src/modules/m_cgiirc.cpp

   1 /*
   2  * InspIRCd -- Internet Relay Chat Daemon
   3  *
   4  *   Copyright (C) 2019 linuxdaemon <linuxdaemon.irc@gmail.com>
   5  *   Copyright (C) 2014 md_5 <git@md-5.net>
   6  *   Copyright (C) 2014 Googolplexed <googol@googolplexed.net>
   7  *   Copyright (C) 2013, 2017-2018, 2020 Sadie Powell <sadie@witchery.services>
   8  *   Copyright (C) 2013 Adam <Adam@anope.org>
   9  *   Copyright (C) 2012-2013, 2015 Attila Molnar <attilamolnar@hush.com>
  10  *   Copyright (C) 2012, 2019 Robby <robby@chatbelgie.be>
  11  *   Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
  12  *   Copyright (C) 2009 Uli Schlachter <psychon@inspircd.org>
  13  *   Copyright (C) 2007-2009 Robin Burchell <robin+git@viroteck.net>
  14  *   Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
  15  *   Copyright (C) 2006-2007, 2010 Craig Edwards <brain@inspircd.org>
  16  *
  17  * This file is part of InspIRCd.  InspIRCd is free software: you can
  18  * redistribute it and/or modify it under the terms of the GNU General Public
  19  * License as published by the Free Software Foundation, version 2.
  20  *
  21  * This program is distributed in the hope that it will be useful, but WITHOUT
  22  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  23  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  24  * details.
  25  *
  26  * You should have received a copy of the GNU General Public License
  27  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  28  */
  29
  30
  31 #include "inspircd.h"
  32 #include "modules/ssl.h"
  33 #include "modules/webirc.h"
  34 #include "modules/whois.h"
  35
  36 enum
  37 {
  38         // InspIRCd-specific.
  39         RPL_WHOISGATEWAY = 350
  40 };
  41
  42 // Encapsulates information about an ident host.
  43 class IdentHost
  44 {
  45  private:
  46         std::string hostmask;
  47         std::string newident;
  48
  49  public:
  50         IdentHost(const std::string& mask, const std::string& ident)
  51                 : hostmask(mask)
  52                 , newident(ident)
  53         {
  54         }
  55
  56         const std::string& GetIdent() const
  57         {
  58                 return newident;
  59         }
  60
  61         bool Matches(LocalUser* user) const
  62         {
  63                 if (!InspIRCd::Match(user->GetRealHost(), hostmask, ascii_case_insensitive_map))
  64                         return false;
  65
  66                 return InspIRCd::MatchCIDR(user->GetIPString(), hostmask, ascii_case_insensitive_map);
  67         }
  68 };
  69
  70 // Encapsulates information about a WebIRC host.
  71 class WebIRCHost
  72 {
  73  private:
  74         std::string hostmask;
  75         std::string fingerprint;
  76         std::string password;
  77         std::string passhash;
  78
  79  public:
  80         WebIRCHost(const std::string& mask, const std::string& fp, const std::string& pass, const std::string& hash)
  81                 : hostmask(mask)
  82                 , fingerprint(fp)
  83                 , password(pass)
  84                 , passhash(hash)
  85         {
  86         }
  87
  88         bool Matches(LocalUser* user, const std::string& pass, UserCertificateAPI& sslapi) const
  89         {
  90                 // Did the user send a valid password?
  91                 if (!password.empty() && !ServerInstance->PassCompare(user, password, pass, passhash))
  92                         return false;
  93
  94                 // Does the user have a valid fingerprint?
  95                 const std::string fp = sslapi ? sslapi->GetFingerprint(user) : "";
  96                 if (!fingerprint.empty() && !InspIRCd::TimingSafeCompare(fp, fingerprint))
  97                         return false;
  98
  99                 // Does the user's hostname match our hostmask?
 100                 if (InspIRCd::Match(user->GetRealHost(), hostmask, ascii_case_insensitive_map))
 101                         return true;
 102
 103                 // Does the user's IP address match our hostmask?
 104                 return InspIRCd::MatchCIDR(user->GetIPString(), hostmask, ascii_case_insensitive_map);
 105         }
 106 };
 107
 108 /*
 109  * WEBIRC
 110  *  This is used for the webirc method of CGIIRC auth, and is (really) the best way to do these things.
 111  *  Syntax: WEBIRC password gateway hostname ip
 112  *  Where password is a shared key, gateway is the name of the WebIRC gateway and version (e.g. cgiirc), hostname
 113  *  is the resolved host of the client issuing the command and IP is the real IP of the client.
 114  *
 115  * How it works:
 116  *  To tie in with the rest of cgiirc module, and to avoid race conditions, /webirc is only processed locally
 117  *  and simply sets metadata on the user, which is later decoded on full connect to give something meaningful.
 118  */
 119 class CommandWebIRC : public SplitCommand
 120 {
 121  public:
 122         std::vector<WebIRCHost> hosts;
 123         bool notify;
 124         StringExtItem gateway;
 125         StringExtItem realhost;
 126         StringExtItem realip;
 127         UserCertificateAPI sslapi;
 128         Events::ModuleEventProvider webircevprov;
 129
 130         CommandWebIRC(Module* Creator)
 131                 : SplitCommand(Creator, "WEBIRC", 4)
 132                 , gateway("cgiirc_gateway", ExtensionItem::EXT_USER, Creator)
 133                 , realhost("cgiirc_realhost", ExtensionItem::EXT_USER, Creator)
 134                 , realip("cgiirc_realip", ExtensionItem::EXT_USER, Creator)
 135                 , sslapi(Creator)
 136                 , webircevprov(Creator, "event/webirc")
 137         {
 138                 allow_empty_last_param = false;
 139                 works_before_reg = true;
 140                 this->syntax = "<password> <gateway> <hostname> <ip> [<flags>]";
 141         }
 142
 143         CmdResult HandleLocal(LocalUser* user, const Params& parameters) CXX11_OVERRIDE
 144         {
 145                 if (user->registered == REG_ALL || realhost.get(user))
 146                         return CMD_FAILURE;
 147
 148                 for (std::vector<WebIRCHost>::const_iterator iter = hosts.begin(); iter != hosts.end(); ++iter)
 149                 {
 150                         // If we don't match the host then skip to the next host.
 151                         if (!iter->Matches(user, parameters[0], sslapi))
 152                                 continue;
 153
 154                         irc::sockets::sockaddrs ipaddr;
 155                         if (!irc::sockets::aptosa(parameters[3], user->client_sa.port(), ipaddr))
 156                         {
 157                                 WriteLog("Connecting user %s (%s) tried to use WEBIRC but gave an invalid IP address.",
 158                                         user->uuid.c_str(), user->GetIPString().c_str());
 159                                 ServerInstance->Users->QuitUser(user, "WEBIRC: IP address is invalid: " + parameters[3]);
 160                                 return CMD_FAILURE;
 161                         }
 162
 163                         // The user matched a WebIRC block!
 164                         gateway.set(user, parameters[1]);
 165                         realhost.set(user, user->GetRealHost());
 166                         realip.set(user, user->GetIPString());
 167
 168                         WriteLog("Connecting user %s is using a WebIRC gateway; changing their IP from %s to %s.",
 169                                 user->uuid.c_str(), user->GetIPString().c_str(), parameters[3].c_str());
 170
 171                         // If we have custom flags then deal with them.
 172                         WebIRC::FlagMap flags;
 173                         const bool hasflags = (parameters.size() > 4);
 174                         if (hasflags)
 175                         {
 176                                 // Parse the flags.
 177                                 irc::spacesepstream flagstream(parameters[4]);
 178                                 for (std::string flag; flagstream.GetToken(flag); )
 179                                 {
 180                                         // Does this flag have a value?
 181                                         const size_t separator = flag.find('=');
 182                                         if (separator == std::string::npos)
 183                                         {
 184                                                 flags[flag];
 185                                                 continue;
 186                                         }
 187
 188                                         // The flag has a value!
 189                                         const std::string key = flag.substr(0, separator);
 190                                         const std::string value = flag.substr(separator + 1);
 191                                         flags[key] = value;
 192                                 }
 193                         }
 194
 195                         // Inform modules about the WebIRC attempt.
 196                         FOREACH_MOD_CUSTOM(webircevprov, WebIRC::EventListener, OnWebIRCAuth, (user, (hasflags ? &flags : NULL)));
 197
 198                         // Set the IP address sent via WEBIRC. We ignore the hostname and lookup
 199                         // instead do our own DNS lookups because of unreliable gateways.
 200                         user->SetClientIP(ipaddr);
 201                         return CMD_SUCCESS;
 202                 }
 203
 204                 WriteLog("Connecting user %s (%s) tried to use WEBIRC but didn't match any configured WebIRC hosts.",
 205                         user->uuid.c_str(), user->GetIPString().c_str());
 206                 ServerInstance->Users->QuitUser(user, "WEBIRC: you don't match any configured WebIRC hosts.");
 207                 return CMD_FAILURE;
 208         }
 209
 210         void WriteLog(const char* message, ...) CUSTOM_PRINTF(2, 3)
 211         {
 212                 std::string buffer;
 213                 VAFORMAT(buffer, message, message);
 214
 215                 // If we are sending a snotice then the message will already be
 216                 // written to the logfile.
 217                 if (notify)
 218                         ServerInstance->SNO->WriteGlobalSno('w', buffer);
 219                 else
 220                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, buffer);
 221         }
 222 };
 223
 224 class ModuleCgiIRC
 225         : public Module
 226         , public WebIRC::EventListener
 227         , public Whois::EventListener
 228 {
 229  private:
 230         CommandWebIRC cmd;
 231         std::vector<IdentHost> hosts;
 232
 233         static bool ParseIdent(LocalUser* user, irc::sockets::sockaddrs& out)
 234         {
 235                 const char* ident = NULL;
 236                 if (user->ident.length() == 8)
 237                 {
 238                         // The ident is an IPv4 address encoded in hexadecimal with two characters
 239                         // per address segment.
 240                         ident = user->ident.c_str();
 241                 }
 242                 else if (user->ident.length() == 9 && user->ident[0] == '~')
 243                 {
 244                         // The same as above but m_ident got to this user before we did. Strip the
 245                         // ident prefix and continue as normal.
 246                         ident = user->ident.c_str() + 1;
 247                 }
 248                 else
 249                 {
 250                         // The user either does not have an IPv4 in their ident or the gateway server
 251                         // is also running an identd. In the latter case there isn't really a lot we
 252                         // can do so we just assume that the client in question is not connecting via
 253                         // an ident gateway.
 254                         return false;
 255                 }
 256
 257                 // Try to convert the IP address to a string. If this fails then the user
 258                 // does not have an IPv4 address in their ident.
 259                 errno = 0;
 260                 unsigned long address = strtoul(ident, NULL, 16);
 261                 if (errno)
 262                         return false;
 263
 264                 out.in4.sin_family = AF_INET;
 265                 out.in4.sin_addr.s_addr = htonl(address);
 266                 return true;
 267         }
 268
 269  public:
 270         ModuleCgiIRC()
 271                 : WebIRC::EventListener(this)
 272                 , Whois::EventListener(this)
 273                 , cmd(this)
 274         {
 275         }
 276
 277         void init() CXX11_OVERRIDE
 278         {
 279                 ServerInstance->SNO->EnableSnomask('w', "CGIIRC");
 280         }
 281
 282         void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE
 283         {
 284                 std::vector<IdentHost> identhosts;
 285                 std::vector<WebIRCHost> webirchosts;
 286
 287                 ConfigTagList tags = ServerInstance->Config->ConfTags("cgihost");
 288                 for (ConfigIter i = tags.first; i != tags.second; ++i)
 289                 {
 290                         ConfigTag* tag = i->second;
 291
 292                         // Ensure that we have the <cgihost:mask> parameter.
 293                         const std::string mask = tag->getString("mask");
 294                         if (mask.empty())
 295                                 throw ModuleException("<cgihost:mask> is a mandatory field, at " + tag->getTagLocation());
 296
 297                         // Determine what lookup type this host uses.
 298                         const std::string type = tag->getString("type");
 299                         if (stdalgo::string::equalsci(type, "ident"))
 300                         {
 301                                 // The IP address should be looked up from the hex IP address.
 302                                 const std::string newident = tag->getString("newident", "gateway", ServerInstance->IsIdent);
 303                                 identhosts.push_back(IdentHost(mask, newident));
 304                         }
 305                         else if (stdalgo::string::equalsci(type, "webirc"))
 306                         {
 307                                 // The IP address will be received via the WEBIRC command.
 308                                 const std::string fingerprint = tag->getString("fingerprint");
 309                                 const std::string password = tag->getString("password");
 310                                 const std::string passwordhash = tag->getString("hash", "plaintext", 1);
 311
 312                                 // WebIRC blocks require a password.
 313                                 if (fingerprint.empty() && password.empty())
 314                                         throw ModuleException("When using <cgihost type=\"webirc\"> either the fingerprint or password field is required, at " + tag->getTagLocation());
 315
 316                                 if (!password.empty() && stdalgo::string::equalsci(passwordhash, "plaintext"))
 317                                 {
 318                                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "<cgihost> tag at %s contains an plain text password, this is insecure!",
 319                                                 tag->getTagLocation().c_str());
 320                                 }
 321
 322                                 webirchosts.push_back(WebIRCHost(mask, fingerprint, password, passwordhash));
 323                         }
 324                         else
 325                         {
 326                                 throw ModuleException(type + " is an invalid <cgihost:mask> type, at " + tag->getTagLocation());
 327                         }
 328                 }
 329
 330                 // The host configuration was valid so we can apply it.
 331                 hosts.swap(identhosts);
 332                 cmd.hosts.swap(webirchosts);
 333
 334                 // Do we send an oper notice when a m_cgiirc client has their IP changed?
 335                 cmd.notify = ServerInstance->Config->ConfValue("cgiirc")->getBool("opernotice", true);
 336         }
 337
 338         ModResult OnSetConnectClass(LocalUser* user, ConnectClass* myclass) CXX11_OVERRIDE
 339         {
 340                 // If <connect:webirc> is not set then we have nothing to do.
 341                 const std::string webirc = myclass->config->getString("webirc");
 342                 if (webirc.empty())
 343                         return MOD_RES_PASSTHRU;
 344
 345                 // If the user is not connecting via a WebIRC gateway then they
 346                 // cannot match this connect class.
 347                 const std::string* gateway = cmd.gateway.get(user);
 348                 if (!gateway)
 349                 {
 350                         ServerInstance->Logs->Log("CONNECTCLASS", LOG_DEBUG, "The %s connect class is not suitable as it requires a connection via a WebIRC gateway",
 351                                         myclass->GetName().c_str());
 352                         return MOD_RES_DENY;
 353                 }
 354
 355                 // If the gateway matches the <connect:webirc> constraint then
 356                 // allow the check to continue. Otherwise, reject it.
 357                 if (!InspIRCd::Match(*gateway, webirc))
 358                 {
 359                         ServerInstance->Logs->Log("CONNECTCLASS", LOG_DEBUG, "The %s connect class is not suitable as the WebIRC gateway name (%s) does not match %s",
 360                                         myclass->GetName().c_str(), gateway->c_str(), webirc.c_str());
 361                         return MOD_RES_DENY;
 362                 }
 363
 364                 return MOD_RES_PASSTHRU;
 365         }
 366
 367         ModResult OnUserRegister(LocalUser* user) CXX11_OVERRIDE
 368         {
 369                 // There is no need to check for gateways if one is already being used.
 370                 if (cmd.realhost.get(user))
 371                         return MOD_RES_PASSTHRU;
 372
 373                 for (std::vector<IdentHost>::const_iterator iter = hosts.begin(); iter != hosts.end(); ++iter)
 374                 {
 375                         // If we don't match the host then skip to the next host.
 376                         if (!iter->Matches(user))
 377                                 continue;
 378
 379                         // We have matched an <cgihost> block! Try to parse the encoded IPv4 address
 380                         // out of the ident.
 381                         irc::sockets::sockaddrs address(user->client_sa);
 382                         if (!ParseIdent(user, address))
 383                                 return MOD_RES_PASSTHRU;
 384
 385                         // Store the hostname and IP of the gateway for later use.
 386                         cmd.realhost.set(user, user->GetRealHost());
 387                         cmd.realip.set(user, user->GetIPString());
 388
 389                         const std::string& newident = iter->GetIdent();
 390                         cmd.WriteLog("Connecting user %s is using an ident gateway; changing their IP from %s to %s and their ident from %s to %s.",
 391                                 user->uuid.c_str(), user->GetIPString().c_str(), address.addr().c_str(), user->ident.c_str(), newident.c_str());
 392
 393                         user->ChangeIdent(newident);
 394                         user->SetClientIP(address);
 395                         break;
 396                 }
 397                 return MOD_RES_PASSTHRU;
 398         }
 399
 400         void OnWebIRCAuth(LocalUser* user, const WebIRC::FlagMap* flags) CXX11_OVERRIDE
 401         {
 402                 // We are only interested in connection flags. If none have been
 403                 // given then we have nothing to do.
 404                 if (!flags)
 405                         return;
 406
 407                 WebIRC::FlagMap::const_iterator cport = flags->find("remote-port");
 408                 if (cport != flags->end())
 409                 {
 410                         // If we can't parse the port then just give up.
 411                         uint16_t port = ConvToNum<uint16_t>(cport->second);
 412                         if (port)
 413                         {
 414                                 switch (user->client_sa.family())
 415                                 {
 416                                         case AF_INET:
 417                                                 user->client_sa.in4.sin_port = htons(port);
 418                                                 break;
 419
 420                                         case AF_INET6:
 421                                                 user->client_sa.in6.sin6_port = htons(port);
 422                                                 break;
 423
 424                                         default:
 425                                                 // If we have reached this point then we have encountered a bug.
 426                                                 ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "BUG: OnWebIRCAuth(%s): socket type %d is unknown!",
 427                                                         user->uuid.c_str(), user->client_sa.family());
 428                                                 return;
 429                                 }
 430                         }
 431                 }
 432
 433                 WebIRC::FlagMap::const_iterator sport = flags->find("local-port");
 434                 if (sport != flags->end())
 435                 {
 436                         // If we can't parse the port then just give up.
 437                         uint16_t port = ConvToNum<uint16_t>(sport->second);
 438                         if (port)
 439                         {
 440                                 switch (user->server_sa.family())
 441                                 {
 442                                         case AF_INET:
 443                                                 user->server_sa.in4.sin_port = htons(port);
 444                                                 break;
 445
 446                                         case AF_INET6:
 447                                                 user->server_sa.in6.sin6_port = htons(port);
 448                                                 break;
 449
 450                                         default:
 451                                                 // If we have reached this point then we have encountered a bug.
 452                                                 ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "BUG: OnWebIRCAuth(%s): socket type %d is unknown!",
 453                                                         user->uuid.c_str(), user->server_sa.family());
 454                                                 return;
 455                                 }
 456                         }
 457                 }
 458         }
 459
 460         void OnWhois(Whois::Context& whois) CXX11_OVERRIDE
 461         {
 462                 if (!whois.IsSelfWhois() && !whois.GetSource()->HasPrivPermission("users/auspex"))
 463                         return;
 464
 465                 // If these fields are not set then the client is not using a gateway.
 466                 const std::string* realhost = cmd.realhost.get(whois.GetTarget());
 467                 const std::string* realip = cmd.realip.get(whois.GetTarget());
 468                 if (!realhost || !realip)
 469                         return;
 470
 471                 const std::string* gateway = cmd.gateway.get(whois.GetTarget());
 472                 if (gateway)
 473                         whois.SendLine(RPL_WHOISGATEWAY, *realhost, *realip, "is connected via the " + *gateway + " WebIRC gateway");
 474                 else
 475                         whois.SendLine(RPL_WHOISGATEWAY, *realhost, *realip, "is connected via an ident gateway");
 476         }
 477
 478         Version GetVersion() CXX11_OVERRIDE
 479         {
 480                 return Version("Adds the ability for IRC gateways to forward the real IP address of users connecting through them.", VF_VENDOR);
 481         }
 482 };
 483
 484 MODULE_INIT(ModuleCgiIRC)