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-rw-r--r--plugins/mod_saslauth.lua2
-rw-r--r--util/sasl.lua171
2 files changed, 156 insertions, 17 deletions
diff --git a/plugins/mod_saslauth.lua b/plugins/mod_saslauth.lua
index 75af5eb6..b95d160d 100644
--- a/plugins/mod_saslauth.lua
+++ b/plugins/mod_saslauth.lua
@@ -94,7 +94,9 @@ add_event_hook("stream-features",
function (session, features)
if not session.username then
t_insert(features, "<mechanisms xmlns='urn:ietf:params:xml:ns:xmpp-sasl'>");
+ -- TODO: Provide PLAIN only if TLS is active, this is a SHOULD from the introduction of RFC 4616. This behavior could be overridden via configuration but will issuing a warning or so.
t_insert(features, "<mechanism>PLAIN</mechanism>");
+ t_insert(features, "<mechanism>DIGEST-MD5</mechanism>");
t_insert(features, "</mechanisms>");
else
t_insert(features, "<bind xmlns='urn:ietf:params:xml:ns:xmpp-bind'><required/></bind>");
diff --git a/util/sasl.lua b/util/sasl.lua
index dbd6326a..8750ce98 100644
--- a/util/sasl.lua
+++ b/util/sasl.lua
@@ -1,41 +1,178 @@
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 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(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 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]+)")
- if self.onAuth(authentication, password) == true then
- self.onWrite(st.stanza("success", {xmlns = "urn:ietf:params:xml:ns:xmpp-sasl"}))
- self.onSuccess(authentication)
+
+ 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
- self.onWrite(st.stanza("failure", {xmlns = "urn:ietf:params:xml:ns:xmpp-sasl"}):tag("temporary-auth-failure"));
+ 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, onAuth, onSuccess, onFail, onWrite)
+function new(mechanism, realm, password)
local object
- if mechanism == "PLAIN" then object = new_plain(onAuth, onSuccess, onFail, onWrite)
+ 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));
- onFail("unsupported-mechanism")
+ return nil
end
return object
end