diff options
Diffstat (limited to 'plugins/mod_saslauth.lua')
| -rw-r--r-- | plugins/mod_saslauth.lua | 388 |
1 files changed, 288 insertions, 100 deletions
diff --git a/plugins/mod_saslauth.lua b/plugins/mod_saslauth.lua index 24c82a1c..201cc477 100644 --- a/plugins/mod_saslauth.lua +++ b/plugins/mod_saslauth.lua @@ -1,111 +1,299 @@ +-- 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 send = require "core.sessionmanager".send_to_session; local sm_bind_resource = require "core.sessionmanager".bind_resource; +local sm_make_authenticated = require "core.sessionmanager".make_authenticated; +local base64 = require "util.encodings".base64; + +local cert_verify_identity = require "util.x509".verify_identity; -local usermanager_validate_credentials = require "core.usermanager".validate_credentials; -local t_concat, t_insert = table.concat, table.insert; +local usermanager_get_sasl_handler = require "core.usermanager".get_sasl_handler; local tostring = tostring; -local log = require "util.logger".init("mod_saslauth"); +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 xmlns_stanzas ='urn:ietf:params:xml:ns:xmpp-stanzas'; - -local new_sasl = require "util.sasl".new; - -add_handler("c2s_unauthed", "auth", xmlns_sasl, - function (session, stanza) - if not session.sasl_handler then - session.sasl_handler = new_sasl(stanza.attr.mechanism, - function (username, password) - -- onAuth - require "core.usermanager" - if usermanager_validate_credentials(session.host, username, password) then - return true; - end - return false; - end, - function (username) - -- onSuccess - local success, err = sessionmanager.make_authenticated(session, username); - if not success then - sessionmanager.destroy_session(session); - return; - end - session.sasl_handler = nil; - session:reset_stream(); - end, - function (reason) - -- onFail - log("debug", "SASL failure, reason: %s", reason); - end, - function (stanza) - -- onWrite - log("debug", "SASL writes: %s", tostring(stanza)); - send(session, stanza); - end - ); - session.sasl_handler:feed(stanza); - else - error("Client tried to negotiate SASL again", 0); - end - - end); - -add_event_hook("stream-features", - function (session, features) - if not session.username then - t_insert(features, "<mechanisms xmlns='urn:ietf:params:xml:ns:xmpp-sasl'>"); - t_insert(features, "<mechanism>PLAIN</mechanism>"); - t_insert(features, "</mechanisms>"); - else - t_insert(features, "<bind xmlns='urn:ietf:params:xml:ns:xmpp-bind'><required/></bind>"); - t_insert(features, "<session xmlns='urn:ietf:params:xml:ns:xmpp-session'/>"); - end - --send [[<register xmlns="http://jabber.org/features/iq-register"/> ]] - end); - -add_iq_handler("c2s", "urn:ietf:params:xml:ns:xmpp-bind", - function (session, stanza) - log("debug", "Client tried to bind to a resource"); - local resource; - if stanza.attr.type == "set" then - local bind = stanza.tags[1]; - - if bind and bind.attr.xmlns == xmlns_bind then - resource = bind:child_with_name("resource"); - if resource then - resource = resource[1]; - end - end + +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(); + session:open_stream(session.from_host, session.to_host); + + module:fire_event("s2s-authenticated", { session = session, host = 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 - local success, err = sm_bind_resource(session, resource); - if not success then - local reply = st.reply(stanza); - reply.attr.type = "error"; - if err == "conflict" then - reply:tag("error", { type = "modify" }) - :tag("conflict", { xmlns = xmlns_stanzas }); - elseif err == "constraint" then - reply:tag("error", { type = "cancel" }) - :tag("resource-constraint", { xmlns = xmlns_stanzas }); - elseif err == "auth" then - reply:tag("error", { type = "cancel" }) - :tag("not-allowed", { xmlns = xmlns_stanzas }); - end - send(session, reply); - else - local reply = st.reply(stanza); - reply:tag("bind", { xmlns = xmlns_bind}) - :tag("jid"):text(session.full_jid); - send(session, reply); + 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); + module:fire_event("s2s-authenticated", { session = session, host = 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, session); + 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, origin); + 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); - -add_iq_handler("c2s", "urn:ietf:params:xml:ns:xmpp-session", - function (session, stanza) - log("debug", "Client tried to bind to a resource"); - send(session, st.reply(stanza)); - 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); 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