Launching the Client from a Web Page¶
This feature allows a web server, such as an intranet or a web portal, to initiate a ThinLinc Client connection with a given configuration on behalf of a user.
Web Integration requires an Apache HTTP Server, configured for TLS, with the ability to run CGI scripts.
Some Linux distributions distributes their Apache HTTP server with the mod_cgi module disabled. This module is required for Web Integration to work. On Ubuntu systems, it can be enabled by running the a2enmod cgi command and restarting the httpd service.
If Web Integration is used over HTTP, an attacker with access to the network may be able to intercept user passwords. To protect from this happening, Web Integration automatically redirects to a HTTPS connection when HTTP is used.
The Web Integration feature is not enabled by default in a ThinLinc
installation. An installation script,
provided for ease of installation.
$ sudo /opt/thinlinc/share/web_integration/install-web-integration
After installing the Apache HTTP configuration file, make sure to restart the httpd service to load the new configuration.
While the installation script works as-is on most supported platforms, two environment variables grants you more control over where the configuration file is installed. This can be useful if you have an httpd installation at a custom location.
If your Apache HTTP server has been installed to a non-standard location, set this environment variable to tell the installation script where the configuration directory is located.
If this parameter is unset, the installation script will attempt to find the configuration directory from a list of known locations.
$ sudo env APACHE_CONF_DIR=/usr/local/etc/httpd/conf.d \ /opt/thinlinc/share/web_integration/install-web-integration
The default behavior of the installation script is to install the configuration file in the configuration directory with the name
thinlinc.conf. If you already have a file with that name in the configuration directory that you wish to keep, set this environment variable to an different name.
$ sudo env APACHE_CONF_NAME=web-integration.conf \ /opt/thinlinc/share/web_integration/install-web-integration
The process works like this:
The CGI script is called with the desired parameters.
The CGI script generates a “launch file”, which is a normal client configuration file. When the browser recieves this file, it launches the locally installed ThinLinc client.
The launch file delivered to the client is generated from the template
/opt/thinlinc/etc/tlclient.conf.webtemplate. The CGI script
performs some substitutions on this file, before sending it to the
client. Currently, the following variables are substituted:
The server name where the CGI script resides.
The user name, specified by the
The password in hexadecimal ASCII notation, specified by the
The value of the
The CGI Script tlclient.cgi¶
The CGI script
tlclient.cgi is used to start the native client,
when launched from a web page. It accepts many parameters which affects
its operation. These are described below:
The desired server name.
The desired user name. No default.
The desired password, in plain text. No default.
The desired password, in hexadecimal ASCII notation. This parameter overrides the
passwordparameter. No default.
After launching the native client, the browser will redirect to the web page specified by this parameter. Default value: the empty string.
This boolean parameter specifies if a login should be directly executed, instead of showing a login form. Default value:
This boolean parameter specifies if the native client should automatically connect to the specified server at startup. Default value:
This boolean parameter specifies if the native client should request that the server starts the session with the command supplied by the client, as indicated by the
start_program_commandparameter. Default value:
This parameter specifies the command to use when starting the session. Default value:
This boolean parameter can be used for debugging and development purposes. It will display and URL with all submitted parameters, and do nothing else. Default value:
This boolean parameter specifies if the native client should activate shadowing. Default value:
This parameter specifies the user to shadow. Default value is the empty string.
To make it easier to test various parameters, the HTML file
cgitest.html is included, in the same location as
tlclient.cgi. It also demonstrates how to create icons on web
pages, which launches ThinLinc sessions.