From 0e7599e756e6c720070f0dbe345bd3a17274fe14 Mon Sep 17 00:00:00 2001
From: Daniel Green <ddgreen@gmail.com>
Date: Tue, 2 Jul 2019 21:32:57 +0100
Subject: [PATCH] Throw if MVM_is_prime called with too many rounds

Valid range is 0..PRIME_SIZE (defined in libtommath).
---
 src/math/bigintops.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/math/bigintops.c b/src/math/bigintops.c
index b1e1e43531..10db4e90f9 100644
--- a/src/math/bigintops.c
+++ b/src/math/bigintops.c
@@ -1203,8 +1203,10 @@ MVMint64 MVM_bigint_is_prime(MVMThreadContext *tc, MVMObject *a, MVMint64 b) {
             return 0;
         }
         else {
-            int result;
-            mp_prime_is_prime(ia, b, &result);
+            int result, err;
+            err = mp_prime_is_prime(ia, b, &result);
+            if (err != MP_OKAY)
+                MVM_exception_throw_adhoc(tc, "Invalid number of rounds (%ld), valid range is 0..%d\n", b, PRIME_SIZE);
             return result;
         }
     } else {