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-- 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 base64 = require "util.encodings".base64;
local nodeprep = require "util.encodings".stringprep.nodeprep;
local usermanager_get_sasl_handler = require "core.usermanager".get_sasl_handler;
local usermanager_user_exists = require "core.usermanager".user_exists;
local t_concat, t_insert = table.concat, table.insert;
local tostring = tostring;
local secure_auth_only = module:get_option("c2s_require_encryption") or module:get_option("require_encryption");
local sasl_backend = module:get_option("sasl_backend") or "builtin";
local anonymous_login = module:get_option("anonymous_login");
local allow_unencrypted_plain_auth = module:get_option("allow_unencrypted_plain_auth")
-- Cyrus config options
local require_provisioning = module:get_option("cyrus_require_provisioning") or false;
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;
if sasl_backend ~= "builtin" then
module:log("error", "Unknown SASL backend: %s", sasl_backend);
error("Unknown SASL backend");
end
local anonymous_authentication_profile = {
anonymous = function(username, realm)
return true; -- for normal usage you should always return true here
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
session.sasl_handler = session.sasl_handler:clean_clone();
elseif status == "success" then
local username = nodeprep(session.sasl_handler.username);
if not(require_provisioning) or usermanager_user_exists(username, session.host) then
local ok, err = sm_make_authenticated(session, session.sasl_handler.username);
if ok then
session.sasl_handler = nil;
session:reset_stream();
else
module:log("warn", "SASL succeeded but username was invalid");
session.sasl_handler = session.sasl_handler:clean_clone();
return "failure", "not-authorized", "User authenticated successfully, but username was invalid";
end
else
module:log("warn", "SASL succeeded but we don't have an account provisioned for %s", username);
session.sasl_handler = session.sasl_handler:clean_clone();
return "failure", "not-authorized", "User authenticated successfully, but not provisioned for XMPP";
end
end
return status, ret, err_msg;
end
local function sasl_handler(session, stanza)
if stanza.name == "auth" then
-- FIXME ignoring duplicates because ejabberd does
local mechanism = stanza.attr.mechanism;
if anonymous_login then
if mechanism ~= "ANONYMOUS" then
return session.send(build_reply("failure", "invalid-mechanism"));
end
elseif mechanism == "ANONYMOUS" then
return session.send(build_reply("failure", "mechanism-too-weak"));
end
if not session.secure and (secure_auth_only or (mechanism == "PLAIN" and not allow_unencrypted_plain_auth)) then
return session.send(build_reply("failure", "encryption-required"));
end
local valid_mechanism = session.sasl_handler:select(mechanism);
if not valid_mechanism then
return session.send(build_reply("failure", "invalid-mechanism"));
end
elseif not session.sasl_handler then
return; -- FIXME ignoring out of order stanzas because ejabberd does
end
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;
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);
end
module:add_handler("c2s_unauthed", "auth", xmlns_sasl, sasl_handler);
module:add_handler("c2s_unauthed", "abort", xmlns_sasl, sasl_handler);
module:add_handler("c2s_unauthed", "response", xmlns_sasl, sasl_handler);
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
if anonymous_login then
origin.sasl_handler = new_sasl(module.host, anonymous_authentication_profile);
else
origin.sasl_handler = usermanager_get_sasl_handler(module.host);
end
features:tag("mechanisms", mechanisms_attr);
for mechanism in pairs(origin.sasl_handler:mechanisms()) do
if mechanism ~= "PLAIN" or origin.secure or allow_unencrypted_plain_auth then
features:tag("mechanism"):text(mechanism):up();
end
end
features:up();
else
features:tag("bind", bind_attr):tag("required"):up():up();
features:tag("session", xmpp_session_attr):tag("optional"):up():up();
end
end);
module:add_iq_handler("c2s", "urn:ietf:params:xml:ns:xmpp-bind", function(session, stanza)
log("debug", "Client requesting a resource bind");
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
end
local success, err_type, err, err_msg = sm_bind_resource(session, resource);
if not success then
session.send(st.error_reply(stanza, err_type, err, err_msg));
else
session.send(st.reply(stanza)
:tag("bind", { xmlns = xmlns_bind})
:tag("jid"):text(session.full_jid));
end
end);
module:add_iq_handler("c2s", "urn:ietf:params:xml:ns:xmpp-session", function(session, stanza)
log("debug", "Client requesting a session");
session.send(st.reply(stanza));
end);
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