Lua

Continue SSH Tunnel Keyboard-Interactive Authentication

Demonstrates the Chilkat SshTunnel.ContinueKeyboardAuth method, which submits a response to a keyboard-interactive prompt. The only argument is the response text; for a request with 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 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 it sees success or failure. On success, BeginAccepting still must be called before the tunnel forwards traffic.

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Lua

local chilkat = require("chilkat")

-- Demonstrates the SshTunnel.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.

local tunnel = chilkat.SshTunnel.new()

-- The tunnel forwards accepted local connections to this destination through the SSH server.
tunnel.dest_hostname = "db.internal.example.com"
tunnel.dest_port = 5432

-- Connect to the SSH server.  This performs the TCP/proxy connection and SSH handshake, but
-- does not authenticate yet.
local sshPort = 22
local success = tunnel:connect("ssh.example.com", sshPort)
if not success then
    print(tunnel.last_error_text)
    return
end

-- Begin keyboard-interactive authentication to receive the server's prompt(s).
local infoRequestXml = tunnel:start_keyboard_auth("mySshLogin")
if not tunnel.last_method_success then
    print(tunnel.last_error_text)
    return
end

-- 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.
local password = "mySshPassword"

-- Submit the response (typically the password).  The returned XML indicates the next prompt or
-- the final result.
local result = tunnel:continue_keyboard_auth(password)
if not tunnel.last_method_success then
    print(tunnel.last_error_text)
    return
end

print(result)

local waitForThreadExit = true
success = tunnel:close_tunnel(waitForThreadExit)
if not success then
    print(tunnel.last_error_text)
    return
end