B4X

Start SFTP Keyboard-Interactive Authentication

Demonstrates the Chilkat SFtp.StartKeyboardAuth method, which begins keyboard-interactive authentication. The only argument is the login name. It returns XML describing the server's prompts, which are answered with ContinueKeyboardAuth.

Background: Keyboard-interactive is the prompt-driven authentication method: rather than assuming a single password, the server sends one or more questions — a password, a one-time code, a security question — and the client answers each. This is how SFTP supports two-factor and other challenge-response schemes. The returned XML tells you exactly what to ask and whether to mask the input.

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Dim success As Boolean = False

'  Demonstrates the SFtp.StartKeyboardAuth method, which begins keyboard-interactive
'  authentication.  The only argument is the login name.  It returns XML describing the server's
'  prompts, which are answered with ContinueKeyboardAuth.

Dim sftp As ChilkatSFtp
sftp.Initialize("sftp")

'  Step 1: Connect the SSH transport.  Port 22 is the usual port.
Dim port As Int = 22
success = sftp.Connect("sftp.example.com", port)
If success = False Then
    Log(sftp.LastErrorText)
    Return
End If


'  Begin keyboard-interactive authentication.  The returned XML describes the server's prompts.
Dim infoRequestXml As String = sftp.StartKeyboardAuth("mySshLogin")
If sftp.LastMethodSuccess = False Then
    Log(sftp.LastErrorText)
    Return
End If

Log(infoRequestXml)

'  Answer the prompt(s) with ContinueKeyboardAuth, then call InitializeSftp.

sftp.Disconnect