Lua

SSH Tunnel Authenticate with a SecureString Password

Demonstrates the Chilkat SshTunnel.AuthenticateSecPw method, which authenticates using SecureString login and password objects. The first argument is the login and the second is the password.

Background: Because a tunnel process is long-lived and holds its SSH credentials for its entire lifetime, protecting them in memory is worthwhile. A SecureString keeps the value encrypted under a randomly generated session key. Populate it from a value obtained at runtime rather than a hard-coded literal.

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Lua

local chilkat = require("chilkat")

-- Demonstrates the SshTunnel.AuthenticateSecPw method, which authenticates using SecureString
-- login and password objects.  The 1st argument is the login and the 2nd is the password.

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"

-- 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(secureLogin, securePassword)
if not success then
    print(tunnel.last_error_text)
    return
end

print("Authenticated with secure strings.")

-- 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