src/modules/extra/m_ssl_gnutls.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2009 InspIRCd Development Team
   6  * See: http://wiki.inspircd.org/Credits
   7  *
   8  * This program is free but copyrighted software; see
   9  *          the file COPYING for details.
  10  *
  11  * ---------------------------------------------------
  12  */
  13
  14 #include "inspircd.h"
  15 #include <gnutls/gnutls.h>
  16 #include <gnutls/x509.h>
  17 #include "transport.h"
  18 #include "m_cap.h"
  19
  20 #ifdef WINDOWS
  21 #pragma comment(lib, "libgnutls-13.lib")
  22 #endif
  23
  24 /* $ModDesc: Provides SSL support for clients */
  25 /* $CompileFlags: pkgconfincludes("gnutls","/gnutls/gnutls.h","") */
  26 /* $LinkerFlags: rpath("pkg-config --libs gnutls") pkgconflibs("gnutls","/libgnutls.so","-lgnutls") */
  27 /* $ModDep: transport.h */
  28 /* $CopyInstall: conf/key.pem $(CONPATH) */
  29 /* $CopyInstall: conf/cert.pem $(CONPATH) */
  30
  31 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING_READ, ISSL_HANDSHAKING_WRITE, ISSL_HANDSHAKEN, ISSL_CLOSING, ISSL_CLOSED };
  32
  33 /** Represents an SSL user's extra data
  34  */
  35 class issl_session : public classbase
  36 {
  37 public:
  38         issl_session()
  39         {
  40                 sess = NULL;
  41         }
  42
  43         gnutls_session_t sess;
  44         issl_status status;
  45         std::string outbuf;
  46 };
  47
  48 class CommandStartTLS : public Command
  49 {
  50         Module* Caller;
  51  public:
  52         CommandStartTLS (InspIRCd* Instance, Module* mod) : Command(Instance,"STARTTLS", 0, 0, true), Caller(mod)
  53         {
  54                 this->source = "m_ssl_gnutls.so";
  55         }
  56
  57         CmdResult Handle (const std::vector<std::string> &parameters, User *user)
  58         {
  59                 /* changed from == REG_ALL to catch clients sending STARTTLS
  60                  * after NICK and USER but before OnUserConnect completes and
  61                  * give a proper error message (see bug #645) - dz
  62                  */
  63                 if (user->registered != REG_NONE)
  64                 {
  65                         user->WriteNumeric(691, "%s :STARTTLS is not permitted after client registration has started", user->nick.c_str());
  66                 }
  67                 else
  68                 {
  69                         if (!user->GetIOHook())
  70                         {
  71                                 user->WriteNumeric(670, "%s :STARTTLS successful, go ahead with TLS handshake", user->nick.c_str());
  72                                 user->AddIOHook(Caller);
  73                                 Caller->OnRawSocketAccept(user->GetFd(), NULL, NULL);
  74                         }
  75                         else
  76                                 user->WriteNumeric(691, "%s :STARTTLS failure", user->nick.c_str());
  77                 }
  78
  79                 return CMD_FAILURE;
  80         }
  81 };
  82
  83 class ModuleSSLGnuTLS : public Module
  84 {
  85         std::set<ListenSocketBase*> listenports;
  86
  87         issl_session* sessions;
  88
  89         gnutls_certificate_credentials x509_cred;
  90         gnutls_dh_params dh_params;
  91
  92         std::string keyfile;
  93         std::string certfile;
  94         std::string cafile;
  95         std::string crlfile;
  96         std::string sslports;
  97         int dh_bits;
  98
  99         bool cred_alloc;
 100
 101         CommandStartTLS starttls;
 102
 103  public:
 104
 105         ModuleSSLGnuTLS(InspIRCd* Me)
 106                 : Module(Me), starttls(Me, this)
 107         {
 108                 ServerInstance->Modules->PublishInterface("BufferedSocketHook", this);
 109
 110                 sessions = new issl_session[ServerInstance->SE->GetMaxFds()];
 111
 112                 gnutls_global_init(); // This must be called once in the program
 113
 114                 cred_alloc = false;
 115                 // Needs the flag as it ignores a plain /rehash
 116                 OnModuleRehash(NULL,"ssl");
 117
 118                 // Void return, guess we assume success
 119                 gnutls_certificate_set_dh_params(x509_cred, dh_params);
 120                 Implementation eventlist[] = { I_On005Numeric, I_OnRawSocketConnect, I_OnRawSocketAccept,
 121                         I_OnRawSocketClose, I_OnRawSocketRead, I_OnRawSocketWrite, I_OnCleanup,
 122                         I_OnBufferFlushed, I_OnRequest, I_OnRehash, I_OnModuleRehash, I_OnPostConnect,
 123                         I_OnEvent, I_OnHookIO };
 124                 ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
 125
 126                 ServerInstance->AddCommand(&starttls);
 127         }
 128
 129         virtual void OnRehash(User* user)
 130         {
 131                 ConfigReader Conf(ServerInstance);
 132
 133                 listenports.clear();
 134                 sslports.clear();
 135
 136                 for (size_t i = 0; i < ServerInstance->ports.size(); i++)
 137                 {
 138                         ListenSocketBase* port = ServerInstance->ports[i];
 139                         std::string desc = port->GetDescription();
 140                         if (desc != "gnutls")
 141                                 continue;
 142
 143                         listenports.insert(port);
 144                         std::string portid = port->GetBindDesc();
 145
 146                         ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT, "m_ssl_gnutls.so: Enabling SSL for port %s", portid.c_str());
 147                         if (port->GetIP() != "127.0.0.1")
 148                                 sslports.append(portid).append(";");
 149                 }
 150
 151                 if (!sslports.empty())
 152                         sslports.erase(sslports.end() - 1);
 153         }
 154
 155         virtual void OnModuleRehash(User* user, const std::string &param)
 156         {
 157                 if(param != "ssl")
 158                         return;
 159
 160                 OnRehash(user);
 161
 162                 ConfigReader Conf(ServerInstance);
 163
 164                 std::string confdir(ServerInstance->ConfigFileName);
 165                 // +1 so we the path ends with a /
 166                 confdir = confdir.substr(0, confdir.find_last_of('/') + 1);
 167
 168                 cafile = Conf.ReadValue("gnutls", "cafile", 0);
 169                 crlfile = Conf.ReadValue("gnutls", "crlfile", 0);
 170                 certfile = Conf.ReadValue("gnutls", "certfile", 0);
 171                 keyfile = Conf.ReadValue("gnutls", "keyfile", 0);
 172                 dh_bits = Conf.ReadInteger("gnutls", "dhbits", 0, false);
 173
 174                 // Set all the default values needed.
 175                 if (cafile.empty())
 176                         cafile = "ca.pem";
 177
 178                 if (crlfile.empty())
 179                         crlfile = "crl.pem";
 180
 181                 if (certfile.empty())
 182                         certfile = "cert.pem";
 183
 184                 if (keyfile.empty())
 185                         keyfile = "key.pem";
 186
 187                 if((dh_bits != 768) && (dh_bits != 1024) && (dh_bits != 2048) && (dh_bits != 3072) && (dh_bits != 4096))
 188                         dh_bits = 1024;
 189
 190                 // Prepend relative paths with the path to the config directory.
 191                 if ((cafile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(cafile)))
 192                         cafile = confdir + cafile;
 193
 194                 if ((crlfile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(crlfile)))
 195                         crlfile = confdir + crlfile;
 196
 197                 if ((certfile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(certfile)))
 198                         certfile = confdir + certfile;
 199
 200                 if ((keyfile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(keyfile)))
 201                         keyfile = confdir + keyfile;
 202
 203                 int ret;
 204
 205                 if (cred_alloc)
 206                 {
 207                         // Deallocate the old credentials
 208                         gnutls_dh_params_deinit(dh_params);
 209                         gnutls_certificate_free_credentials(x509_cred);
 210                 }
 211                 else
 212                         cred_alloc = true;
 213
 214                 if((ret = gnutls_certificate_allocate_credentials(&x509_cred)) < 0)
 215                         ServerInstance->Logs->Log("m_ssl_gnutls",DEBUG, "m_ssl_gnutls.so: Failed to allocate certificate credentials: %s", gnutls_strerror(ret));
 216
 217                 if((ret = gnutls_dh_params_init(&dh_params)) < 0)
 218                         ServerInstance->Logs->Log("m_ssl_gnutls",DEBUG, "m_ssl_gnutls.so: Failed to initialise DH parameters: %s", gnutls_strerror(ret));
 219
 220                 if((ret =gnutls_certificate_set_x509_trust_file(x509_cred, cafile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 221                         ServerInstance->Logs->Log("m_ssl_gnutls",DEBUG, "m_ssl_gnutls.so: Failed to set X.509 trust file '%s': %s", cafile.c_str(), gnutls_strerror(ret));
 222
 223                 if((ret = gnutls_certificate_set_x509_crl_file (x509_cred, crlfile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 224                         ServerInstance->Logs->Log("m_ssl_gnutls",DEBUG, "m_ssl_gnutls.so: Failed to set X.509 CRL file '%s': %s", crlfile.c_str(), gnutls_strerror(ret));
 225
 226                 if((ret = gnutls_certificate_set_x509_key_file (x509_cred, certfile.c_str(), keyfile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 227                 {
 228                         // If this fails, no SSL port will work. At all. So, do the smart thing - throw a ModuleException
 229                         throw ModuleException("Unable to load GnuTLS server certificate (" + certfile + ", key: " + keyfile + "): " + std::string(gnutls_strerror(ret)));
 230                 }
 231
 232                 // This may be on a large (once a day or week) timer eventually.
 233                 GenerateDHParams();
 234         }
 235
 236         void GenerateDHParams()
 237         {
 238                 // Generate Diffie Hellman parameters - for use with DHE
 239                 // kx algorithms. These should be discarded and regenerated
 240                 // once a day, once a week or once a month. Depending on the
 241                 // security requirements.
 242
 243                 int ret;
 244
 245                 if((ret = gnutls_dh_params_generate2(dh_params, dh_bits)) < 0)
 246                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to generate DH parameters (%d bits): %s", dh_bits, gnutls_strerror(ret));
 247         }
 248
 249         virtual ~ModuleSSLGnuTLS()
 250         {
 251                 gnutls_dh_params_deinit(dh_params);
 252                 gnutls_certificate_free_credentials(x509_cred);
 253                 gnutls_global_deinit();
 254                 ServerInstance->Modules->UnpublishInterface("BufferedSocketHook", this);
 255                 delete[] sessions;
 256         }
 257
 258         virtual void OnCleanup(int target_type, void* item)
 259         {
 260                 if(target_type == TYPE_USER)
 261                 {
 262                         User* user = static_cast<User*>(item);
 263
 264                         if (user->GetIOHook() == this)
 265                         {
 266                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 267                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 268                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 269                                 user->DelIOHook();
 270                         }
 271                         if (user->GetExt("ssl_cert"))
 272                         {
 273                                 ssl_cert* tofree;
 274                                 user->GetExt("ssl_cert", tofree);
 275                                 delete tofree;
 276                                 user->Shrink("ssl_cert");
 277                         }
 278                 }
 279         }
 280
 281         virtual Version GetVersion()
 282         {
 283                 return Version("$Id$", VF_VENDOR, API_VERSION);
 284         }
 285
 286
 287         virtual void On005Numeric(std::string &output)
 288         {
 289                 if (!sslports.empty())
 290                         output.append(" SSL=" + sslports);
 291                 output.append(" STARTTLS");
 292         }
 293
 294         virtual void OnHookIO(EventHandler* user, ListenSocketBase* lsb)
 295         {
 296                 if (!user->GetIOHook() && listenports.find(lsb) != listenports.end())
 297                 {
 298                         /* Hook the user with our module */
 299                         user->AddIOHook(this);
 300                 }
 301         }
 302
 303         virtual const char* OnRequest(Request* request)
 304         {
 305                 ISHRequest* ISR = static_cast<ISHRequest*>(request);
 306                 if (strcmp("IS_NAME", request->GetId()) == 0)
 307                 {
 308                         return "gnutls";
 309                 }
 310                 else if (strcmp("IS_HOOK", request->GetId()) == 0)
 311                 {
 312                         const char* ret = "OK";
 313                         try
 314                         {
 315                                 ret = ISR->Sock->AddIOHook(this) ? "OK" : NULL;
 316                         }
 317                         catch (ModuleException &e)
 318                         {
 319                                 return NULL;
 320                         }
 321                         return ret;
 322                 }
 323                 else if (strcmp("IS_UNHOOK", request->GetId()) == 0)
 324                 {
 325                         return ISR->Sock->DelIOHook() ? "OK" : NULL;
 326                 }
 327                 else if (strcmp("IS_HSDONE", request->GetId()) == 0)
 328                 {
 329                         if (ISR->Sock->GetFd() < 0)
 330                                 return "OK";
 331
 332                         issl_session* session = &sessions[ISR->Sock->GetFd()];
 333                         return (session->status == ISSL_HANDSHAKING_READ || session->status == ISSL_HANDSHAKING_WRITE) ? NULL : "OK";
 334                 }
 335                 else if (strcmp("IS_ATTACH", request->GetId()) == 0)
 336                 {
 337                         if (ISR->Sock->GetFd() > -1)
 338                         {
 339                                 issl_session* session = &sessions[ISR->Sock->GetFd()];
 340                                 if (session->sess)
 341                                 {
 342                                         if (static_cast<Extensible*>(ServerInstance->SE->GetRef(ISR->Sock->GetFd())) == static_cast<Extensible*>(ISR->Sock))
 343                                         {
 344                                                 VerifyCertificate(session, ISR->Sock);
 345                                                 return "OK";
 346                                         }
 347                                 }
 348                         }
 349                 }
 350                 else if (strcmp("GET_FP", request->GetId()) == 0)
 351                 {
 352                         if (ISR->Sock->GetFd() > -1)
 353                         {
 354                                 issl_session* session = &sessions[ISR->Sock->GetFd()];
 355                                 if (session->sess)
 356                                 {
 357                                         Extensible* ext = ISR->Sock;
 358                                         ssl_cert* certinfo;
 359                                         if (ext->GetExt("ssl_cert",certinfo))
 360                                                 return certinfo->GetFingerprint().c_str();
 361                                 }
 362                         }
 363                 }
 364                 return NULL;
 365         }
 366
 367
 368         virtual void OnRawSocketAccept(int fd, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server)
 369         {
 370                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 371                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 372                         return;
 373
 374                 issl_session* session = &sessions[fd];
 375
 376                 /* For STARTTLS: Don't try and init a session on a socket that already has a session */
 377                 if (session->sess)
 378                         return;
 379
 380                 gnutls_init(&session->sess, GNUTLS_SERVER);
 381
 382                 gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
 383                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 384                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 385
 386                 gnutls_transport_set_ptr(session->sess, reinterpret_cast<gnutls_transport_ptr_t>(fd)); // Give gnutls the fd for the socket.
 387
 388                 gnutls_certificate_server_set_request(session->sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
 389
 390                 Handshake(session, fd);
 391         }
 392
 393         virtual void OnRawSocketConnect(int fd)
 394         {
 395                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 396                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 397                         return;
 398
 399                 issl_session* session = &sessions[fd];
 400
 401                 gnutls_init(&session->sess, GNUTLS_CLIENT);
 402
 403                 gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
 404                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 405                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 406                 gnutls_transport_set_ptr(session->sess, reinterpret_cast<gnutls_transport_ptr_t>(fd)); // Give gnutls the fd for the socket.
 407
 408                 Handshake(session, fd);
 409         }
 410
 411         virtual void OnRawSocketClose(int fd)
 412         {
 413                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 414                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds()))
 415                         return;
 416
 417                 CloseSession(&sessions[fd]);
 418
 419                 EventHandler* user = ServerInstance->SE->GetRef(fd);
 420
 421                 if ((user) && (user->GetExt("ssl_cert")))
 422                 {
 423                         ssl_cert* tofree;
 424                         user->GetExt("ssl_cert", tofree);
 425                         delete tofree;
 426                         user->Shrink("ssl_cert");
 427                 }
 428         }
 429
 430         virtual int OnRawSocketRead(int fd, char* buffer, unsigned int count, int &readresult)
 431         {
 432                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 433                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 434                         return 0;
 435
 436                 issl_session* session = &sessions[fd];
 437
 438                 if (!session->sess)
 439                 {
 440                         readresult = 0;
 441                         CloseSession(session);
 442                         return 1;
 443                 }
 444
 445                 if (session->status == ISSL_HANDSHAKING_READ)
 446                 {
 447                         // The handshake isn't finished, try to finish it.
 448
 449                         if(!Handshake(session, fd))
 450                         {
 451                                 errno = session->status == ISSL_CLOSING ? EIO : EAGAIN;
 452                                 // Couldn't resume handshake.
 453                                 return -1;
 454                         }
 455                 }
 456                 else if (session->status == ISSL_HANDSHAKING_WRITE)
 457                 {
 458                         errno = EAGAIN;
 459                         MakePollWrite(fd);
 460                         return -1;
 461                 }
 462
 463                 // If we resumed the handshake then session->status will be ISSL_HANDSHAKEN.
 464
 465                 if (session->status == ISSL_HANDSHAKEN)
 466                 {
 467                         unsigned int len = 0;
 468                         while (len < count)
 469                         {
 470                                 int ret = gnutls_record_recv(session->sess, buffer + len, count - len);
 471                                 if (ret > 0)
 472                                 {
 473                                         len += ret;
 474                                 }
 475                                 else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 476                                 {
 477                                         break;
 478                                 }
 479                                 else
 480                                 {
 481                                         if (ret != 0)
 482                                                 ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT,
 483                                                         "m_ssl_gnutls.so: Error while reading on fd %d: %s",
 484                                                         fd, gnutls_strerror(ret));
 485
 486                                         // if ret == 0, client closed connection.
 487                                         readresult = 0;
 488                                         CloseSession(session);
 489                                         return 1;
 490                                 }
 491                         }
 492                         readresult = len;
 493                         if (len)
 494                         {
 495                                 return 1;
 496                         }
 497                         else
 498                         {
 499                                 errno = EAGAIN;
 500                                 return -1;
 501                         }
 502                 }
 503                 else if (session->status == ISSL_CLOSING)
 504                         readresult = 0;
 505
 506                 return 1;
 507         }
 508
 509         virtual int OnRawSocketWrite(int fd, const char* buffer, int count)
 510         {
 511                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 512                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 513                         return 0;
 514
 515                 issl_session* session = &sessions[fd];
 516                 const char* sendbuffer = buffer;
 517
 518                 if (!session->sess)
 519                 {
 520                         CloseSession(session);
 521                         return 1;
 522                 }
 523
 524                 session->outbuf.append(sendbuffer, count);
 525                 sendbuffer = session->outbuf.c_str();
 526                 count = session->outbuf.size();
 527
 528                 if (session->status == ISSL_HANDSHAKING_WRITE || session->status == ISSL_HANDSHAKING_READ)
 529                 {
 530                         // The handshake isn't finished, try to finish it.
 531                         Handshake(session, fd);
 532                         errno = session->status == ISSL_CLOSING ? EIO : EAGAIN;
 533                         return -1;
 534                 }
 535
 536                 int ret = 0;
 537
 538                 if (session->status == ISSL_HANDSHAKEN)
 539                 {
 540                         ret = gnutls_record_send(session->sess, sendbuffer, count);
 541
 542                         if (ret == 0)
 543                         {
 544                                 CloseSession(session);
 545                         }
 546                         else if (ret < 0)
 547                         {
 548                                 if(ret != GNUTLS_E_AGAIN && ret != GNUTLS_E_INTERRUPTED)
 549                                 {
 550                                         ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT,
 551                                                         "m_ssl_gnutls.so: Error while writing to fd %d: %s",
 552                                                         fd, gnutls_strerror(ret));
 553                                         CloseSession(session);
 554                                 }
 555                                 else
 556                                 {
 557                                         errno = EAGAIN;
 558                                 }
 559                         }
 560                         else
 561                         {
 562                                 session->outbuf = session->outbuf.substr(ret);
 563                         }
 564                 }
 565
 566                 if (!session->outbuf.empty())
 567                         MakePollWrite(fd);
 568
 569                 /* Who's smart idea was it to return 1 when we havent written anything?
 570                  * This fucks the buffer up in BufferedSocket :p
 571                  */
 572                 return ret < 1 ? 0 : ret;
 573         }
 574
 575         bool Handshake(issl_session* session, int fd)
 576         {
 577                 int ret = gnutls_handshake(session->sess);
 578
 579                 if (ret < 0)
 580                 {
 581                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 582                         {
 583                                 // Handshake needs resuming later, read() or write() would have blocked.
 584
 585                                 if(gnutls_record_get_direction(session->sess) == 0)
 586                                 {
 587                                         // gnutls_handshake() wants to read() again.
 588                                         session->status = ISSL_HANDSHAKING_READ;
 589                                 }
 590                                 else
 591                                 {
 592                                         // gnutls_handshake() wants to write() again.
 593                                         session->status = ISSL_HANDSHAKING_WRITE;
 594                                         MakePollWrite(fd);
 595                                 }
 596                         }
 597                         else
 598                         {
 599                                 // Handshake failed.
 600                                 ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT,
 601                                                 "m_ssl_gnutls.so: Handshake failed on fd %d: %s",
 602                                                 fd, gnutls_strerror(ret));
 603                                 CloseSession(session);
 604                                 session->status = ISSL_CLOSING;
 605                         }
 606
 607                         return false;
 608                 }
 609                 else
 610                 {
 611                         // Handshake complete.
 612                         // This will do for setting the ssl flag...it could be done earlier if it's needed. But this seems neater.
 613                         EventHandler *extendme = ServerInstance->SE->GetRef(fd);
 614                         if (extendme)
 615                         {
 616                                 extendme->Extend("ssl");
 617                         }
 618
 619                         // Change the seesion state
 620                         session->status = ISSL_HANDSHAKEN;
 621
 622                         // Finish writing, if any left
 623                         MakePollWrite(fd);
 624
 625                         return true;
 626                 }
 627         }
 628
 629         virtual void OnPostConnect(User* user)
 630         {
 631                 // This occurs AFTER OnUserConnect so we can be sure the
 632                 // protocol module has propagated the NICK message.
 633                 if (user->GetIOHook() == this && (IS_LOCAL(user)))
 634                 {
 635                         ssl_cert* certdata = VerifyCertificate(&sessions[user->GetFd()],user);
 636                         if (sessions[user->GetFd()].sess)
 637                         {
 638                                 std::string cipher = gnutls_kx_get_name(gnutls_kx_get(sessions[user->GetFd()].sess));
 639                                 cipher.append("-").append(gnutls_cipher_get_name(gnutls_cipher_get(sessions[user->GetFd()].sess))).append("-");
 640                                 cipher.append(gnutls_mac_get_name(gnutls_mac_get(sessions[user->GetFd()].sess)));
 641                                 user->WriteServ("NOTICE %s :*** You are connected using SSL cipher \"%s\"", user->nick.c_str(), cipher.c_str());
 642                         }
 643
 644                         ServerInstance->PI->SendMetaData(user, "ssl", "ON");
 645                         if (certdata)
 646                                 ServerInstance->PI->SendMetaData(user, "ssl_cert", certdata->GetMetaLine().c_str());
 647                 }
 648         }
 649
 650         void MakePollWrite(int fd)
 651         {
 652                 //OnRawSocketWrite(fd, NULL, 0);
 653                 EventHandler* eh = ServerInstance->SE->GetRef(fd);
 654                 if (eh)
 655                         ServerInstance->SE->WantWrite(eh);
 656         }
 657
 658         virtual void OnBufferFlushed(User* user)
 659         {
 660                 if (user->GetIOHook() == this)
 661                 {
 662                         issl_session* session = &sessions[user->GetFd()];
 663                         if (session && session->outbuf.size())
 664                                 OnRawSocketWrite(user->GetFd(), NULL, 0);
 665                 }
 666         }
 667
 668         void CloseSession(issl_session* session)
 669         {
 670                 if(session->sess)
 671                 {
 672                         gnutls_bye(session->sess, GNUTLS_SHUT_WR);
 673                         gnutls_deinit(session->sess);
 674                 }
 675
 676                 session->outbuf.clear();
 677                 session->sess = NULL;
 678                 session->status = ISSL_NONE;
 679         }
 680
 681         ssl_cert* VerifyCertificate(issl_session* session, Extensible* user)
 682         {
 683                 if (!session->sess || !user)
 684                         return NULL;
 685
 686                 unsigned int status;
 687                 const gnutls_datum_t* cert_list;
 688                 int ret;
 689                 unsigned int cert_list_size;
 690                 gnutls_x509_crt_t cert;
 691                 char name[MAXBUF];
 692                 unsigned char digest[MAXBUF];
 693                 size_t digest_size = sizeof(digest);
 694                 size_t name_size = sizeof(name);
 695                 ssl_cert* certinfo = new ssl_cert;
 696
 697                 user->Extend("ssl_cert",certinfo);
 698
 699                 /* This verification function uses the trusted CAs in the credentials
 700                  * structure. So you must have installed one or more CA certificates.
 701                  */
 702                 ret = gnutls_certificate_verify_peers2(session->sess, &status);
 703
 704                 if (ret < 0)
 705                 {
 706                         certinfo->error = std::string(gnutls_strerror(ret));
 707                         return certinfo;
 708                 }
 709
 710                 certinfo->invalid = (status & GNUTLS_CERT_INVALID);
 711                 certinfo->unknownsigner = (status & GNUTLS_CERT_SIGNER_NOT_FOUND);
 712                 certinfo->revoked = (status & GNUTLS_CERT_REVOKED);
 713                 certinfo->trusted = !(status & GNUTLS_CERT_SIGNER_NOT_CA);
 714
 715                 /* Up to here the process is the same for X.509 certificates and
 716                  * OpenPGP keys. From now on X.509 certificates are assumed. This can
 717                  * be easily extended to work with openpgp keys as well.
 718                  */
 719                 if (gnutls_certificate_type_get(session->sess) != GNUTLS_CRT_X509)
 720                 {
 721                         certinfo->error = "No X509 keys sent";
 722                         return certinfo;
 723                 }
 724
 725                 ret = gnutls_x509_crt_init(&cert);
 726                 if (ret < 0)
 727                 {
 728                         certinfo->error = gnutls_strerror(ret);
 729                         return certinfo;
 730                 }
 731
 732                 cert_list_size = 0;
 733                 cert_list = gnutls_certificate_get_peers(session->sess, &cert_list_size);
 734                 if (cert_list == NULL)
 735                 {
 736                         certinfo->error = "No certificate was found";
 737                         return certinfo;
 738                 }
 739
 740                 /* This is not a real world example, since we only check the first
 741                  * certificate in the given chain.
 742                  */
 743
 744                 ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
 745                 if (ret < 0)
 746                 {
 747                         certinfo->error = gnutls_strerror(ret);
 748                         return certinfo;
 749                 }
 750
 751                 gnutls_x509_crt_get_dn(cert, name, &name_size);
 752                 certinfo->dn = name;
 753
 754                 gnutls_x509_crt_get_issuer_dn(cert, name, &name_size);
 755                 certinfo->issuer = name;
 756
 757                 if ((ret = gnutls_x509_crt_get_fingerprint(cert, GNUTLS_DIG_MD5, digest, &digest_size)) < 0)
 758                 {
 759                         certinfo->error = gnutls_strerror(ret);
 760                 }
 761                 else
 762                 {
 763                         certinfo->fingerprint = irc::hex(digest, digest_size);
 764                 }
 765
 766                 /* Beware here we do not check for errors.
 767                  */
 768                 if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
 769                 {
 770                         certinfo->error = "Not activated, or expired certificate";
 771                 }
 772
 773                 gnutls_x509_crt_deinit(cert);
 774
 775                 return certinfo;
 776         }
 777
 778         void OnEvent(Event* ev)
 779         {
 780                 GenericCapHandler(ev, "tls", "tls");
 781         }
 782
 783         void Prioritize()
 784         {
 785                 Module* server = ServerInstance->Modules->Find("m_spanningtree.so");
 786                 ServerInstance->Modules->SetPriority(this, I_OnPostConnect, PRIORITY_AFTER, &server);
 787         }
 788 };
 789
 790 MODULE_INIT(ModuleSSLGnuTLS)