plugins/mod_saslauth.lua

   1 -- Prosody IM v0.4
   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 t_concat, t_insert = table.concat, table.insert;
  19 local tostring = tostring;
  20 local jid_split = require "util.jid".split
  21 local md5 = require "util.hashes".md5;
  22 local config = require "core.configmanager";
  23
  24 local log = require "util.logger".init("mod_saslauth");
  25
  26 local xmlns_sasl ='urn:ietf:params:xml:ns:xmpp-sasl';
  27 local xmlns_bind ='urn:ietf:params:xml:ns:xmpp-bind';
  28 local xmlns_stanzas ='urn:ietf:params:xml:ns:xmpp-stanzas';
  29
  30 local new_sasl = require "util.sasl".new;
  31
  32 local function build_reply(status, ret, err_msg)
  33         local reply = st.stanza(status, {xmlns = xmlns_sasl});
  34         if status == "challenge" then
  35                 log("debug", ret or "");
  36                 reply:text(base64.encode(ret or ""));
  37         elseif status == "failure" then
  38                 reply:tag(ret):up();
  39                 if err_msg then reply:tag("text"):text(err_msg); end
  40         elseif status == "success" then
  41                 log("debug", ret or "");
  42                 reply:text(base64.encode(ret or ""));
  43         else
  44                 error("Unknown sasl status: "..status);
  45         end
  46         return reply;
  47 end
  48
  49 local function handle_status(session, status)
  50         if status == "failure" then
  51                 session.sasl_handler = nil;
  52         elseif status == "success" then
  53                 if not session.sasl_handler.username then error("SASL succeeded but we didn't get a username!"); end -- TODO move this to sessionmanager
  54                 sm_make_authenticated(session, session.sasl_handler.username);
  55                 session.sasl_handler = nil;
  56                 session:reset_stream();
  57         end
  58 end
  59
  60 local function password_callback(node, host, mechanism, decoder)
  61         local password = (datamanager_load(node, host, "accounts") or {}).password; -- FIXME handle hashed passwords
  62         local func = function(x) return x; end;
  63         if password then
  64                 if mechanism == "PLAIN" then
  65                         return func, password;
  66                 elseif mechanism == "DIGEST-MD5" then
  67                         if decoder then node, host, password = decoder(node), decoder(host), decoder(password); end
  68                         return func, md5(node..":"..host..":"..password);
  69                 end
  70         end
  71         return func, nil;
  72 end
  73
  74 local function sasl_handler(session, stanza)
  75         if stanza.name == "auth" then
  76                 -- FIXME ignoring duplicates because ejabberd does
  77                 if config.get(session.host or "*", "core", "anonymous_login") and stanza.attr.mechanism ~= "ANONYMOUS" then
  78                         return session.send(build_reply("failure", "invalid-mechanism"));
  79                 elseif stanza.attr.mechanism == "ANONYMOUS" then
  80                         return session.send(build_reply("failure", "mechanism-too-weak"));
  81                 end
  82                 session.sasl_handler = new_sasl(stanza.attr.mechanism, session.host, password_callback);
  83                 if not session.sasl_handler then
  84                         return session.send(build_reply("failure", "invalid-mechanism"));
  85                 end
  86         elseif not session.sasl_handler then
  87                 return; -- FIXME ignoring out of order stanzas because ejabberd does
  88         end
  89         local text = stanza[1];
  90         if text then
  91                 text = base64.decode(text);
  92                 log("debug", text);
  93                 if not text then
  94                         session.sasl_handler = nil;
  95                         session.send(build_reply("failure", "incorrect-encoding"));
  96                         return;
  97                 end
  98         end
  99         local status, ret, err_msg = session.sasl_handler:feed(text);
 100         handle_status(session, status);
 101         local s = build_reply(status, ret, err_msg);
 102         log("debug", "sasl reply: "..tostring(s));
 103         session.send(s);
 104 end
 105
 106 module:add_handler("c2s_unauthed", "auth", xmlns_sasl, sasl_handler);
 107 module:add_handler("c2s_unauthed", "abort", xmlns_sasl, sasl_handler);
 108 module:add_handler("c2s_unauthed", "response", xmlns_sasl, sasl_handler);
 109
 110 local mechanisms_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-sasl' };
 111 local bind_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-bind' };
 112 local xmpp_session_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-session' };
 113 module:add_event_hook("stream-features",
 114                 function (session, features)
 115                         if not session.username then
 116                                 features:tag("mechanisms", mechanisms_attr);
 117                                 -- 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.
 118                                         if config.get(session.host or "*", "core", "anonymous_login") then
 119                                                 features:tag("mechanism"):text("ANONYMOUS"):up();
 120                                         else
 121                                                 features:tag("mechanism"):text("DIGEST-MD5"):up();
 122                                                 features:tag("mechanism"):text("PLAIN"):up();
 123                                         end
 124                                 features:up();
 125                         else
 126                                 features:tag("bind", bind_attr):tag("required"):up():up();
 127                                 features:tag("session", xmpp_session_attr):up();
 128                         end
 129                 end);
 130
 131 module:add_iq_handler("c2s", "urn:ietf:params:xml:ns:xmpp-bind",
 132                 function (session, stanza)
 133                         log("debug", "Client tried to bind to a resource");
 134                         local resource;
 135                         if stanza.attr.type == "set" then
 136                                 local bind = stanza.tags[1];
 137                                 if bind and bind.attr.xmlns == xmlns_bind then
 138                                         resource = bind:child_with_name("resource");
 139                                         if resource then
 140                                                 resource = resource[1];
 141                                         end
 142                                 end
 143                         end
 144                         local success, err_type, err, err_msg = sm_bind_resource(session, resource);
 145                         if not success then
 146                                 session.send(st.error_reply(stanza, err_type, err, err_msg));
 147                         else
 148                                 session.send(st.reply(stanza)
 149                                         :tag("bind", { xmlns = xmlns_bind})
 150                                         :tag("jid"):text(session.full_jid));
 151                         end
 152                 end);
 153
 154 module:add_iq_handler("c2s", "urn:ietf:params:xml:ns:xmpp-session",
 155                 function (session, stanza)
 156                         log("debug", "Client tried to bind to a resource");
 157                         session.send(st.reply(stanza));
 158                 end);