-- Prosody IM -- Copyright (C) 2008-2010 Matthew Wild -- Copyright (C) 2008-2010 Waqas Hussain -- -- This project is MIT/X11 licensed. Please see the -- COPYING file in the source package for more information. -- local st = require "util.stanza"; local sm_bind_resource = require "core.sessionmanager".bind_resource; local sm_make_authenticated = require "core.sessionmanager".make_authenticated; local s2s_make_authenticated = require "core.s2smanager".make_authenticated; local base64 = require "util.encodings".base64; local cert_verify_identity = require "util.x509".verify_identity; local usermanager_get_sasl_handler = require "core.usermanager".get_sasl_handler; local tostring = tostring; local secure_auth_only = module:get_option("c2s_require_encryption") or module:get_option("require_encryption"); local allow_unencrypted_plain_auth = module:get_option("allow_unencrypted_plain_auth") local log = module._log; local xmlns_sasl ='urn:ietf:params:xml:ns:xmpp-sasl'; local xmlns_bind ='urn:ietf:params:xml:ns:xmpp-bind'; local function build_reply(status, ret, err_msg) local reply = st.stanza(status, {xmlns = xmlns_sasl}); if status == "challenge" then --log("debug", "CHALLENGE: %s", ret or ""); reply:text(base64.encode(ret or "")); elseif status == "failure" then reply:tag(ret):up(); if err_msg then reply:tag("text"):text(err_msg); end elseif status == "success" then --log("debug", "SUCCESS: %s", ret or ""); reply:text(base64.encode(ret or "")); else module:log("error", "Unknown sasl status: %s", status); end return reply; end local function handle_status(session, status, ret, err_msg) if status == "failure" then module:fire_event("authentication-failure", { session = session, condition = ret, text = err_msg }); session.sasl_handler = session.sasl_handler:clean_clone(); elseif status == "success" then local ok, err = sm_make_authenticated(session, session.sasl_handler.username); if ok then module:fire_event("authentication-success", { session = session }); session.sasl_handler = nil; session:reset_stream(); else module:log("warn", "SASL succeeded but username was invalid"); module:fire_event("authentication-failure", { session = session, condition = "not-authorized", text = err }); session.sasl_handler = session.sasl_handler:clean_clone(); return "failure", "not-authorized", "User authenticated successfully, but username was invalid"; end end return status, ret, err_msg; end local function sasl_process_cdata(session, stanza) local text = stanza[1]; if text then text = base64.decode(text); --log("debug", "AUTH: %s", text:gsub("[%z\001-\008\011\012\014-\031]", " ")); if not text then session.sasl_handler = nil; session.send(build_reply("failure", "incorrect-encoding")); return true; end end local status, ret, err_msg = session.sasl_handler:process(text); status, ret, err_msg = handle_status(session, status, ret, err_msg); local s = build_reply(status, ret, err_msg); log("debug", "sasl reply: %s", tostring(s)); session.send(s); return true; end module:hook_stanza(xmlns_sasl, "success", function (session, stanza) if session.type ~= "s2sout_unauthed" or session.external_auth ~= "attempting" then return; end module:log("debug", "SASL EXTERNAL with %s succeeded", session.to_host); session.external_auth = "succeeded" session:reset_stream(); local default_stream_attr = {xmlns = "jabber:server", ["xmlns:stream"] = "http://etherx.jabber.org/streams", ["xmlns:db"] = 'jabber:server:dialback', version = "1.0", to = session.to_host, from = session.from_host}; session.sends2s("<?xml version='1.0'?>"); session.sends2s(st.stanza("stream:stream", default_stream_attr):top_tag()); s2s_make_authenticated(session, session.to_host); return true; end) module:hook_stanza(xmlns_sasl, "failure", function (session, stanza) if session.type ~= "s2sout_unauthed" or session.external_auth ~= "attempting" then return; end module:log("info", "SASL EXTERNAL with %s failed", session.to_host) -- TODO: Log the failure reason session.external_auth = "failed" end, 500) module:hook_stanza(xmlns_sasl, "failure", function (session, stanza) -- TODO: Dialback wasn't loaded. Do something useful. end, 90) module:hook_stanza("http://etherx.jabber.org/streams", "features", function (session, stanza) if session.type ~= "s2sout_unauthed" or not session.secure then return; end local mechanisms = stanza:get_child("mechanisms", xmlns_sasl) if mechanisms then for mech in mechanisms:childtags() do if mech[1] == "EXTERNAL" then module:log("debug", "Initiating SASL EXTERNAL with %s", session.to_host); local reply = st.stanza("auth", {xmlns = xmlns_sasl, mechanism = "EXTERNAL"}); reply:text(base64.encode(session.from_host)) session.sends2s(reply) session.external_auth = "attempting" return true end end end end, 150); local function s2s_external_auth(session, stanza) local mechanism = stanza.attr.mechanism; if not session.secure then if mechanism == "EXTERNAL" then session.sends2s(build_reply("failure", "encryption-required")) else session.sends2s(build_reply("failure", "invalid-mechanism")) end return true; end if mechanism ~= "EXTERNAL" or session.cert_chain_status ~= "valid" then session.sends2s(build_reply("failure", "invalid-mechanism")) return true; end local text = stanza[1] if not text then session.sends2s(build_reply("failure", "malformed-request")) return true end -- Either the value is "=" and we've already verified the external -- cert identity, or the value is a string and either matches the -- from_host ( text = base64.decode(text) if not text then session.sends2s(build_reply("failure", "incorrect-encoding")) return true; end if session.cert_identity_status == "valid" then if text ~= "" and text ~= session.from_host then session.sends2s(build_reply("failure", "invalid-authzid")) return true end else if text == "" then session.sends2s(build_reply("failure", "invalid-authzid")) return true end local cert = session.conn:socket():getpeercertificate() if (cert_verify_identity(text, "xmpp-server", cert)) then session.cert_identity_status = "valid" else session.cert_identity_status = "invalid" session.sends2s(build_reply("failure", "invalid-authzid")) return true end end session.external_auth = "succeeded" if not session.from_host then session.from_host = text; end session.sends2s(build_reply("success")) local domain = text ~= "" and text or session.from_host; module:log("info", "Accepting SASL EXTERNAL identity from %s", domain); s2s_make_authenticated(session, domain); session:reset_stream(); return true end module:hook("stanza/urn:ietf:params:xml:ns:xmpp-sasl:auth", function(event) local session, stanza = event.origin, event.stanza; if session.type == "s2sin_unauthed" then return s2s_external_auth(session, stanza) end if session.type ~= "c2s_unauthed" then return; end if session.sasl_handler and session.sasl_handler.selected then session.sasl_handler = nil; -- allow starting a new SASL negotiation before completing an old one end if not session.sasl_handler then session.sasl_handler = usermanager_get_sasl_handler(module.host); end local mechanism = stanza.attr.mechanism; if not session.secure and (secure_auth_only or (mechanism == "PLAIN" and not allow_unencrypted_plain_auth)) then session.send(build_reply("failure", "encryption-required")); return true; end local valid_mechanism = session.sasl_handler:select(mechanism); if not valid_mechanism then session.send(build_reply("failure", "invalid-mechanism")); return true; end return sasl_process_cdata(session, stanza); end); module:hook("stanza/urn:ietf:params:xml:ns:xmpp-sasl:response", function(event) local session = event.origin; if not(session.sasl_handler and session.sasl_handler.selected) then session.send(build_reply("failure", "not-authorized", "Out of order SASL element")); return true; end return sasl_process_cdata(session, event.stanza); end); module:hook("stanza/urn:ietf:params:xml:ns:xmpp-sasl:abort", function(event) local session = event.origin; session.sasl_handler = nil; session.send(build_reply("failure", "aborted")); return true; end); local mechanisms_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-sasl' }; local bind_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-bind' }; local xmpp_session_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-session' }; module:hook("stream-features", function(event) local origin, features = event.origin, event.features; if not origin.username then if secure_auth_only and not origin.secure then return; end origin.sasl_handler = usermanager_get_sasl_handler(module.host); local mechanisms = st.stanza("mechanisms", mechanisms_attr); for mechanism in pairs(origin.sasl_handler:mechanisms()) do if mechanism ~= "PLAIN" or origin.secure or allow_unencrypted_plain_auth then mechanisms:tag("mechanism"):text(mechanism):up(); end end if mechanisms[1] then features:add_child(mechanisms); end else features:tag("bind", bind_attr):tag("required"):up():up(); features:tag("session", xmpp_session_attr):tag("optional"):up():up(); end end); module:hook("s2s-stream-features", function(event) local origin, features = event.origin, event.features; if origin.secure and origin.type == "s2sin_unauthed" then -- Offer EXTERNAL if chain is valid and either we didn't validate -- the identity or it passed. if origin.cert_chain_status == "valid" and origin.cert_identity_status ~= "invalid" then --TODO: Configurable module:log("debug", "Offering SASL EXTERNAL") features:tag("mechanisms", { xmlns = xmlns_sasl }) :tag("mechanism"):text("EXTERNAL") :up():up(); end end end); module:hook("iq/self/urn:ietf:params:xml:ns:xmpp-bind:bind", function(event) local origin, stanza = event.origin, event.stanza; local resource; if stanza.attr.type == "set" then local bind = stanza.tags[1]; resource = bind:child_with_name("resource"); resource = resource and #resource.tags == 0 and resource[1] or nil; end local success, err_type, err, err_msg = sm_bind_resource(origin, resource); if success then origin.send(st.reply(stanza) :tag("bind", { xmlns = xmlns_bind }) :tag("jid"):text(origin.full_jid)); origin.log("debug", "Resource bound: %s", origin.full_jid); else origin.send(st.error_reply(stanza, err_type, err, err_msg)); origin.log("debug", "Resource bind failed: %s", err_msg or err); end return true; end); local function handle_legacy_session(event) event.origin.send(st.reply(event.stanza)); return true; end module:hook("iq/self/urn:ietf:params:xml:ns:xmpp-session:session", handle_legacy_session); module:hook("iq/host/urn:ietf:params:xml:ns:xmpp-session:session", handle_legacy_session);