SSLOn (Socket function)
Turn on SSL processing (Socket class)
This callable method turns on SSL processing, that is, starts an SSL handshake as a client on a connection. SSLOn has an effect similar to $Sock_Ssl_On.
Syntax
[%number =] socket:SSLOn
Syntax terms
| %number | This is a numeric variable to contain the returned indicator of success of the function. The possible return values are listed in "Return codes" below. |
|---|---|
| socket | A variable or an expression that is a reference to a Socket object. |
Return codes
The method's return value (%number) is one of these:
| 0 | Successfully switched to SSL. |
|---|---|
| -110 | Attempted on non-SSL port. SSLOn can only be attempted on a port with SSL and SSLOPT on the JANUS DEFINE command. |
| -111 | SSL handshake error. Likely result of trying to use the SSLOn method against a non-SSL port. |
| -112 | Have pending incoming data. The SSLOn method is invalid until all incoming (presumably) non-SSL data has been received. |
| -149 | Other error during connection. |
Usage notes
- SSLOn makes it possible to:
- Make an initial connection from a Janus Sockets client application to a proxy server
- Issue the HTTP CONNECT method/command to connect to a server through the proxy
- Communicate via SSL with the back end server, simply having the proxy server act as a "tunnel" for the SSL data
As shown in "Examples" below, the SSLOn method should be used after a positive response has been received for a CONNECT method request on a Janus Sockets client socket.
Examples
The following code shows the use of the SSLOn method;
%sock is Object Socket %sock = New('WEBDROPS', 'proxy') %r = %sock:Set('LINEND', '0D0A') %r = %sock:Set('PRSTOK', '0D0A') %r = %sock:Send('CONNECT ') %r = %sock:Send('sirius-software.com:443') %r = %sock:SendWithLineEnd(' HTTP/1.0') %r = %sock:SendWithLineEnd() %r = %sock:ReceiveAndParse(%s) If $WORD(%s, , 2) Ne '200' Then Call CONNECT_ERROR End If Repeat Forever %r = %sock:ReceiveAndParse(%s) If $LSTR_LEN(%s) Eq 0 Then Loop End End If End Repeat %r = %sock:SSLOn If %r Then Call SSL_ERROR End If %r = %sock:Send('GET ') %r = %sock:Send(%URL) %r = %sock:SendWithLineEnd(' HTTP/1.0') %r = %sock:SendWithLineEnd() ...
For more information about HTTP tunneling and the CONNECT method, see http://www.ietf.org/rfc/rfc2817.txt. Many other references are also available on the web.