Tcl

Start SSH Tunnel Keyboard-Interactive Authentication

Demonstrates the Chilkat SshTunnel.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: the server sends one or more questions — a password, a one-time code, a security question — and the client answers each. This is how a tunnel supports two-factor and other challenge-response schemes. The returned XML says exactly what to ask and whether to mask the input.

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Tcl


load ./chilkat.dll

set success 0

#  Demonstrates the SshTunnel.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.

set tunnel [new_CkSshTunnel]

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

#  Connect to the SSH server.  This performs the TCP/proxy connection and SSH handshake, but
#  does not authenticate yet.
set sshPort 22
set success [CkSshTunnel_Connect $tunnel "ssh.example.com" $sshPort]
if {$success == 0} then {
    puts [CkSshTunnel_lastErrorText $tunnel]
    delete_CkSshTunnel $tunnel
    exit
}

#  Begin keyboard-interactive authentication.  The returned XML describes the server's prompts.
set infoRequestXml [CkSshTunnel_startKeyboardAuth $tunnel "mySshLogin"]
if {[CkSshTunnel_get_LastMethodSuccess $tunnel] == 0} then {
    puts [CkSshTunnel_lastErrorText $tunnel]
    delete_CkSshTunnel $tunnel
    exit
}

puts "$infoRequestXml"

#  Answer the prompt(s) with ContinueKeyboardAuth, then call BeginAccepting.

set waitForThreadExit 1
set success [CkSshTunnel_CloseTunnel $tunnel $waitForThreadExit]
if {$success == 0} then {
    puts [CkSshTunnel_lastErrorText $tunnel]
    delete_CkSshTunnel $tunnel
    exit
}


delete_CkSshTunnel $tunnel