kc3-lang/libtommath/mp_prime_rabin_miller_trials.c

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• Hash : 3cdcec43
  Author :
  Date : 2019-10-29T18:41:25
  

  first batch of simplifications

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• mp_prime_rabin_miller_trials.c

• #include "tommath_private.h"
  #ifdef MP_PRIME_RABIN_MILLER_TRIALS_C
  /* LibTomMath, multiple-precision integer library -- Tom St Denis */
  /* SPDX-License-Identifier: Unlicense */
  
  static const struct {
     int k, t;
  } sizes[] = {
     {    80, -1 }, /* Use deterministic algorithm for size <= 80 bits */
     {    81, 37 }, /* max. error = 2^(-96)*/
     {    96, 32 }, /* max. error = 2^(-96)*/
     {   128, 40 }, /* max. error = 2^(-112)*/
     {   160, 35 }, /* max. error = 2^(-112)*/
     {   256, 27 }, /* max. error = 2^(-128)*/
     {   384, 16 }, /* max. error = 2^(-128)*/
     {   512, 18 }, /* max. error = 2^(-160)*/
     {   768, 11 }, /* max. error = 2^(-160)*/
     {   896, 10 }, /* max. error = 2^(-160)*/
     {  1024, 12 }, /* max. error = 2^(-192)*/
     {  1536, 8  }, /* max. error = 2^(-192)*/
     {  2048, 6  }, /* max. error = 2^(-192)*/
     {  3072, 4  }, /* max. error = 2^(-192)*/
     {  4096, 5  }, /* max. error = 2^(-256)*/
     {  5120, 4  }, /* max. error = 2^(-256)*/
     {  6144, 4  }, /* max. error = 2^(-256)*/
     {  8192, 3  }, /* max. error = 2^(-256)*/
     {  9216, 3  }, /* max. error = 2^(-256)*/
     { 10240, 2  }  /* For bigger keysizes use always at least 2 Rounds */
  };
  
  /* returns # of RM trials required for a given bit size */
  int mp_prime_rabin_miller_trials(int size)
  {
     int x;
  
     for (x = 0; x < (int)(sizeof(sizes)/(sizeof(sizes[0]))); x++) {
        if (sizes[x].k == size) {
           return sizes[x].t;
        }
        if (sizes[x].k > size) {
           return (x == 0) ? sizes[0].t : sizes[x - 1].t;
        }
     }
     return sizes[x-1].t;
  }
  
  
  #endif
  

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