src/modules/m_sasl.cpp

   1 /*
   2  * InspIRCd -- Internet Relay Chat Daemon
   3  *
   4  *   Copyright (C) 2016 Adam <Adam@anope.org>
   5  *   Copyright (C) 2014 Mantas Mikulėnas <grawity@gmail.com>
   6  *   Copyright (C) 2013-2016, 2018 Attila Molnar <attilamolnar@hush.com>
   7  *   Copyright (C) 2013, 2017-2019 Sadie Powell <sadie@witchery.services>
   8  *   Copyright (C) 2013 Daniel Vassdal <shutter@canternet.org>
   9  *   Copyright (C) 2012, 2019 Robby <robby@chatbelgie.be>
  10  *   Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
  11  *   Copyright (C) 2008, 2010 Craig Edwards <brain@inspircd.org>
  12  *   Copyright (C) 2008 Thomas Stagner <aquanight@inspircd.org>
  13  *
  14  * This file is part of InspIRCd.  InspIRCd is free software: you can
  15  * redistribute it and/or modify it under the terms of the GNU General Public
  16  * License as published by the Free Software Foundation, version 2.
  17  *
  18  * This program is distributed in the hope that it will be useful, but WITHOUT
  19  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  20  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  21  * details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  25  */
  26
  27
  28 #include "inspircd.h"
  29 #include "modules/cap.h"
  30 #include "modules/account.h"
  31 #include "modules/sasl.h"
  32 #include "modules/ssl.h"
  33 #include "modules/server.h"
  34
  35 enum
  36 {
  37         // From IRCv3 sasl-3.1
  38         RPL_SASLSUCCESS = 903,
  39         ERR_SASLFAIL = 904,
  40         ERR_SASLTOOLONG = 905,
  41         ERR_SASLABORTED = 906,
  42         RPL_SASLMECHS = 908
  43 };
  44
  45 static std::string sasl_target;
  46
  47 class ServerTracker
  48         : public ServerProtocol::LinkEventListener
  49 {
  50         // Stop GCC warnings about the deprecated OnServerSplit event.
  51         using ServerProtocol::LinkEventListener::OnServerSplit;
  52
  53         bool online;
  54
  55         void Update(const Server* server, bool linked)
  56         {
  57                 if (sasl_target == "*")
  58                         return;
  59
  60                 if (InspIRCd::Match(server->GetName(), sasl_target))
  61                 {
  62                         ServerInstance->Logs->Log(MODNAME, LOG_VERBOSE, "SASL target server \"%s\" %s", sasl_target.c_str(), (linked ? "came online" : "went offline"));
  63                         online = linked;
  64                 }
  65         }
  66
  67         void OnServerLink(const Server* server) CXX11_OVERRIDE
  68         {
  69                 Update(server, true);
  70         }
  71
  72         void OnServerSplit(const Server* server, bool error) CXX11_OVERRIDE
  73         {
  74                 Update(server, false);
  75         }
  76
  77  public:
  78         ServerTracker(Module* mod)
  79                 : ServerProtocol::LinkEventListener(mod)
  80         {
  81                 Reset();
  82         }
  83
  84         void Reset()
  85         {
  86                 if (sasl_target == "*")
  87                 {
  88                         online = true;
  89                         return;
  90                 }
  91
  92                 online = false;
  93
  94                 ProtocolInterface::ServerList servers;
  95                 ServerInstance->PI->GetServerList(servers);
  96                 for (ProtocolInterface::ServerList::const_iterator i = servers.begin(); i != servers.end(); ++i)
  97                 {
  98                         const ProtocolInterface::ServerInfo& server = *i;
  99                         if (InspIRCd::Match(server.servername, sasl_target))
 100                         {
 101                                 online = true;
 102                                 break;
 103                         }
 104                 }
 105         }
 106
 107         bool IsOnline() const { return online; }
 108 };
 109
 110 class SASLCap : public Cap::Capability
 111 {
 112         std::string mechlist;
 113         const ServerTracker& servertracker;
 114
 115         bool OnRequest(LocalUser* user, bool adding) CXX11_OVERRIDE
 116         {
 117                 // Servers MUST NAK any sasl capability request if the authentication layer
 118                 // is unavailable.
 119                 return servertracker.IsOnline();
 120         }
 121
 122         bool OnList(LocalUser* user) CXX11_OVERRIDE
 123         {
 124                 // Servers MUST NOT advertise the sasl capability if the authentication layer
 125                 // is unavailable.
 126                 return servertracker.IsOnline();
 127         }
 128
 129         const std::string* GetValue(LocalUser* user) const CXX11_OVERRIDE
 130         {
 131                 return &mechlist;
 132         }
 133
 134  public:
 135         SASLCap(Module* mod, const ServerTracker& tracker)
 136                 : Cap::Capability(mod, "sasl")
 137                 , servertracker(tracker)
 138         {
 139         }
 140
 141         void SetMechlist(const std::string& newmechlist)
 142         {
 143                 if (mechlist == newmechlist)
 144                         return;
 145
 146                 mechlist = newmechlist;
 147                 NotifyValueChange();
 148         }
 149 };
 150
 151 enum SaslState { SASL_INIT, SASL_COMM, SASL_DONE };
 152 enum SaslResult { SASL_OK, SASL_FAIL, SASL_ABORT };
 153
 154 static Events::ModuleEventProvider* saslevprov;
 155
 156 static void SendSASL(LocalUser* user, const std::string& agent, char mode, const std::vector<std::string>& parameters)
 157 {
 158         CommandBase::Params params;
 159         params.push_back(user->uuid);
 160         params.push_back(agent);
 161         params.push_back(ConvToStr(mode));
 162         params.insert(params.end(), parameters.begin(), parameters.end());
 163
 164         if (!ServerInstance->PI->SendEncapsulatedData(sasl_target, "SASL", params))
 165         {
 166                 FOREACH_MOD_CUSTOM(*saslevprov, SASLEventListener, OnSASLAuth, (params));
 167         }
 168 }
 169
 170 static ClientProtocol::EventProvider* g_protoev;
 171
 172 /**
 173  * Tracks SASL authentication state like charybdis does. --nenolod
 174  */
 175 class SaslAuthenticator
 176 {
 177  private:
 178         std::string agent;
 179         LocalUser* user;
 180         SaslState state;
 181         SaslResult result;
 182         bool state_announced;
 183
 184         void SendHostIP(UserCertificateAPI& sslapi)
 185         {
 186                 std::vector<std::string> params;
 187                 params.push_back(user->GetRealHost());
 188                 params.push_back(user->GetIPString());
 189                 params.push_back(sslapi && sslapi->GetCertificate(user) ? "S" : "P");
 190
 191                 SendSASL(user, "*", 'H', params);
 192         }
 193
 194  public:
 195         SaslAuthenticator(LocalUser* user_, const std::string& method, UserCertificateAPI& sslapi)
 196                 : user(user_)
 197                 , state(SASL_INIT)
 198                 , state_announced(false)
 199         {
 200                 SendHostIP(sslapi);
 201
 202                 std::vector<std::string> params;
 203                 params.push_back(method);
 204
 205                 const std::string fp = sslapi ? sslapi->GetFingerprint(user) : "";
 206                 if (fp.size())
 207                         params.push_back(fp);
 208
 209                 SendSASL(user, "*", 'S', params);
 210         }
 211
 212         SaslResult GetSaslResult(const std::string &result_)
 213         {
 214                 if (result_ == "F")
 215                         return SASL_FAIL;
 216
 217                 if (result_ == "A")
 218                         return SASL_ABORT;
 219
 220                 return SASL_OK;
 221         }
 222
 223         /* checks for and deals with a state change. */
 224         SaslState ProcessInboundMessage(const CommandBase::Params& msg)
 225         {
 226                 switch (this->state)
 227                 {
 228                  case SASL_INIT:
 229                         this->agent = msg[0];
 230                         this->state = SASL_COMM;
 231                         /* fall through */
 232                  case SASL_COMM:
 233                         if (msg[0] != this->agent)
 234                                 return this->state;
 235
 236                         if (msg.size() < 4)
 237                                 return this->state;
 238
 239                         if (msg[2] == "C")
 240                         {
 241                                 ClientProtocol::Message authmsg("AUTHENTICATE");
 242                                 authmsg.PushParamRef(msg[3]);
 243
 244                                 ClientProtocol::Event authevent(*g_protoev, authmsg);
 245                                 LocalUser* const localuser = IS_LOCAL(user);
 246                                 if (localuser)
 247                                         localuser->Send(authevent);
 248                         }
 249                         else if (msg[2] == "D")
 250                         {
 251                                 this->state = SASL_DONE;
 252                                 this->result = this->GetSaslResult(msg[3]);
 253                         }
 254                         else if (msg[2] == "M")
 255                                 this->user->WriteNumeric(RPL_SASLMECHS, msg[3], "are available SASL mechanisms");
 256                         else
 257                                 ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Services sent an unknown SASL message \"%s\" \"%s\"", msg[2].c_str(), msg[3].c_str());
 258
 259                         break;
 260                  case SASL_DONE:
 261                         break;
 262                  default:
 263                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "WTF: SaslState is not a known state (%d)", this->state);
 264                         break;
 265                 }
 266
 267                 return this->state;
 268         }
 269
 270         bool SendClientMessage(const std::vector<std::string>& parameters)
 271         {
 272                 if (this->state != SASL_COMM)
 273                         return true;
 274
 275                 SendSASL(this->user, this->agent, 'C', parameters);
 276
 277                 if (parameters[0].c_str()[0] == '*')
 278                 {
 279                         this->state = SASL_DONE;
 280                         this->result = SASL_ABORT;
 281                         return false;
 282                 }
 283
 284                 return true;
 285         }
 286
 287         void AnnounceState(void)
 288         {
 289                 if (this->state_announced)
 290                         return;
 291
 292                 switch (this->result)
 293                 {
 294                  case SASL_OK:
 295                         this->user->WriteNumeric(RPL_SASLSUCCESS, "SASL authentication successful");
 296                         break;
 297                  case SASL_ABORT:
 298                         this->user->WriteNumeric(ERR_SASLABORTED, "SASL authentication aborted");
 299                         break;
 300                  case SASL_FAIL:
 301                         this->user->WriteNumeric(ERR_SASLFAIL, "SASL authentication failed");
 302                         break;
 303                  default:
 304                         break;
 305                 }
 306
 307                 this->state_announced = true;
 308         }
 309 };
 310
 311 class CommandAuthenticate : public SplitCommand
 312 {
 313  private:
 314          // The maximum length of an AUTHENTICATE request.
 315          static const size_t MAX_AUTHENTICATE_SIZE = 400;
 316
 317  public:
 318         SimpleExtItem<SaslAuthenticator>& authExt;
 319         Cap::Capability& cap;
 320         UserCertificateAPI sslapi;
 321
 322         CommandAuthenticate(Module* Creator, SimpleExtItem<SaslAuthenticator>& ext, Cap::Capability& Cap)
 323                 : SplitCommand(Creator, "AUTHENTICATE", 1)
 324                 , authExt(ext)
 325                 , cap(Cap)
 326                 , sslapi(Creator)
 327         {
 328                 works_before_reg = true;
 329                 allow_empty_last_param = false;
 330         }
 331
 332         CmdResult HandleLocal(LocalUser* user, const Params& parameters) CXX11_OVERRIDE
 333         {
 334                 {
 335                         if (!cap.get(user))
 336                                 return CMD_FAILURE;
 337
 338                         if (parameters[0].find(' ') != std::string::npos || parameters[0][0] == ':')
 339                                 return CMD_FAILURE;
 340
 341                         if (parameters[0].length() > MAX_AUTHENTICATE_SIZE)
 342                         {
 343                                 user->WriteNumeric(ERR_SASLTOOLONG, "SASL message too long");
 344                                 return CMD_FAILURE;
 345                         }
 346
 347                         SaslAuthenticator *sasl = authExt.get(user);
 348                         if (!sasl)
 349                                 authExt.set(user, new SaslAuthenticator(user, parameters[0], sslapi));
 350                         else if (sasl->SendClientMessage(parameters) == false)  // IAL abort extension --nenolod
 351                         {
 352                                 sasl->AnnounceState();
 353                                 authExt.unset(user);
 354                         }
 355                 }
 356                 return CMD_FAILURE;
 357         }
 358 };
 359
 360 class CommandSASL : public Command
 361 {
 362  public:
 363         SimpleExtItem<SaslAuthenticator>& authExt;
 364         CommandSASL(Module* Creator, SimpleExtItem<SaslAuthenticator>& ext) : Command(Creator, "SASL", 2), authExt(ext)
 365         {
 366                 this->flags_needed = FLAG_SERVERONLY; // should not be called by users
 367         }
 368
 369         CmdResult Handle(User* user, const Params& parameters) CXX11_OVERRIDE
 370         {
 371                 User* target = ServerInstance->FindUUID(parameters[1]);
 372                 if (!target)
 373                 {
 374                         ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "User not found in sasl ENCAP event: %s", parameters[1].c_str());
 375                         return CMD_FAILURE;
 376                 }
 377
 378                 SaslAuthenticator *sasl = authExt.get(target);
 379                 if (!sasl)
 380                         return CMD_FAILURE;
 381
 382                 SaslState state = sasl->ProcessInboundMessage(parameters);
 383                 if (state == SASL_DONE)
 384                 {
 385                         sasl->AnnounceState();
 386                         authExt.unset(target);
 387                 }
 388                 return CMD_SUCCESS;
 389         }
 390
 391         RouteDescriptor GetRouting(User* user, const Params& parameters) CXX11_OVERRIDE
 392         {
 393                 return ROUTE_BROADCAST;
 394         }
 395 };
 396
 397 class ModuleSASL : public Module
 398 {
 399         SimpleExtItem<SaslAuthenticator> authExt;
 400         ServerTracker servertracker;
 401         SASLCap cap;
 402         CommandAuthenticate auth;
 403         CommandSASL sasl;
 404         Events::ModuleEventProvider sasleventprov;
 405         ClientProtocol::EventProvider protoev;
 406
 407  public:
 408         ModuleSASL()
 409                 : authExt("sasl_auth", ExtensionItem::EXT_USER, this)
 410                 , servertracker(this)
 411                 , cap(this, servertracker)
 412                 , auth(this, authExt, cap)
 413                 , sasl(this, authExt)
 414                 , sasleventprov(this, "event/sasl")
 415                 , protoev(this, auth.name)
 416         {
 417                 saslevprov = &sasleventprov;
 418                 g_protoev = &protoev;
 419         }
 420
 421         void init() CXX11_OVERRIDE
 422         {
 423                 if (!ServerInstance->Modules->Find("m_services_account.so") || !ServerInstance->Modules->Find("m_cap.so"))
 424                         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!");
 425         }
 426
 427         void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE
 428         {
 429                 std::string target = ServerInstance->Config->ConfValue("sasl")->getString("target");
 430                 if (target.empty())
 431                         throw ModuleException("<sasl:target> must be set to the name of your services server!");
 432
 433                 sasl_target = target;
 434                 servertracker.Reset();
 435         }
 436
 437         void OnDecodeMetaData(Extensible* target, const std::string& extname, const std::string& extdata) CXX11_OVERRIDE
 438         {
 439                 if ((target == NULL) && (extname == "saslmechlist"))
 440                         cap.SetMechlist(extdata);
 441         }
 442
 443         Version GetVersion() CXX11_OVERRIDE
 444         {
 445                 return Version("Provides support for IRC Authentication Layer (aka: SASL) via AUTHENTICATE", VF_VENDOR);
 446         }
 447 };
 448
 449 MODULE_INIT(ModuleSASL)