1 files changed, 26 insertions, 1 deletions

diff --git a/src/regress/lib/libcrypto/bn/bn_mod_exp.c b/src/regress/lib/libcrypto/bn/bn_mod_exp.c
index c16959c945..10647ad3dd 100644
--- a/src/regress/lib/libcrypto/bn/bn_mod_exp.c
+++ b/src/regress/lib/libcrypto/bn/bn_mod_exp.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: bn_mod_exp.c,v 1.24 2023/03/26 20:13:26 tb Exp $ */
+/*      $OpenBSD: bn_mod_exp.c,v 1.25 2023/03/26 22:09:08 tb Exp $ */
 
 /*
  * Copyright (c) 2022,2023 Theo Buehler <tb@openbsd.org>
@@ -589,6 +589,30 @@ run_bn_mod_exp2_tests(void)
         return failed;
 }
 
+/*
+ * Small test for a crash reported by Guido Vranken, fixed in bn_exp2.c r1.13.
+ * https://github.com/openssl/openssl/issues/17648
+ */
+
+static int
+test_bn_mod_exp2_mont_crash(void)
+{
+        BIGNUM *m;
+        int failed = 0;
+
+        if ((m = BN_new()) == NULL)
+                errx(1, "BN_new");
+
+        if (BN_mod_exp2_mont(NULL, NULL, NULL, NULL, NULL, m, NULL, NULL)) {
+                fprintf(stderr, "BN_mod_exp2_mont succeeded\n");
+                failed |= 1;
+        }
+
+        BN_free(m);
+
+        return failed;
+}
+
 int
 main(void)
 {
@@ -597,6 +621,7 @@ main(void)
         failed |= run_bn_mod_exp_zero_tests();
         failed |= run_bn_mod_exp_tests();
         failed |= run_bn_mod_exp2_tests();
+        failed |= test_bn_mod_exp2_mont_crash();
 
         return failed;
 }