util.filters: Fix inserting items so that higher priority filters run first
[prosody.git] / util / sasl.lua
index dbd6326a74e2cde7707180868a8d575971d94280..afb3861b08f90d70db33d9657da4df77efe43036 100644 (file)
@@ -1,43 +1,96 @@
+-- sasl.lua v0.4
+-- Copyright (C) 2008-2010 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 pairs, ipairs = pairs, ipairs;
+local t_insert = table.insert;
+local type = type
+local setmetatable = setmetatable;
+local assert = assert;
+local require = require;
 
-local base64 = require "base64"
-local log = require "util.logger".init("sasl");
-local tostring = tostring;
-local st = require "util.stanza";
-local s_match = string.match;
 module "sasl"
 
+--[[
+Authentication Backend Prototypes:
+
+state = false : disabled
+state = true : enabled
+state = nil : non-existant
+]]
+
+local method = {};
+method.__index = method;
+local mechanisms = {};
+local backend_mechanism = {};
+
+-- register a new SASL mechanims
+function registerMechanism(name, backends, f)
+       assert(type(name) == "string", "Parameter name MUST be a string.");
+       assert(type(backends) == "string" or type(backends) == "table", "Parameter backends MUST be either a string or a table.");
+       assert(type(f) == "function", "Parameter f MUST be a function.");
+       mechanisms[name] = f
+       for _, backend_name in ipairs(backends) do
+               if backend_mechanism[backend_name] == nil then backend_mechanism[backend_name] = {}; end
+               t_insert(backend_mechanism[backend_name], name);
+       end
+end
+
+-- create a new SASL object which can be used to authenticate clients
+function new(realm, profile)
+       local mechanisms = profile.mechanisms;
+       if not mechanisms then
+               mechanisms = {};
+               for backend, f in pairs(profile) do
+                       if backend_mechanism[backend] then
+                               for _, mechanism in ipairs(backend_mechanism[backend]) do
+                                       mechanisms[mechanism] = true;
+                               end
+                       end
+               end
+               profile.mechanisms = mechanisms;
+       end
+       return setmetatable({ profile = profile, realm = realm, mechs = mechanisms }, method);
+end
 
-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
-       return object
+-- get a fresh clone with the same realm and profile
+function method:clean_clone()
+       return new(self.realm, self.profile)
 end
 
+-- get a list of possible SASL mechanims to use
+function method:mechanisms()
+       return self.mechs;
+end
 
-function new(mechanism, onAuth, onSuccess, onFail, onWrite)
-       local object
-       if mechanism == "PLAIN" then object = new_plain(onAuth, onSuccess, onFail, onWrite)
-       else
-               log("debug", "Unsupported SASL mechanism: "..tostring(mechanism));
-               onFail("unsupported-mechanism")
+-- select a mechanism to use
+function method:select(mechanism)
+       if not self.selected and self.mechs[mechanism] then
+               self.selected = mechanism;
+               return true;
        end
-       return object
 end
 
-return _M;
\ No newline at end of file
+-- feed new messages to process into the library
+function method:process(message)
+       --if message == "" or message == nil then return "failure", "malformed-request" end
+       return mechanisms[self.selected](self, message);
+end
+
+-- load the mechanisms
+require "util.sasl.plain"     .init(registerMechanism);
+require "util.sasl.digest-md5".init(registerMechanism);
+require "util.sasl.anonymous" .init(registerMechanism);
+require "util.sasl.scram"     .init(registerMechanism);
+
+return _M;