---
-- 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;
@KyuuKazami