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