-local base64 = require "base64"
+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 s_match = string.match;
-module "sasl"
+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
+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("");
- --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
- if stanza.attr.xmlns ~= "urn:ietf:params:xml:ns:xmpp-sasl" then self.onFail("invalid-stanza-namespace") end
- local response = base64.decode(stanza[1])
- 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
+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(",$", "")
+ return data
+ end
+
+ local function parse(data)
+ message = {}
+ for k, v in gmatch(data, [[([%w%-]+)="?([^",]*)"?,?]]) do -- FIXME The hacky regex makes me shudder
+ message[k] = v
+ end
+ return message
+ end
+
+ local object = { mechanism = "DIGEST-MD5", realm = realm, password_handler = password_handler}
+
+ --TODO: something better than math.random would be nice, maybe OpenSSL's random number generator
+ object.nonce = generate_uuid()
+ object.step = 0
+ object.nonce_count = {}
+
+ function object.feed(self, message)
+ self.step = self.step + 1
+ if (self.step == 1) then
+ local challenge = serialize({ nonce = object.nonce,
+ qop = "auth",
+ charset = "utf-8",
+ algorithm = "md5-sess",
+ realm = self.realm});
+ return "challenge", challenge
+ elseif (self.step == 2) then
+ local response = parse(message)
+ -- check for replay attack
+ if response["nc"] then
+ if self.nonce_count[response["nc"]] then return "failure", "not-authorized" end
+ end
+
+ -- check for username, it's REQUIRED by RFC 2831
+ if not response["username"] then
+ return "failure", "malformed-request"
+ end
+ self["username"] = response["username"]
+
+ -- check for nonce, ...
+ if not response["nonce"] then
+ return "failure", "malformed-request"
+ else
+ -- check if it's the right nonce
+ if response["nonce"] ~= tostring(self.nonce) then return "failure", "malformed-request" end
+ end
+
+ if not response["cnonce"] then return "failure", "malformed-request", "Missing entry for cnonce in SASL message." end
+ if not response["qop"] then response["qop"] = "auth" end
+
+ if response["realm"] == nil then response["realm"] = "" end
+
+ local domain = ""
+ local protocol = ""
+ if response["digest-uri"] then
+ protocol, domain = response["digest-uri"]:match("(%w+)/(.*)$")
+ 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, onAuth, onSuccess, onFail, onWrite)
+function new(mechanism, realm, password_handler)
local object
- if mechanism == "PLAIN" then object = new_plain(onAuth, onSuccess, onFail, onWrite)
+ 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));
- onFail("unsupported-mechanism")
+ return nil
end
return object
end
projects / prosody.git / blobdiff