Tcl

Continue SSH Keyboard-Interactive Authentication

Demonstrates the Chilkat Ssh.ContinueKeyboardAuth method, which submits a response to a keyboard-interactive prompt. The only argument is the response text; for a request containing multiple prompts, an XML response is supplied instead. It returns XML indicating the next prompt or the final result.

Background: This is the second half of the keyboard-interactive exchange started by StartKeyboardAuth. A server may issue several rounds of prompts, so a robust client loops: submit answers, read the returned XML, and continue until authentication succeeds or fails. Prompt responses are typically secrets, so obtain them from interactive input rather than embedding them in code.

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Tcl


load ./chilkat.dll

set success 0

#  Demonstrates the Ssh.ContinueKeyboardAuth method, which submits a response to a
#  keyboard-interactive prompt.  The only argument is the response.  For multiple prompts, an
#  XML response is supplied instead.

set ssh [new_CkSsh]

#  Connect to the SSH server.  Port 22 is the usual SSH port.
set sshPort 22
set success [CkSsh_Connect $ssh "ssh.example.com" $sshPort]
if {$success == 0} then {
    puts [CkSsh_lastErrorText $ssh]
    delete_CkSsh $ssh
    exit
}

#  Begin keyboard-interactive authentication to receive the server's prompt(s).
set infoRequestXml [CkSsh_startKeyboardAuth $ssh "mySshLogin"]
if {[CkSsh_get_LastMethodSuccess $ssh] == 0} then {
    puts [CkSsh_lastErrorText $ssh]
    delete_CkSsh $ssh
    exit
}

#  Normally you would not hard-code the response (typically the password) in source.  You
#  should instead obtain it from an interactive prompt.
set response "mySshPassword"

#  Submit the response.  The returned XML indicates the next prompt or the final result.
set result [CkSsh_continueKeyboardAuth $ssh $response]
if {[CkSsh_get_LastMethodSuccess $ssh] == 0} then {
    puts [CkSsh_lastErrorText $ssh]
    delete_CkSsh $ssh
    exit
}

puts "$result"

CkSsh_Disconnect $ssh

delete_CkSsh $ssh