PowerShell

SFTP Authenticate with a SecureString Password and Private Key

Demonstrates the Chilkat SFtp.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. Supply the path to your own key file.

Background: This is the SecureString form of two-factor SFTP 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 the process.

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

$success = $false

#  Demonstrates the SFtp.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.

$sftp = New-Object Chilkat.SFtp

#  Step 1: Connect the SSH transport.  Port 22 is the usual port.
$port = 22
$success = $sftp.Connect("sftp.example.com",$port)
if ($success -eq $false) {
    $($sftp.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 = $sftp.AuthenticateSecPwPk($secureLogin,$securePassword,$privKey)
if ($success -eq $false) {
    $($sftp.LastErrorText)
    exit
}

#  Step 3: Open the SFTP subsystem.  This must be done after authentication and before any
#  file or directory operations.
$success = $sftp.InitializeSftp()
if ($success -eq $false) {
    $($sftp.LastErrorText)
    exit
}

$("Authenticated.")

$sftp.Disconnect()