plugins/mod_saslauth.lua

   1 -- Prosody IM
   2 -- Copyright (C) 2008-2010 Matthew Wild
   3 -- Copyright (C) 2008-2010 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
  16 local nodeprep = require "util.encodings".stringprep.nodeprep;
  17 local datamanager_load = require "util.datamanager".load;
  18 local usermanager_get_provider = require "core.usermanager".get_provider;
  19 local usermanager_get_sasl_handler = require "core.usermanager".get_sasl_handler;
  20 local usermanager_user_exists = require "core.usermanager".user_exists;
  21 local usermanager_get_password = require "core.usermanager".get_password;
  22 local usermanager_test_password = require "core.usermanager".test_password;
  23 local t_concat, t_insert = table.concat, table.insert;
  24 local tostring = tostring;
  25 local jid_split = require "util.jid".split;
  26 local md5 = require "util.hashes".md5;
  27 local config = require "core.configmanager";
  28
  29 local secure_auth_only = module:get_option("c2s_require_encryption") or module:get_option("require_encryption");
  30 local sasl_backend = module:get_option("sasl_backend") or "builtin";
  31 local anonymous_login = module:get_option("anonymous_login");
  32
  33 -- Cyrus config options
  34 local require_provisioning = module:get_option("cyrus_require_provisioning") or false;
  35 local cyrus_service_realm = module:get_option("cyrus_service_realm");
  36 local cyrus_service_name = module:get_option("cyrus_service_name");
  37 local cyrus_application_name = module:get_option("cyrus_application_name");
  38
  39 local log = module._log;
  40
  41 local xmlns_sasl ='urn:ietf:params:xml:ns:xmpp-sasl';
  42 local xmlns_bind ='urn:ietf:params:xml:ns:xmpp-bind';
  43 local xmlns_stanzas ='urn:ietf:params:xml:ns:xmpp-stanzas';
  44
  45 local new_sasl;
  46 if sasl_backend == "builtin" then
  47         new_sasl = require "util.sasl".new;
  48 elseif sasl_backend == "cyrus" then
  49         prosody.unlock_globals(); --FIXME: Figure out why this is needed and
  50                                   -- why cyrussasl isn't caught by the sandbox
  51         local ok, cyrus = pcall(require, "util.sasl_cyrus");
  52         prosody.lock_globals();
  53         if ok then
  54                 local cyrus_new = cyrus.new;
  55                 new_sasl = function(realm)
  56                         return cyrus_new(
  57                                 cyrus_service_realm or realm,
  58                                 cyrus_service_name or "xmpp",
  59                                 cyrus_application_name or "prosody"
  60                         );
  61                 end
  62         else
  63                 module:log("error", "Failed to load Cyrus SASL because: %s", cyrus);
  64                 error("Failed to load Cyrus SASL");
  65         end
  66 else
  67         module:log("error", "Unknown SASL backend: %s", sasl_backend);
  68         error("Unknown SASL backend");
  69 end
  70
  71 local anonymous_authentication_profile = {
  72         anonymous = function(username, realm)
  73                 return true; -- for normal usage you should always return true here
  74         end
  75 };
  76
  77 local function build_reply(status, ret, err_msg)
  78         local reply = st.stanza(status, {xmlns = xmlns_sasl});
  79         if status == "challenge" then
  80                 --log("debug", "CHALLENGE: %s", ret or "");
  81                 reply:text(base64.encode(ret or ""));
  82         elseif status == "failure" then
  83                 reply:tag(ret):up();
  84                 if err_msg then reply:tag("text"):text(err_msg); end
  85         elseif status == "success" then
  86                 --log("debug", "SUCCESS: %s", ret or "");
  87                 reply:text(base64.encode(ret or ""));
  88         else
  89                 module:log("error", "Unknown sasl status: %s", status);
  90         end
  91         return reply;
  92 end
  93
  94 local function handle_status(session, status, ret, err_msg)
  95         if status == "failure" then
  96                 session.sasl_handler = session.sasl_handler:clean_clone();
  97         elseif status == "success" then
  98                 local username = nodeprep(session.sasl_handler.username);
  99
 100                 if not(require_provisioning) or usermanager_user_exists(username, session.host) then
 101                         local ok, err = sm_make_authenticated(session, session.sasl_handler.username);
 102                         if ok then
 103                                 session.sasl_handler = nil;
 104                                 session:reset_stream();
 105                         else
 106                                 module:log("warn", "SASL succeeded but username was invalid");
 107                                 session.sasl_handler = session.sasl_handler:clean_clone();
 108                                 return "failure", "not-authorized", "User authenticated successfully, but username was invalid";
 109                         end
 110                 else
 111                         module:log("warn", "SASL succeeded but we don't have an account provisioned for %s", username);
 112                         session.sasl_handler = session.sasl_handler:clean_clone();
 113                         return "failure", "not-authorized", "User authenticated successfully, but not provisioned for XMPP";
 114                 end
 115         end
 116         return status, ret, err_msg;
 117 end
 118
 119 local function sasl_handler(session, stanza)
 120         if stanza.name == "auth" then
 121                 -- FIXME ignoring duplicates because ejabberd does
 122                 if anonymous_login then
 123                         if stanza.attr.mechanism ~= "ANONYMOUS" then
 124                                 return session.send(build_reply("failure", "invalid-mechanism"));
 125                         end
 126                 elseif stanza.attr.mechanism == "ANONYMOUS" then
 127                         return session.send(build_reply("failure", "mechanism-too-weak"));
 128                 end
 129                 local valid_mechanism = session.sasl_handler:select(stanza.attr.mechanism);
 130                 if not valid_mechanism then
 131                         return session.send(build_reply("failure", "invalid-mechanism"));
 132                 end
 133                 if secure_auth_only and not session.secure then
 134                         return session.send(build_reply("failure", "encryption-required"));
 135                 end
 136         elseif not session.sasl_handler then
 137                 return; -- FIXME ignoring out of order stanzas because ejabberd does
 138         end
 139         local text = stanza[1];
 140         if text then
 141                 text = base64.decode(text);
 142                 --log("debug", "AUTH: %s", text:gsub("[%z\001-\008\011\012\014-\031]", " "));
 143                 if not text then
 144                         session.sasl_handler = nil;
 145                         session.send(build_reply("failure", "incorrect-encoding"));
 146                         return;
 147                 end
 148         end
 149         local status, ret, err_msg = session.sasl_handler:process(text);
 150         status, ret, err_msg = handle_status(session, status, ret, err_msg);
 151         local s = build_reply(status, ret, err_msg);
 152         log("debug", "sasl reply: %s", tostring(s));
 153         session.send(s);
 154 end
 155
 156 module:add_handler("c2s_unauthed", "auth", xmlns_sasl, sasl_handler);
 157 module:add_handler("c2s_unauthed", "abort", xmlns_sasl, sasl_handler);
 158 module:add_handler("c2s_unauthed", "response", xmlns_sasl, sasl_handler);
 159
 160 local mechanisms_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-sasl' };
 161 local bind_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-bind' };
 162 local xmpp_session_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-session' };
 163 module:hook("stream-features", function(event)
 164         local origin, features = event.origin, event.features;
 165         if not origin.username then
 166                 if secure_auth_only and not origin.secure then
 167                         return;
 168                 end
 169                 local realm = module:get_option("sasl_realm") or origin.host;
 170                 if anonymous_login then
 171                         origin.sasl_handler = new_sasl(realm, anonymous_authentication_profile);
 172                 else
 173                         origin.sasl_handler = usermanager_get_sasl_handler(module.host);
 174                         if not (module:get_option("allow_unencrypted_plain_auth")) and not origin.secure then
 175                                 origin.sasl_handler:forbidden({"PLAIN"});
 176                         end
 177                 end
 178                 features:tag("mechanisms", mechanisms_attr);
 179                 for k in pairs(origin.sasl_handler:mechanisms()) do
 180                         features:tag("mechanism"):text(k):up();
 181                 end
 182                 features:up();
 183         else
 184                 features:tag("bind", bind_attr):tag("required"):up():up();
 185                 features:tag("session", xmpp_session_attr):tag("optional"):up():up();
 186         end
 187 end);
 188
 189 module:add_iq_handler("c2s", "urn:ietf:params:xml:ns:xmpp-bind", function(session, stanza)
 190         log("debug", "Client requesting a resource bind");
 191         local resource;
 192         if stanza.attr.type == "set" then
 193                 local bind = stanza.tags[1];
 194                 if bind and bind.attr.xmlns == xmlns_bind then
 195                         resource = bind:child_with_name("resource");
 196                         if resource then
 197                                 resource = resource[1];
 198                         end
 199                 end
 200         end
 201         local success, err_type, err, err_msg = sm_bind_resource(session, resource);
 202         if not success then
 203                 session.send(st.error_reply(stanza, err_type, err, err_msg));
 204         else
 205                 session.send(st.reply(stanza)
 206                         :tag("bind", { xmlns = xmlns_bind})
 207                         :tag("jid"):text(session.full_jid));
 208         end
 209 end);
 210
 211 module:add_iq_handler("c2s", "urn:ietf:params:xml:ns:xmpp-session", function(session, stanza)
 212         log("debug", "Client requesting a session");
 213         session.send(st.reply(stanza));
 214 end);