SSH Tunnel (Port Forwarding via direct-tcpip channel)

Demonstrates how to create an SSH tunnel to a remote hostname:port via a direct-tcpip channel.

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'  Important: It is helpful to send the contents of the
'  ssh.LastErrorText property when requesting support.

Dim ssh As New Chilkat.Ssh()

'  Any string automatically begins a fully-functional 30-day trial.
Dim success As Boolean
success = ssh.UnlockComponent("Anything for 30-day trial")
If (success <> true) Then
    MsgBox(ssh.LastErrorText)
    Exit Sub
End If


'  Connect to an SSH server:
Dim hostname As String
Dim port As Long

'  Hostname may be an IP address or hostname:
hostname = "192.168.1.108"
port = 22

success = ssh.Connect(hostname,port)
If (success <> true) Then
    MsgBox(ssh.LastErrorText)
    Exit Sub
End If


'  Wait a max of 5 seconds when reading responses..
ssh.IdleTimeoutMs = 5000

'  Authenticate using login/password:
success = ssh.AuthenticatePw("myLogin","myPassword")
If (success <> true) Then
    MsgBox(ssh.LastErrorText)
    Exit Sub
End If


'  Open a direct-tcpip channel.  We want the SSH server to connect
'  to www.chilkatsoft.com, port 80 (i.e. the web server).
'  Data sent through the SSH tunnel is forwarded to the remote
'  host:port.  (Note: The remote host:port does not need to be
'  a web server.  It can be anything.  It can be your own
'  customer application server that listens on a port, or any
'  other type of server.)
'  When we read from the SSH channel, we'll be reading data
'  sent from the remote host:port (i.e. the web server in this
'  example).
Dim channelNum As Long
channelNum = ssh.OpenDirectTcpIpChannel("www.chilkatsoft.com",80)
If (channelNum < 0) Then
    MsgBox(ssh.LastErrorText)
    Exit Sub
End If


'  Build a simple HTTP GET request for http://www.chilkatsoft.com/xyz.html
Dim httpReq As String
httpReq = "GET /xyz.html HTTP/1.1\r\nHost: www.chilkatsoft.com\r\n\r\n"

'  Send the HTTP request:
success = ssh.ChannelSendString(channelNum,httpReq,"ansi")
If (success <> true) Then
    MsgBox(ssh.LastErrorText)
    Exit Sub
End If


'  Get the HTTP response.
'  First read the HTTP response header which ends with a double CRLF.
'  Calling ChannelReceiveUntilMatch will receive until match string is seen,
'  or until a timeout occurs (IdleTimeoutMs property).  ChannelReceiveUntilMatch
'  may read beyond the match string, but it will stop reading as soon as the match
'  string is seen.
Dim caseSensitive As Boolean
caseSensitive = false
Dim matchStr As String
matchStr = "\r\n\r\n"
success = ssh.ChannelReceiveUntilMatch(channelNum,matchStr,"ansi",caseSensitive)
If (success <> true) Then
    MsgBox(ssh.LastErrorText)
    Exit Sub
End If


'  Extract the HTTP header from the receive buffer.
'  (GetReceiveTextS extracts up to and including the match string from the receive buffer)
Dim responseHeader As String
responseHeader = ssh.GetReceivedTextS(channelNum,matchStr,"ansi")
TextBox1.Text = TextBox1.Text & "---- HTTP Response Header ----" & vbCrLf
TextBox1.Text = TextBox1.Text & responseHeader & vbCrLf

'  Now get the body of the HTTP response (this is the HTML content
'  of http://www.chilkatsoft.com/xyz.html
'  It's possible we've already received the entire HTTP response in the
'  call to ChannelReceiveUntilMatch.  Therefore, we'll poll for any remaining data
'  and wait a max of .2 seconds.
Dim numBytesRead As Long
Dim pollTimeoutMs As Long
pollTimeoutMs = 200
numBytesRead = ssh.ChannelPoll(channelNum,pollTimeoutMs)
'  We're not checking for an error here.
'  A return value of -2 means that no data was available and the poll simply timed out (not an error)
'  A return value of -1 indicates an error.
'  A return value greater than 0 indicates that additional data was received.

TextBox1.Text = TextBox1.Text & "---- HTML BODY ----" & vbCrLf

'  Extract the remainder of the accumulated data in the internal receive buffer.
'  This should be our HTML body:
Dim htmlBody As String
htmlBody = ssh.GetReceivedText(channelNum,"ansi")
TextBox1.Text = TextBox1.Text & htmlBody & vbCrLf

'  Close the channel:
success = ssh.ChannelSendClose(channelNum)
If (success <> true) Then
    MsgBox(ssh.LastErrorText)
    Exit Sub
End If


'  Disconnect
ssh.Disconnect()