Mercurial > lxmppd-hg-xmllex / changeset
changeset
Rewrote SASL Digest-MD5 responce generating code, fixed some realm related issue and tested it successfully with Psi. Thanks to dwd, remko and jake.
Wed, 12 Nov 2008 21:38:46 +0100
- author
- Tobias Markmann <tm@ayena.de>
- date
- Wed, 12 Nov 2008 21:38:46 +0100
- changeset 280
- 516f4c901991
- parent 279
- 76bad8b64018
- child 282
- 80e7de32b618
Rewrote SASL Digest-MD5 responce generating code, fixed some realm related issue and tested it successfully with Psi. Thanks to dwd, remko and jake.
| util/sasl.lua | file | annotate | diff | comparison | revisions |
--- a/util/sasl.lua Mon Nov 10 16:29:19 2008 +0100 +++ b/util/sasl.lua Wed Nov 12 21:38:46 2008 +0100 @@ -8,6 +8,7 @@ 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 @@ -32,39 +33,14 @@ self.onSuccess(authentication) else self.onWrite(st.stanza("failure", {xmlns = "urn:ietf:params:xml:ns:xmpp-sasl"}):tag("temporary-auth-failure")); + self.onFail("Wrong password.") end end return object end - ---[[ -SERVER: -nonce="3145176401",qop="auth",charset=utf-8,algorithm=md5-sess - -CLIENT: username="tobiasfar",nonce="3145176401",cnonce="pJiW7hzeZLvOSAf7gBzwTzLWe4obYOVDlnNESzQCzGg=",nc=00000001,digest-uri="xmpp/jabber.org",qop=auth,response=99a93ba75235136e6403c3a2ba37089d,charset=utf-8 - -username="tobias",nonce="4406697386",cnonce="wUnT7vYrOB0V8D/lKd5bhpaNCk+hLJwc8T4CBCqp7WM=",nc=00000001,digest-uri="xmpp/luaetta.ath.cx",qop=auth,response=d202b8a1bdf8204816fb23c5f87b6b63,charset=utf-8 - -SERVER: -rspauth=ab66d28c260e97da577ce3aac46a8991 -]]-- local function new_digest_md5(onAuth, onSuccess, onFail, onWrite) - local function H(s) - return md5.sum(s) - end - - local function KD(k, s) - return H(k..":"..s) - end - - local function HEX(n) - return md5.sumhexa(n) - end - - local function HMAC(k, s) - return crypto.hmac.digest("md5", s, k, true) - end + --TODO maybe support for authzid local function serialize(message) local data = "" @@ -76,15 +52,18 @@ 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["rspauth"] then data = data..[[rspauth=]]..message.algorith.."," 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 = {} - for k, v in gmatch(data, [[([%w%-]+)="?([%w%-%/%.]+)"?,?]]) do + 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 @@ -93,8 +72,8 @@ onWrite = onWrite } --TODO: something better than math.random would be nice, maybe OpenSSL's random number generator - object.nonce = math.random(0, 9) - for i = 1, 9 do object.nonce = object.nonce..math.random(0, 9) end + object.nonce = generate_uuid() + log("debug", "SASL nonce: "..object.nonce) object.step = 1 object.nonce_count = {} local challenge = base64.encode(serialize({ nonce = object.nonce, @@ -103,6 +82,7 @@ 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 @@ -110,62 +90,77 @@ if (self.step == 2) then local response = parse(base64.decode(stanza[1])) -- check for replay attack - if response["nonce-count"] then - if self.nonce_count[response["nonce-count"]] then self.onFail("not-authorized") end + 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"] ~= self.nonce then self.onFail("malformed-request") end + 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 - local hostname = "" + if response["realm"] == nil then response["realm"] = "" end + + local domain = "" local protocol = "" if response["digest-uri"] then - protocol, hostname = response["digest-uri"]:match("(%w+)/(.*)$") + 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"] - local A1 = H("tobias:luaetta.ath.cx:tobias")..":"..response["nonce"]..response["cnonce"] - local A2 = "AUTHENTICATE:"..response["digest-uri"] - local response_value = HEX(KD(HEX(H(A1)), response["nonce"]..":"..response["nonce-count"]..":"..response["cnonce-value"]..":"..response["qop"]..":"..HEX(H(A2)))) + --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); - - if response["qop"] == "auth" then - + 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 - - --local response_value = HEX(KD(HEX(H(A1)), response["nonce"]..":"..response["nonce-count"]..":"..response["cnonce-value"]..":"..response["qop"]..":"..HEX(H(A2)))) - end - --[[ - local authorization = s_match(response, "([^&%z]+)") - local authentication = s_match(response, "%z([^&%z]+)%z") - local password = s_match(response, "%z[^&%z]+%z([^&%z]+)") - if self.onAuth(authentication, password) == true then - self.onWrite(st.stanza("success", {xmlns = "urn:ietf:params:xml:ns:xmpp-sasl"})) - self.onSuccess(authentication) - else - self.onWrite(st.stanza("failure", {xmlns = "urn:ietf:params:xml:ns:xmpp-sasl"}):tag("temporary-auth-failure")); - end]]-- end return object end
