memory allocated by boringssl have to be freed using `OPENSSL_free`
diff --git a/lib/openssl.c b/lib/openssl.c
index 1443885..c64a8db 100644
--- a/lib/openssl.c
+++ b/lib/openssl.c
@@ -1710,7 +1710,7 @@
     *verifier = verify_sign;
     ret = 0;
 Exit:
-    free(expected_pubkey.base);
+    OPENSSL_free(expected_pubkey.base);
     return ret;
 }