Edit File: imap.lua
--- -- A library implementing a minor subset of the IMAP protocol, currently the -- CAPABILITY, LOGIN and AUTHENTICATE functions. The library was initially -- written by Brandon Enright and later extended and converted to OO-form by -- Patrik Karlsson <patrik@cqure.net> -- -- The library consists of a <code>Helper</code>, class which is the main -- interface for script writers, and the <code>IMAP</code> class providing -- all protocol-level functionality. -- -- The following example illustrates the reommended use of the library: -- <code> -- local helper = imap.Helper:new(host, port) -- helper:connect() -- helper:login("user","password","PLAIN") -- helper:close() -- </code> -- -- @copyright Same as Nmap--See http://nmap.org/book/man-legal.html -- @author = "Brandon Enright, Patrik Karlsson" -- Version 0.2 -- Revised 07/15/2011 - v0.2 - added the IMAP and Helper classes -- added support for LOGIN and AUTHENTICATE -- <patrik@cqure.net> local base64 = require "base64" local comm = require "comm" local sasl = require "sasl" local stdnse = require "stdnse" local table = require "table" _ENV = stdnse.module("imap", stdnse.seeall) IMAP = { --- Creates a new instance of the IMAP class -- -- @param host table as received by the script action method -- @param port table as received by the script action method -- @param options table containing options, currently -- <code>timeout<code> - number containing the seconds to wait for -- a response new = function(self, host, port, options) local o = { host = host, port = port, counter = 1, timeout = ( options and options.timeout ) or 10000 } setmetatable(o, self) self.__index = self return o end, --- Receives a response from the IMAP server -- -- @return status true on success, false on failure -- @return data string containing the received data receive = function(self) local data = "" repeat local status, tmp = self.socket:receive_buf("\r\n", false) if( not(status) ) then return false, tmp end data = data .. tmp until( tmp:match(("^A%04d"):format(self.counter - 1)) or tmp:match("^%+")) return true, data end, --- Sends a request to the IMAP server -- -- @param cmd string containing the command to send to the server eg. -- eg. (AUTHENTICATE, LOGIN) -- @param params string containing the command parameters -- @return true on success, false on failure -- @return err string containing the error if status was false send = function(self, cmd, params) local data if ( not(params) ) then data = ("A%04d %s\r\n"):format(self.counter, cmd) else data = ("A%04d %s %s\r\n"):format(self.counter, cmd, params) end local status, err = self.socket:send(data) if ( not(status) ) then return false, err end self.counter = self.counter + 1 return true end, --- Connect to the server -- -- @return status true on success, false on failure -- @return banner string containing the server banner connect = function(self) local socket, banner, opt = comm.tryssl( self.host, self.port, "", { recv_before = true } ) if ( not(socket) ) then return false, "ERROR: Failed to connect to server" end socket:set_timeout(self.timeout) if ( not(socket) or not(banner) ) then return false, "ERROR: Failed to connect to server" end self.socket = socket return true, banner end, --- Authenticate to the server (non PLAIN text mode) -- Currently supported algorithms are CRAM-MD5 and CRAM-SHA1 -- -- @param username string containing the username -- @param pass string containing the password -- @param mech string containing a authentication mechanism, currently -- CRAM-MD5 or CRAM-SHA1 -- @return status true if login was successful, false on failure -- @return err string containing the error message if status was false authenticate = function(self, username, pass, mech) assert( mech == "NTLM" or mech == "DIGEST-MD5" or mech == "CRAM-MD5" or mech == "PLAIN", "Unsupported authentication mechanism") local status, err = self:send("AUTHENTICATE", mech) if( not(status) ) then return false, "ERROR: Failed to send data" end local status, data = self:receive() if( not(status) ) then return false, "ERROR: Failed to receive challenge" end if ( mech == "NTLM" ) then -- sniffed of the wire, seems to always be the same -- decodes to some NTLMSSP blob greatness status, data = self.socket:send("TlRMTVNTUAABAAAAB7IIogYABgA3AAAADwAPACgAAAAFASgKAAAAD0FCVVNFLUFJUi5MT0NBTERPTUFJTg==\r\n") if ( not(status) ) then return false, "ERROR: Failed to send NTLM packet" end status, data = self:receive() if ( not(status) ) then return false, "ERROR: Failed to receieve NTLM challenge" end end if ( data:match(("^A%04d "):format(self.counter-1)) ) then return false, "ERROR: Authentication mechanism not supported" end local digest, auth_data if ( not(data:match("^+")) ) then return false, "ERROR: Failed to receive proper response from server" end data = base64.dec(data:match("^+ (.*)")) -- All mechanisms expect username and pass -- add the otheronce for those who need them local mech_params = { username, pass, data, "imap" } auth_data = sasl.Helper:new(mech):encode(table.unpack(mech_params)) auth_data = base64.enc(auth_data) .. "\r\n" status, data = self.socket:send(auth_data) if( not(status) ) then return false, "ERROR: Failed to send data" end status, data = self:receive() if( not(status) ) then return false, "ERROR: Failed to receive data" end if ( mech == "DIGEST-MD5" ) then local rspauth = data:match("^+ (.*)") if ( rspauth ) then rspauth = base64.dec(rspauth) status, data = self.socket:send("\r\n") status, data = self:receive() end end if ( data:match(("^A%04d OK"):format(self.counter - 1)) ) then return true end return false, "Login failed" end, --- Login to the server using PLAIN text authentication -- -- @param username string containing the username -- @param password string containing the password -- @return status true on success, false on failure -- @return err string containing the error message if status was false login = function(self, username, password) local status, err = self:send("LOGIN", ("\"%s\" \"%s\""):format(username, password)) if( not(status) ) then return false, "ERROR: Failed to send data" end local status, data = self:receive() if( not(status) ) then return false, "ERROR: Failed to receive data" end if ( data:match(("^A%04d OK"):format(self.counter - 1)) ) then return true end return false, "Login failed" end, --- Retrieves a list of server capabilities (eg. supported authentication -- mechanisms, QUOTA, UIDPLUS, ACL ...) -- -- @return status true on success, false on failure -- @return capas array containing the capabilities that are supported capabilities = function(self) local capas = {} local proto = (self.port.version and self.port.version.service_tunnel == "ssl" and "ssl") or "tcp" local status, err = self:send("CAPABILITY") if( not(status) ) then return false, err end local status, line = self:receive() if (not(status)) then capas.CAPABILITY = false else while status do if ( line:match("^%*%s+CAPABILITY") ) then line = line:gsub("^%*%s+CAPABILITY", "") for capability in line:gmatch("[%w%+=-]+") do capas[capability] = true end break end status, line = self.socket:receive() end end return true, capas end, --- Closes the connection to the IMAP server -- @return true on success, false on failure close = function(self) return self.socket:close() end } -- The helper class, that servers as interface to script writers Helper = { -- @param host table as received by the script action method -- @param port table as received by the script action method -- @param options table containing options, currently -- <code>timeout<code> - number containing the seconds to wait for -- a response new = function(self, host, port, options) local o = { client = IMAP:new( host, port, options ) } setmetatable(o, self) self.__index = self return o end, --- Connects to the IMAP server -- @return status true on success, false on failure connect = function(self) return self.client:connect() end, --- Login to the server using eithe plain-text or using the authentication -- mechanism provided in the mech argument. -- -- @param username string containing the username -- @param password string containing the password -- @param mech [optional] containing the authentication mechanism to use -- @return status true on success, false on failure login = function(self, username, password, mech) if ( not(mech) or mech == "LOGIN" ) then return self.client:login(username, password) else return self.client:authenticate(username, password, mech) end end, --- Retrieves a list of server capabilities (eg. supported authentication -- mechanisms, QUOTA, UIDPLUS, ACL ...) -- -- @return status true on success, false on failure -- @return capas array containing the capabilities that are supported capabilities = function(self) return self.client:capabilities() end, --- Closes the connection to the IMAP server -- @return true on success, false on failure close = function(self) return self.client:close() end, } return _ENV;