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util/sasl.lua @ 512:eb50ee09c2bb
'install' libs to util before top-level make install
author | Matthew Wild <mwild1@gmail.com> |
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date | Sun, 30 Nov 2008 19:31:43 +0000 |
parent | 508:4fd60ae97535 |
child | 519:cccd610a0ef9 |
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local md5 = require "util.hashes".md5; local log = require "util.logger".init("sasl"); local tostring = tostring; local st = require "util.stanza"; local generate_uuid = require "util.uuid".generate; local t_insert, t_concat = table.insert, table.concat; local to_byte, to_char = string.byte, string.char; 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 local idna_ascii = require "util.encodings".idna.to_ascii local idna_unicode = require "util.encodings".idna.to_unicode module "sasl" local function new_plain(realm, password_handler) local object = { mechanism = "PLAIN", realm = realm, password_handler = password_handler} function object.feed(self, message) if message == "" or message == nil then return "failure", "malformed-request" end 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]+)") if authentication == nil or password == nil then return "failure", "malformed-request" end local password_encoding, correct_password = self.password_handler(authentication, self.realm, "PLAIN") if correct_password == nil then return "failure", "not-authorized" elseif correct_password == false then return "failure", "account-disabled" end local claimed_password = "" if password_encoding == nil then claimed_password = password else claimed_password = password_encoding(password) end self.username = authentication if claimed_password == correct_password then return "success" else return "failure", "not-authorized" end end return object end local function new_digest_md5(realm, password_handler) --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 latin1toutf8(str) local p = {}; for ch in gmatch(str, ".") do ch = to_byte(ch); if (ch < 0x80) then t_insert(p, to_char(ch)); elseif (ch < 0xC0) then t_insert(p, to_char(0xC2, ch)); else t_insert(p, to_char(0xC3, ch - 64)); end end return t_concat(p); end local function parse(data) message = {} for k, v in gmatch(data, [[([%w%-]+)="?([^",]*)"?,?]]) do -- FIXME The hacky regex makes me shudder message[k] = v end return message end local object = { mechanism = "DIGEST-MD5", realm = realm, password_handler = password_handler} --TODO: something better than math.random would be nice, maybe OpenSSL's random number generator object.nonce = generate_uuid() object.step = 0 object.nonce_count = {} function object.feed(self, message) self.step = self.step + 1 if (self.step == 1) then local challenge = serialize({ nonce = object.nonce, qop = "auth", charset = "utf-8", algorithm = "md5-sess", realm = self.realm}); return "challenge", challenge elseif (self.step == 2) then local response = parse(message) -- check for replay attack if response["nc"] then if self.nonce_count[response["nc"]] then return "failure", "not-authorized" end end -- check for username, it's REQUIRED by RFC 2831 if not response["username"] then return "failure", "malformed-request" end self["username"] = response["username"] -- check for nonce, ... if not response["nonce"] then return "failure", "malformed-request" else -- check if it's the right nonce if response["nonce"] ~= tostring(self.nonce) then return "failure", "malformed-request" end end if not response["cnonce"] then return "failure", "malformed-request", "Missing entry for cnonce in SASL message." end if not response["qop"] then response["qop"] = "auth" end if response["realm"] == nil then response["realm"] = "" end if response["charset"] == nil then response["username"] = latin1toutf8(response["username"]) response["realm"] = latin1toutf8(response["realm"]) elseif response["charset"] ~= "utf-8" then return "failure", "incorrect-encoding", "The client's response uses "..response["charset"].." for encoding with isn't supported by sasl.lua. Supported encodings are latin or utf-8." end local domain = "" local protocol = "" if response["digest-uri"] then protocol, domain = response["digest-uri"]:match("(%w+)/(.*)$") if protocol == nil or domain == nil then return "failure", "malformed-request" end else return "failure", "malformed-request", "Missing entry for digest-uri in SASL message." end --TODO maybe realm support self.username = response["username"] local password_encoding, Y = self.password_handler(response["username"], response["realm"], "DIGEST-MD5") if Y == nil then return "failure", "not-authorized" elseif Y == false then return "failure", "account-disabled" end local A1 = Y..":"..response["nonce"]..":"..response["cnonce"]--:authzid local A2 = "AUTHENTICATE:"..protocol.."/"..idna_ascii(domain) local HA1 = md5(A1, true) local HA2 = md5(A2, true) local KD = HA1..":"..response["nonce"]..":"..response["nc"]..":"..response["cnonce"]..":"..response["qop"]..":"..HA2 local response_value = md5(KD, true) if response_value == response["response"] then -- calculate rspauth A2 = ":"..protocol.."/"..idna_ascii(domain) HA1 = md5(A1, true) HA2 = md5(A2, true) KD = HA1..":"..response["nonce"]..":"..response["nc"]..":"..response["cnonce"]..":"..response["qop"]..":"..HA2 local rspauth = md5(KD, true) self.authenticated = true return "challenge", serialize({rspauth = rspauth}) else return "failure", "not-authorized", "The response provided by the client doesn't match the one we calculated." end elseif self.step == 3 then if self.authenticated ~= nil then return "success" else return "failure", "malformed-request" end end end return object end function new(mechanism, realm, password_handler) local object if mechanism == "PLAIN" then object = new_plain(realm, password_handler) elseif mechanism == "DIGEST-MD5" then object = new_digest_md5(realm, password_handler) else log("debug", "Unsupported SASL mechanism: "..tostring(mechanism)); return nil end return object end return _M;