kc3-lang/libtommath/bn_mp_fread.c

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• Hash : f51249b6
  Author :
  Date : 2018-02-02T12:07:21
  

  clean-up file headers

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• bn_mp_fread.c

• #include <tommath_private.h>
  #ifdef BN_MP_FREAD_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.
   */
  
  #ifndef LTM_NO_FILE
  /* read a bigint from a file stream in ASCII */
  int mp_fread(mp_int *a, int radix, FILE *stream)
  {
     int err, ch, neg, y;
     unsigned pos;
  
     /* clear a */
     mp_zero(a);
  
     /* if first digit is - then set negative */
     ch = fgetc(stream);
     if (ch == (int)'-') {
        neg = MP_NEG;
        ch = fgetc(stream);
     } else {
        neg = MP_ZPOS;
     }
  
     for (;;) {
        pos = (unsigned)(ch - (int)'(');
        if (mp_s_rmap_reverse_sz < pos) {
           break;
        }
  
        y = (int)mp_s_rmap_reverse[pos];
  
        if ((y == 0xff) || (y >= radix)) {
           break;
        }
  
        /* shift up and add */
        if ((err = mp_mul_d(a, (mp_digit)radix, a)) != MP_OKAY) {
           return err;
        }
        if ((err = mp_add_d(a, (mp_digit)y, a)) != MP_OKAY) {
           return err;
        }
  
        ch = fgetc(stream);
     }
     if (mp_cmp_d(a, 0uL) != MP_EQ) {
        a->sign = neg;
     }
  
     return MP_OKAY;
  }
  #endif
  
  #endif
  
  /* ref:         $Format:%D$ */
  /* git commit:  $Format:%H$ */
  /* commit time: $Format:%ai$ */
  

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