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