000000000000000000000000000000;hb=109c20e6f822c6efa465af31249e5608469253b6;hpb=9ae3b1434e51788e6feb72e1415ec800d05c535a diff --git a/libs/libtommath/bn_mp_reduce_is_2k_l.c b/libs/libtommath/bn_mp_reduce_is_2k_l.c new file mode 100644 index 0000000..c4b42c9 --- /dev/null +++ b/libs/libtommath/bn_mp_reduce_is_2k_l.c @@ -0,0 +1,44 @@ +#include +#ifdef BN_MP_REDUCE_IS_2K_L_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@gmail.com, http://math.libtomcrypt.com + */ + +/* determines if reduce_2k_l can be used */ +int mp_reduce_is_2k_l(mp_int *a) +{ + int ix, iy; + + if (a->used == 0) { + return MP_NO; + } else if (a->used == 1) { + return MP_YES; + } else if (a->used > 1) { + /* if more than half of the digits are -1 we're sold */ + for (iy = ix = 0; ix < a->used; ix++) { + if (a->dp[ix] == MP_MASK) { + ++iy; + } + } + return (iy >= (a->used/2)) ? MP_YES : MP_NO; + + } + return MP_NO; +} + +#endif + +/* $Source: /cvs/libtom/libtommath/bn_mp_reduce_is_2k_l.c,v $ */ +/* $Revision: 1.3 $ */ +/* $Date: 2006/03/31 14:18:44 $ */