Better error handling for SSL

luprex/core/cpp/driver-common.cpp

@@ -278,7 +278,9 @@ class Driver {
         } else if (error == SSL_ERROR_WANT_WRITE) {
             chan.ready_on_pollout = true;
         } else {
-            close_channel(chan, drvssl::errors_string());
+            std::string error = drvssl::error_string();
+            if (error == "") error = "unknown error";
+            close_channel(chan, error);
         }
     }
 
@@ -349,7 +351,7 @@ class Driver {
     }
 
     void advance_channel(ChanInfo &chan) {
-        drvssl::assert_errors_empty();
+        drvssl::clear_all_errors();
         switch (chan.state) {
             case CHAN_PLAINTEXT:
                 advance_plaintext(chan);
@@ -367,7 +369,6 @@ class Driver {
                 assert(false);
                 break;
         }
-        drvssl::assert_errors_empty();
     }
 
     void handle_socket_input_output() {
@@ -527,7 +528,6 @@ class Driver {
         ssl_client_insecure_ctx_.reset(drvssl::new_context(SSL_VERIFY_NONE));
         ssl_load_certificate_authorities(ssl_client_secure_ctx_.get());
         drvssl::ctx_load_dummy_cert(ssl_server_ctx_.get());
-        drvssl::assert_errors_empty();
 
         handle_lua_source();
         recorder_.drv_invoke_event_init(argc, argv);