src/modules/m_sasl.cpp

   1 /*
   2  * InspIRCd -- Internet Relay Chat Daemon
   3  *
   4  *   Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
   5  *   Copyright (C) 2008 Craig Edwards <craigedwards@brainbox.cc>
   6  *
   7  * This file is part of InspIRCd.  InspIRCd is free software: you can
   8  * redistribute it and/or modify it under the terms of the GNU General Public
   9  * License as published by the Free Software Foundation, version 2.
  10  *
  11  * This program is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  13  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  14  * details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20
  21 #include "inspircd.h"
  22 #include "modules/cap.h"
  23 #include "modules/account.h"
  24 #include "modules/sasl.h"
  25 #include "modules/ssl.h"
  26 #include "modules/server.h"
  27
  28 enum
  29 {
  30         // From IRCv3 sasl-3.1
  31         RPL_SASLSUCCESS = 903,
  32         ERR_SASLFAIL = 904,
  33         ERR_SASLTOOLONG = 905,
  34         ERR_SASLABORTED = 906,
  35         RPL_SASLMECHS = 908
  36 };
  37
  38 static std::string sasl_target;
  39
  40 class ServerTracker
  41         : public ServerProtocol::LinkEventListener
  42 {
  43         // Stop GCC warnings about the deprecated OnServerSplit event.
  44         using ServerProtocol::LinkEventListener::OnServerSplit;
  45
  46         bool online;
  47
  48         void Update(const Server* server, bool linked)
  49         {
  50                 if (sasl_target == "*")
  51                         return;
  52
  53                 if (InspIRCd::Match(server->GetName(), sasl_target))
  54                 {
  55                         ServerInstance->Logs->Log(MODNAME, LOG_VERBOSE, "SASL target server \"%s\" %s", sasl_target.c_str(), (linked ? "came online" : "went offline"));
  56                         online = linked;
  57                 }
  58         }
  59
  60         void OnServerLink(const Server* server) CXX11_OVERRIDE
  61         {
  62                 Update(server, true);
  63         }
  64
  65         void OnServerSplit(const Server* server, bool error) CXX11_OVERRIDE
  66         {
  67                 Update(server, false);
  68         }
  69
  70  public:
  71         ServerTracker(Module* mod)
  72                 : ServerProtocol::LinkEventListener(mod)
  73         {
  74                 Reset();
  75         }
  76
  77         void Reset()
  78         {
  79                 if (sasl_target == "*")
  80                 {
  81                         online = true;
  82                         return;
  83                 }
  84
  85                 online = false;
  86
  87                 ProtocolInterface::ServerList servers;
  88                 ServerInstance->PI->GetServerList(servers);
  89                 for (ProtocolInterface::ServerList::const_iterator i = servers.begin(); i != servers.end(); ++i)
  90                 {
  91                         const ProtocolInterface::ServerInfo& server = *i;
  92                         if (InspIRCd::Match(server.servername, sasl_target))
  93                         {
  94                                 online = true;
  95                                 break;
  96                         }
  97                 }
  98         }
  99
 100         bool IsOnline() const { return online; }
 101 };
 102
 103 class SASLCap : public Cap::Capability
 104 {
 105         std::string mechlist;
 106         const ServerTracker& servertracker;
 107
 108         bool OnRequest(LocalUser* user, bool adding) CXX11_OVERRIDE
 109         {
 110                 // Servers MUST NAK any sasl capability request if the authentication layer
 111                 // is unavailable.
 112                 return servertracker.IsOnline();
 113         }
 114
 115         bool OnList(LocalUser* user) CXX11_OVERRIDE
 116         {
 117                 // Servers MUST NOT advertise the sasl capability if the authentication layer
 118                 // is unavailable.
 119                 return servertracker.IsOnline();
 120         }
 121
 122         const std::string* GetValue(LocalUser* user) const CXX11_OVERRIDE
 123         {
 124                 return &mechlist;
 125         }
 126
 127  public:
 128         SASLCap(Module* mod, const ServerTracker& tracker)
 129                 : Cap::Capability(mod, "sasl")
 130                 , servertracker(tracker)
 131         {
 132         }
 133
 134         void SetMechlist(const std::string& newmechlist)
 135         {
 136                 if (mechlist == newmechlist)
 137                         return;
 138
 139                 mechlist = newmechlist;
 140                 NotifyValueChange();
 141         }
 142 };
 143
 144 enum SaslState { SASL_INIT, SASL_COMM, SASL_DONE };
 145 enum SaslResult { SASL_OK, SASL_FAIL, SASL_ABORT };
 146
 147 static Events::ModuleEventProvider* saslevprov;
 148
 149 static void SendSASL(LocalUser* user, const std::string& agent, char mode, const std::vector<std::string>& parameters)
 150 {
 151         CommandBase::Params params;
 152         params.push_back(user->uuid);
 153         params.push_back(agent);
 154         params.push_back(ConvToStr(mode));
 155         params.insert(params.end(), parameters.begin(), parameters.end());
 156
 157         if (!ServerInstance->PI->SendEncapsulatedData(sasl_target, "SASL", params))
 158         {
 159                 FOREACH_MOD_CUSTOM(*saslevprov, SASLEventListener, OnSASLAuth, (params));
 160         }
 161 }
 162
 163 static ClientProtocol::EventProvider* g_protoev;
 164
 165 /**
 166  * Tracks SASL authentication state like charybdis does. --nenolod
 167  */
 168 class SaslAuthenticator
 169 {
 170  private:
 171         std::string agent;
 172         LocalUser* user;
 173         SaslState state;
 174         SaslResult result;
 175         bool state_announced;
 176
 177         void SendHostIP(UserCertificateAPI& sslapi)
 178         {
 179                 std::vector<std::string> params;
 180                 params.push_back(user->GetRealHost());
 181                 params.push_back(user->GetIPString());
 182                 params.push_back(sslapi && sslapi->GetCertificate(user) ? "S" : "P");
 183
 184                 SendSASL(user, "*", 'H', params);
 185         }
 186
 187  public:
 188         SaslAuthenticator(LocalUser* user_, const std::string& method, UserCertificateAPI& sslapi)
 189                 : user(user_)
 190                 , state(SASL_INIT)
 191                 , state_announced(false)
 192         {
 193                 SendHostIP(sslapi);
 194
 195                 std::vector<std::string> params;
 196                 params.push_back(method);
 197
 198                 const std::string fp = sslapi ? sslapi->GetFingerprint(user) : "";
 199                 if (fp.size())
 200                         params.push_back(fp);
 201
 202                 SendSASL(user, "*", 'S', params);
 203         }
 204
 205         SaslResult GetSaslResult(const std::string &result_)
 206         {
 207                 if (result_ == "F")
 208                         return SASL_FAIL;
 209
 210                 if (result_ == "A")
 211                         return SASL_ABORT;
 212
 213                 return SASL_OK;
 214         }
 215
 216         /* checks for and deals with a state change. */
 217         SaslState ProcessInboundMessage(const CommandBase::Params& msg)
 218         {
 219                 switch (this->state)
 220                 {
 221                  case SASL_INIT:
 222                         this->agent = msg[0];
 223                         this->state = SASL_COMM;
 224                         /* fall through */
 225                  case SASL_COMM:
 226                         if (msg[0] != this->agent)
 227                                 return this->state;
 228
 229                         if (msg.size() < 4)
 230                                 return this->state;
 231
 232                         if (msg[2] == "C")
 233                         {
 234                                 ClientProtocol::Message authmsg("AUTHENTICATE");
 235                                 authmsg.PushParamRef(msg[3]);
 236
 237                                 ClientProtocol::Event authevent(*g_protoev, authmsg);
 238                                 LocalUser* const localuser = IS_LOCAL(user);
 239                                 if (localuser)
 240                                         localuser->Send(authevent);
 241                         }
 242                         else if (msg[2] == "D")
 243                         {
 244                                 this->state = SASL_DONE;
 245                                 this->result = this->GetSaslResult(msg[3]);
 246                         }
 247                         else if (msg[2] == "M")
 248                                 this->user->WriteNumeric(RPL_SASLMECHS, msg[3], "are available SASL mechanisms");
 249                         else
 250                                 ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Services sent an unknown SASL message \"%s\" \"%s\"", msg[2].c_str(), msg[3].c_str());
 251
 252                         break;
 253                  case SASL_DONE:
 254                         break;
 255                  default:
 256                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "WTF: SaslState is not a known state (%d)", this->state);
 257                         break;
 258                 }
 259
 260                 return this->state;
 261         }
 262
 263         bool SendClientMessage(const std::vector<std::string>& parameters)
 264         {
 265                 if (this->state != SASL_COMM)
 266                         return true;
 267
 268                 SendSASL(this->user, this->agent, 'C', parameters);
 269
 270                 if (parameters[0].c_str()[0] == '*')
 271                 {
 272                         this->state = SASL_DONE;
 273                         this->result = SASL_ABORT;
 274                         return false;
 275                 }
 276
 277                 return true;
 278         }
 279
 280         void AnnounceState(void)
 281         {
 282                 if (this->state_announced)
 283                         return;
 284
 285                 switch (this->result)
 286                 {
 287                  case SASL_OK:
 288                         this->user->WriteNumeric(RPL_SASLSUCCESS, "SASL authentication successful");
 289                         break;
 290                  case SASL_ABORT:
 291                         this->user->WriteNumeric(ERR_SASLABORTED, "SASL authentication aborted");
 292                         break;
 293                  case SASL_FAIL:
 294                         this->user->WriteNumeric(ERR_SASLFAIL, "SASL authentication failed");
 295                         break;
 296                  default:
 297                         break;
 298                 }
 299
 300                 this->state_announced = true;
 301         }
 302 };
 303
 304 class CommandAuthenticate : public SplitCommand
 305 {
 306  private:
 307          // The maximum length of an AUTHENTICATE request.
 308          static const size_t MAX_AUTHENTICATE_SIZE = 400;
 309
 310  public:
 311         SimpleExtItem<SaslAuthenticator>& authExt;
 312         Cap::Capability& cap;
 313         UserCertificateAPI sslapi;
 314
 315         CommandAuthenticate(Module* Creator, SimpleExtItem<SaslAuthenticator>& ext, Cap::Capability& Cap)
 316                 : SplitCommand(Creator, "AUTHENTICATE", 1)
 317                 , authExt(ext)
 318                 , cap(Cap)
 319                 , sslapi(Creator)
 320         {
 321                 works_before_reg = true;
 322                 allow_empty_last_param = false;
 323         }
 324
 325         CmdResult HandleLocal(LocalUser* user, const Params& parameters) CXX11_OVERRIDE
 326         {
 327                 {
 328                         if (!cap.get(user))
 329                                 return CMD_FAILURE;
 330
 331                         if (parameters[0].find(' ') != std::string::npos || parameters[0][0] == ':')
 332                                 return CMD_FAILURE;
 333
 334                         if (parameters[0].length() > MAX_AUTHENTICATE_SIZE)
 335                         {
 336                                 user->WriteNumeric(ERR_SASLTOOLONG, "SASL message too long");
 337                                 return CMD_FAILURE;
 338                         }
 339
 340                         SaslAuthenticator *sasl = authExt.get(user);
 341                         if (!sasl)
 342                                 authExt.set(user, new SaslAuthenticator(user, parameters[0], sslapi));
 343                         else if (sasl->SendClientMessage(parameters) == false)  // IAL abort extension --nenolod
 344                         {
 345                                 sasl->AnnounceState();
 346                                 authExt.unset(user);
 347                         }
 348                 }
 349                 return CMD_FAILURE;
 350         }
 351 };
 352
 353 class CommandSASL : public Command
 354 {
 355  public:
 356         SimpleExtItem<SaslAuthenticator>& authExt;
 357         CommandSASL(Module* Creator, SimpleExtItem<SaslAuthenticator>& ext) : Command(Creator, "SASL", 2), authExt(ext)
 358         {
 359                 this->flags_needed = FLAG_SERVERONLY; // should not be called by users
 360         }
 361
 362         CmdResult Handle(User* user, const Params& parameters) CXX11_OVERRIDE
 363         {
 364                 User* target = ServerInstance->FindUUID(parameters[1]);
 365                 if (!target)
 366                 {
 367                         ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "User not found in sasl ENCAP event: %s", parameters[1].c_str());
 368                         return CMD_FAILURE;
 369                 }
 370
 371                 SaslAuthenticator *sasl = authExt.get(target);
 372                 if (!sasl)
 373                         return CMD_FAILURE;
 374
 375                 SaslState state = sasl->ProcessInboundMessage(parameters);
 376                 if (state == SASL_DONE)
 377                 {
 378                         sasl->AnnounceState();
 379                         authExt.unset(target);
 380                 }
 381                 return CMD_SUCCESS;
 382         }
 383
 384         RouteDescriptor GetRouting(User* user, const Params& parameters) CXX11_OVERRIDE
 385         {
 386                 return ROUTE_BROADCAST;
 387         }
 388 };
 389
 390 class ModuleSASL : public Module
 391 {
 392         SimpleExtItem<SaslAuthenticator> authExt;
 393         ServerTracker servertracker;
 394         SASLCap cap;
 395         CommandAuthenticate auth;
 396         CommandSASL sasl;
 397         Events::ModuleEventProvider sasleventprov;
 398         ClientProtocol::EventProvider protoev;
 399
 400  public:
 401         ModuleSASL()
 402                 : authExt("sasl_auth", ExtensionItem::EXT_USER, this)
 403                 , servertracker(this)
 404                 , cap(this, servertracker)
 405                 , auth(this, authExt, cap)
 406                 , sasl(this, authExt)
 407                 , sasleventprov(this, "event/sasl")
 408                 , protoev(this, auth.name)
 409         {
 410                 saslevprov = &sasleventprov;
 411                 g_protoev = &protoev;
 412         }
 413
 414         void init() CXX11_OVERRIDE
 415         {
 416                 if (!ServerInstance->Modules->Find("m_services_account.so") || !ServerInstance->Modules->Find("m_cap.so"))
 417                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "WARNING: m_services_account and m_cap are not loaded! m_sasl will NOT function correctly until these two modules are loaded!");
 418         }
 419
 420         void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE
 421         {
 422                 std::string target = ServerInstance->Config->ConfValue("sasl")->getString("target");
 423                 if (target.empty())
 424                         throw ModuleException("<sasl:target> must be set to the name of your services server!");
 425
 426                 sasl_target = target;
 427                 servertracker.Reset();
 428         }
 429
 430         void OnDecodeMetaData(Extensible* target, const std::string& extname, const std::string& extdata) CXX11_OVERRIDE
 431         {
 432                 if ((target == NULL) && (extname == "saslmechlist"))
 433                         cap.SetMechlist(extdata);
 434         }
 435
 436         Version GetVersion() CXX11_OVERRIDE
 437         {
 438                 return Version("Provides support for IRC Authentication Layer (aka: SASL) via AUTHENTICATE", VF_VENDOR);
 439         }
 440 };
 441
 442 MODULE_INIT(ModuleSASL)