kc3-lang/libtommath/bn_mp_read_unsigned_bin.c

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• Hash : 4534056c
  Author :
  Date : 2019-05-13T00:22:18
  

  use enums mp_err, mp_ord, mp_bool, mp_sign * MP_USE_ENUMS enables enums * Wc++-compat catches some implicit conversions if MP_USE_ENUMS is defined * 100% backwards compatible API/ABI if MP_USE_ENUMS is not defined

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• bn_mp_read_unsigned_bin.c

• #include "tommath_private.h"
  #ifdef BN_MP_READ_UNSIGNED_BIN_C
  /* LibTomMath, multiple-precision integer library -- Tom St Denis */
  /* SPDX-License-Identifier: Unlicense */
  
  /* reads a unsigned char array, assumes the msb is stored first [big endian] */
  mp_err mp_read_unsigned_bin(mp_int *a, const unsigned char *b, int c)
  {
     mp_err res;
  
     /* make sure there are at least two digits */
     if (a->alloc < 2) {
        if ((res = mp_grow(a, 2)) != MP_OKAY) {
           return res;
        }
     }
  
     /* zero the int */
     mp_zero(a);
  
     /* read the bytes in */
     while (c-- > 0) {
        if ((res = mp_mul_2d(a, 8, a)) != MP_OKAY) {
           return res;
        }
  
  #ifndef MP_8BIT
        a->dp[0] |= *b++;
        a->used += 1;
  #else
        a->dp[0] = (*b & MP_MASK);
        a->dp[1] |= ((*b++ >> 7) & 1u);
        a->used += 2;
  #endif
     }
     mp_clamp(a);
     return MP_OKAY;
  }
  #endif
  

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