plugins/mod_saslauth.lua

   1 -- Prosody IM v0.4
   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 local config = require "core.configmanager";
  21
  22 local log = require "util.logger".init("mod_saslauth");
  23
  24 local xmlns_sasl ='urn:ietf:params:xml:ns:xmpp-sasl';
  25 local xmlns_bind ='urn:ietf:params:xml:ns:xmpp-bind';
  26 local xmlns_stanzas ='urn:ietf:params:xml:ns:xmpp-stanzas';
  27
  28 local new_sasl = require "util.sasl".new;
  29
  30 local function build_reply(status, ret, err_msg)
  31         local reply = st.stanza(status, {xmlns = xmlns_sasl});
  32         if status == "challenge" then
  33                 log("debug", ret or "");
  34                 reply:text(base64.encode(ret or ""));
  35         elseif status == "failure" then
  36                 reply:tag(ret):up();
  37                 if err_msg then reply:tag("text"):text(err_msg); end
  38         elseif status == "success" then
  39                 log("debug", ret or "");
  40                 reply:text(base64.encode(ret or ""));
  41         else
  42                 error("Unknown sasl status: "..status);
  43         end
  44         return reply;
  45 end
  46
  47 local function handle_status(session, status)
  48         if status == "failure" then
  49                 session.sasl_handler = nil;
  50         elseif status == "success" then
  51                 if not session.sasl_handler.username then error("SASL succeeded but we didn't get a username!"); end -- TODO move this to sessionmanager
  52                 sessionmanager.make_authenticated(session, session.sasl_handler.username);
  53                 session.sasl_handler = nil;
  54                 session:reset_stream();
  55         end
  56 end
  57
  58 local function password_callback(node, host, mechanism, decoder)
  59         local password = (datamanager.load(node, host, "accounts") or {}).password; -- FIXME handle hashed passwords
  60         local func = function(x) return x; end;
  61         if password then
  62                 if mechanism == "PLAIN" then
  63                         return func, password;
  64                 elseif mechanism == "DIGEST-MD5" then
  65                         if decoder then node, host, password = decoder(node), decoder(host), decoder(password); end
  66                         return func, md5(node..":"..host..":"..password);
  67                 end
  68         end
  69         return func, nil;
  70 end
  71
  72 local function sasl_handler(session, stanza)
  73         if stanza.name == "auth" then
  74                 -- FIXME ignoring duplicates because ejabberd does
  75                 if config.get(session.host or "*", "core", "anonymous_login") and stanza.attr.mechanism ~= "ANONYMOUS" then
  76                         return session.send(build_reply("failure", "invalid-mechanism"));
  77                 elseif stanza.attr.mechanism == "ANONYMOUS" then
  78                         return session.send(build_reply("failure", "mechanism-too-weak"));
  79                 end
  80                 session.sasl_handler = new_sasl(stanza.attr.mechanism, session.host, password_callback);
  81                 if not session.sasl_handler then
  82                         return session.send(build_reply("failure", "invalid-mechanism"));
  83                 end
  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                 log("debug", text);
  91                 if not text then
  92                         session.sasl_handler = nil;
  93                         session.send(build_reply("failure", "incorrect-encoding"));
  94                         return;
  95                 end
  96         end
  97         local status, ret, err_msg = session.sasl_handler:feed(text);
  98         handle_status(session, status);
  99         local s = build_reply(status, ret, err_msg);
 100         log("debug", "sasl reply: "..tostring(s));
 101         session.send(s);
 102 end
 103
 104 module:add_handler("c2s_unauthed", "auth", xmlns_sasl, sasl_handler);
 105 module:add_handler("c2s_unauthed", "abort", xmlns_sasl, sasl_handler);
 106 module:add_handler("c2s_unauthed", "response", xmlns_sasl, sasl_handler);
 107
 108 local mechanisms_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-sasl' };
 109 local bind_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-bind' };
 110 local xmpp_session_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-session' };
 111 module:add_event_hook("stream-features",
 112                 function (session, features)
 113                         if not session.username then
 114                                 features:tag("mechanisms", mechanisms_attr);
 115                                 -- 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.
 116                                         if config.get(session.host or "*", "core", "anonymous_login") then
 117                                                 features:tag("mechanism"):text("ANONYMOUS"):up();
 118                                         else
 119                                                 features:tag("mechanism"):text("DIGEST-MD5"):up();
 120                                                 features:tag("mechanism"):text("PLAIN"):up();
 121                                         end
 122                                 features:up();
 123                         else
 124                                 features:tag("bind", bind_attr):tag("required"):up():up();
 125                                 features:tag("session", xmpp_session_attr):up();
 126                         end
 127                 end);
 128
 129 module:add_iq_handler("c2s", "urn:ietf:params:xml:ns:xmpp-bind",
 130                 function (session, stanza)
 131                         log("debug", "Client tried to bind to a resource");
 132                         local resource;
 133                         if stanza.attr.type == "set" then
 134                                 local bind = stanza.tags[1];
 135                                 if bind and bind.attr.xmlns == xmlns_bind then
 136                                         resource = bind:child_with_name("resource");
 137                                         if resource then
 138                                                 resource = resource[1];
 139                                         end
 140                                 end
 141                         end
 142                         local success, err_type, err, err_msg = sm_bind_resource(session, resource);
 143                         if not success then
 144                                 session.send(st.error_reply(stanza, err_type, err, err_msg));
 145                         else
 146                                 session.send(st.reply(stanza)
 147                                         :tag("bind", { xmlns = xmlns_bind})
 148                                         :tag("jid"):text(session.full_jid));
 149                         end
 150                 end);
 151
 152 module:add_iq_handler("c2s", "urn:ietf:params:xml:ns:xmpp-session",
 153                 function (session, stanza)
 154                         log("debug", "Client tried to bind to a resource");
 155                         session.send(st.reply(stanza));
 156                 end);