kc3-lang/libtommath/mp_invmod.c

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• Hash : 1cc289d2
  Author :
  Date : 2019-11-09T20:23:03
  

  better use of mp_isneg() and mp_iszero()

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• mp_invmod.c

• #include "tommath_private.h"
  #ifdef MP_INVMOD_C
  /* LibTomMath, multiple-precision integer library -- Tom St Denis */
  /* SPDX-License-Identifier: Unlicense */
  
  /* hac 14.61, pp608 */
  mp_err mp_invmod(const mp_int *a, const mp_int *b, mp_int *c)
  {
     /* b cannot be negative and has to be >1 */
     if (mp_isneg(b) || (mp_cmp_d(b, 1uL) != MP_GT)) {
        return MP_VAL;
     }
  
     /* if the modulus is odd we can use a faster routine instead */
     if (MP_HAS(S_MP_INVMOD_ODD) && mp_isodd(b)) {
        return s_mp_invmod_odd(a, b, c);
     }
  
     return MP_HAS(S_MP_INVMOD)
            ? s_mp_invmod(a, b, c)
            : MP_VAL;
  }
  #endif
  

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