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