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