+-- 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 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 to_unicode = require "util.encodings".idna.to_unicode;
local s_match = string.match;
local gmatch = string.gmatch
local string = string
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(realm, password_handler)
- local object = { mechanism = "PLAIN", realm = realm, password_handler = password_handler}
+-- Credentials handler:
+-- Arguments: ("PLAIN", user, host, password)
+-- Returns: true (success) | false (fail) | nil (user unknown)
+local function new_plain(realm, credentials_handler)
+ local object = { mechanism = "PLAIN", realm = realm, credentials_handler = credentials_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
+
+ if authentication == nil or password == nil then return "failure", "malformed-request" end
+ self.username = authentication
+ local auth_success = self.credentials_handler("PLAIN", self.username, self.realm, password)
+
+ if auth_success then
+ return "success"
+ elseif auth_success == nil then
+ return "failure", "account-disabled"
+ else
+ return "failure", "not-authorized"
+ end
+ end
+ return object
end
-local function new_digest_md5(realm, password_handler)
- --TODO maybe support for authzid
+-- credentials_handler:
+-- Arguments: (mechanism, node, domain, realm, decoder)
+-- Returns: Password encoding, (plaintext) password
+-- implementing RFC 2831
+local function new_digest_md5(realm, credentials_handler)
+ --TODO complete 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["realm"] then data = data..[[realm="]]..message.realm..[[",]] end
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 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%-]+)="?([^",]*)"?,?]]) do -- FIXME The hacky regex makes me shudder
- message[k] = v
+ message[k] = v;
end
- return message
+ 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 = {}
-
+ local object = { mechanism = "DIGEST-MD5", realm = realm, credentials_handler = credentials_handler};
+
+ object.nonce = generate_uuid();
+ object.step = 0;
+ object.nonce_count = {};
+
function object.feed(self, message)
- self.step = self.step + 1
+ self.step = self.step + 1;
if (self.step == 1) then
- local challenge = serialize({ nonce = object.nonce,
+ local challenge = serialize({ nonce = object.nonce,
qop = "auth",
charset = "utf-8",
algorithm = "md5-sess",
- realm = idna_ascii(self.realm)});
- return "challenge", challenge
+ realm = self.realm});
+ return "challenge", challenge;
elseif (self.step == 2) then
- local response = parse(message)
+ 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"
+ return "failure", "malformed-request";
end
- self["username"] = response["username"]
-
+ self["username"] = response["username"];
+
-- check for nonce, ...
if not response["nonce"] then
- return "failure", "malformed-request"
+ 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["realm"] == nil or response["realm"] == "" then
+ response["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+)/(.*)$")
+ 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"], idna_unicode(response["realm"]), "DIGEST-MD5")
+ self.username = response["username"];
+ local password_encoding, Y = self.credentials_handler("DIGEST-MD5", response["username"], self.realm, response["realm"], 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.."/"..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)
-
+ local A1 = "";
+ if response.authzid then
+ if response.authzid == self.username.."@"..self.realm then
+ -- COMPAT
+ log("warn", "Client is violating XMPP RFC. See section 6.1 of RFC 3920.");
+ A1 = Y..":"..response["nonce"]..":"..response["cnonce"]..":"..response.authzid;
+ else
+ A1 = "?";
+ end
+ else
+ A1 = Y..":"..response["nonce"]..":"..response["cnonce"];
+ end
+ 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.."/"..idna_ascii(domain)
-
- HA1 = md5(A1, true)
- HA2 = md5(A2, true)
-
+ 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})
+ 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
+ end
elseif self.step == 3 then
if self.authenticated ~= nil then return "success"
else return "failure", "malformed-request" end
end
end
+ return object;
+end
+
+-- Credentials handler: Can be nil. If specified, should take the mechanism as
+-- the only argument, and return true for OK, or false for not-OK (TODO)
+local function new_anonymous(realm, credentials_handler)
+ local object = { mechanism = "ANONYMOUS", realm = realm, credentials_handler = credentials_handler}
+ function object.feed(self, message)
+ return "success"
+ end
+ object["username"] = generate_uuid()
return object
end
-function new(mechanism, realm, password_handler)
+
+function new(mechanism, realm, credentials_handler)
local object
- if mechanism == "PLAIN" then object = new_plain(realm, password_handler)
- elseif mechanism == "DIGEST-MD5" then object = new_digest_md5(realm, password_handler)
+ if mechanism == "PLAIN" then object = new_plain(realm, credentials_handler)
+ elseif mechanism == "DIGEST-MD5" then object = new_digest_md5(realm, credentials_handler)
+ elseif mechanism == "ANONYMOUS" then object = new_anonymous(realm, credentials_handler)
else
log("debug", "Unsupported SASL mechanism: "..tostring(mechanism));
return nil
return object
end
-return _M;
\ No newline at end of file
+return _M;
projects / prosody.git / blobdiff