plugins/mod_saslauth.lua

   1 -- Prosody IM
   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
  16 local nodeprep = require "util.encodings".stringprep.nodeprep;
  17 local datamanager_load = require "util.datamanager".load;
  18 local usermanager_validate_credentials = require "core.usermanager".validate_credentials;
  19 local usermanager_get_supported_methods = require "core.usermanager".get_supported_methods;
  20 local usermanager_user_exists = require "core.usermanager".user_exists;
  21 local usermanager_get_password = require "core.usermanager".get_password;
  22 local t_concat, t_insert = table.concat, table.insert;
  23 local tostring = tostring;
  24 local jid_split = require "util.jid".split
  25 local md5 = require "util.hashes".md5;
  26 local config = require "core.configmanager";
  27
  28 local secure_auth_only = config.get(module:get_host(), "core", "c2s_require_encryption") or config.get(module:get_host(), "core", "require_encryption");
  29
  30 local log = module._log;
  31
  32 local xmlns_sasl ='urn:ietf:params:xml:ns:xmpp-sasl';
  33 local xmlns_bind ='urn:ietf:params:xml:ns:xmpp-bind';
  34 local xmlns_stanzas ='urn:ietf:params:xml:ns:xmpp-stanzas';
  35
  36 local new_sasl
  37 if config.get(module:get_host(), "core", "cyrus_service_name") then
  38         cyrus_new = require "util.sasl_cyrus".new;
  39         new_sasl = function(realm)
  40                         return cyrus_new(realm, config.get(module:get_host(), "core", "cyrus_service_name"))
  41                 end
  42 else
  43         new_sasl = require "util.sasl".new;
  44 end
  45
  46 default_authentication_profile = {
  47         plain = function(username, realm)
  48                         local prepped_username = nodeprep(username);
  49                         if not prepped_username then
  50                                 log("debug", "NODEprep failed on username: %s", username);
  51                                 return "", nil;
  52                         end
  53                         local password = usermanager_get_password(prepped_username, realm);
  54                         if not password then
  55                                 return "", nil;
  56                         end
  57                         return password, true;
  58                 end
  59 };
  60
  61 anonymous_authentication_profile = {
  62         anonymous = function(username, realm)
  63                         return true; -- for normal usage you should always return true here
  64                 end
  65 }
  66
  67 local function build_reply(status, ret, err_msg)
  68         local reply = st.stanza(status, {xmlns = xmlns_sasl});
  69         if status == "challenge" then
  70                 log("debug", "%s", ret or "");
  71                 reply:text(base64.encode(ret or ""));
  72         elseif status == "failure" then
  73                 reply:tag(ret):up();
  74                 if err_msg then reply:tag("text"):text(err_msg); end
  75         elseif status == "success" then
  76                 log("debug", "%s", ret or "");
  77                 reply:text(base64.encode(ret or ""));
  78         else
  79                 module:log("error", "Unknown sasl status: %s", status);
  80         end
  81         return reply;
  82 end
  83
  84 local function handle_status(session, status)
  85         if status == "failure" then
  86                 session.sasl_handler = session.sasl_handler:clean_clone();
  87         elseif status == "success" then
  88                 local username = nodeprep(session.sasl_handler.username);
  89                 if not username then -- TODO move this to sessionmanager
  90                         module:log("warn", "SASL succeeded but we didn't get a username!");
  91                         session.sasl_handler = nil;
  92                         session:reset_stream();
  93                         return;
  94                 end
  95                 sm_make_authenticated(session, session.sasl_handler.username);
  96                 session.sasl_handler = nil;
  97                 session:reset_stream();
  98         end
  99 end
 100
 101 local function sasl_handler(session, stanza)
 102         if stanza.name == "auth" then
 103                 -- FIXME ignoring duplicates because ejabberd does
 104                 if config.get(session.host or "*", "core", "anonymous_login") then
 105                         if stanza.attr.mechanism ~= "ANONYMOUS" then
 106                                 return session.send(build_reply("failure", "invalid-mechanism"));
 107                         end
 108                 elseif stanza.attr.mechanism == "ANONYMOUS" then
 109                         return session.send(build_reply("failure", "mechanism-too-weak"));
 110                 end
 111                 local valid_mechanism = session.sasl_handler:select(stanza.attr.mechanism);
 112                 if not valid_mechanism then
 113                         return session.send(build_reply("failure", "invalid-mechanism"));
 114                 end
 115                 if secure_auth_only and not session.secure then
 116                         return session.send(build_reply("failure", "encryption-required"));
 117                 end
 118         elseif not session.sasl_handler then
 119                 return; -- FIXME ignoring out of order stanzas because ejabberd does
 120         end
 121         local text = stanza[1];
 122         if text then
 123                 text = base64.decode(text);
 124                 log("debug", "%s", text:gsub("[%z\001-\008\011\012\014-\031]", " "));
 125                 if not text then
 126                         session.sasl_handler = nil;
 127                         session.send(build_reply("failure", "incorrect-encoding"));
 128                         return;
 129                 end
 130         end
 131         local status, ret, err_msg = session.sasl_handler:process(text);
 132         handle_status(session, status);
 133         local s = build_reply(status, ret, err_msg);
 134         log("debug", "sasl reply: %s", tostring(s));
 135         session.send(s);
 136 end
 137
 138 module:add_handler("c2s_unauthed", "auth", xmlns_sasl, sasl_handler);
 139 module:add_handler("c2s_unauthed", "abort", xmlns_sasl, sasl_handler);
 140 module:add_handler("c2s_unauthed", "response", xmlns_sasl, sasl_handler);
 141
 142 local mechanisms_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-sasl' };
 143 local bind_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-bind' };
 144 local xmpp_session_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-session' };
 145 module:add_event_hook("stream-features",
 146                 function (session, features)
 147                         if not session.username then
 148                                 if secure_auth_only and not session.secure then
 149                                         return;
 150                                 end
 151                                 if module:get_option("anonymous_login") then
 152                                         session.sasl_handler = new_sasl(session.host, anonymous_authentication_profile);
 153                                 else
 154                                         session.sasl_handler = new_sasl(session.host, default_authentication_profile);
 155                                         if not (module:get_option("allow_unencrypted_plain_auth")) and not session.secure then
 156                                                 session.sasl_handler:forbidden({"PLAIN"});
 157                                         end
 158                                 end
 159                                 features:tag("mechanisms", mechanisms_attr);
 160                                 for k, v in pairs(session.sasl_handler:mechanisms()) do
 161                                         features:tag("mechanism"):text(v):up();
 162                                 end
 163                                 features:up();
 164                         else
 165                                 features:tag("bind", bind_attr):tag("required"):up():up();
 166                                 features:tag("session", xmpp_session_attr):tag("optional"):up():up();
 167                         end
 168                 end);
 169
 170 module:add_iq_handler("c2s", "urn:ietf:params:xml:ns:xmpp-bind",
 171                 function (session, stanza)
 172                         log("debug", "Client requesting a resource bind");
 173                         local resource;
 174                         if stanza.attr.type == "set" then
 175                                 local bind = stanza.tags[1];
 176                                 if bind and bind.attr.xmlns == xmlns_bind then
 177                                         resource = bind:child_with_name("resource");
 178                                         if resource then
 179                                                 resource = resource[1];
 180                                         end
 181                                 end
 182                         end
 183                         local success, err_type, err, err_msg = sm_bind_resource(session, resource);
 184                         if not success then
 185                                 session.send(st.error_reply(stanza, err_type, err, err_msg));
 186                         else
 187                                 session.send(st.reply(stanza)
 188                                         :tag("bind", { xmlns = xmlns_bind})
 189                                         :tag("jid"):text(session.full_jid));
 190                         end
 191                 end);
 192
 193 module:add_iq_handler("c2s", "urn:ietf:params:xml:ns:xmpp-session",
 194                 function (session, stanza)
 195                         log("debug", "Client requesting a session");
 196                         session.send(st.reply(stanza));
 197                 end);