Mercurial > dropbear
view libtommath/bn_mp_reduce_is_2k_l.c @ 378:a124aff0cbf1
merge of '182c2d8dbd5321ef4d1df8758936f4dc7127015f'
and '31dcd7a22983ef19d6c63248e415e71d292dd0ec'
author | Matt Johnston <matt@ucc.asn.au> |
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date | Wed, 06 Dec 2006 13:11:41 +0000 |
parents | eed26cff980b |
children | 5ff8218bcee9 |
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#include <tommath.h> #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, [email protected], http://math.libtomcrypt.org */ /* 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