From 9b448bdc083bd1044518a15a15163daa7701fc7a Mon Sep 17 00:00:00 2001
From: czurnieden <czurnieden@gmx.de>
Date: Mon, 7 May 2018 23:11:04 +0200
Subject: [PATCH] exchanged direct call to Miller-Rabin in mp_prime_next_prime
 with mp_prime_is_prime

---
 bn_mp_prime_is_prime.c   |  9 +++------
 bn_mp_prime_next_prime.c | 17 ++---------------
 2 files changed, 5 insertions(+), 21 deletions(-)

diff --git a/bn_mp_prime_is_prime.c b/bn_mp_prime_is_prime.c
index e309bae..6ed5d62 100644
--- a/bn_mp_prime_is_prime.c
+++ b/bn_mp_prime_is_prime.c
@@ -35,7 +35,6 @@ int mp_prime_is_prime(const mp_int *a, int t, int *result)
 
    /* valid value of t? */
    if (t > PRIME_SIZE) {
-      puts("t > PRIME_SIZE");
       return MP_VAL;
    }
 
@@ -54,7 +53,6 @@ int mp_prime_is_prime(const mp_int *a, int t, int *result)
 
    /* N must be odd */
    if (mp_iseven(a) == MP_YES) {
-      *result = 0;
       return MP_OKAY;
    }
    /* N is not a perfect square: floor(sqrt(N))^2 != N */
@@ -62,14 +60,13 @@ int mp_prime_is_prime(const mp_int *a, int t, int *result)
       return err;
    }
    if (res != 0) {
-      *result = 0;
       return MP_OKAY;
    }
 
    /* is the input equal to one of the primes in the table? */
    for (ix = 0; ix < PRIME_SIZE; ix++) {
       if (mp_cmp_d(a, ltm_prime_tab[ix]) == MP_EQ) {
-         *result = 1;
+         *result = MP_YES;
          return MP_OKAY;
       }
    }
@@ -126,14 +123,14 @@ int mp_prime_is_prime(const mp_int *a, int t, int *result)
    }
 //#endif
 // commented out for testing purposes
-//#ifdef LTM_USE_FROBENIUS_UNDERWOOD_TEST
+#ifdef LTM_USE_FROBENIUS_UNDERWOOD_TEST
    if ((err = mp_prime_frobenius_underwood(a, &res)) != MP_OKAY) {
       goto LBL_B;
    }
    if (res == MP_NO) {
       goto LBL_B;
    }
-//#endif
+#endif
 #endif
 
    /*
diff --git a/bn_mp_prime_next_prime.c b/bn_mp_prime_next_prime.c
index 89e2841..44ab116 100644
--- a/bn_mp_prime_next_prime.c
+++ b/bn_mp_prime_next_prime.c
@@ -24,11 +24,6 @@ int mp_prime_next_prime(mp_int *a, int t, int bbs_style)
    mp_digit res_tab[PRIME_SIZE], step, kstep;
    mp_int   b;
 
-   /* ensure t is valid */
-   if ((t <= 0) || (t > PRIME_SIZE)) {
-      return MP_VAL;
-   }
-
    /* force positive */
    a->sign = MP_ZPOS;
 
@@ -141,17 +136,9 @@ int mp_prime_next_prime(mp_int *a, int t, int bbs_style)
          continue;
       }
 
-      /* is this prime? */
-      for (x = 0; x < t; x++) {
-         mp_set(&b, ltm_prime_tab[x]);
-         if ((err = mp_prime_miller_rabin(a, &b, &res)) != MP_OKAY) {
-            goto LBL_ERR;
-         }
-         if (res == MP_NO) {
-            break;
-         }
+      if ((err = mp_prime_is_prime(a, t, &res)) != MP_OKAY) {
+         goto LBL_ERR;
       }
-
       if (res == MP_YES) {
          break;
       }