--- a/libtommath/bn_mp_prime_fermat.c	Wed Feb 28 22:11:39 2018 +0800
+++ b/libtommath/bn_mp_prime_fermat.c	Thu Oct 15 19:55:15 2020 +0800
@@ -1,62 +1,47 @@
-#include <tommath_private.h>
+#include "tommath_private.h"
 #ifdef BN_MP_PRIME_FERMAT_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, [email protected], http://libtom.org
- */
+/* LibTomMath, multiple-precision integer library -- Tom St Denis */
+/* SPDX-License-Identifier: Unlicense */
 
 /* performs one Fermat test.
- * 
+ *
  * If "a" were prime then b**a == b (mod a) since the order of
  * the multiplicative sub-group would be phi(a) = a-1.  That means
  * it would be the same as b**(a mod (a-1)) == b**1 == b (mod a).
  *
  * Sets result to 1 if the congruence holds, or zero otherwise.
  */
-int mp_prime_fermat (mp_int * a, mp_int * b, int *result)
+mp_err mp_prime_fermat(const mp_int *a, const mp_int *b, mp_bool *result)
 {
-  mp_int  t;
-  int     err;
+   mp_int  t;
+   mp_err  err;
 
-  /* default to composite  */
-  *result = MP_NO;
+   /* default to composite  */
+   *result = MP_NO;
 
-  /* ensure b > 1 */
-  if (mp_cmp_d(b, 1) != MP_GT) {
-     return MP_VAL;
-  }
+   /* ensure b > 1 */
+   if (mp_cmp_d(b, 1uL) != MP_GT) {
+      return MP_VAL;
+   }
 
-  /* init t */
-  if ((err = mp_init (&t)) != MP_OKAY) {
-    return err;
-  }
+   /* init t */
+   if ((err = mp_init(&t)) != MP_OKAY) {
+      return err;
+   }
+
+   /* compute t = b**a mod a */
+   if ((err = mp_exptmod(b, a, a, &t)) != MP_OKAY) {
+      goto LBL_T;
+   }
 
-  /* compute t = b**a mod a */
-  if ((err = mp_exptmod (b, a, a, &t)) != MP_OKAY) {
-    goto LBL_T;
-  }
+   /* is it equal to b? */
+   if (mp_cmp(&t, b) == MP_EQ) {
+      *result = MP_YES;
+   }
 
-  /* is it equal to b? */
-  if (mp_cmp (&t, b) == MP_EQ) {
-    *result = MP_YES;
-  }
-
-  err = MP_OKAY;
-LBL_T:mp_clear (&t);
-  return err;
+   err = MP_OKAY;
+LBL_T:
+   mp_clear(&t);
+   return err;
 }
 #endif
-
-/* ref:         $Format:%D$ */
-/* git commit:  $Format:%H$ */
-/* commit time: $Format:%ai$ */