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