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util/sasl.lua @ 286:7e4908d4bdf6
Merge with Waqas changes to mod_saslauth.
author | Tobias Markmann <tm@ayena.de> |
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date | Sat, 15 Nov 2008 19:25:51 +0100 |
parent | 285:372d0891e8fd |
child | 288:dc53343af9ac |
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local base64 = require "base64" local md5 = require "md5" local crypto = require "crypto" local log = require "util.logger".init("sasl"); local tostring = tostring; local st = require "util.stanza"; local generate_uuid = require "util.uuid".generate; local s_match = string.match; local gmatch = string.gmatch local string = string local math = require "math" local type = type local error = error local print = print module "sasl" local function new_plain(realm, password_handler) local object = { mechanism = "PLAIN", realm = realm, password_handler = password_handler} object.feed = function(self, message) log("debug", "feed: "..message) local response = message local authorization = s_match(response, "([^&%z]+)") local authentication = s_match(response, "%z([^&%z]+)%z") local password = s_match(response, "%z[^&%z]+%z([^&%z]+)") local password_encoding, correct_password = self.password_handler(authentication.."@"..self.realm, "PLAIN") local claimed_password = "" if password_encoding == nil then claimed_password = password else claimed_password = password_encoding(password) end if claimed_password == correct_password then return "success", nil else return "failure", "not-authorized" end end return object end local function new_digest_md5(onAuth, onSuccess, onFail, onWrite) --TODO maybe support for authzid local function serialize(message) local data = "" if type(message) ~= "table" then error("serialize needs an argument of type table.") end -- testing all possible values if message["nonce"] then data = data..[[nonce="]]..message.nonce..[[",]] end if message["qop"] then data = data..[[qop="]]..message.qop..[[",]] end if message["charset"] then data = data..[[charset=]]..message.charset.."," end if message["algorithm"] then data = data..[[algorithm=]]..message.algorithm.."," end if message["realm"] then data = data..[[realm="]]..message.realm..[[",]] end if message["rspauth"] then data = data..[[rspauth=]]..message.rspauth.."," end data = data:gsub(",$", "") return data end local function parse(data) message = {} log("debug", "parse-message: "..data) for k, v in gmatch(data, [[([%w%-]+)="?([%w%-%/%.%+=]+)"?,?]]) do message[k] = v log("debug", " "..k.." = "..v) end return message end local object = { mechanism = "DIGEST-MD5", onAuth = onAuth, onSuccess = onSuccess, onFail = onFail, onWrite = onWrite } --TODO: something better than math.random would be nice, maybe OpenSSL's random number generator object.nonce = generate_uuid() log("debug", "SASL nonce: "..object.nonce) object.step = 1 object.nonce_count = {} local challenge = base64.encode(serialize({ nonce = object.nonce, qop = "auth", charset = "utf-8", algorithm = "md5-sess"} )); object.onWrite(st.stanza("challenge", {xmlns = "urn:ietf:params:xml:ns:xmpp-sasl"}):text(challenge)) object.feed = function(self, stanza) log("debug", "SASL step: "..self.step) if stanza.name ~= "response" and stanza.name ~= "auth" then self.onFail("invalid-stanza-tag") end if stanza.attr.xmlns ~= "urn:ietf:params:xml:ns:xmpp-sasl" then self.onFail("invalid-stanza-namespace") end if stanza.name == "auth" then return end self.step = self.step + 1 if (self.step == 2) then local response = parse(base64.decode(stanza[1])) -- check for replay attack if response["nc"] then if self.nonce_count[response["nc"]] then self.onFail("not-authorized") end end -- check for username, it's REQUIRED by RFC 2831 if not response["username"] then self.onFail("malformed-request") end self["username"] = response["username"] -- check for nonce, ... if not response["nonce"] then self.onFail("malformed-request") else -- check if it's the right nonce if response["nonce"] ~= tostring(self.nonce) then self.onFail("malformed-request") end end if not response["cnonce"] then self.onFail("malformed-request") end if not response["qop"] then response["qop"] = "auth" end if response["realm"] == nil then response["realm"] = "" end local domain = "" local protocol = "" if response["digest-uri"] then protocol, domain = response["digest-uri"]:match("(%w+)/(.*)$") else error("No digest-uri") end -- compare response_value with own calculation --local A1 = usermanager.get_md5(response["username"], hostname)..":"..response["nonce"]..response["cnonce"] --FIXME actual username and password here :P local X = "tobias:"..response["realm"]..":tobias" local Y = md5.sum(X) local A1 = Y..":"..response["nonce"]..":"..response["cnonce"]--:authzid local A2 = "AUTHENTICATE:"..protocol.."/"..domain local HA1 = md5.sumhexa(A1) local HA2 = md5.sumhexa(A2) local KD = HA1..":"..response["nonce"]..":"..response["nc"]..":"..response["cnonce"]..":"..response["qop"]..":"..HA2 local response_value = md5.sumhexa(KD) log("debug", "response_value: "..response_value); log("debug", "response: "..response["response"]); if response_value == response["response"] then -- calculate rspauth A2 = ":"..protocol.."/"..domain HA1 = md5.sumhexa(A1) HA2 = md5.sumhexa(A2) KD = HA1..":"..response["nonce"]..":"..response["nc"]..":"..response["cnonce"]..":"..response["qop"]..":"..HA2 local rspauth = md5.sumhexa(KD) self.onWrite(st.stanza("challenge", {xmlns = "urn:ietf:params:xml:ns:xmpp-sasl"}):text(base64.encode(serialize({rspauth = rspauth})))) else self.onWrite(st.stanza("response", {xmlns = "urn:ietf:params:xml:ns:xmpp-sasl"})) self.onFail() end elseif self.step == 3 then if stanza.name == "response" then self.onWrite(st.stanza("success", {xmlns = "urn:ietf:params:xml:ns:xmpp-sasl"})) self.onSuccess(self.username) else self.onFail("Third step isn't a response stanza.") end end end return object end function new(mechanism, realm, password) local object if mechanism == "PLAIN" then object = new_plain(realm, password) --elseif mechanism == "DIGEST-MD5" then object = new_digest_md5(ream, password) else log("debug", "Unsupported SASL mechanism: "..tostring(mechanism)); return nil end return object end return _M;