1 files changed, 36 insertions, 0 deletions
diff --git a/security/nss/fuzz/mpi_div_target.cc b/security/nss/fuzz/mpi_div_target.cc
new file mode 100644
index 000000000..08c714ee6
--- /dev/null
+++ b/security/nss/fuzz/mpi_div_target.cc
@@ -0,0 +1,36 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * This target fuzzes NSS mpi against openssl bignum.
+ * It therefore requires openssl to be installed.
+ */
+
+#include "mpi_helper.h"
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
+  // We require at least size 3 to get two integers from Data.
+  if (size < 3) {
+    return 0;
+  }
+  INIT_FOUR_NUMBERS
+
+  // We can't divide by 0.
+  if (mp_cmp_z(&b) == 0) {
+    CLEANUP_AND_RETURN
+  }
+
+  // Compare with OpenSSL division
+  assert(mp_div(&a, &b, &c, &r) == MP_OKAY);
+  BN_div(C, R, A, B, ctx);
+  check_equal(C, &c, max_size);
+  check_equal(R, &r, max_size);
+
+  // Check c * b + r == a
+  assert(mp_mul(&c, &b, &c) == MP_OKAY);
+  assert(mp_add(&c, &r, &c) == MP_OKAY);
+  assert(mp_cmp(&c, &a) == 0);
+
+  CLEANUP_AND_RETURN
+}