#include <tommath.h>#ifdef BN_MP_SQR_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 *//* computes b = a*a */intmp_sqr (mp_int * a, mp_int * b){  int     res;#ifdef BN_MP_TOOM_SQR_C  /* use Toom-Cook? */  if (a->used >= TOOM_SQR_CUTOFF) {    res = mp_toom_sqr(a, b);  /* Karatsuba? */  } else #endif#ifdef BN_MP_KARATSUBA_SQR_Cif (a->used >= KARATSUBA_SQR_CUTOFF) {    res = mp_karatsuba_sqr (a, b);  } else #endif  {#ifdef BN_FAST_S_MP_SQR_C    /* can we use the fast comba multiplier? */    if ((a->used * 2 + 1) < MP_WARRAY &&          a->used <          (1 << (sizeof(mp_word) * CHAR_BIT - 2*DIGIT_BIT - 1))) {      res = fast_s_mp_sqr (a, b);    } else#endif#ifdef BN_S_MP_SQR_C      res = s_mp_sqr (a, b);#else      res = MP_VAL;#endif  }  b->sign = MP_ZPOS;  return res;}#endif