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 bool isin(const std::string &host, int port, const std::vector<std::string> &portlist)
  34 {
  35         if (std::find(portlist.begin(), portlist.end(), "*:" + ConvToStr(port)) != portlist.end())
  36                 return true;
  37
  38         if (std::find(portlist.begin(), portlist.end(), ":" + ConvToStr(port)) != portlist.end())
  39                 return true;
  40
  41         return std::find(portlist.begin(), portlist.end(), host + ":" + ConvToStr(port)) != portlist.end();
  42 }
  43
  44 /** Represents an SSL user's extra data
  45  */
  46 class issl_session : public classbase
  47 {
  48 public:
  49         issl_session()
  50         {
  51                 sess = NULL;
  52         }
  53
  54         gnutls_session_t sess;
  55         issl_status status;
  56         std::string outbuf;
  57 };
  58
  59 class CommandStartTLS : public Command
  60 {
  61         Module* Caller;
  62  public:
  63         CommandStartTLS (InspIRCd* Instance, Module* mod) : Command(Instance,"STARTTLS", 0, 0, true), Caller(mod)
  64         {
  65                 this->source = "m_ssl_gnutls.so";
  66         }
  67
  68         CmdResult Handle (const std::vector<std::string> &parameters, User *user)
  69         {
  70                 /* changed from == REG_ALL to catch clients sending STARTTLS
  71                  * after NICK and USER but before OnUserConnect completes and
  72                  * give a proper error message (see bug #645) - dz
  73                  */
  74                 if (user->registered != REG_NONE)
  75                 {
  76                         user->WriteNumeric(691, "%s :STARTTLS is not permitted after client registration has started", user->nick.c_str());
  77                 }
  78                 else
  79                 {
  80                         if (!user->GetIOHook())
  81                         {
  82                                 user->WriteNumeric(670, "%s :STARTTLS successful, go ahead with TLS handshake", user->nick.c_str());
  83                                 user->AddIOHook(Caller);
  84                                 Caller->OnRawSocketAccept(user->GetFd(), NULL, NULL);
  85                         }
  86                         else
  87                                 user->WriteNumeric(691, "%s :STARTTLS failure", user->nick.c_str());
  88                 }
  89
  90                 return CMD_FAILURE;
  91         }
  92 };
  93
  94 class ModuleSSLGnuTLS : public Module
  95 {
  96         std::vector<std::string> listenports;
  97
  98         issl_session* sessions;
  99
 100         gnutls_certificate_credentials x509_cred;
 101         gnutls_dh_params dh_params;
 102
 103         std::string keyfile;
 104         std::string certfile;
 105         std::string cafile;
 106         std::string crlfile;
 107         std::string sslports;
 108         int dh_bits;
 109
 110         int clientactive;
 111         bool cred_alloc;
 112
 113         CommandStartTLS starttls;
 114
 115  public:
 116
 117         ModuleSSLGnuTLS(InspIRCd* Me)
 118                 : Module(Me), starttls(Me, this)
 119         {
 120                 ServerInstance->Modules->PublishInterface("BufferedSocketHook", this);
 121
 122                 sessions = new issl_session[ServerInstance->SE->GetMaxFds()];
 123
 124                 gnutls_global_init(); // This must be called once in the program
 125
 126                 cred_alloc = false;
 127                 // Needs the flag as it ignores a plain /rehash
 128                 OnModuleRehash(NULL,"ssl");
 129
 130                 // Void return, guess we assume success
 131                 gnutls_certificate_set_dh_params(x509_cred, dh_params);
 132                 Implementation eventlist[] = { I_On005Numeric, I_OnRawSocketConnect, I_OnRawSocketAccept,
 133                         I_OnRawSocketClose, I_OnRawSocketRead, I_OnRawSocketWrite, I_OnCleanup,
 134                         I_OnBufferFlushed, I_OnRequest, I_OnUnloadModule, I_OnRehash, I_OnModuleRehash,
 135                         I_OnPostConnect, I_OnEvent, I_OnHookUserIO };
 136                 ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
 137
 138                 ServerInstance->AddCommand(&starttls);
 139         }
 140
 141         virtual void OnRehash(User* user)
 142         {
 143                 ConfigReader Conf(ServerInstance);
 144
 145                 listenports.clear();
 146                 clientactive = 0;
 147                 sslports.clear();
 148
 149                 for(int index = 0; index < Conf.Enumerate("bind"); index++)
 150                 {
 151                         // For each <bind> tag
 152                         std::string x = Conf.ReadValue("bind", "type", index);
 153                         if(((x.empty()) || (x == "clients")) && (Conf.ReadValue("bind", "ssl", index) == "gnutls"))
 154                         {
 155                                 // Get the port we're meant to be listening on with SSL
 156                                 std::string port = Conf.ReadValue("bind", "port", index);
 157                                 std::string addr = Conf.ReadValue("bind", "address", index);
 158
 159                                 if (!addr.empty())
 160                                 {
 161                                         // normalize address, important for IPv6
 162                                         int portint = 0;
 163                                         irc::sockets::sockaddrs bin;
 164                                         if (irc::sockets::aptosa(addr.c_str(), portint, &bin))
 165                                                 irc::sockets::satoap(&bin, addr, portint);
 166                                 }
 167
 168                                 irc::portparser portrange(port, false);
 169                                 long portno = -1;
 170                                 while ((portno = portrange.GetToken()))
 171                                 {
 172                                         clientactive++;
 173                                         try
 174                                         {
 175                                                 listenports.push_back(addr + ":" + ConvToStr(portno));
 176
 177                                                 for (size_t i = 0; i < ServerInstance->ports.size(); i++)
 178                                                         if ((ServerInstance->ports[i]->GetPort() == portno) && (ServerInstance->ports[i]->GetIP() == addr))
 179                                                                 ServerInstance->ports[i]->SetDescription("ssl");
 180                                                 ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Enabling SSL for port %ld", portno);
 181
 182                                                 if (addr != "127.0.0.1")
 183                                                         sslports.append((addr.empty() ? "*" : addr)).append(":").append(ConvToStr(portno)).append(";");
 184                                         }
 185                                         catch (ModuleException &e)
 186                                         {
 187                                                 ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: FAILED to enable SSL on port %ld: %s. Maybe it's already hooked by the same port on a different IP, or you have an other SSL or similar module loaded?", portno, e.GetReason());
 188                                         }
 189                                 }
 190                         }
 191                 }
 192
 193                 if (!sslports.empty())
 194                         sslports.erase(sslports.end() - 1);
 195         }
 196
 197         virtual void OnModuleRehash(User* user, const std::string &param)
 198         {
 199                 if(param != "ssl")
 200                         return;
 201
 202                 OnRehash(user);
 203
 204                 ConfigReader Conf(ServerInstance);
 205
 206                 std::string confdir(ServerInstance->ConfigFileName);
 207                 // +1 so we the path ends with a /
 208                 confdir = confdir.substr(0, confdir.find_last_of('/') + 1);
 209
 210                 cafile = Conf.ReadValue("gnutls", "cafile", 0);
 211                 crlfile = Conf.ReadValue("gnutls", "crlfile", 0);
 212                 certfile = Conf.ReadValue("gnutls", "certfile", 0);
 213                 keyfile = Conf.ReadValue("gnutls", "keyfile", 0);
 214                 dh_bits = Conf.ReadInteger("gnutls", "dhbits", 0, false);
 215
 216                 // Set all the default values needed.
 217                 if (cafile.empty())
 218                         cafile = "ca.pem";
 219
 220                 if (crlfile.empty())
 221                         crlfile = "crl.pem";
 222
 223                 if (certfile.empty())
 224                         certfile = "cert.pem";
 225
 226                 if (keyfile.empty())
 227                         keyfile = "key.pem";
 228
 229                 if((dh_bits != 768) && (dh_bits != 1024) && (dh_bits != 2048) && (dh_bits != 3072) && (dh_bits != 4096))
 230                         dh_bits = 1024;
 231
 232                 // Prepend relative paths with the path to the config directory.
 233                 if ((cafile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(cafile)))
 234                         cafile = confdir + cafile;
 235
 236                 if ((crlfile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(crlfile)))
 237                         crlfile = confdir + crlfile;
 238
 239                 if ((certfile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(certfile)))
 240                         certfile = confdir + certfile;
 241
 242                 if ((keyfile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(keyfile)))
 243                         keyfile = confdir + keyfile;
 244
 245                 int ret;
 246
 247                 if (cred_alloc)
 248                 {
 249                         // Deallocate the old credentials
 250                         gnutls_dh_params_deinit(dh_params);
 251                         gnutls_certificate_free_credentials(x509_cred);
 252                 }
 253                 else
 254                         cred_alloc = true;
 255
 256                 if((ret = gnutls_certificate_allocate_credentials(&x509_cred)) < 0)
 257                         ServerInstance->Logs->Log("m_ssl_gnutls",DEBUG, "m_ssl_gnutls.so: Failed to allocate certificate credentials: %s", gnutls_strerror(ret));
 258
 259                 if((ret = gnutls_dh_params_init(&dh_params)) < 0)
 260                         ServerInstance->Logs->Log("m_ssl_gnutls",DEBUG, "m_ssl_gnutls.so: Failed to initialise DH parameters: %s", gnutls_strerror(ret));
 261
 262                 if((ret =gnutls_certificate_set_x509_trust_file(x509_cred, cafile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 263                         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));
 264
 265                 if((ret = gnutls_certificate_set_x509_crl_file (x509_cred, crlfile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 266                         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));
 267
 268                 if((ret = gnutls_certificate_set_x509_key_file (x509_cred, certfile.c_str(), keyfile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 269                 {
 270                         // If this fails, no SSL port will work. At all. So, do the smart thing - throw a ModuleException
 271                         throw ModuleException("Unable to load GnuTLS server certificate (" + certfile + ", key: " + keyfile + "): " + std::string(gnutls_strerror(ret)));
 272                 }
 273
 274                 // This may be on a large (once a day or week) timer eventually.
 275                 GenerateDHParams();
 276         }
 277
 278         void GenerateDHParams()
 279         {
 280                 // Generate Diffie Hellman parameters - for use with DHE
 281                 // kx algorithms. These should be discarded and regenerated
 282                 // once a day, once a week or once a month. Depending on the
 283                 // security requirements.
 284
 285                 int ret;
 286
 287                 if((ret = gnutls_dh_params_generate2(dh_params, dh_bits)) < 0)
 288                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to generate DH parameters (%d bits): %s", dh_bits, gnutls_strerror(ret));
 289         }
 290
 291         virtual ~ModuleSSLGnuTLS()
 292         {
 293                 gnutls_dh_params_deinit(dh_params);
 294                 gnutls_certificate_free_credentials(x509_cred);
 295                 gnutls_global_deinit();
 296                 ServerInstance->Modules->UnpublishInterface("BufferedSocketHook", this);
 297                 delete[] sessions;
 298         }
 299
 300         virtual void OnCleanup(int target_type, void* item)
 301         {
 302                 if(target_type == TYPE_USER)
 303                 {
 304                         User* user = static_cast<User*>(item);
 305
 306                         if (user->GetIOHook() == this)
 307                         {
 308                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 309                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 310                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 311                                 user->DelIOHook();
 312                         }
 313                         if (user->GetExt("ssl_cert"))
 314                         {
 315                                 ssl_cert* tofree;
 316                                 user->GetExt("ssl_cert", tofree);
 317                                 delete tofree;
 318                                 user->Shrink("ssl_cert");
 319                         }
 320                 }
 321         }
 322
 323         virtual void OnUnloadModule(Module* mod, const std::string &name)
 324         {
 325                 if(mod == this)
 326                 {
 327                         for(unsigned int i = 0; i < listenports.size(); i++)
 328                         {
 329                                 for (size_t j = 0; j < ServerInstance->ports.size(); j++)
 330                                         if (listenports[i] == (ServerInstance->ports[j]->GetIP()+":"+ConvToStr(ServerInstance->ports[j]->GetPort())))
 331                                                 ServerInstance->ports[j]->SetDescription("plaintext");
 332                         }
 333                 }
 334         }
 335
 336         virtual Version GetVersion()
 337         {
 338                 return Version("$Id$", VF_VENDOR, API_VERSION);
 339         }
 340
 341
 342         virtual void On005Numeric(std::string &output)
 343         {
 344                 if (!sslports.empty())
 345                         output.append(" SSL=" + sslports);
 346                 output.append(" STARTTLS");
 347         }
 348
 349         virtual void OnHookUserIO(User* user)
 350         {
 351                 if (!user->GetIOHook() && isin(user->GetServerIP(),user->GetServerPort(),listenports))
 352                 {
 353                         /* Hook the user with our module */
 354                         user->AddIOHook(this);
 355                 }
 356         }
 357
 358         virtual const char* OnRequest(Request* request)
 359         {
 360                 ISHRequest* ISR = static_cast<ISHRequest*>(request);
 361                 if (strcmp("IS_NAME", request->GetId()) == 0)
 362                 {
 363                         return "gnutls";
 364                 }
 365                 else if (strcmp("IS_HOOK", request->GetId()) == 0)
 366                 {
 367                         const char* ret = "OK";
 368                         try
 369                         {
 370                                 ret = ISR->Sock->AddIOHook(this) ? "OK" : NULL;
 371                         }
 372                         catch (ModuleException &e)
 373                         {
 374                                 return NULL;
 375                         }
 376                         return ret;
 377                 }
 378                 else if (strcmp("IS_UNHOOK", request->GetId()) == 0)
 379                 {
 380                         return ISR->Sock->DelIOHook() ? "OK" : NULL;
 381                 }
 382                 else if (strcmp("IS_HSDONE", request->GetId()) == 0)
 383                 {
 384                         if (ISR->Sock->GetFd() < 0)
 385                                 return "OK";
 386
 387                         issl_session* session = &sessions[ISR->Sock->GetFd()];
 388                         return (session->status == ISSL_HANDSHAKING_READ || session->status == ISSL_HANDSHAKING_WRITE) ? NULL : "OK";
 389                 }
 390                 else if (strcmp("IS_ATTACH", request->GetId()) == 0)
 391                 {
 392                         if (ISR->Sock->GetFd() > -1)
 393                         {
 394                                 issl_session* session = &sessions[ISR->Sock->GetFd()];
 395                                 if (session->sess)
 396                                 {
 397                                         if (static_cast<Extensible*>(ServerInstance->SE->GetRef(ISR->Sock->GetFd())) == static_cast<Extensible*>(ISR->Sock))
 398                                         {
 399                                                 VerifyCertificate(session, ISR->Sock);
 400                                                 return "OK";
 401                                         }
 402                                 }
 403                         }
 404                 }
 405                 else if (strcmp("GET_FP", request->GetId()) == 0)
 406                 {
 407                         if (ISR->Sock->GetFd() > -1)
 408                         {
 409                                 issl_session* session = &sessions[ISR->Sock->GetFd()];
 410                                 if (session->sess)
 411                                 {
 412                                         Extensible* ext = ISR->Sock;
 413                                         ssl_cert* certinfo;
 414                                         if (ext->GetExt("ssl_cert",certinfo))
 415                                                 return certinfo->GetFingerprint().c_str();
 416                                 }
 417                         }
 418                 }
 419                 return NULL;
 420         }
 421
 422
 423         virtual void OnRawSocketAccept(int fd, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server)
 424         {
 425                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 426                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 427                         return;
 428
 429                 issl_session* session = &sessions[fd];
 430
 431                 /* For STARTTLS: Don't try and init a session on a socket that already has a session */
 432                 if (session->sess)
 433                         return;
 434
 435                 gnutls_init(&session->sess, GNUTLS_SERVER);
 436
 437                 gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
 438                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 439                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 440
 441                 gnutls_transport_set_ptr(session->sess, reinterpret_cast<gnutls_transport_ptr_t>(fd)); // Give gnutls the fd for the socket.
 442
 443                 gnutls_certificate_server_set_request(session->sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
 444
 445                 Handshake(session, fd);
 446         }
 447
 448         virtual void OnRawSocketConnect(int fd)
 449         {
 450                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 451                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 452                         return;
 453
 454                 issl_session* session = &sessions[fd];
 455
 456                 gnutls_init(&session->sess, GNUTLS_CLIENT);
 457
 458                 gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
 459                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 460                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 461                 gnutls_transport_set_ptr(session->sess, reinterpret_cast<gnutls_transport_ptr_t>(fd)); // Give gnutls the fd for the socket.
 462
 463                 Handshake(session, fd);
 464         }
 465
 466         virtual void OnRawSocketClose(int fd)
 467         {
 468                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 469                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds()))
 470                         return;
 471
 472                 CloseSession(&sessions[fd]);
 473
 474                 EventHandler* user = ServerInstance->SE->GetRef(fd);
 475
 476                 if ((user) && (user->GetExt("ssl_cert")))
 477                 {
 478                         ssl_cert* tofree;
 479                         user->GetExt("ssl_cert", tofree);
 480                         delete tofree;
 481                         user->Shrink("ssl_cert");
 482                 }
 483         }
 484
 485         virtual int OnRawSocketRead(int fd, char* buffer, unsigned int count, int &readresult)
 486         {
 487                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 488                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 489                         return 0;
 490
 491                 issl_session* session = &sessions[fd];
 492
 493                 if (!session->sess)
 494                 {
 495                         readresult = 0;
 496                         CloseSession(session);
 497                         return 1;
 498                 }
 499
 500                 if (session->status == ISSL_HANDSHAKING_READ)
 501                 {
 502                         // The handshake isn't finished, try to finish it.
 503
 504                         if(!Handshake(session, fd))
 505                         {
 506                                 errno = session->status == ISSL_CLOSING ? EIO : EAGAIN;
 507                                 // Couldn't resume handshake.
 508                                 return -1;
 509                         }
 510                 }
 511                 else if (session->status == ISSL_HANDSHAKING_WRITE)
 512                 {
 513                         errno = EAGAIN;
 514                         MakePollWrite(fd);
 515                         return -1;
 516                 }
 517
 518                 // If we resumed the handshake then session->status will be ISSL_HANDSHAKEN.
 519
 520                 if (session->status == ISSL_HANDSHAKEN)
 521                 {
 522                         unsigned int len = 0;
 523                         while (len < count)
 524                         {
 525                                 int ret = gnutls_record_recv(session->sess, buffer + len, count - len);
 526                                 if (ret > 0)
 527                                 {
 528                                         len += ret;
 529                                 }
 530                                 else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 531                                 {
 532                                         break;
 533                                 }
 534                                 else
 535                                 {
 536                                         if (ret != 0)
 537                                                 ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT,
 538                                                         "m_ssl_gnutls.so: Error while reading on fd %d: %s",
 539                                                         fd, gnutls_strerror(ret));
 540
 541                                         // if ret == 0, client closed connection.
 542                                         readresult = 0;
 543                                         CloseSession(session);
 544                                         return 1;
 545                                 }
 546                         }
 547                         readresult = len;
 548                         if (len)
 549                         {
 550                                 return 1;
 551                         }
 552                         else
 553                         {
 554                                 errno = EAGAIN;
 555                                 return -1;
 556                         }
 557                 }
 558                 else if (session->status == ISSL_CLOSING)
 559                         readresult = 0;
 560
 561                 return 1;
 562         }
 563
 564         virtual int OnRawSocketWrite(int fd, const char* buffer, int count)
 565         {
 566                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 567                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 568                         return 0;
 569
 570                 issl_session* session = &sessions[fd];
 571                 const char* sendbuffer = buffer;
 572
 573                 if (!session->sess)
 574                 {
 575                         CloseSession(session);
 576                         return 1;
 577                 }
 578
 579                 session->outbuf.append(sendbuffer, count);
 580                 sendbuffer = session->outbuf.c_str();
 581                 count = session->outbuf.size();
 582
 583                 if (session->status == ISSL_HANDSHAKING_WRITE || session->status == ISSL_HANDSHAKING_READ)
 584                 {
 585                         // The handshake isn't finished, try to finish it.
 586                         Handshake(session, fd);
 587                         errno = session->status == ISSL_CLOSING ? EIO : EAGAIN;
 588                         return -1;
 589                 }
 590
 591                 int ret = 0;
 592
 593                 if (session->status == ISSL_HANDSHAKEN)
 594                 {
 595                         ret = gnutls_record_send(session->sess, sendbuffer, count);
 596
 597                         if (ret == 0)
 598                         {
 599                                 CloseSession(session);
 600                         }
 601                         else if (ret < 0)
 602                         {
 603                                 if(ret != GNUTLS_E_AGAIN && ret != GNUTLS_E_INTERRUPTED)
 604                                 {
 605                                         ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT,
 606                                                         "m_ssl_gnutls.so: Error while writing to fd %d: %s",
 607                                                         fd, gnutls_strerror(ret));
 608                                         CloseSession(session);
 609                                 }
 610                                 else
 611                                 {
 612                                         errno = EAGAIN;
 613                                 }
 614                         }
 615                         else
 616                         {
 617                                 session->outbuf = session->outbuf.substr(ret);
 618                         }
 619                 }
 620
 621                 if (!session->outbuf.empty())
 622                         MakePollWrite(fd);
 623
 624                 /* Who's smart idea was it to return 1 when we havent written anything?
 625                  * This fucks the buffer up in BufferedSocket :p
 626                  */
 627                 return ret < 1 ? 0 : ret;
 628         }
 629
 630         bool Handshake(issl_session* session, int fd)
 631         {
 632                 int ret = gnutls_handshake(session->sess);
 633
 634                 if (ret < 0)
 635                 {
 636                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 637                         {
 638                                 // Handshake needs resuming later, read() or write() would have blocked.
 639
 640                                 if(gnutls_record_get_direction(session->sess) == 0)
 641                                 {
 642                                         // gnutls_handshake() wants to read() again.
 643                                         session->status = ISSL_HANDSHAKING_READ;
 644                                 }
 645                                 else
 646                                 {
 647                                         // gnutls_handshake() wants to write() again.
 648                                         session->status = ISSL_HANDSHAKING_WRITE;
 649                                         MakePollWrite(fd);
 650                                 }
 651                         }
 652                         else
 653                         {
 654                                 // Handshake failed.
 655                                 ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT,
 656                                                 "m_ssl_gnutls.so: Handshake failed on fd %d: %s",
 657                                                 fd, gnutls_strerror(ret));
 658                                 CloseSession(session);
 659                                 session->status = ISSL_CLOSING;
 660                         }
 661
 662                         return false;
 663                 }
 664                 else
 665                 {
 666                         // Handshake complete.
 667                         // This will do for setting the ssl flag...it could be done earlier if it's needed. But this seems neater.
 668                         EventHandler *extendme = ServerInstance->SE->GetRef(fd);
 669                         if (extendme)
 670                         {
 671                                 if (!extendme->GetExt("ssl"))
 672                                         extendme->Extend("ssl", "ON");
 673                         }
 674
 675                         // Change the seesion state
 676                         session->status = ISSL_HANDSHAKEN;
 677
 678                         // Finish writing, if any left
 679                         MakePollWrite(fd);
 680
 681                         return true;
 682                 }
 683         }
 684
 685         virtual void OnPostConnect(User* user)
 686         {
 687                 // This occurs AFTER OnUserConnect so we can be sure the
 688                 // protocol module has propagated the NICK message.
 689                 if (user->GetIOHook() == this && (IS_LOCAL(user)))
 690                 {
 691                         ssl_cert* certdata = VerifyCertificate(&sessions[user->GetFd()],user);
 692                         if (sessions[user->GetFd()].sess)
 693                         {
 694                                 std::string cipher = gnutls_kx_get_name(gnutls_kx_get(sessions[user->GetFd()].sess));
 695                                 cipher.append("-").append(gnutls_cipher_get_name(gnutls_cipher_get(sessions[user->GetFd()].sess))).append("-");
 696                                 cipher.append(gnutls_mac_get_name(gnutls_mac_get(sessions[user->GetFd()].sess)));
 697                                 user->WriteServ("NOTICE %s :*** You are connected using SSL cipher \"%s\"", user->nick.c_str(), cipher.c_str());
 698                         }
 699
 700                         ServerInstance->PI->SendMetaData(user, "ssl", "ON");
 701                         if (certdata)
 702                                 ServerInstance->PI->SendMetaData(user, "ssl_cert", certdata->GetMetaLine().c_str());
 703                 }
 704         }
 705
 706         void MakePollWrite(int fd)
 707         {
 708                 //OnRawSocketWrite(fd, NULL, 0);
 709                 EventHandler* eh = ServerInstance->SE->GetRef(fd);
 710                 if (eh)
 711                         ServerInstance->SE->WantWrite(eh);
 712         }
 713
 714         virtual void OnBufferFlushed(User* user)
 715         {
 716                 if (user->GetIOHook() == this)
 717                 {
 718                         issl_session* session = &sessions[user->GetFd()];
 719                         if (session && session->outbuf.size())
 720                                 OnRawSocketWrite(user->GetFd(), NULL, 0);
 721                 }
 722         }
 723
 724         void CloseSession(issl_session* session)
 725         {
 726                 if(session->sess)
 727                 {
 728                         gnutls_bye(session->sess, GNUTLS_SHUT_WR);
 729                         gnutls_deinit(session->sess);
 730                 }
 731
 732                 session->outbuf.clear();
 733                 session->sess = NULL;
 734                 session->status = ISSL_NONE;
 735         }
 736
 737         ssl_cert* VerifyCertificate(issl_session* session, Extensible* user)
 738         {
 739                 if (!session->sess || !user)
 740                         return NULL;
 741
 742                 unsigned int status;
 743                 const gnutls_datum_t* cert_list;
 744                 int ret;
 745                 unsigned int cert_list_size;
 746                 gnutls_x509_crt_t cert;
 747                 char name[MAXBUF];
 748                 unsigned char digest[MAXBUF];
 749                 size_t digest_size = sizeof(digest);
 750                 size_t name_size = sizeof(name);
 751                 ssl_cert* certinfo = new ssl_cert;
 752
 753                 user->Extend("ssl_cert",certinfo);
 754
 755                 /* This verification function uses the trusted CAs in the credentials
 756                  * structure. So you must have installed one or more CA certificates.
 757                  */
 758                 ret = gnutls_certificate_verify_peers2(session->sess, &status);
 759
 760                 if (ret < 0)
 761                 {
 762                         certinfo->error = std::string(gnutls_strerror(ret));
 763                         return certinfo;
 764                 }
 765
 766                 certinfo->invalid = (status & GNUTLS_CERT_INVALID);
 767                 certinfo->unknownsigner = (status & GNUTLS_CERT_SIGNER_NOT_FOUND);
 768                 certinfo->revoked = (status & GNUTLS_CERT_REVOKED);
 769                 certinfo->trusted = !(status & GNUTLS_CERT_SIGNER_NOT_CA);
 770
 771                 /* Up to here the process is the same for X.509 certificates and
 772                  * OpenPGP keys. From now on X.509 certificates are assumed. This can
 773                  * be easily extended to work with openpgp keys as well.
 774                  */
 775                 if (gnutls_certificate_type_get(session->sess) != GNUTLS_CRT_X509)
 776                 {
 777                         certinfo->error = "No X509 keys sent";
 778                         return certinfo;
 779                 }
 780
 781                 ret = gnutls_x509_crt_init(&cert);
 782                 if (ret < 0)
 783                 {
 784                         certinfo->error = gnutls_strerror(ret);
 785                         return certinfo;
 786                 }
 787
 788                 cert_list_size = 0;
 789                 cert_list = gnutls_certificate_get_peers(session->sess, &cert_list_size);
 790                 if (cert_list == NULL)
 791                 {
 792                         certinfo->error = "No certificate was found";
 793                         return certinfo;
 794                 }
 795
 796                 /* This is not a real world example, since we only check the first
 797                  * certificate in the given chain.
 798                  */
 799
 800                 ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
 801                 if (ret < 0)
 802                 {
 803                         certinfo->error = gnutls_strerror(ret);
 804                         return certinfo;
 805                 }
 806
 807                 gnutls_x509_crt_get_dn(cert, name, &name_size);
 808                 certinfo->dn = name;
 809
 810                 gnutls_x509_crt_get_issuer_dn(cert, name, &name_size);
 811                 certinfo->issuer = name;
 812
 813                 if ((ret = gnutls_x509_crt_get_fingerprint(cert, GNUTLS_DIG_MD5, digest, &digest_size)) < 0)
 814                 {
 815                         certinfo->error = gnutls_strerror(ret);
 816                 }
 817                 else
 818                 {
 819                         certinfo->fingerprint = irc::hex(digest, digest_size);
 820                 }
 821
 822                 /* Beware here we do not check for errors.
 823                  */
 824                 if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
 825                 {
 826                         certinfo->error = "Not activated, or expired certificate";
 827                 }
 828
 829                 gnutls_x509_crt_deinit(cert);
 830
 831                 return certinfo;
 832         }
 833
 834         void OnEvent(Event* ev)
 835         {
 836                 GenericCapHandler(ev, "tls", "tls");
 837         }
 838
 839         void Prioritize()
 840         {
 841                 Module* server = ServerInstance->Modules->Find("m_spanningtree.so");
 842                 ServerInstance->Modules->SetPriority(this, I_OnPostConnect, PRIORITY_AFTER, &server);
 843         }
 844 };
 845
 846 MODULE_INIT(ModuleSSLGnuTLS)