Some early attempts on DIGEST-MD5.

1 files changed, 144 insertions, 2 deletions

diff --git a/util/sasl.lua b/util/sasl.lua
index dbd6326a..ef1009c2 100644
--- a/util/sasl.lua
+++ b/util/sasl.lua
@@ -1,16 +1,23 @@
 
 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;
-module "sasl"
+local math = require "math"
+local type = type
+local error = error
+local print = print
 
+module "sasl"
 
 local function new_plain(onAuth, onSuccess, onFail, onWrite)
 	local object = { mechanism = "PLAIN", onAuth = onAuth, onSuccess = onSuccess, onFail = onFail,
 	 				onWrite = onWrite}
-	--local challenge = base64.encode("");
+	local challenge = base64.encode("");
 	--onWrite(st.stanza("challenge", {xmlns = "urn:ietf:params:xml:ns:xmpp-sasl"}):text(challenge))
 	object.feed = 	function(self, stanza)
 						if stanza.name ~= "response" and stanza.name ~= "auth" then self.onFail("invalid-stanza-tag") end
@@ -30,9 +37,144 @@ local function new_plain(onAuth, onSuccess, onFail, onWrite)
 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
+
+	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["rspauth"] then data = data..[[rspauth=]]..message.algorith.."," end
+		data = data:gsub(",$", "")
+		return data
+	end
+	
+	local function parse(data)
+		message = {}
+		for k, v in string.gmatch(data, [[([%w%-])="?[%w%-]"?,?]]) do
+			message[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 = math.random(0, 9)
+	for i = 1, 9 do object.nonce = object.nonce..math.random(0, 9) end
+	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)
+						print(tostring(stanza))
+						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
+							
+							log("debug", tostring(stanza[1]))
+							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
+							end
+							
+							-- check for username, it's REQUIRED by RFC 2831
+							if not response["username"] then
+								self.onFail("malformed-request")
+							end
+							
+							-- 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
+							end
+							
+							if not response["cnonce"] then self.onFail("malformed-request") end
+							if not response["qop"] then response["qop"] = "auth" end
+							
+							local hostname = ""
+							if response["digest-uri"] then
+								local uri = response["digest-uri"]:gmatch("^(%w)/(%w)")
+								local protocol = uri[1]
+								log(protocol)
+								local hostname = uri[2]
+								log(hostname)
+							end
+														
+							-- compare response_value with own calculation
+							local A1-- = H(response["username"]..":"..realm-value, ":", passwd } ),
+							        --   ":", nonce-value, ":", cnonce-value)
+							local A2
+							
+							local response_value = HEX(KD(HEX(H(A1)), response["nonce"]..":"..response["nonce-count"]..":"..response["cnonce-value"]..":"..response["qop"]..":"..HEX(H(A2))))
+							
+							if response["qop"] == "auth" then
+							
+							else
+							
+							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
+
 function new(mechanism, onAuth, onSuccess, onFail, onWrite)
 	local object
 	if mechanism == "PLAIN" then object = new_plain(onAuth, onSuccess, onFail, onWrite)
+	elseif mechanism == "DIGEST-MD5" then object = new_digest_md5(onAuth, onSuccess, onFail, onWrite)
 	else
 		log("debug", "Unsupported SASL mechanism: "..tostring(mechanism));
 		onFail("unsupported-mechanism")