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Diffstat (limited to 'nselib/imap.lua')
| -rw-r--r-- | nselib/imap.lua | 280 |
1 files changed, 280 insertions, 0 deletions
diff --git a/nselib/imap.lua b/nselib/imap.lua new file mode 100644 index 0000000..9e786a6 --- /dev/null +++ b/nselib/imap.lua @@ -0,0 +1,280 @@ +--- +-- 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 recommended 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 https://nmap.org/book/man-legal.html +-- @author Brandon Enright +-- @author 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 match = require "match" +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(match.pattern_limit("\r\n", 1024), 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, "", { request_timeout=self.timeout, recv_before=true } ) + 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 receive 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 either 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; |