#include #ifdef BN_MP_DR_IS_MODULUS_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 a number is a valid DR modulus */ int mp_dr_is_modulus(mp_int *a) { int ix; /* must be at least two digits */ if (a->used < 2) { return 0; } /* must be of the form b**k - a [a <= b] so all * but the first digit must be equal to -1 (mod b). */ for (ix = 1; ix < a->used; ix++) { if (a->dp[ix] != MP_MASK) { return 0; } } return 1; } #endif /* $Source: /root/tcl/repos-to-convert/tcl/libtommath/bn_mp_dr_is_modulus.c,v $ */ /* $Revision: 1.1.1.3 $ */ /* $Date: 2006/12/01 00:08:11 $ */