SQL Server
SQL Server
WebSocket through SSH Tunnel
See more WebSocket Examples
This example shows how to establish a WebSocket connection through an SSH tunnel. The WebSocket protocol communications will be encapsulated within an SSH tunnel.Chilkat SQL Server Downloads
-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
DECLARE @hr int
DECLARE @iTmp0 int
-- Important: Do not use nvarchar(max). See the warning about using nvarchar(max).
DECLARE @sTmp0 nvarchar(4000)
DECLARE @success int
SELECT @success = 0
-- This example requires the Chilkat API to have been previously unlocked.
-- See Global Unlock Sample for sample code.
-- --------------------------------------------------
-- This example borrows the code from the REST through SSH Tunnel example.
-- We first use the Chilkat Socket object to establish a connection to the WebSocket server through an SSH Tunnel.
-- Next, the Rest object uses the Socket object for its connection.
-- Finally, the WebSocket object uses the Rest object for its connection.
--
-- Hopefully the flexibility of this architecture is easy to see. All of the HTTP functionality of the Rest object,
-- such as HTTP authentication, custom headers, etc. is available to the WebSocket. Likewise, all of the advanced functionality
-- of the Socket object is in turn available to the Rest object.
-- The high-level steps for accomplishing the task of running the WebSocket protocol through an SSH accomplished as follows:
-- 1) Create the SSH tunnel using Chilkat Socket.
-- 2) Open a port-forwarding channel (to the WebSocket server) within the tunnel.
-- 2) Tell Rest to use the Socket object.
-- 3) Tell WebSocket to use the Rest object.
DECLARE @tunnel int
EXEC @hr = sp_OACreate 'Chilkat.Socket', @tunnel OUT
IF @hr <> 0
BEGIN
PRINT 'Failed to create ActiveX component'
RETURN
END
DECLARE @sshHostname nvarchar(4000)
SELECT @sshHostname = 'sftp.example.com'
DECLARE @sshPort int
SELECT @sshPort = 22
-- Connect to an SSH server and establish the SSH tunnel:
EXEC sp_OAMethod @tunnel, 'SshOpenTunnel', @success OUT, @sshHostname, @sshPort
IF @success = 0
BEGIN
EXEC sp_OAGetProperty @tunnel, 'LastErrorText', @sTmp0 OUT
PRINT @sTmp0
EXEC @hr = sp_OADestroy @tunnel
RETURN
END
-- Authenticate with the SSH server via a login/password
-- or with a public key.
-- This example demonstrates SSH password authentication.
EXEC sp_OAMethod @tunnel, 'SshAuthenticatePw', @success OUT, 'mySshLogin', 'mySshPassword'
IF @success = 0
BEGIN
EXEC sp_OAGetProperty @tunnel, 'LastErrorText', @sTmp0 OUT
PRINT @sTmp0
EXEC @hr = sp_OADestroy @tunnel
RETURN
END
-- OK, the SSH tunnel is setup. Now open a channel within the tunnel.
DECLARE @bTls int
SELECT @bTls = 1
DECLARE @port int
SELECT @port = 443
DECLARE @maxWaitMs int
SELECT @maxWaitMs = 5000
-- This returns a socket object that is a single channel within the SSH tunnel.
-- The SSH channel is our logical port-forwarded connection through the SSH tunnel.
-- Note: This example establishes a TLS connection to the target WebSocket server.
-- (The TLS protocol will run on the logical channel within the SSH tunnel.)
-- Your application can just as easily make a non-TLS connection by changing the arguments
-- passed to SshNewChannel.
DECLARE @channel int
EXEC @hr = sp_OACreate 'Chilkat.Socket', @channel OUT
EXEC sp_OAMethod @tunnel, 'SshNewChannel', @success OUT, 'some-websocket-server.com', @port, @bTls, @maxWaitMs, @channel
IF @success = 0
BEGIN
EXEC sp_OAGetProperty @tunnel, 'LastErrorText', @sTmp0 OUT
PRINT @sTmp0
EXEC @hr = sp_OADestroy @tunnel
EXEC @hr = sp_OADestroy @channel
RETURN
END
-- Create a REST object and tell it to use the SSH channel.
-- This connection is a TLS running on an SSH channel through an SSH tunnel.
-- In other words, TLS is wrapped within the SSH tunnel.
DECLARE @rest int
EXEC @hr = sp_OACreate 'Chilkat.Rest', @rest OUT
EXEC sp_OAMethod @rest, 'UseConnection', @success OUT, @channel, 0
IF @success = 0
BEGIN
EXEC sp_OAGetProperty @rest, 'LastErrorText', @sTmp0 OUT
PRINT @sTmp0
EXEC @hr = sp_OADestroy @tunnel
EXEC @hr = sp_OADestroy @channel
EXEC @hr = sp_OADestroy @rest
RETURN
END
-- Finally, tell our WebSocket object to use the Rest object..
DECLARE @ws int
EXEC @hr = sp_OACreate 'Chilkat.WebSocket', @ws OUT
-- Tell the WebSocket to use this connection.
EXEC sp_OAMethod @ws, 'UseConnection', @success OUT, @rest
IF @success = 0
BEGIN
EXEC sp_OAGetProperty @ws, 'LastErrorText', @sTmp0 OUT
PRINT @sTmp0
EXEC @hr = sp_OADestroy @tunnel
EXEC @hr = sp_OADestroy @channel
EXEC @hr = sp_OADestroy @rest
EXEC @hr = sp_OADestroy @ws
RETURN
END
-- Add the standard WebSocket open handshake headers that will be needed.
-- (This adds the required HTTP request headers to the rest object.)
EXEC sp_OAMethod @ws, 'AddClientHeaders', @success OUT
-- Add any additional headers that might be desired.
-- Two common WebSocketSpecific headers are "Sec-WebSocket-Protocol" and "Origin".
EXEC sp_OAMethod @rest, 'AddHeader', @success OUT, 'Sec-WebSocket-Protocol', 'x-some-websocket-subprotocol'
EXEC sp_OAMethod @rest, 'AddHeader', @success OUT, 'Origin', 'http://some-websocket-server.com'
-- Do the open handshake.
DECLARE @responseBody nvarchar(4000)
EXEC sp_OAMethod @rest, 'FullRequestNoBody', @responseBody OUT, 'GET', '/something'
EXEC sp_OAGetProperty @rest, 'LastMethodSuccess', @iTmp0 OUT
IF @iTmp0 = 0
BEGIN
EXEC sp_OAGetProperty @rest, 'LastErrorText', @sTmp0 OUT
PRINT @sTmp0
EXEC @hr = sp_OADestroy @tunnel
EXEC @hr = sp_OADestroy @channel
EXEC @hr = sp_OADestroy @rest
EXEC @hr = sp_OADestroy @ws
RETURN
END
-- If successful, the HTTP response status code should be 101,
-- and the response body will be empty. (If it failed, we'll have a look
-- at the response body..)
DECLARE @statusCode int
EXEC sp_OAGetProperty @rest, 'ResponseStatusCode', @statusCode OUT
PRINT 'Response status code: ' + @statusCode
IF @statusCode <> 101
BEGIN
PRINT @responseBody
PRINT '-- Failed because of unexpected response status code.'
EXEC @hr = sp_OADestroy @tunnel
EXEC @hr = sp_OADestroy @channel
EXEC @hr = sp_OADestroy @rest
EXEC @hr = sp_OADestroy @ws
RETURN
END
-- We have the expected 101 response, so let's now validate the
-- contents of the response, such as the value sent by the server in the
-- Sec-WebSocket-Accept header.
EXEC sp_OAMethod @ws, 'ValidateServerHandshake', @success OUT
IF @success = 0
BEGIN
EXEC sp_OAGetProperty @ws, 'LastErrorText', @sTmp0 OUT
PRINT @sTmp0
EXEC @hr = sp_OADestroy @tunnel
EXEC @hr = sp_OADestroy @channel
EXEC @hr = sp_OADestroy @rest
EXEC @hr = sp_OADestroy @ws
RETURN
END
PRINT 'WebSocket connection successful.'
-- The application may now begin sending and receiving frames on the WebSocket connection.
-- (At this point, we're done with the rest object...)
EXEC @hr = sp_OADestroy @tunnel
EXEC @hr = sp_OADestroy @channel
EXEC @hr = sp_OADestroy @rest
EXEC @hr = sp_OADestroy @ws
END
GO