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 sm_make_authenticated = require "core.sessionmanager".make_authenticated;
  14 local base64 = require "util.encodings".base64;
  15 local to_unicode = require "util.encodings".idna.to_unicode;
  16
  17 local datamanager_load = require "util.datamanager".load;
  18 local usermanager_validate_credentials = require "core.usermanager".validate_credentials;
  19 local t_concat, t_insert = table.concat, table.insert;
  20 local tostring = tostring;
  21 local jid_split = require "util.jid".split
  22 local md5 = require "util.hashes".md5;
  23 local config = require "core.configmanager";
  24
  25 local secure_auth_only = config.get(module:get_host(), "core", "require_encryption");
  26
  27 local log = module._log;
  28
  29 local xmlns_sasl ='urn:ietf:params:xml:ns:xmpp-sasl';
  30 local xmlns_bind ='urn:ietf:params:xml:ns:xmpp-bind';
  31 local xmlns_stanzas ='urn:ietf:params:xml:ns:xmpp-stanzas';
  32
  33 local new_sasl = require "util.sasl".new;
  34
  35 local function build_reply(status, ret, err_msg)
  36         local reply = st.stanza(status, {xmlns = xmlns_sasl});
  37         if status == "challenge" then
  38                 log("debug", "%s", ret or "");
  39                 reply:text(base64.encode(ret or ""));
  40         elseif status == "failure" then
  41                 reply:tag(ret):up();
  42                 if err_msg then reply:tag("text"):text(err_msg); end
  43         elseif status == "success" then
  44                 log("debug", "%s", ret or "");
  45                 reply:text(base64.encode(ret or ""));
  46         else
  47                 module:log("error", "Unknown sasl status: %s", status);
  48         end
  49         return reply;
  50 end
  51
  52 local function handle_status(session, status)
  53         if status == "failure" then
  54                 session.sasl_handler = nil;
  55         elseif status == "success" then
  56                 if not session.sasl_handler.username then -- TODO move this to sessionmanager
  57                         module:log("warn", "SASL succeeded but we didn't get a username!");
  58                         session.sasl_handler = nil;
  59                         session:reset_stream();
  60                         return;
  61                 end
  62                 sm_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, hostname, realm, mechanism, decoder)
  69         local password = (datamanager_load(node, to_unicode(hostname), "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, hostname, password = decoder(node), decoder(hostname), decoder(password); end
  76                         return func, md5(node..":"..realm..":"..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                 if config.get(session.host or "*", "core", "anonymous_login") then
  86                         if stanza.attr.mechanism ~= "ANONYMOUS" then
  87                                 return session.send(build_reply("failure", "invalid-mechanism"));
  88                         end
  89                 elseif stanza.attr.mechanism == "ANONYMOUS" then
  90                         return session.send(build_reply("failure", "mechanism-too-weak"));
  91                 end
  92                 session.sasl_handler = new_sasl(stanza.attr.mechanism, session.host, password_callback);
  93                 if not session.sasl_handler then
  94                         return session.send(build_reply("failure", "invalid-mechanism"));
  95                 end
  96         elseif not session.sasl_handler then
  97                 return; -- FIXME ignoring out of order stanzas because ejabberd does
  98         end
  99         local text = stanza[1];
 100         if text then
 101                 text = base64.decode(text);
 102                 log("debug", "%s", text);
 103                 if not text then
 104                         session.sasl_handler = nil;
 105                         session.send(build_reply("failure", "incorrect-encoding"));
 106                         return;
 107                 end
 108         end
 109         local status, ret, err_msg = session.sasl_handler:feed(text);
 110         handle_status(session, status);
 111         local s = build_reply(status, ret, err_msg);
 112         log("debug", "sasl reply: %s", tostring(s));
 113         session.send(s);
 114 end
 115
 116 module:add_handler("c2s_unauthed", "auth", xmlns_sasl, sasl_handler);
 117 module:add_handler("c2s_unauthed", "abort", xmlns_sasl, sasl_handler);
 118 module:add_handler("c2s_unauthed", "response", xmlns_sasl, sasl_handler);
 119
 120 local mechanisms_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-sasl' };
 121 local bind_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-bind' };
 122 local xmpp_session_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-session' };
 123 module:add_event_hook("stream-features",
 124                 function (session, features)
 125                         if not session.username then
 126                                 if secure_auth_only and not session.secure then
 127                                         return;
 128                                 end
 129                                 features:tag("mechanisms", mechanisms_attr);
 130                                 -- 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.
 131                                         if config.get(session.host or "*", "core", "anonymous_login") then
 132                                                 features:tag("mechanism"):text("ANONYMOUS"):up();
 133                                         else
 134                                                 features:tag("mechanism"):text("DIGEST-MD5"):up();
 135                                                 features:tag("mechanism"):text("PLAIN"):up();
 136                                         end
 137                                 features:up();
 138                         else
 139                                 features:tag("bind", bind_attr):tag("required"):up():up();
 140                                 features:tag("session", xmpp_session_attr):up();
 141                         end
 142                 end);
 143
 144 module:add_iq_handler("c2s", "urn:ietf:params:xml:ns:xmpp-bind",
 145                 function (session, stanza)
 146                         log("debug", "Client requesting a resource bind");
 147                         local resource;
 148                         if stanza.attr.type == "set" then
 149                                 local bind = stanza.tags[1];
 150                                 if bind and bind.attr.xmlns == xmlns_bind then
 151                                         resource = bind:child_with_name("resource");
 152                                         if resource then
 153                                                 resource = resource[1];
 154                                         end
 155                                 end
 156                         end
 157                         local success, err_type, err, err_msg = sm_bind_resource(session, resource);
 158                         if not success then
 159                                 session.send(st.error_reply(stanza, err_type, err, err_msg));
 160                         else
 161                                 session.send(st.reply(stanza)
 162                                         :tag("bind", { xmlns = xmlns_bind})
 163                                         :tag("jid"):text(session.full_jid));
 164                         end
 165                 end);
 166
 167 module:add_iq_handler("c2s", "urn:ietf:params:xml:ns:xmpp-session",
 168                 function (session, stanza)
 169                         log("debug", "Client requesting a session");
 170                         session.send(st.reply(stanza));
 171                 end);