corrected preprocessor branch in bn_mp_montgomery_setup.c

Author: czurnieden

bn_mp_montgomery_setup.c

@@ -25,7 +25,7 @@ mp_err mp_montgomery_setup(const mp_int *n, mp_digit *rho)
    x = (((b + 2u) & 4u) << 1) + b; /* here x*a==1 mod 2**4 */
    x *= 2u - (b * x);              /* here x*a==1 mod 2**8 */
    x *= 2u - (b * x);              /* here x*a==1 mod 2**16 */
-#if (defined(MP_64BIT) || defined(MP_16BIT))
+#if defined(MP_64BIT) || !(defined(MP_16BIT))
    x *= 2u - (b * x);              /* here x*a==1 mod 2**32 */
 #endif
 #ifdef MP_64BIT

bn_mp_prime_is_prime.c

@@ -100,7 +100,12 @@ mp_err mp_prime_is_prime(const mp_int *a, int t, mp_bool *result)
     */
 #ifndef LTM_USE_FIPS_ONLY
    if (t >= 0) {
-#ifdef LTM_USE_FROBENIUS_TEST
+      /*
+       * Use a Frobenius-Underwood test instead of the Lucas-Selfridge test for
+       * MP_8BIT (It is unknown if the Lucas-Selfridge test works with 16-bit
+       * integers but the necesssary analysis is on the todo-list).
+       */
+#ifdef (LTM_USE_FROBENIUS_TEST)
       err = mp_prime_frobenius_underwood(a, &res);
       if ((err != MP_OKAY) && (err != MP_ITER)) {
          goto LBL_B;
@@ -228,7 +233,6 @@ mp_err mp_prime_is_prime(const mp_int *a, int t, mp_bool *result)
           * an unsigned int and "mask" on the other side is most probably not.
           */
          fips_rand = (unsigned int)(b.dp[0] & (mp_digit) mask);
-
          if (fips_rand > (unsigned int)(INT_MAX - MP_DIGIT_BIT)) {
             len = INT_MAX / MP_DIGIT_BIT;
          } else {

bn_mp_prime_strong_lucas_selfridge.c

@@ -278,6 +278,5 @@ mp_err mp_prime_strong_lucas_selfridge(const mp_int *a, mp_bool *result)
    mp_clear_multi(&Q2kdz, &T4z, &T3z, &T2z, &T1z, &Qkdz, &Q2mz, &Qmz, &V2mz, &U2mz, &Vz, &Uz, &Np1, &gcd, &Dz, NULL);
    return err;
 }
-
 #endif
 #endif