plugins/mod_saslauth.lua

   1 -- Prosody IM v0.2
   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 base64 = require "util.encodings".base64;
  25
  26 local usermanager_validate_credentials = require "core.usermanager".validate_credentials;
  27 local t_concat, t_insert = table.concat, table.insert;
  28 local tostring = tostring;
  29 local jid_split = require "util.jid".split
  30 local md5 = require "util.hashes".md5;
  31
  32 local log = require "util.logger".init("mod_saslauth");
  33
  34 local xmlns_sasl ='urn:ietf:params:xml:ns:xmpp-sasl';
  35 local xmlns_bind ='urn:ietf:params:xml:ns:xmpp-bind';
  36 local xmlns_stanzas ='urn:ietf:params:xml:ns:xmpp-stanzas';
  37
  38 local new_sasl = require "util.sasl".new;
  39
  40 local function build_reply(status, ret, err_msg)
  41         local reply = st.stanza(status, {xmlns = xmlns_sasl});
  42         if status == "challenge" then
  43                 log("challenge", ret or "");
  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                 log("success", ret or "");
  50                 reply:text(base64.encode(ret or ""));
  51         else
  52                 error("Unknown sasl status: "..status);
  53         end
  54         return reply;
  55 end
  56
  57 local function handle_status(session, status)
  58         if status == "failure" then
  59                 session.sasl_handler = nil;
  60         elseif status == "success" then
  61                 if not session.sasl_handler.username then error("SASL succeeded but we didn't get a username!"); end -- TODO move this to sessionmanager
  62                 sessionmanager.make_authenticated(session, session.sasl_handler.username);
  63                 session.sasl_handler = nil;
  64                 session:reset_stream();
  65         end
  66 end
  67
  68 local function password_callback(node, host, mechanism, decoder)
  69         local password = (datamanager.load(node, host, "accounts") or {}).password; -- FIXME handle hashed passwords
  70         local func = function(x) return x; end;
  71         if password then
  72                 if mechanism == "PLAIN" then
  73                         return func, password;
  74                 elseif mechanism == "DIGEST-MD5" then
  75                         if decoder then node, host, password = decoder(node), decoder(host), decoder(password); end
  76                         return func, md5(node..":"..host..":"..password);
  77                 end
  78         end
  79         return func, nil;
  80 end
  81
  82 local function sasl_handler(session, stanza)
  83         if stanza.name == "auth" then
  84                 -- FIXME ignoring duplicates because ejabberd does
  85                 session.sasl_handler = new_sasl(stanza.attr.mechanism, session.host, password_callback);
  86         elseif not session.sasl_handler then
  87                 return; -- FIXME ignoring out of order stanzas because ejabberd does
  88         end
  89         local text = stanza[1];
  90         if text then
  91                 text = base64.decode(text);
  92                 log("recieved", text);
  93                 if not text then
  94                         session.sasl_handler = nil;
  95                         session.send(build_reply("failure", "incorrect-encoding"));
  96                         return;
  97                 end
  98         end
  99         local status, ret, err_msg = session.sasl_handler:feed(text);
 100         handle_status(session, status);
 101         local s = build_reply(status, ret, err_msg);
 102         log("debug", "sasl reply: "..tostring(s));
 103         session.send(s);
 104 end
 105
 106 module:add_handler("c2s_unauthed", "auth", xmlns_sasl, sasl_handler);
 107 module:add_handler("c2s_unauthed", "abort", xmlns_sasl, sasl_handler);
 108 module:add_handler("c2s_unauthed", "response", xmlns_sasl, sasl_handler);
 109
 110 local mechanisms_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-sasl' };
 111 local bind_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-bind' };
 112 local xmpp_session_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-session' };
 113 module:add_event_hook("stream-features",
 114                 function (session, features)
 115                         if not session.username then
 116                                 features:tag("mechanisms", mechanisms_attr);
 117                                 -- 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.
 118                                         features:tag("mechanism"):text("PLAIN"):up();
 119                                         features:tag("mechanism"):text("DIGEST-MD5"):up();
 120                                 features:up();
 121                         else
 122                                 features:tag("bind", bind_attr):tag("required"):up():up();
 123                                 features:tag("session", xmpp_session_attr):up();
 124                         end
 125                 end);
 126
 127 module:add_iq_handler("c2s", "urn:ietf:params:xml:ns:xmpp-bind",
 128                 function (session, stanza)
 129                         log("debug", "Client tried to bind to a resource");
 130                         local resource;
 131                         if stanza.attr.type == "set" then
 132                                 local bind = stanza.tags[1];
 133                                 if bind and bind.attr.xmlns == xmlns_bind then
 134                                         resource = bind:child_with_name("resource");
 135                                         if resource then
 136                                                 resource = resource[1];
 137                                         end
 138                                 end
 139                         end
 140                         local success, err_type, err, err_msg = sm_bind_resource(session, resource);
 141                         if not success then
 142                                 session.send(st.error_reply(stanza, err_type, err, err_msg));
 143                         else
 144                                 session.send(st.reply(stanza)
 145                                         :tag("bind", { xmlns = xmlns_bind})
 146                                         :tag("jid"):text(session.full_jid));
 147                         end
 148                 end);
 149
 150 module:add_iq_handler("c2s", "urn:ietf:params:xml:ns:xmpp-session",
 151                 function (session, stanza)
 152                         log("debug", "Client tried to bind to a resource");
 153                         session.send(st.reply(stanza));
 154                 end);