Disable server verification if system CA certificates not found

src/tlstransport.cpp

@@ -269,9 +269,14 @@ TlsTransport::TlsTransport(shared_ptr<TcpTransport> lower, string host, state_ca
 		SSL_CTX_set_quiet_shutdown(mCtx, 1);
 		SSL_CTX_set_info_callback(mCtx, InfoCallback);
 
-		SSL_CTX_set_default_verify_paths(mCtx);
-		SSL_CTX_set_verify(mCtx, SSL_VERIFY_PEER, NULL);
-		SSL_CTX_set_verify_depth(mCtx, 4);
+		if (SSL_CTX_set_default_verify_paths(mCtx)) {
+			PLOG_INFO << "SSL root CA certificates available, server verification enabled";
+			SSL_CTX_set_verify(mCtx, SSL_VERIFY_PEER, NULL);
+			SSL_CTX_set_verify_depth(mCtx, 4);
+		} else {
+			PLOG_WARNING << "SSL root CA certificates unavailable, server verification disabled";
+			SSL_CTX_set_verify(mCtx, SSL_VERIFY_NONE, NULL);
+		}
 
 		if (!(mSsl = SSL_new(mCtx)))
 			throw std::runtime_error("Failed to create SSL instance");