Lua

SSH Tunnel Authenticate with a SecureString Password and Private Key

Demonstrates the Chilkat SshTunnel.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. Absolute paths may also be used. Supply the path to your own key file.

Background: This is the SecureString form of two-factor tunnel 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 a long-running process.

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Lua

local chilkat = require("chilkat")

-- Demonstrates the SshTunnel.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.

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

-- 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"

-- Load the SSH private key.  LoadText reads the file's text, which is then imported.
local privKey = chilkat.SshKey.new()
local keyText = privKey:load_text("qa_data/id_rsa")
if not privKey.last_method_success then
    print(privKey.last_error_text)
    return
end

success = privKey:from_open_ssh_private_key(keyText)
if not success then
    print(privKey.last_error_text)
    return
end

-- Place the login and password into SecureString objects.
local secureLogin = chilkat.SecureString.new()
secureLogin:append("mySshLogin")
local securePassword = chilkat.SecureString.new()
securePassword:append(password)

success = tunnel:authenticate_sec_pw_pk(secureLogin, securePassword, privKey)
if not success then
    print(tunnel.last_error_text)
    return
end

print("Authenticated.")

-- After authenticating, call BeginAccepting to start listening for local connections to forward.

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