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SSH Tunnel Authenticate with a SecureString Password and Private Key

Demonstrates the Chilkat SshTunnel.AuthenticateSecPwPk method, which authenticates using SecureString login and password objects together with a private key. The third argument is the SshKey private key.

Note: The private-key path is relative to the application's current working directory. Absolute paths may also be used. Supply the path to your own key file.

Background: This is the SecureString form of two-factor tunnel authentication: the password is held encrypted in memory and combined with a private key for servers that require both. It is the most protective option when a deployment mandates two-factor SSH and you also want to minimize plaintext credential exposure in a long-running process.

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

$success = $false

#  Demonstrates the SshTunnel.AuthenticateSecPwPk method, which authenticates using SecureString
#  login and password objects together with a private key.  The 1st argument is the username, the
#  2nd is the password, and the 3rd is an SshKey private key.

$tunnel = New-Object Chilkat.SshTunnel

#  The tunnel forwards accepted local connections to this destination through the SSH server.
$tunnel.DestHostname = "db.internal.example.com"
$tunnel.DestPort = 5432

#  Connect to the SSH server.  This performs the TCP/proxy connection and SSH handshake, but
#  does not authenticate yet.
$sshPort = 22
$success = $tunnel.Connect("ssh.example.com",$sshPort)
if ($success -eq $false) {
    $($tunnel.LastErrorText)
    exit
}

#  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.
$password = "mySshPassword"

#  Load the SSH private key.  LoadText reads the file's text, which is then imported.
$privKey = New-Object Chilkat.SshKey
$keyText = $privKey.LoadText("qa_data/id_rsa")
if ($privKey.LastMethodSuccess -eq $false) {
    $($privKey.LastErrorText)
    exit
}

$success = $privKey.FromOpenSshPrivateKey($keyText)
if ($success -eq $false) {
    $($privKey.LastErrorText)
    exit
}

#  Place the login and password into SecureString objects.
$secureLogin = New-Object Chilkat.SecureString
$secureLogin.Append("mySshLogin")
$securePassword = New-Object Chilkat.SecureString
$securePassword.Append($password)

$success = $tunnel.AuthenticateSecPwPk($secureLogin,$securePassword,$privKey)
if ($success -eq $false) {
    $($tunnel.LastErrorText)
    exit
}

$("Authenticated.")

#  After authenticating, call BeginAccepting to start listening for local connections to forward.

$waitForThreadExit = $true
$success = $tunnel.CloseTunnel($waitForThreadExit)
if ($success -eq $false) {
    $($tunnel.LastErrorText)
    exit
}