+-- sasl.lua v0.4
+-- Copyright (C) 2008-2009 Tobias Markmann
+--
+-- All rights reserved.
+--
+-- Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
+--
+-- * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
+-- * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
+-- * Neither the name of Tobias Markmann nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.
+--
+-- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-local base64 = require "base64"
-local md5 = require "md5"
-local crypto = require "crypto"
+
+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(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
-
---[[
-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 new_digest_md5(realm, password_handler)
+ --TODO maybe support for authzid
local function serialize(message)
local data = ""
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 utf8tolatin1ifpossible(passwd)
+ local i = 1;
+ while i <= #passwd do
+ local passwd_i = to_byte(passwd:sub(i, i));
+ if passwd_i > 0x7F then
+ if passwd_i < 0xC0 or passwd_i > 0xC3 then
+ return passwd;
+ end
+ i = i + 1;
+ passwd_i = to_byte(passwd:sub(i, i));
+ if passwd_i < 0x80 or passwd_i > 0xBF then
+ return passwd;
+ end
+ end
+ i = i + 1;
+ end
+
+ local p = {};
+ local j = 0;
+ i = 1;
+ while (i <= #passwd) do
+ local passwd_i = to_byte(passwd:sub(i, i));
+ if passwd_i > 0x7F then
+ i = i + 1;
+ local passwd_i_1 = to_byte(passwd:sub(i, i));
+ t_insert(p, to_char(passwd_i%4*64 + passwd_i_1%64)); -- I'm so clever
+ else
+ t_insert(p, to_char(passwd_i));
+ end
+ i = i + 1;
+ end
+ return t_concat(p);
+ 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%-]+)="?([%w%-%/%.]+)"?,?]]) do
+ 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", onAuth = onAuth, onSuccess = onSuccess, onFail = onFail,
- onWrite = onWrite }
+ 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 = math.random(0, 9)
- for i = 1, 9 do object.nonce = object.nonce..math.random(0, 9) end
- object.step = 1
+ object.nonce = generate_uuid()
+ object.step = 0
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)
- 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["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 = ""
- local protocol = ""
- if response["digest-uri"] then
- protocol, hostname = 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))))
-
- log("debug", "response_value: "..response_value);
-
- 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
+
+ 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 or response["realm"] == "" then
+ response["realm"] = self.realm;
+ elseif response["realm"] ~= self.realm then
+ return "failure", "not-authorized", "Incorrect realm value";
+ end
+
+ local decoder;
+ if response["charset"] == nil then
+ decoder = utf8tolatin1ifpossible;
+ 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", decoder)
+ 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.."/"..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.."/"..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
+
+local function new_anonymous(realm, password_handler)
+ local object = { mechanism = "ANONYMOUS", realm = realm, password_handler = password_handler}
+ function object.feed(self, message)
+ return "success"
+ end
+ --TODO: From XEP-0175 "It is RECOMMENDED for the node identifier to be a UUID as specified in RFC 4122 [5]." So util.uuid() should (or have an option to) behave as specified in RFC 4122.
+ object["username"] = generate_uuid()
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)
- elseif mechanism == "DIGEST-MD5" then object = new_digest_md5(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)
+ elseif mechanism == "ANONYMOUS" then object = new_anonymous(realm, password_handler)
else
log("debug", "Unsupported SASL mechanism: "..tostring(mechanism));
- onFail("unsupported-mechanism")
+ return nil
end
return object
end
-return _M;
\ No newline at end of file
+return _M;
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