Lua Requires Chilkat v9.5.0.55+

TCP or TLS over Multiple Hop SSH to Remote Server

See more Socket/SSL/TLS Examples

Demonstrates how to use the Chilkat Socket API to connect to a remote server (using TCP or TLS) tunneled through mulitple-hop SSH. The scheme looks like this:

Application => ServerSSH1 => ServerSSH2 => DestinationServer

The ConnectThroughSsh and UseSsh methods are used to accomplish this task.

Lua

local chilkat = require("chilkat")

-- This example requires the Chilkat API to have been previously unlocked.
-- See Global Unlock Sample for sample code.

local ssh1 = chilkat.Ssh.new()

-- Connect directly to the 1st SSH server.
local success = ssh1:connect("serverssh1.com", 22)
if not success then
    print(ssh1.last_error_text)
    return
end

-- Authenticate using login/password:
success = ssh1:authenticate_pw("ssh1Login", "ssh1Password")
if not success then
    print(ssh1.last_error_text)
    return
end

-- Connect through the 1st SSH connection to reach a 2nd SSH server.
-- Note: Any number of SSH connections may be simultaneously tunneled through a single
-- existing SSH connection.
local ssh2 = chilkat.Ssh.new()
success = ssh2:connect_through_ssh(ssh1, "serverssh2.com", 22)
if not success then
    print(ssh2.last_error_text)
    return
end

-- Authenticate with ssh2...
success = ssh2:authenticate_pw("ssh2Login", "ssh2Password")
if not success then
    print(ssh2.last_error_text)
    return
end

local socket = chilkat.Socket.new()

-- Tell the socket object to connect to our destination server though the ssh2 tunnel (which itself is routed through ssh1).
-- The connection looks like this:  ApplicationSocket(TLS) => ServerSSH1 => ServerSSH2 => DestinationServer
success = socket:use_ssh(ssh2)
if not success then
    print(socket.last_error_text)
    return
end

-- Connect using TLS to www.chilkatsoft.com
-- We could also tunnel a bare TCP connection by specifying port 80 with useTls = false.
local useTls = true
local maxWaitMillisec = 20000
success = socket:connect("www.chilkatsoft.com", 443, useTls, maxWaitMillisec)
if not success then
    print(socket.last_error_text)
    return
end

-- Once the multiple hop SSH tunneled connection is setup,  the socket programming
-- is identical to the normal case where we have a direct connection.

-- Tell the socket object that all text is to be sent in the utf-8 encoding,
-- and the text received is assumed to be utf-8.
socket.string_charset = "utf-8"

-- Send an HTTP HEAD request:
success = socket:send_string("HEAD / HTTP/1.1\r\nHost: www.chilkatsoft.com\r\n\r\n")
if not success then
    print(socket.last_error_text)
    return
end

-- Wait a maximum of 4 seconds while no data is forthcoming:
socket.max_read_idle_ms = 4000

-- Get the 1st response line, which should be "HTTP/1.1 200 OK"
local responseStatusLine = socket:receive_to_crlf()
if not socket.last_method_success then
    print(socket.last_error_text)
    return
end

print("StatusLine: " .. responseStatusLine)

-- Now get the 1st line of the response header:
local responseHeaderLine = socket:receive_to_crlf()
if not socket.last_method_success then
    print(socket.last_error_text)
    return
end

print("HeaderLine: " .. responseHeaderLine)

-- Now read the remainder of the response header by reading until a double CRLF is seen:
local remainderOfHeader = socket:receive_until_match("\r\n\r\n")
if not socket.last_method_success then
    print(socket.last_error_text)
    return
end

print("Remainder: " .. remainderOfHeader)

-- Close the connection with the server.  This closes the tunnel through ssh2.
-- Wait a max of 20 seconds (20000 millsec)
success = socket:close(20000)

-- Close the connection with ssh2.  (This closes the the tunnel through ssh1.)
-- The connection with ssh1 is still alive, and may be used for more connections.
ssh2:disconnect()

ssh1:disconnect()