plugins/mod_saslauth.lua

   1 -- Prosody IM v0.3
   2 -- Copyright (C) 2008-2009 Matthew Wild
   3 -- Copyright (C) 2008-2009 Waqas Hussain
   4 --
   5 -- This project is MIT/X11 licensed. Please see the
   6 -- COPYING file in the source package for more information.
   7 --
   8
   9
  10
  11 local st = require "util.stanza";
  12 local sm_bind_resource = require "core.sessionmanager".bind_resource;
  13 local base64 = require "util.encodings".base64;
  14
  15 local usermanager_validate_credentials = require "core.usermanager".validate_credentials;
  16 local t_concat, t_insert = table.concat, table.insert;
  17 local tostring = tostring;
  18 local jid_split = require "util.jid".split
  19 local md5 = require "util.hashes".md5;
  20
  21 local log = require "util.logger".init("mod_saslauth");
  22
  23 local xmlns_sasl ='urn:ietf:params:xml:ns:xmpp-sasl';
  24 local xmlns_bind ='urn:ietf:params:xml:ns:xmpp-bind';
  25 local xmlns_stanzas ='urn:ietf:params:xml:ns:xmpp-stanzas';
  26
  27 local new_sasl = require "util.sasl".new;
  28
  29 local function build_reply(status, ret, err_msg)
  30         local reply = st.stanza(status, {xmlns = xmlns_sasl});
  31         if status == "challenge" then
  32                 log("debug", ret or "");
  33                 reply:text(base64.encode(ret or ""));
  34         elseif status == "failure" then
  35                 reply:tag(ret):up();
  36                 if err_msg then reply:tag("text"):text(err_msg); end
  37         elseif status == "success" then
  38                 log("debug", ret or "");
  39                 reply:text(base64.encode(ret or ""));
  40         else
  41                 error("Unknown sasl status: "..status);
  42         end
  43         return reply;
  44 end
  45
  46 local function handle_status(session, status)
  47         if status == "failure" then
  48                 session.sasl_handler = nil;
  49         elseif status == "success" then
  50                 if not session.sasl_handler.username then error("SASL succeeded but we didn't get a username!"); end -- TODO move this to sessionmanager
  51                 sessionmanager.make_authenticated(session, session.sasl_handler.username);
  52                 session.sasl_handler = nil;
  53                 session:reset_stream();
  54         end
  55 end
  56
  57 local function password_callback(node, host, mechanism, decoder)
  58         local password = (datamanager.load(node, host, "accounts") or {}).password; -- FIXME handle hashed passwords
  59         local func = function(x) return x; end;
  60         if password then
  61                 if mechanism == "PLAIN" then
  62                         return func, password;
  63                 elseif mechanism == "DIGEST-MD5" then
  64                         if decoder then node, host, password = decoder(node), decoder(host), decoder(password); end
  65                         return func, md5(node..":"..host..":"..password);
  66                 end
  67         end
  68         return func, nil;
  69 end
  70
  71 local function sasl_handler(session, stanza)
  72         if stanza.name == "auth" then
  73                 -- FIXME ignoring duplicates because ejabberd does
  74                 session.sasl_handler = new_sasl(stanza.attr.mechanism, session.host, password_callback);
  75         elseif not session.sasl_handler then
  76                 return; -- FIXME ignoring out of order stanzas because ejabberd does
  77         end
  78         local text = stanza[1];
  79         if text then
  80                 text = base64.decode(text);
  81                 log("debug", text);
  82                 if not text then
  83                         session.sasl_handler = nil;
  84                         session.send(build_reply("failure", "incorrect-encoding"));
  85                         return;
  86                 end
  87         end
  88         local status, ret, err_msg = session.sasl_handler:feed(text);
  89         handle_status(session, status);
  90         local s = build_reply(status, ret, err_msg);
  91         log("debug", "sasl reply: "..tostring(s));
  92         session.send(s);
  93 end
  94
  95 module:add_handler("c2s_unauthed", "auth", xmlns_sasl, sasl_handler);
  96 module:add_handler("c2s_unauthed", "abort", xmlns_sasl, sasl_handler);
  97 module:add_handler("c2s_unauthed", "response", xmlns_sasl, sasl_handler);
  98
  99 local mechanisms_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-sasl' };
 100 local bind_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-bind' };
 101 local xmpp_session_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-session' };
 102 module:add_event_hook("stream-features",
 103                 function (session, features)
 104                         if not session.username then
 105                                 features:tag("mechanisms", mechanisms_attr);
 106                                 -- 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.
 107                                         features:tag("mechanism"):text("PLAIN"):up();
 108                                         features:tag("mechanism"):text("DIGEST-MD5"):up();
 109                                 features:up();
 110                         else
 111                                 features:tag("bind", bind_attr):tag("required"):up():up();
 112                                 features:tag("session", xmpp_session_attr):up();
 113                         end
 114                 end);
 115
 116 module:add_iq_handler("c2s", "urn:ietf:params:xml:ns:xmpp-bind",
 117                 function (session, stanza)
 118                         log("debug", "Client tried to bind to a resource");
 119                         local resource;
 120                         if stanza.attr.type == "set" then
 121                                 local bind = stanza.tags[1];
 122                                 if bind and bind.attr.xmlns == xmlns_bind then
 123                                         resource = bind:child_with_name("resource");
 124                                         if resource then
 125                                                 resource = resource[1];
 126                                         end
 127                                 end
 128                         end
 129                         local success, err_type, err, err_msg = sm_bind_resource(session, resource);
 130                         if not success then
 131                                 session.send(st.error_reply(stanza, err_type, err, err_msg));
 132                         else
 133                                 session.send(st.reply(stanza)
 134                                         :tag("bind", { xmlns = xmlns_bind})
 135                                         :tag("jid"):text(session.full_jid));
 136                         end
 137                 end);
 138
 139 module:add_iq_handler("c2s", "urn:ietf:params:xml:ns:xmpp-session",
 140                 function (session, stanza)
 141                         log("debug", "Client tried to bind to a resource");
 142                         session.send(st.reply(stanza));
 143                 end);