| #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, tomstdenis@iahu.ca, 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 |