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 datamanager_load = require "util.datamanager".load;
  17 local usermanager_validate_credentials = require "core.usermanager".validate_credentials;
  18 local usermanager_get_supported_methods = require "core.usermanager".get_supported_methods;
  19 local usermanager_user_exists = require "core.usermanager".user_exists;
  20 local usermanager_get_password = require "core.usermanager".get_password;
  21 local t_concat, t_insert = table.concat, table.insert;
  22 local tostring = tostring;
  23 local jid_split = require "util.jid".split
  24 local md5 = require "util.hashes".md5;
  25 local config = require "core.configmanager";
  26
  27 local secure_auth_only = config.get(module:get_host(), "core", "require_encryption");
  28
  29 local log = module._log;
  30
  31 local xmlns_sasl ='urn:ietf:params:xml:ns:xmpp-sasl';
  32 local xmlns_bind ='urn:ietf:params:xml:ns:xmpp-bind';
  33 local xmlns_stanzas ='urn:ietf:params:xml:ns:xmpp-stanzas';
  34
  35 local new_sasl = require "util.sasl".new;
  36
  37 default_authentication_profile = {
  38         plain = function(username, realm)
  39                         return usermanager_get_password(username, realm), true;
  40                 end
  41 };
  42
  43 local function build_reply(status, ret, err_msg)
  44         local reply = st.stanza(status, {xmlns = xmlns_sasl});
  45         if status == "challenge" then
  46                 log("debug", "%s", ret or "");
  47                 reply:text(base64.encode(ret or ""));
  48         elseif status == "failure" then
  49                 reply:tag(ret):up();
  50                 if err_msg then reply:tag("text"):text(err_msg); end
  51         elseif status == "success" then
  52                 log("debug", "%s", ret or "");
  53                 reply:text(base64.encode(ret or ""));
  54         else
  55                 module:log("error", "Unknown sasl status: %s", status);
  56         end
  57         return reply;
  58 end
  59
  60 local function handle_status(session, status)
  61         if status == "failure" then
  62                 session.sasl_handler = nil;
  63         elseif status == "success" then
  64                 if not session.sasl_handler.username then -- TODO move this to sessionmanager
  65                         module:log("warn", "SASL succeeded but we didn't get a username!");
  66                         session.sasl_handler = nil;
  67                         session:reset_stream();
  68                         return;
  69                 end
  70                 sm_make_authenticated(session, session.sasl_handler.username);
  71                 session.sasl_handler = nil;
  72                 session:reset_stream();
  73         end
  74 end
  75
  76 local function credentials_callback(mechanism, ...)
  77         if mechanism == "PLAIN" then
  78                 local username, hostname, password = ...;
  79                 local response = usermanager_validate_credentials(hostname, username, password, mechanism);
  80                 if response == nil then
  81                         return false;
  82                 else
  83                         return response;
  84                 end
  85         elseif mechanism == "DIGEST-MD5" then
  86                 function func(x) return x; end
  87                 local node, domain, realm, decoder = ...;
  88                 local password = usermanager_get_password(node, domain);
  89                 if password then
  90                         if decoder then
  91                                 node, realm, password = decoder(node), decoder(realm), decoder(password);
  92                         end
  93                         return func, md5(node..":"..realm..":"..password);
  94                 else
  95                         return func, nil;
  96                 end
  97         end
  98 end
  99
 100 local function sasl_handler(session, stanza)
 101         if stanza.name == "auth" then
 102                 -- FIXME ignoring duplicates because ejabberd does
 103                 if config.get(session.host or "*", "core", "anonymous_login") then
 104                         if stanza.attr.mechanism ~= "ANONYMOUS" then
 105                                 return session.send(build_reply("failure", "invalid-mechanism"));
 106                         end
 107                 elseif stanza.attr.mechanism == "ANONYMOUS" then
 108                         return session.send(build_reply("failure", "mechanism-too-weak"));
 109                 end
 110                 local valid_mechanism = session.sasl_handler:select(stanza.attr.mechanism);
 111                 if not valid_mechanism then
 112                         return session.send(build_reply("failure", "invalid-mechanism"));
 113                 end
 114         elseif not session.sasl_handler then
 115                 return; -- FIXME ignoring out of order stanzas because ejabberd does
 116         end
 117         local text = stanza[1];
 118         if text then
 119                 text = base64.decode(text);
 120                 log("debug", "%s", text);
 121                 if not text then
 122                         session.sasl_handler = nil;
 123                         session.send(build_reply("failure", "incorrect-encoding"));
 124                         return;
 125                 end
 126         end
 127         local status, ret, err_msg = session.sasl_handler:process(text);
 128         handle_status(session, status);
 129         local s = build_reply(status, ret, err_msg);
 130         log("debug", "sasl reply: %s", tostring(s));
 131         session.send(s);
 132 end
 133
 134 module:add_handler("c2s_unauthed", "auth", xmlns_sasl, sasl_handler);
 135 module:add_handler("c2s_unauthed", "abort", xmlns_sasl, sasl_handler);
 136 module:add_handler("c2s_unauthed", "response", xmlns_sasl, sasl_handler);
 137
 138 local mechanisms_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-sasl' };
 139 local bind_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-bind' };
 140 local xmpp_session_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-session' };
 141 module:add_event_hook("stream-features",
 142                 function (session, features)
 143                         if not session.username then
 144                                 if secure_auth_only and not session.secure then
 145                                         return;
 146                                 end
 147                                 session.sasl_handler = new_sasl(session.host, default_authentication_profile);
 148                                 features:tag("mechanisms", mechanisms_attr);
 149                                 -- 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.
 150                                         if config.get(session.host or "*", "core", "anonymous_login") then
 151                                                 features:tag("mechanism"):text("ANONYMOUS"):up();
 152                                         else
 153                                                 for k, v in pairs(session.sasl_handler:mechanisms()) do
 154                                                         features:tag("mechanism"):text(v):up();
 155                                                 end
 156                                         end
 157                                 features:up();
 158                         else
 159                                 features:tag("bind", bind_attr):tag("required"):up():up();
 160                                 features:tag("session", xmpp_session_attr):up();
 161                         end
 162                 end);
 163
 164 module:add_iq_handler("c2s", "urn:ietf:params:xml:ns:xmpp-bind",
 165                 function (session, stanza)
 166                         log("debug", "Client requesting a resource bind");
 167                         local resource;
 168                         if stanza.attr.type == "set" then
 169                                 local bind = stanza.tags[1];
 170                                 if bind and bind.attr.xmlns == xmlns_bind then
 171                                         resource = bind:child_with_name("resource");
 172                                         if resource then
 173                                                 resource = resource[1];
 174                                         end
 175                                 end
 176                         end
 177                         local success, err_type, err, err_msg = sm_bind_resource(session, resource);
 178                         if not success then
 179                                 session.send(st.error_reply(stanza, err_type, err, err_msg));
 180                         else
 181                                 session.send(st.reply(stanza)
 182                                         :tag("bind", { xmlns = xmlns_bind})
 183                                         :tag("jid"):text(session.full_jid));
 184                         end
 185                 end);
 186
 187 module:add_iq_handler("c2s", "urn:ietf:params:xml:ns:xmpp-session",
 188                 function (session, stanza)
 189                         log("debug", "Client requesting a session");
 190                         session.send(st.reply(stanza));
 191                 end);