Check if pkcs11_cert is NULL before freeing it

When running openvpn --show-tls with mbedtls, it showed a null pointer
error at the end because of this.

Signed-off-by: Max Fillinger <maximilian.fillinger@foxcrypto.com>
Acked-by: Arne Schwabe <arne@rfc2549.org>
Message-Id: <20221123154912.28394-1-maximilian.fillinger@foxcrypto.com>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg25530.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>

diff --git a/src/openvpn/ssl_mbedtls.c b/src/openvpn/ssl_mbedtls.c
index ea06cf7038a14bc256e7497cd585c254e7e2c24c..b0e42d8f75dcbecba42d9fae8c637f96c7e49a82 100644 (file)
--- a/src/openvpn/ssl_mbedtls.c
+++ b/src/openvpn/ssl_mbedtls.c
@@ -165,7 +165,13 @@ tls_ctx_free(struct tls_root_ctx *ctx)
         free(ctx->crl);
 
 #if defined(ENABLE_PKCS11)
-        pkcs11h_certificate_freeCertificate(ctx->pkcs11_cert);
+        /* ...freeCertificate() can handle NULL ptrs, but if pkcs11 helper
+         * has not been initialized, it will ASSERT() - so, do not pass NULL
+         */
+        if (ctx->pkcs11_cert)
+        {
+            pkcs11h_certificate_freeCertificate(ctx->pkcs11_cert);
+        }
 #endif
 
         free(ctx->allowed_ciphers);