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