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