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 "m_cap.h"
  23 #include "account.h"
  24 #include "sasl.h"
  25 #include "ssl.h"
  26
  27 /* $ModDesc: Provides support for IRC Authentication Layer (aka: atheme SASL) via AUTHENTICATE. */
  28
  29 enum SaslState { SASL_INIT, SASL_COMM, SASL_DONE };
  30 enum SaslResult { SASL_OK, SASL_FAIL, SASL_ABORT };
  31
  32 static std::string sasl_target = "*";
  33
  34 static void SendSASL(const parameterlist& params)
  35 {
  36         if (!ServerInstance->PI->SendEncapsulatedData(params))
  37         {
  38                 SASLFallback(NULL, params);
  39         }
  40 }
  41
  42 /**
  43  * Tracks SASL authentication state like charybdis does. --nenolod
  44  */
  45 class SaslAuthenticator
  46 {
  47  private:
  48         std::string agent;
  49         User *user;
  50         SaslState state;
  51         SaslResult result;
  52         bool state_announced;
  53
  54         /* taken from m_services_account */
  55         static bool ReadCGIIRCExt(const char* extname, User* user, std::string& out)
  56         {
  57                 ExtensionItem* wiext = ServerInstance->Extensions.GetItem(extname);
  58                 if (!wiext)
  59                         return false;
  60
  61                 if (wiext->creator->ModuleSourceFile != "m_cgiirc.so")
  62                         return false;
  63
  64                 StringExtItem* stringext = static_cast<StringExtItem*>(wiext);
  65                 std::string* addr = stringext->get(user);
  66                 if (!addr)
  67                         return false;
  68
  69                 out = *addr;
  70                 return true;
  71         }
  72
  73
  74         void SendHostIP()
  75         {
  76                 std::string host, ip;
  77
  78                 if (!ReadCGIIRCExt("cgiirc_webirc_hostname", user, host))
  79                 {
  80                         host = user->host;
  81                 }
  82                 if (!ReadCGIIRCExt("cgiirc_webirc_ip", user, ip))
  83                 {
  84                         ip = user->GetIPString();
  85                 }
  86                 else
  87                 {
  88                         /* IP addresses starting with a : on irc are a Bad Thing (tm) */
  89                         if (ip.c_str()[0] == ':')
  90                                 ip.insert(ip.begin(),1,'0');
  91                 }
  92
  93                 parameterlist params;
  94                 params.push_back(sasl_target);
  95                 params.push_back("SASL");
  96                 params.push_back(user->uuid);
  97                 params.push_back("*");
  98                 params.push_back("H");
  99                 params.push_back(host);
 100                 params.push_back(ip);
 101
 102                 LocalUser* lu = IS_LOCAL(user);
 103                 if (lu)
 104                 {
 105                         // NOTE: SaslAuthenticator instances are only created for local
 106                         // users so this parameter will always be appended.
 107                         SocketCertificateRequest req(&lu->eh, ServerInstance->Modules->Find("m_sasl.so"));
 108                         params.push_back(req.cert ? "S" : "P");
 109                 }
 110
 111                 SendSASL(params);
 112         }
 113
 114  public:
 115         SaslAuthenticator(User* user_, const std::string& method)
 116                 : user(user_), state(SASL_INIT), state_announced(false)
 117         {
 118                 SendHostIP();
 119
 120                 parameterlist params;
 121                 params.push_back(sasl_target);
 122                 params.push_back("SASL");
 123                 params.push_back(user->uuid);
 124                 params.push_back("*");
 125                 params.push_back("S");
 126                 params.push_back(method);
 127
 128                 if (method == "EXTERNAL" && IS_LOCAL(user_))
 129                 {
 130                         SocketCertificateRequest req(&((LocalUser*)user_)->eh, ServerInstance->Modules->Find("m_sasl.so"));
 131                         std::string fp = req.GetFingerprint();
 132
 133                         if (fp.size())
 134                                 params.push_back(fp);
 135                 }
 136
 137                 SendSASL(params);
 138         }
 139
 140         SaslResult GetSaslResult(const std::string &result_)
 141         {
 142                 if (result_ == "F")
 143                         return SASL_FAIL;
 144
 145                 if (result_ == "A")
 146                         return SASL_ABORT;
 147
 148                 return SASL_OK;
 149         }
 150
 151         /* checks for and deals with a state change. */
 152         SaslState ProcessInboundMessage(const std::vector<std::string> &msg)
 153         {
 154                 switch (this->state)
 155                 {
 156                  case SASL_INIT:
 157                         this->agent = msg[0];
 158                         this->state = SASL_COMM;
 159                         /* fall through */
 160                  case SASL_COMM:
 161                         if (msg[0] != this->agent)
 162                                 return this->state;
 163
 164                         if (msg.size() < 4)
 165                                 return this->state;
 166
 167                         if (msg[2] == "C")
 168                                 this->user->Write("AUTHENTICATE %s", msg[3].c_str());
 169                         else if (msg[2] == "D")
 170                         {
 171                                 this->state = SASL_DONE;
 172                                 this->result = this->GetSaslResult(msg[3]);
 173                         }
 174                         else if (msg[2] == "M")
 175                                 this->user->WriteNumeric(908, "%s %s :are available SASL mechanisms", this->user->nick.c_str(), msg[3].c_str());
 176                         else
 177                                 ServerInstance->Logs->Log("m_sasl", DEFAULT, "Services sent an unknown SASL message \"%s\" \"%s\"", msg[2].c_str(), msg[3].c_str());
 178
 179                         break;
 180                  case SASL_DONE:
 181                         break;
 182                  default:
 183                         ServerInstance->Logs->Log("m_sasl", DEFAULT, "WTF: SaslState is not a known state (%d)", this->state);
 184                         break;
 185                 }
 186
 187                 return this->state;
 188         }
 189
 190         void Abort(void)
 191         {
 192                 this->state = SASL_DONE;
 193                 this->result = SASL_ABORT;
 194         }
 195
 196         bool SendClientMessage(const std::vector<std::string>& parameters)
 197         {
 198                 if (this->state != SASL_COMM)
 199                         return true;
 200
 201                 parameterlist params;
 202                 params.push_back(sasl_target);
 203                 params.push_back("SASL");
 204                 params.push_back(this->user->uuid);
 205                 params.push_back(this->agent);
 206                 params.push_back("C");
 207
 208                 params.insert(params.end(), parameters.begin(), parameters.end());
 209
 210                 SendSASL(params);
 211
 212                 if (parameters[0].c_str()[0] == '*')
 213                 {
 214                         this->Abort();
 215                         return false;
 216                 }
 217
 218                 return true;
 219         }
 220
 221         void AnnounceState(void)
 222         {
 223                 if (this->state_announced)
 224                         return;
 225
 226                 switch (this->result)
 227                 {
 228                  case SASL_OK:
 229                         this->user->WriteNumeric(903, "%s :SASL authentication successful", this->user->nick.c_str());
 230                         break;
 231                  case SASL_ABORT:
 232                         this->user->WriteNumeric(906, "%s :SASL authentication aborted", this->user->nick.c_str());
 233                         break;
 234                  case SASL_FAIL:
 235                         this->user->WriteNumeric(904, "%s :SASL authentication failed", this->user->nick.c_str());
 236                         break;
 237                  default:
 238                         break;
 239                 }
 240
 241                 this->state_announced = true;
 242         }
 243 };
 244
 245 class CommandAuthenticate : public Command
 246 {
 247  public:
 248         SimpleExtItem<SaslAuthenticator>& authExt;
 249         GenericCap& cap;
 250         CommandAuthenticate(Module* Creator, SimpleExtItem<SaslAuthenticator>& ext, GenericCap& Cap)
 251                 : Command(Creator, "AUTHENTICATE", 1), authExt(ext), cap(Cap)
 252         {
 253                 works_before_reg = true;
 254                 allow_empty_last_param = false;
 255         }
 256
 257         CmdResult Handle (const std::vector<std::string>& parameters, User *user)
 258         {
 259                 /* Only allow AUTHENTICATE on unregistered clients */
 260                 if (user->registered != REG_ALL)
 261                 {
 262                         if (!cap.ext.get(user))
 263                                 return CMD_FAILURE;
 264
 265                         if (parameters[0].find(' ') != std::string::npos || parameters[0][0] == ':')
 266                                 return CMD_FAILURE;
 267
 268                         SaslAuthenticator *sasl = authExt.get(user);
 269                         if (!sasl)
 270                                 authExt.set(user, new SaslAuthenticator(user, parameters[0]));
 271                         else if (sasl->SendClientMessage(parameters) == false)  // IAL abort extension --nenolod
 272                         {
 273                                 sasl->AnnounceState();
 274                                 authExt.unset(user);
 275                         }
 276                 }
 277                 return CMD_FAILURE;
 278         }
 279 };
 280
 281 class CommandSASL : public Command
 282 {
 283  public:
 284         SimpleExtItem<SaslAuthenticator>& authExt;
 285         CommandSASL(Module* Creator, SimpleExtItem<SaslAuthenticator>& ext) : Command(Creator, "SASL", 2), authExt(ext)
 286         {
 287                 this->flags_needed = FLAG_SERVERONLY; // should not be called by users
 288         }
 289
 290         CmdResult Handle(const std::vector<std::string>& parameters, User *user)
 291         {
 292                 User* target = ServerInstance->FindNick(parameters[1]);
 293                 if ((!target) || (IS_SERVER(target)))
 294                 {
 295                         ServerInstance->Logs->Log("m_sasl", DEBUG,"User not found in sasl ENCAP event: %s", parameters[1].c_str());
 296                         return CMD_FAILURE;
 297                 }
 298
 299                 SaslAuthenticator *sasl = authExt.get(target);
 300                 if (!sasl)
 301                         return CMD_FAILURE;
 302
 303                 SaslState state = sasl->ProcessInboundMessage(parameters);
 304                 if (state == SASL_DONE)
 305                 {
 306                         sasl->AnnounceState();
 307                         authExt.unset(target);
 308                 }
 309                 return CMD_SUCCESS;
 310         }
 311
 312         RouteDescriptor GetRouting(User* user, const std::vector<std::string>& parameters)
 313         {
 314                 return ROUTE_BROADCAST;
 315         }
 316 };
 317
 318 class ModuleSASL : public Module
 319 {
 320         SimpleExtItem<SaslAuthenticator> authExt;
 321         GenericCap cap;
 322         CommandAuthenticate auth;
 323         CommandSASL sasl;
 324  public:
 325         ModuleSASL()
 326                 : authExt("sasl_auth", this), cap(this, "sasl"), auth(this, authExt, cap), sasl(this, authExt)
 327         {
 328         }
 329
 330         void init()
 331         {
 332                 OnRehash(NULL);
 333                 Implementation eventlist[] = { I_OnEvent, I_OnUserConnect, I_OnRehash };
 334                 ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
 335
 336                 ServiceProvider* providelist[] = { &auth, &sasl, &authExt };
 337                 ServerInstance->Modules->AddServices(providelist, 3);
 338
 339                 if (!ServerInstance->Modules->Find("m_services_account.so") || !ServerInstance->Modules->Find("m_cap.so"))
 340                         ServerInstance->Logs->Log("m_sasl", DEFAULT, "WARNING: m_services_account.so and m_cap.so are not loaded! m_sasl.so will NOT function correctly until these two modules are loaded!");
 341         }
 342
 343         void OnRehash(User*)
 344         {
 345                 sasl_target = ServerInstance->Config->ConfValue("sasl")->getString("target", "*");
 346         }
 347
 348         void OnUserConnect(LocalUser *user)
 349         {
 350                 SaslAuthenticator *sasl_ = authExt.get(user);
 351                 if (sasl_)
 352                 {
 353                         sasl_->Abort();
 354                         authExt.unset(user);
 355                 }
 356         }
 357
 358         Version GetVersion()
 359         {
 360                 return Version("Provides support for IRC Authentication Layer (aka: SASL) via AUTHENTICATE.", VF_VENDOR);
 361         }
 362
 363         void OnEvent(Event &ev)
 364         {
 365                 cap.HandleEvent(ev);
 366         }
 367 };
 368
 369 MODULE_INIT(ModuleSASL)