| 1 | -- Prosody IM |
| 2 | -- Copyright (C) 2008-2010 Matthew Wild |
| 3 | -- Copyright (C) 2008-2010 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 s2s_make_authenticated = require "core.s2smanager".make_authenticated; |
| 15 | local base64 = require "util.encodings".base64; |
| 16 | |
| 17 | local cert_verify_identity = require "util.x509".verify_identity; |
| 18 | |
| 19 | local nodeprep = require "util.encodings".stringprep.nodeprep; |
| 20 | local usermanager_get_sasl_handler = require "core.usermanager".get_sasl_handler; |
| 21 | local tostring = tostring; |
| 22 | |
| 23 | local secure_auth_only = module:get_option("c2s_require_encryption") or module:get_option("require_encryption"); |
| 24 | local allow_unencrypted_plain_auth = module:get_option("allow_unencrypted_plain_auth") |
| 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 function build_reply(status, ret, err_msg) |
| 33 | local reply = st.stanza(status, {xmlns = xmlns_sasl}); |
| 34 | if status == "challenge" then |
| 35 | --log("debug", "CHALLENGE: %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", "SUCCESS: %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, ret, err_msg) |
| 50 | if status == "failure" then |
| 51 | session.sasl_handler = session.sasl_handler:clean_clone(); |
| 52 | elseif status == "success" then |
| 53 | local username = nodeprep(session.sasl_handler.username); |
| 54 | |
| 55 | local ok, err = sm_make_authenticated(session, session.sasl_handler.username); |
| 56 | if ok then |
| 57 | session.sasl_handler = nil; |
| 58 | session:reset_stream(); |
| 59 | else |
| 60 | module:log("warn", "SASL succeeded but username was invalid"); |
| 61 | session.sasl_handler = session.sasl_handler:clean_clone(); |
| 62 | return "failure", "not-authorized", "User authenticated successfully, but username was invalid"; |
| 63 | end |
| 64 | end |
| 65 | return status, ret, err_msg; |
| 66 | end |
| 67 | |
| 68 | local function sasl_process_cdata(session, stanza) |
| 69 | local text = stanza:get_text(); |
| 70 | if text then |
| 71 | text = base64.decode(text); |
| 72 | --log("debug", "AUTH: %s", text:gsub("[%z\001-\008\011\012\014-\031]", " ")); |
| 73 | if not text then |
| 74 | session.sasl_handler = nil; |
| 75 | session.send(build_reply("failure", "incorrect-encoding")); |
| 76 | return true; |
| 77 | end |
| 78 | end |
| 79 | local status, ret, err_msg = session.sasl_handler:process(text); |
| 80 | status, ret, err_msg = handle_status(session, status, ret, err_msg); |
| 81 | local s = build_reply(status, ret, err_msg); |
| 82 | log("debug", "sasl reply: %s", tostring(s)); |
| 83 | session.send(s); |
| 84 | return true; |
| 85 | end |
| 86 | |
| 87 | module:hook_stanza(xmlns_sasl, "success", function (session, stanza) |
| 88 | if session.type ~= "s2sout_unauthed" or session.external_auth ~= "attempting" then return; end |
| 89 | module:log("debug", "SASL EXTERNAL with %s succeeded", session.to_host); |
| 90 | session.external_auth = "succeeded" |
| 91 | session:reset_stream(); |
| 92 | |
| 93 | local default_stream_attr = {xmlns = "jabber:server", ["xmlns:stream"] = "http://etherx.jabber.org/streams", |
| 94 | ["xmlns:db"] = 'jabber:server:dialback', version = "1.0", to = session.to_host, from = session.from_host}; |
| 95 | session.sends2s("<?xml version='1.0'?>"); |
| 96 | session.sends2s(st.stanza("stream:stream", default_stream_attr):top_tag()); |
| 97 | |
| 98 | s2s_make_authenticated(session, session.to_host); |
| 99 | return true; |
| 100 | end) |
| 101 | |
| 102 | module:hook_stanza(xmlns_sasl, "failure", function (session, stanza) |
| 103 | if session.type ~= "s2sout_unauthed" or session.external_auth ~= "attempting" then return; end |
| 104 | |
| 105 | module:log("info", "SASL EXTERNAL with %s failed", session.to_host) |
| 106 | -- TODO: Log the failure reason |
| 107 | session.external_auth = "failed" |
| 108 | end, 500) |
| 109 | |
| 110 | module:hook_stanza(xmlns_sasl, "failure", function (session, stanza) |
| 111 | -- TODO: Dialback wasn't loaded. Do something useful. |
| 112 | end, 90) |
| 113 | |
| 114 | module:hook_stanza("http://etherx.jabber.org/streams", "features", function (session, stanza) |
| 115 | if session.type ~= "s2sout_unauthed" or not session.secure then return; end |
| 116 | |
| 117 | local mechanisms = stanza:get_child("mechanisms", xmlns_sasl) |
| 118 | if mechanisms then |
| 119 | for mech in mechanisms:childtags() do |
| 120 | if mech[1] == "EXTERNAL" then |
| 121 | module:log("debug", "Initiating SASL EXTERNAL with %s", session.to_host); |
| 122 | local reply = st.stanza("auth", {xmlns = xmlns_sasl, mechanism = "EXTERNAL"}); |
| 123 | reply:text(base64.encode(session.from_host)) |
| 124 | session.sends2s(reply) |
| 125 | session.external_auth = "attempting" |
| 126 | return true |
| 127 | end |
| 128 | end |
| 129 | end |
| 130 | end, 150); |
| 131 | |
| 132 | local function s2s_external_auth(session, stanza) |
| 133 | local mechanism = stanza.attr.mechanism; |
| 134 | |
| 135 | if not session.secure then |
| 136 | if mechanism == "EXTERNAL" then |
| 137 | session.sends2s(build_reply("failure", "encryption-required")) |
| 138 | else |
| 139 | session.sends2s(build_reply("failure", "invalid-mechanism")) |
| 140 | end |
| 141 | return true; |
| 142 | end |
| 143 | |
| 144 | if mechanism ~= "EXTERNAL" or session.cert_chain_status ~= "valid" then |
| 145 | session.sends2s(build_reply("failure", "invalid-mechanism")) |
| 146 | return true; |
| 147 | end |
| 148 | |
| 149 | local text = stanza[1] |
| 150 | if not text then |
| 151 | session.sends2s(build_reply("failure", "malformed-request")) |
| 152 | return true |
| 153 | end |
| 154 | |
| 155 | -- Either the value is "=" and we've already verified the external |
| 156 | -- cert identity, or the value is a string and either matches the |
| 157 | -- from_host ( |
| 158 | |
| 159 | text = base64.decode(text) |
| 160 | if not text then |
| 161 | session.sends2s(build_reply("failure", "incorrect-encoding")) |
| 162 | return true; |
| 163 | end |
| 164 | |
| 165 | if session.cert_identity_status == "valid" then |
| 166 | if text ~= "" and text ~= session.from_host then |
| 167 | session.sends2s(build_reply("failure", "invalid-authzid")) |
| 168 | return true |
| 169 | end |
| 170 | else |
| 171 | if text == "" then |
| 172 | session.sends2s(build_reply("failure", "invalid-authzid")) |
| 173 | return true |
| 174 | end |
| 175 | |
| 176 | local cert = session.conn:socket():getpeercertificate() |
| 177 | if (cert_verify_identity(text, "xmpp-server", cert)) then |
| 178 | session.cert_identity_status = "valid" |
| 179 | else |
| 180 | session.cert_identity_status = "invalid" |
| 181 | session.sends2s(build_reply("failure", "invalid-authzid")) |
| 182 | return true |
| 183 | end |
| 184 | end |
| 185 | |
| 186 | session.external_auth = "succeeded" |
| 187 | |
| 188 | if not session.from_host then |
| 189 | session.from_host = text; |
| 190 | end |
| 191 | session.sends2s(build_reply("success")) |
| 192 | module:log("info", "Accepting SASL EXTERNAL identity from %s", text or session.from_host); |
| 193 | s2s_make_authenticated(session, text or session.from_host) |
| 194 | session:reset_stream(); |
| 195 | return true |
| 196 | end |
| 197 | |
| 198 | module:hook("stanza/urn:ietf:params:xml:ns:xmpp-sasl:auth", function(event) |
| 199 | local session, stanza = event.origin, event.stanza; |
| 200 | if session.type == "s2sin_unauthed" then |
| 201 | return s2s_external_auth(session, stanza) |
| 202 | end |
| 203 | |
| 204 | if session.type ~= "c2s_unauthed" then return; end |
| 205 | |
| 206 | if session.sasl_handler and session.sasl_handler.selected then |
| 207 | session.sasl_handler = nil; -- allow starting a new SASL negotiation before completing an old one |
| 208 | end |
| 209 | if not session.sasl_handler then |
| 210 | session.sasl_handler = usermanager_get_sasl_handler(module.host); |
| 211 | end |
| 212 | local mechanism = stanza.attr.mechanism; |
| 213 | if not session.secure and (secure_auth_only or (mechanism == "PLAIN" and not allow_unencrypted_plain_auth)) then |
| 214 | session.send(build_reply("failure", "encryption-required")); |
| 215 | return true; |
| 216 | end |
| 217 | local valid_mechanism = session.sasl_handler:select(mechanism); |
| 218 | if not valid_mechanism then |
| 219 | session.send(build_reply("failure", "invalid-mechanism")); |
| 220 | return true; |
| 221 | end |
| 222 | return sasl_process_cdata(session, stanza); |
| 223 | end); |
| 224 | module:hook("stanza/urn:ietf:params:xml:ns:xmpp-sasl:response", function(event) |
| 225 | local session = event.origin; |
| 226 | if not(session.sasl_handler and session.sasl_handler.selected) then |
| 227 | session.send(build_reply("failure", "not-authorized", "Out of order SASL element")); |
| 228 | return true; |
| 229 | end |
| 230 | return sasl_process_cdata(session, event.stanza); |
| 231 | end); |
| 232 | module:hook("stanza/urn:ietf:params:xml:ns:xmpp-sasl:abort", function(event) |
| 233 | local session = event.origin; |
| 234 | session.sasl_handler = nil; |
| 235 | session.send(build_reply("failure", "aborted")); |
| 236 | return true; |
| 237 | end); |
| 238 | |
| 239 | local mechanisms_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-sasl' }; |
| 240 | local bind_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-bind' }; |
| 241 | local xmpp_session_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-session' }; |
| 242 | module:hook("stream-features", function(event) |
| 243 | local origin, features = event.origin, event.features; |
| 244 | if not origin.username then |
| 245 | if secure_auth_only and not origin.secure then |
| 246 | return; |
| 247 | end |
| 248 | origin.sasl_handler = usermanager_get_sasl_handler(module.host); |
| 249 | features:tag("mechanisms", mechanisms_attr); |
| 250 | for mechanism in pairs(origin.sasl_handler:mechanisms()) do |
| 251 | if mechanism ~= "PLAIN" or origin.secure or allow_unencrypted_plain_auth then |
| 252 | features:tag("mechanism"):text(mechanism):up(); |
| 253 | end |
| 254 | end |
| 255 | features:up(); |
| 256 | else |
| 257 | features:tag("bind", bind_attr):tag("required"):up():up(); |
| 258 | features:tag("session", xmpp_session_attr):tag("optional"):up():up(); |
| 259 | end |
| 260 | end); |
| 261 | |
| 262 | module:hook("s2s-stream-features", function(event) |
| 263 | local origin, features = event.origin, event.features; |
| 264 | if origin.secure and origin.type == "s2sin_unauthed" then |
| 265 | -- Offer EXTERNAL if chain is valid and either we didn't validate |
| 266 | -- the identity or it passed. |
| 267 | if origin.cert_chain_status == "valid" and origin.cert_identity_status ~= "invalid" then --TODO: Configurable |
| 268 | module:log("debug", "Offering SASL EXTERNAL") |
| 269 | features:tag("mechanisms", { xmlns = xmlns_sasl }) |
| 270 | :tag("mechanism"):text("EXTERNAL") |
| 271 | :up():up(); |
| 272 | end |
| 273 | end |
| 274 | end); |
| 275 | |
| 276 | module:hook("iq/self/urn:ietf:params:xml:ns:xmpp-bind:bind", function(event) |
| 277 | local origin, stanza = event.origin, event.stanza; |
| 278 | local resource; |
| 279 | if stanza.attr.type == "set" then |
| 280 | local bind = stanza.tags[1]; |
| 281 | resource = bind:child_with_name("resource"); |
| 282 | resource = resource and #resource.tags == 0 and resource[1] or nil; |
| 283 | end |
| 284 | local success, err_type, err, err_msg = sm_bind_resource(origin, resource); |
| 285 | if success then |
| 286 | origin.send(st.reply(stanza) |
| 287 | :tag("bind", { xmlns = xmlns_bind }) |
| 288 | :tag("jid"):text(origin.full_jid)); |
| 289 | origin.log("debug", "Resource bound: %s", origin.full_jid); |
| 290 | else |
| 291 | origin.send(st.error_reply(stanza, err_type, err, err_msg)); |
| 292 | origin.log("debug", "Resource bind failed: %s", err_msg or err); |
| 293 | end |
| 294 | return true; |
| 295 | end); |
| 296 | |
| 297 | local function handle_legacy_session(event) |
| 298 | event.origin.send(st.reply(event.stanza)); |
| 299 | return true; |
| 300 | end |
| 301 | |
| 302 | module:hook("iq/self/urn:ietf:params:xml:ns:xmpp-session:session", handle_legacy_session); |
| 303 | module:hook("iq/host/urn:ietf:params:xml:ns:xmpp-session:session", handle_legacy_session); |