PowerShell Requires Chilkat v11.0.0+

TCP Socket through SSH Tunnel (Port Forwarding)

See more Socket/SSL/TLS Examples

Demonstrates using Chilkat Socket to communicate to a TCP service through an SSH tunnel. This example will connect to an NIST time server and (using the old Time Protocol (RFC 868)), will read the current GMT time.

Note: This is not necessarily a recommended means for getting the current date/time. The most commonly used time protocol is the Network Time Protocol (RFC-1305). The intent of this example is to show how TCP communications can occur through an SSH tunnel.

PowerShell

Add-Type -Path "C:\chilkat\ChilkatDotNet47-x64\ChilkatDotNet47.dll"

$success = $false

#  This example requires the Chilkat API to have been previously unlocked.
#  See Global Unlock Sample for sample code.

$tunnel = New-Object Chilkat.Socket

$sshHostname = "sftp.example.com"
$sshPort = 22

#  Connect to an SSH server and establish the SSH tunnel:
$success = $tunnel.SshOpenTunnel($sshHostname,$sshPort)
if ($success -eq $false) {
    $($tunnel.LastErrorText)
    exit
}

#  Authenticate with the SSH server via a login/password
#  or with a public key.
#  This example demonstrates SSH password authentication.
$success = $tunnel.SshAuthenticatePw("mySshLogin","mySshPassword")
if ($success -eq $false) {
    $($tunnel.LastErrorText)
    exit
}

#  OK, the SSH tunnel is setup.  Now open a channel within the tunnel.
#  Once the channel is obtained, the Socket API may
#  be used exactly the same as usual, except all communications
#  are sent through the channel in the SSH tunnel.
#  Any number of channels may be created from the same SSH tunnel.
#  Multiple channels may coexist at the same time.

#  Connect to an NIST time server and read the current date/time
$maxWaitMs = 4000
$useTls = $false
$channel = New-Object Chilkat.Socket
$success = $tunnel.SshNewChannel("time-c.nist.gov",37,$useTls,$maxWaitMs,$channel)
if ($success -eq $false) {
    $($tunnel.LastErrorText)
    exit
}

#  The time server will send a big-endian 32-bit integer representing
#  the number of seconds since since 00:00 (midnight) 1 January 1900 GMT.
#  The ReceiveInt32 method will receive a 4-byte integer, but returns
#  $true or $false to indicate success.  If successful, the integer
#  is obtained via the ReceivedInt property.
$bigEndian = $true
$success = $channel.ReceiveInt32($bigEndian)
if ($success -eq $false) {
    $($channel.LastErrorText)
    exit
}

$dt = New-Object Chilkat.CkDateTime
$dt.SetFromNtpTime($channel.ReceivedInt)

#  Show the current local date/time
$bLocalTime = $true
$("Current local date/time: " + $dt.GetAsRfc822($bLocalTime))

#  Close the SSH channel.
$success = $channel.Close($maxWaitMs)
if ($success -ne $true) {
    $($channel.LastErrorText)
    exit
}

#  It is possible to create a new channel from the existing SSH tunnel for the next connection:
#  Any number of channels may be created from the same SSH tunnel.
#  Multiple channels may coexist at the same time.
$success = $tunnel.SshNewChannel("time-a.nist.gov",37,$useTls,$maxWaitMs,$channel)
if ($success -eq $false) {
    $($tunnel.LastErrorText)
    exit
}

#  Review the LastErrorText to see that the connection was made via the SSH tunnel:
$($tunnel.LastErrorText)

#  Close the connection to time-a.nist.gov.  This is actually closing our channel
#  within the SSH tunnel, but keeps the tunnel open for the next port-forwarded connection.
$success = $channel.Close($maxWaitMs)
if ($success -ne $true) {
    $($channel.LastErrorText)
    exit
}

#  Finally, close the SSH tunnel.
$success = $tunnel.SshCloseTunnel()
if ($success -eq $false) {
    $($tunnel.LastErrorText)
    exit
}

$("TCP SSH tunneling example completed.")