VB.NET

Open an SSH Session Channel

Demonstrates the Chilkat Ssh.OpenSessionChannel method, which opens a new SSH session channel. It takes no arguments and returns the channel number, or -1 on failure. The transport must already be connected and authenticated.

Background: SSH multiplexes independent channels over one authenticated connection, and a session channel is the one used to run a command, start a shell, or invoke a subsystem. Opening the channel is only the container — nothing runs until you follow it with an exec, shell, or subsystem request. Always test for a negative return rather than assuming success.

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Dim success As Boolean = False

'  Demonstrates the Ssh.OpenSessionChannel method, which opens a new SSH session channel.  It
'  takes no arguments and returns the channel number, or -1 on failure.  The transport must
'  already be connected and authenticated.

Dim ssh As New Chilkat.Ssh

Dim sshPort As Integer = 22
success = ssh.Connect("ssh.example.com",sshPort)
If (success = False) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If


'  Normally you would not hard-code the password in source.  You should instead obtain it
'  from an interactive prompt, environment variable, or a secrets vault.
Dim password As String = "mySshPassword"

success = ssh.AuthenticatePw("mySshLogin",password)
If (success = False) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If


'  Open a session channel.  A negative return value indicates failure.
Dim channelNum As Integer = ssh.OpenSessionChannel()
If (channelNum < 0) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If


Debug.WriteLine("Opened session channel: " & channelNum)

'  Opening the channel does not start a shell or command -- send an exec, shell, or subsystem
'  request next.

ssh.Disconnect()