plugins/mod_saslauth.lua

   1 -- Prosody IM v0.1
   2 -- Copyright (C) 2008 Matthew Wild
   3 -- Copyright (C) 2008 Waqas Hussain
   4 --
   5 -- This program is free software; you can redistribute it and/or
   6 -- modify it under the terms of the GNU General Public License
   7 -- as published by the Free Software Foundation; either version 2
   8 -- of the License, or (at your option) any later version.
   9 --
  10 -- This program is distributed in the hope that it will be useful,
  11 -- but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 -- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 -- GNU General Public License for more details.
  14 --
  15 -- You should have received a copy of the GNU General Public License
  16 -- along with this program; if not, write to the Free Software
  17 -- Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  18 --
  19
  20
  21
  22 local st = require "util.stanza";
  23 local sm_bind_resource = require "core.sessionmanager".bind_resource;
  24 local jid
  25 local base64 = require "util.encodings".base64;
  26
  27 local usermanager_validate_credentials = require "core.usermanager".validate_credentials;
  28 local t_concat, t_insert = table.concat, table.insert;
  29 local tostring = tostring;
  30 local jid_split = require "util.jid".split
  31 local md5 = require "util.hashes".md5;
  32
  33 local log = require "util.logger".init("mod_saslauth");
  34
  35 local xmlns_sasl ='urn:ietf:params:xml:ns:xmpp-sasl';
  36 local xmlns_bind ='urn:ietf:params:xml:ns:xmpp-bind';
  37 local xmlns_stanzas ='urn:ietf:params:xml:ns:xmpp-stanzas';
  38
  39 local new_sasl = require "util.sasl".new;
  40
  41 local function build_reply(status, ret, err_msg)
  42         local reply = st.stanza(status, {xmlns = xmlns_sasl});
  43         if status == "challenge" then
  44                 reply:text(base64.encode(ret or ""));
  45         elseif status == "failure" then
  46                 reply:tag(ret):up();
  47                 if err_msg then reply:tag("text"):text(err_msg); end
  48         elseif status == "success" then
  49                 reply:text(base64.encode(ret or ""));
  50         else
  51                 error("Unknown sasl status: "..status);
  52         end
  53         return reply;
  54 end
  55
  56 local function handle_status(session, status)
  57         if status == "failure" then
  58                 session.sasl_handler = nil;
  59         elseif status == "success" then
  60                 if not session.sasl_handler.username then error("SASL succeeded but we didn't get a username!"); end -- TODO move this to sessionmanager
  61                 sessionmanager.make_authenticated(session, session.sasl_handler.username);
  62                 session.sasl_handler = nil;
  63                 session:reset_stream();
  64         end
  65 end
  66
  67 local function password_callback(node, host, mechanism, raw_host)
  68         local password = (datamanager.load(node, host, "accounts") or {}).password; -- FIXME handle hashed passwords
  69         local func = function(x) return x; end;
  70         if password then
  71                 if mechanism == "PLAIN" then
  72                         return func, password;
  73                 elseif mechanism == "DIGEST-MD5" then
  74                         return func, md5(node..":"..raw_host..":"..password);
  75                 end
  76         end
  77         return func, nil;
  78 end
  79
  80 function sasl_handler(session, stanza)
  81         if stanza.name == "auth" then
  82                 -- FIXME ignoring duplicates because ejabberd does
  83                 session.sasl_handler = new_sasl(stanza.attr.mechanism, session.host, password_callback);
  84         elseif not session.sasl_handler then
  85                 return; -- FIXME ignoring out of order stanzas because ejabberd does
  86         end
  87         local text = stanza[1];
  88         if text then
  89                 text = base64.decode(text);
  90                 if not text then
  91                         session.sasl_handler = nil;
  92                         session.send(build_reply("failure", "incorrect-encoding"));
  93                         return;
  94                 end
  95         end
  96         local status, ret, err_msg = session.sasl_handler:feed(text);
  97         handle_status(session, status);
  98         local s = build_reply(status, ret, err_msg);
  99         log("debug", "sasl reply: "..tostring(s));
 100         session.send(s);
 101 end
 102
 103 module:add_handler("c2s_unauthed", "auth", xmlns_sasl, sasl_handler);
 104 module:add_handler("c2s_unauthed", "abort", xmlns_sasl, sasl_handler);
 105 module:add_handler("c2s_unauthed", "response", xmlns_sasl, sasl_handler);
 106
 107 local mechanisms_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-sasl' };
 108 local bind_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-bind' };
 109 local xmpp_session_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-session' };
 110 module:add_event_hook("stream-features",
 111                                         function (session, features)
 112                                                 if not session.username then
 113                                                         features:tag("mechanisms", mechanisms_attr);
 114                                                         -- 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.
 115                                                                 features:tag("mechanism"):text("PLAIN"):up();
 116                                                                 features:tag("mechanism"):text("DIGEST-MD5"):up();
 117                                                         features:up();
 118                                                 else
 119                                                         features:tag("bind", bind_attr):tag("required"):up():up();
 120                                                         features:tag("session", xmpp_session_attr):up();
 121                                                 end
 122                                         end);
 123
 124 module:add_iq_handler("c2s", "urn:ietf:params:xml:ns:xmpp-bind",
 125                 function (session, stanza)
 126                         log("debug", "Client tried to bind to a resource");
 127                         local resource;
 128                         if stanza.attr.type == "set" then
 129                                 local bind = stanza.tags[1];
 130                                 if bind and bind.attr.xmlns == xmlns_bind then
 131                                         resource = bind:child_with_name("resource");
 132                                         if resource then
 133                                                 resource = resource[1];
 134                                         end
 135                                 end
 136                         end
 137                         local success, err_type, err, err_msg = sm_bind_resource(session, resource);
 138                         if not success then
 139                                 session.send(st.error_reply(stanza, err_type, err, err_msg));
 140                         else
 141                                 session.send(st.reply(stanza)
 142                                         :tag("bind", { xmlns = xmlns_bind})
 143                                         :tag("jid"):text(session.full_jid));
 144                         end
 145                 end);
 146
 147 module:add_iq_handler("c2s", "urn:ietf:params:xml:ns:xmpp-session",
 148                 function (session, stanza)
 149                         log("debug", "Client tried to bind to a resource");
 150                         session.send(st.reply(stanza));
 151                 end);