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://www.inspircd.org/wiki/index.php/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: exec("libgnutls-config --cflags") */
  26 /* $LinkerFlags: rpath("libgnutls-config --libs") exec("libgnutls-config --libs") */
  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         int inbufoffset;
  58         char* inbuf;
  59         int fd;
  60 };
  61
  62 class CommandStartTLS : public Command
  63 {
  64         Module* Caller;
  65  public:
  66         CommandStartTLS (InspIRCd* Instance, Module* mod) : Command(Instance,"STARTTLS", 0, 0, true), Caller(mod)
  67         {
  68                 this->source = "m_ssl_gnutls.so";
  69         }
  70
  71         CmdResult Handle (const std::vector<std::string> &parameters, User *user)
  72         {
  73                 /* changed from == REG_ALL to catch clients sending STARTTLS
  74                  * after NICK and USER but before OnUserConnect completes and
  75                  * give a proper error message (see bug #645) - dz
  76                  */
  77                 if (user->registered != REG_NONE)
  78                 {
  79                         ServerInstance->Users->QuitUser(user, "STARTTLS is not permitted after client registration has started");
  80                 }
  81                 else
  82                 {
  83                         if (!user->GetIOHook())
  84                         {
  85                                 user->WriteNumeric(670, "%s :STARTTLS successful, go ahead with TLS handshake", user->nick.c_str());
  86                                 user->AddIOHook(Caller);
  87                                 Caller->OnRawSocketAccept(user->GetFd(), user->GetIPString(), user->GetPort());
  88                         }
  89                         else
  90                                 user->WriteNumeric(691, "%s :STARTTLS failure", user->nick.c_str());
  91                 }
  92
  93                 return CMD_FAILURE;
  94         }
  95 };
  96
  97 class ModuleSSLGnuTLS : public Module
  98 {
  99
 100         ConfigReader* Conf;
 101
 102         char* dummy;
 103
 104         std::vector<std::string> listenports;
 105
 106         int inbufsize;
 107         issl_session* sessions;
 108
 109         gnutls_certificate_credentials x509_cred;
 110         gnutls_dh_params dh_params;
 111
 112         std::string keyfile;
 113         std::string certfile;
 114         std::string cafile;
 115         std::string crlfile;
 116         std::string sslports;
 117         int dh_bits;
 118
 119         int clientactive;
 120         bool cred_alloc;
 121
 122         CommandStartTLS* starttls;
 123
 124  public:
 125
 126         ModuleSSLGnuTLS(InspIRCd* Me)
 127                 : Module(Me)
 128         {
 129                 ServerInstance->Modules->PublishInterface("BufferedSocketHook", this);
 130
 131                 sessions = new issl_session[ServerInstance->SE->GetMaxFds()];
 132
 133                 // Not rehashable...because I cba to reduce all the sizes of existing buffers.
 134                 inbufsize = ServerInstance->Config->NetBufferSize;
 135
 136                 gnutls_global_init(); // This must be called once in the program
 137
 138                 cred_alloc = false;
 139                 // Needs the flag as it ignores a plain /rehash
 140                 OnRehash(NULL,"ssl");
 141
 142                 // Void return, guess we assume success
 143                 gnutls_certificate_set_dh_params(x509_cred, dh_params);
 144                 Implementation eventlist[] = { I_On005Numeric, I_OnRawSocketConnect, I_OnRawSocketAccept, I_OnRawSocketClose, I_OnRawSocketRead, I_OnRawSocketWrite, I_OnCleanup,
 145                         I_OnBufferFlushed, I_OnRequest, I_OnSyncUserMetaData, I_OnDecodeMetaData, I_OnUnloadModule, I_OnRehash, I_OnWhois, I_OnPostConnect, I_OnEvent, I_OnHookUserIO };
 146                 ServerInstance->Modules->Attach(eventlist, this, 17);
 147
 148                 starttls = new CommandStartTLS(ServerInstance, this);
 149                 ServerInstance->AddCommand(starttls);
 150         }
 151
 152         virtual void OnRehash(User* user, const std::string &param)
 153         {
 154                 Conf = new ConfigReader(ServerInstance);
 155
 156                 listenports.clear();
 157                 clientactive = 0;
 158                 sslports.clear();
 159
 160                 for(int index = 0; index < Conf->Enumerate("bind"); index++)
 161                 {
 162                         // For each <bind> tag
 163                         std::string x = Conf->ReadValue("bind", "type", index);
 164                         if(((x.empty()) || (x == "clients")) && (Conf->ReadValue("bind", "ssl", index) == "gnutls"))
 165                         {
 166                                 // Get the port we're meant to be listening on with SSL
 167                                 std::string port = Conf->ReadValue("bind", "port", index);
 168                                 std::string addr = Conf->ReadValue("bind", "address", index);
 169
 170                                 irc::portparser portrange(port, false);
 171                                 long portno = -1;
 172                                 while ((portno = portrange.GetToken()))
 173                                 {
 174                                         clientactive++;
 175                                         try
 176                                         {
 177                                                 listenports.push_back(addr + ":" + ConvToStr(portno));
 178
 179                                                 for (size_t i = 0; i < ServerInstance->Config->ports.size(); i++)
 180                                                         if ((ServerInstance->Config->ports[i]->GetPort() == portno) && (ServerInstance->Config->ports[i]->GetIP() == addr))
 181                                                                 ServerInstance->Config->ports[i]->SetDescription("ssl");
 182                                                 ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Enabling SSL for port %ld", portno);
 183
 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                 if(param != "ssl")
 198                 {
 199                         delete Conf;
 200                         return;
 201                 }
 202
 203                 std::string confdir(ServerInstance->ConfigFileName);
 204                 // +1 so we the path ends with a /
 205                 confdir = confdir.substr(0, confdir.find_last_of('/') + 1);
 206
 207                 cafile  = Conf->ReadValue("gnutls", "cafile", 0);
 208                 crlfile = Conf->ReadValue("gnutls", "crlfile", 0);
 209                 certfile        = Conf->ReadValue("gnutls", "certfile", 0);
 210                 keyfile = Conf->ReadValue("gnutls", "keyfile", 0);
 211                 dh_bits = Conf->ReadInteger("gnutls", "dhbits", 0, false);
 212
 213                 // Set all the default values needed.
 214                 if (cafile.empty())
 215                         cafile = "ca.pem";
 216
 217                 if (crlfile.empty())
 218                         crlfile = "crl.pem";
 219
 220                 if (certfile.empty())
 221                         certfile = "cert.pem";
 222
 223                 if (keyfile.empty())
 224                         keyfile = "key.pem";
 225
 226                 if((dh_bits != 768) && (dh_bits != 1024) && (dh_bits != 2048) && (dh_bits != 3072) && (dh_bits != 4096))
 227                         dh_bits = 1024;
 228
 229                 // Prepend relative paths with the path to the config directory.
 230                 if ((cafile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(cafile)))
 231                         cafile = confdir + cafile;
 232
 233                 if ((crlfile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(crlfile)))
 234                         crlfile = confdir + crlfile;
 235
 236                 if ((certfile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(certfile)))
 237                         certfile = confdir + certfile;
 238
 239                 if ((keyfile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(keyfile)))
 240                         keyfile = confdir + keyfile;
 241
 242                 int ret;
 243
 244                 if (cred_alloc)
 245                 {
 246                         // Deallocate the old credentials
 247                         gnutls_dh_params_deinit(dh_params);
 248                         gnutls_certificate_free_credentials(x509_cred);
 249                 }
 250                 else
 251                         cred_alloc = true;
 252
 253                 if((ret = gnutls_certificate_allocate_credentials(&x509_cred)) < 0)
 254                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to allocate certificate credentials: %s", gnutls_strerror(ret));
 255
 256                 if((ret = gnutls_dh_params_init(&dh_params)) < 0)
 257                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to initialise DH parameters: %s", gnutls_strerror(ret));
 258
 259                 if((ret =gnutls_certificate_set_x509_trust_file(x509_cred, cafile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 260                         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));
 261
 262                 if((ret = gnutls_certificate_set_x509_crl_file (x509_cred, crlfile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 263                         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));
 264
 265                 if((ret = gnutls_certificate_set_x509_key_file (x509_cred, certfile.c_str(), keyfile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 266                 {
 267                         // If this fails, no SSL port will work. At all. So, do the smart thing - throw a ModuleException
 268                         throw ModuleException("Unable to load GnuTLS server certificate (" + certfile + ", key: " + keyfile + "): " + std::string(gnutls_strerror(ret)));
 269                 }
 270
 271                 // This may be on a large (once a day or week) timer eventually.
 272                 GenerateDHParams();
 273
 274                 delete Conf;
 275         }
 276
 277         void GenerateDHParams()
 278         {
 279                 // Generate Diffie Hellman parameters - for use with DHE
 280                 // kx algorithms. These should be discarded and regenerated
 281                 // once a day, once a week or once a month. Depending on the
 282                 // security requirements.
 283
 284                 int ret;
 285
 286                 if((ret = gnutls_dh_params_generate2(dh_params, dh_bits)) < 0)
 287                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to generate DH parameters (%d bits): %s", dh_bits, gnutls_strerror(ret));
 288         }
 289
 290         virtual ~ModuleSSLGnuTLS()
 291         {
 292                 gnutls_dh_params_deinit(dh_params);
 293                 gnutls_certificate_free_credentials(x509_cred);
 294                 gnutls_global_deinit();
 295                 ServerInstance->Modules->UnpublishInterface("BufferedSocketHook", this);
 296                 delete[] sessions;
 297         }
 298
 299         virtual void OnCleanup(int target_type, void* item)
 300         {
 301                 if(target_type == TYPE_USER)
 302                 {
 303                         User* user = (User*)item;
 304
 305                         if (user->GetIOHook() == this)
 306                         {
 307                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 308                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 309                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 310                                 user->DelIOHook();
 311                         }
 312                         if (user->GetExt("ssl_cert", dummy))
 313                         {
 314                                 ssl_cert* tofree;
 315                                 user->GetExt("ssl_cert", tofree);
 316                                 delete tofree;
 317                                 user->Shrink("ssl_cert");
 318                         }
 319                 }
 320         }
 321
 322         virtual void OnUnloadModule(Module* mod, const std::string &name)
 323         {
 324                 if(mod == this)
 325                 {
 326                         for(unsigned int i = 0; i < listenports.size(); i++)
 327                         {
 328                                 for (size_t j = 0; j < ServerInstance->Config->ports.size(); j++)
 329                                         if (listenports[i] == (ServerInstance->Config->ports[j]->GetIP()+":"+ConvToStr(ServerInstance->Config->ports[j]->GetPort())))
 330                                                 ServerInstance->Config->ports[j]->SetDescription("plaintext");
 331                         }
 332                 }
 333         }
 334
 335         virtual Version GetVersion()
 336         {
 337                 return Version("$Id$", VF_VENDOR, API_VERSION);
 338         }
 339
 340
 341         virtual void On005Numeric(std::string &output)
 342         {
 343                 output.append(" SSL=" + sslports);
 344         }
 345
 346         virtual void OnHookUserIO(User* user, const std::string &targetip)
 347         {
 348                 if (!user->GetIOHook() && isin(targetip,user->GetPort(),listenports))
 349                 {
 350                         /* Hook the user with our module */
 351                         user->AddIOHook(this);
 352                 }
 353         }
 354
 355         virtual const char* OnRequest(Request* request)
 356         {
 357                 ISHRequest* ISR = (ISHRequest*)request;
 358                 if (strcmp("IS_NAME", request->GetId()) == 0)
 359                 {
 360                         return "gnutls";
 361                 }
 362                 else if (strcmp("IS_HOOK", request->GetId()) == 0)
 363                 {
 364                         const char* ret = "OK";
 365                         try
 366                         {
 367                                 ret = ISR->Sock->AddIOHook((Module*)this) ? "OK" : NULL;
 368                         }
 369                         catch (ModuleException &e)
 370                         {
 371                                 return NULL;
 372                         }
 373                         return ret;
 374                 }
 375                 else if (strcmp("IS_UNHOOK", request->GetId()) == 0)
 376                 {
 377                         return ISR->Sock->DelIOHook() ? "OK" : NULL;
 378                 }
 379                 else if (strcmp("IS_HSDONE", request->GetId()) == 0)
 380                 {
 381                         if (ISR->Sock->GetFd() < 0)
 382                                 return "OK";
 383
 384                         issl_session* session = &sessions[ISR->Sock->GetFd()];
 385                         return (session->status == ISSL_HANDSHAKING_READ || session->status == ISSL_HANDSHAKING_WRITE) ? NULL : "OK";
 386                 }
 387                 else if (strcmp("IS_ATTACH", request->GetId()) == 0)
 388                 {
 389                         if (ISR->Sock->GetFd() > -1)
 390                         {
 391                                 issl_session* session = &sessions[ISR->Sock->GetFd()];
 392                                 if (session->sess)
 393                                 {
 394                                         if ((Extensible*)ServerInstance->FindDescriptor(ISR->Sock->GetFd()) == (Extensible*)(ISR->Sock))
 395                                         {
 396                                                 VerifyCertificate(session, (BufferedSocket*)ISR->Sock);
 397                                                 return "OK";
 398                                         }
 399                                 }
 400                         }
 401                 }
 402                 return NULL;
 403         }
 404
 405
 406         virtual void OnRawSocketAccept(int fd, const std::string &ip, int localport)
 407         {
 408                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 409                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 410                         return;
 411
 412                 issl_session* session = &sessions[fd];
 413
 414                 /* For STARTTLS: Don't try and init a session on a socket that already has a session */
 415                 if (session->sess)
 416                         return;
 417
 418                 session->fd = fd;
 419                 session->inbuf = new char[inbufsize];
 420                 session->inbufoffset = 0;
 421
 422                 gnutls_init(&session->sess, GNUTLS_SERVER);
 423
 424                 gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
 425                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 426                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 427
 428                 /* This is an experimental change to avoid a warning on 64bit systems about casting between integer and pointer of different sizes
 429                  * This needs testing, but it's easy enough to rollback if need be
 430                  * Old: gnutls_transport_set_ptr(session->sess, (gnutls_transport_ptr_t) fd); // Give gnutls the fd for the socket.
 431                  * New: gnutls_transport_set_ptr(session->sess, &fd); // Give gnutls the fd for the socket.
 432                  *
 433                  * With testing this seems to...not work :/
 434                  */
 435
 436                 gnutls_transport_set_ptr(session->sess, (gnutls_transport_ptr_t) fd); // Give gnutls the fd for the socket.
 437
 438                 gnutls_certificate_server_set_request(session->sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
 439
 440                 Handshake(session);
 441         }
 442
 443         virtual void OnRawSocketConnect(int fd)
 444         {
 445                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 446                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 447                         return;
 448
 449                 issl_session* session = &sessions[fd];
 450
 451                 session->fd = fd;
 452                 session->inbuf = new char[inbufsize];
 453                 session->inbufoffset = 0;
 454
 455                 gnutls_init(&session->sess, GNUTLS_CLIENT);
 456
 457                 gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
 458                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 459                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 460                 gnutls_transport_set_ptr(session->sess, (gnutls_transport_ptr_t) fd); // Give gnutls the fd for the socket.
 461
 462                 Handshake(session);
 463         }
 464
 465         virtual void OnRawSocketClose(int fd)
 466         {
 467                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 468                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds()))
 469                         return;
 470
 471                 CloseSession(&sessions[fd]);
 472
 473                 EventHandler* user = ServerInstance->SE->GetRef(fd);
 474
 475                 if ((user) && (user->GetExt("ssl_cert", dummy)))
 476                 {
 477                         ssl_cert* tofree;
 478                         user->GetExt("ssl_cert", tofree);
 479                         delete tofree;
 480                         user->Shrink("ssl_cert");
 481                 }
 482         }
 483
 484         virtual int OnRawSocketRead(int fd, char* buffer, unsigned int count, int &readresult)
 485         {
 486                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 487                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 488                         return 0;
 489
 490                 issl_session* session = &sessions[fd];
 491
 492                 if (!session->sess)
 493                 {
 494                         readresult = 0;
 495                         CloseSession(session);
 496                         return 1;
 497                 }
 498
 499                 if (session->status == ISSL_HANDSHAKING_READ)
 500                 {
 501                         // The handshake isn't finished, try to finish it.
 502
 503                         if(!Handshake(session))
 504                         {
 505                                 // Couldn't resume handshake.
 506                                 return -1;
 507                         }
 508                 }
 509                 else if (session->status == ISSL_HANDSHAKING_WRITE)
 510                 {
 511                         errno = EAGAIN;
 512                         MakePollWrite(session);
 513                         return -1;
 514                 }
 515
 516                 // If we resumed the handshake then session->status will be ISSL_HANDSHAKEN.
 517
 518                 if (session->status == ISSL_HANDSHAKEN)
 519                 {
 520                         // Is this right? Not sure if the unencrypted data is garaunteed to be the same length.
 521                         // Read into the inbuffer, offset from the beginning by the amount of data we have that insp hasn't taken yet.
 522                         int ret = gnutls_record_recv(session->sess, session->inbuf + session->inbufoffset, inbufsize - session->inbufoffset);
 523
 524                         if (ret == 0)
 525                         {
 526                                 // Client closed connection.
 527                                 readresult = 0;
 528                                 CloseSession(session);
 529                                 return 1;
 530                         }
 531                         else if (ret < 0)
 532                         {
 533                                 if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 534                                 {
 535                                         errno = EAGAIN;
 536                                         return -1;
 537                                 }
 538                                 else
 539                                 {
 540                                         ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT,
 541                                                         "m_ssl_gnutls.so: Error while reading on fd %d: %s",
 542                                                         session->fd, gnutls_strerror(ret));
 543                                         readresult = 0;
 544                                         CloseSession(session);
 545                                 }
 546                         }
 547                         else
 548                         {
 549                                 // Read successfully 'ret' bytes into inbuf + inbufoffset
 550                                 // There are 'ret' + 'inbufoffset' bytes of data in 'inbuf'
 551                                 // 'buffer' is 'count' long
 552
 553                                 unsigned int length = ret + session->inbufoffset;
 554
 555                                 if(count <= length)
 556                                 {
 557                                         memcpy(buffer, session->inbuf, count);
 558                                         // Move the stuff left in inbuf to the beginning of it
 559                                         memmove(session->inbuf, session->inbuf + count, (length - count));
 560                                         // Now we need to set session->inbufoffset to the amount of data still waiting to be handed to insp.
 561                                         session->inbufoffset = length - count;
 562                                         // Insp uses readresult as the count of how much data there is in buffer, so:
 563                                         readresult = count;
 564                                 }
 565                                 else
 566                                 {
 567                                         // There's not as much in the inbuf as there is space in the buffer, so just copy the whole thing.
 568                                         memcpy(buffer, session->inbuf, length);
 569                                         // Zero the offset, as there's nothing there..
 570                                         session->inbufoffset = 0;
 571                                         // As above
 572                                         readresult = length;
 573                                 }
 574                         }
 575                 }
 576                 else if(session->status == ISSL_CLOSING)
 577                         readresult = 0;
 578
 579                 return 1;
 580         }
 581
 582         virtual int OnRawSocketWrite(int fd, const char* buffer, int count)
 583         {
 584                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 585                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 586                         return 0;
 587
 588                 issl_session* session = &sessions[fd];
 589                 const char* sendbuffer = buffer;
 590
 591                 if (!session->sess)
 592                 {
 593                         CloseSession(session);
 594                         return 1;
 595                 }
 596
 597                 session->outbuf.append(sendbuffer, count);
 598                 sendbuffer = session->outbuf.c_str();
 599                 count = session->outbuf.size();
 600
 601                 if (session->status == ISSL_HANDSHAKING_WRITE || session->status == ISSL_HANDSHAKING_READ)
 602                 {
 603                         // The handshake isn't finished, try to finish it.
 604                         Handshake(session);
 605                         errno = EAGAIN;
 606                         return -1;
 607                 }
 608
 609                 int ret = 0;
 610
 611                 if (session->status == ISSL_HANDSHAKEN)
 612                 {
 613                         ret = gnutls_record_send(session->sess, sendbuffer, count);
 614
 615                         if (ret == 0)
 616                         {
 617                                 CloseSession(session);
 618                         }
 619                         else if (ret < 0)
 620                         {
 621                                 if(ret != GNUTLS_E_AGAIN && ret != GNUTLS_E_INTERRUPTED)
 622                                 {
 623                                         ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT,
 624                                                         "m_ssl_gnutls.so: Error while writing to fd %d: %s",
 625                                                         session->fd, gnutls_strerror(ret));
 626                                         CloseSession(session);
 627                                 }
 628                                 else
 629                                 {
 630                                         errno = EAGAIN;
 631                                 }
 632                         }
 633                         else
 634                         {
 635                                 session->outbuf = session->outbuf.substr(ret);
 636                         }
 637                 }
 638
 639                 MakePollWrite(session);
 640
 641                 /* Who's smart idea was it to return 1 when we havent written anything?
 642                  * This fucks the buffer up in BufferedSocket :p
 643                  */
 644                 return ret < 1 ? 0 : ret;
 645         }
 646
 647         // :kenny.chatspike.net 320 Om Epy|AFK :is a Secure Connection
 648         virtual void OnWhois(User* source, User* dest)
 649         {
 650                 if (!clientactive)
 651                         return;
 652
 653                 // Bugfix, only send this numeric for *our* SSL users
 654                 if (dest->GetExt("ssl", dummy))
 655                 {
 656                         ServerInstance->SendWhoisLine(source, dest, 320, "%s %s :is using a secure connection", source->nick.c_str(), dest->nick.c_str());
 657                 }
 658         }
 659
 660         virtual void OnSyncUserMetaData(User* user, Module* proto, void* opaque, const std::string &extname, bool displayable)
 661         {
 662                 // check if the linking module wants to know about OUR metadata
 663                 if(extname == "ssl")
 664                 {
 665                         // check if this user has an swhois field to send
 666                         if(user->GetExt(extname, dummy))
 667                         {
 668                                 // call this function in the linking module, let it format the data how it
 669                                 // sees fit, and send it on its way. We dont need or want to know how.
 670                                 proto->ProtoSendMetaData(opaque, TYPE_USER, user, extname, displayable ? "Enabled" : "ON");
 671                         }
 672                 }
 673         }
 674
 675         virtual void OnDecodeMetaData(int target_type, void* target, const std::string &extname, const std::string &extdata)
 676         {
 677                 // check if its our metadata key, and its associated with a user
 678                 if ((target_type == TYPE_USER) && (extname == "ssl"))
 679                 {
 680                         User* dest = (User*)target;
 681                         // if they dont already have an ssl flag, accept the remote server's
 682                         if (!dest->GetExt(extname, dummy))
 683                         {
 684                                 dest->Extend(extname, "ON");
 685                         }
 686                 }
 687         }
 688
 689         bool Handshake(issl_session* session)
 690         {
 691                 int ret = gnutls_handshake(session->sess);
 692
 693                 if (ret < 0)
 694                 {
 695                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 696                         {
 697                                 // Handshake needs resuming later, read() or write() would have blocked.
 698
 699                                 if(gnutls_record_get_direction(session->sess) == 0)
 700                                 {
 701                                         // gnutls_handshake() wants to read() again.
 702                                         session->status = ISSL_HANDSHAKING_READ;
 703                                 }
 704                                 else
 705                                 {
 706                                         // gnutls_handshake() wants to write() again.
 707                                         session->status = ISSL_HANDSHAKING_WRITE;
 708                                         MakePollWrite(session);
 709                                 }
 710                         }
 711                         else
 712                         {
 713                                 // Handshake failed.
 714                                 ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT,
 715                                                 "m_ssl_gnutls.so: Handshake failed on fd %d: %s",
 716                                                 session->fd, gnutls_strerror(ret));
 717                                 CloseSession(session);
 718                                 session->status = ISSL_CLOSING;
 719                         }
 720
 721                         return false;
 722                 }
 723                 else
 724                 {
 725                         // Handshake complete.
 726                         // This will do for setting the ssl flag...it could be done earlier if it's needed. But this seems neater.
 727                         User* extendme = ServerInstance->FindDescriptor(session->fd);
 728                         if (extendme)
 729                         {
 730                                 if (!extendme->GetExt("ssl", dummy))
 731                                         extendme->Extend("ssl", "ON");
 732                         }
 733
 734                         // Change the seesion state
 735                         session->status = ISSL_HANDSHAKEN;
 736
 737                         // Finish writing, if any left
 738                         MakePollWrite(session);
 739
 740                         return true;
 741                 }
 742         }
 743
 744         virtual void OnPostConnect(User* user)
 745         {
 746                 // This occurs AFTER OnUserConnect so we can be sure the
 747                 // protocol module has propagated the NICK message.
 748                 if (user->GetIOHook() == this && (IS_LOCAL(user)))
 749                 {
 750                         // Tell whatever protocol module we're using that we need to inform other servers of this metadata NOW.
 751                         ServerInstance->PI->SendMetaData(user, TYPE_USER, "SSL", "on");
 752
 753                         VerifyCertificate(&sessions[user->GetFd()],user);
 754                         if (sessions[user->GetFd()].sess)
 755                         {
 756                                 std::string cipher = gnutls_kx_get_name(gnutls_kx_get(sessions[user->GetFd()].sess));
 757                                 cipher.append("-").append(gnutls_cipher_get_name(gnutls_cipher_get(sessions[user->GetFd()].sess))).append("-");
 758                                 cipher.append(gnutls_mac_get_name(gnutls_mac_get(sessions[user->GetFd()].sess)));
 759                                 user->WriteServ("NOTICE %s :*** You are connected using SSL cipher \"%s\"", user->nick.c_str(), cipher.c_str());
 760                         }
 761                 }
 762         }
 763
 764         void MakePollWrite(issl_session* session)
 765         {
 766                 //OnRawSocketWrite(session->fd, NULL, 0);
 767                 EventHandler* eh = ServerInstance->FindDescriptor(session->fd);
 768                 if (eh)
 769                         ServerInstance->SE->WantWrite(eh);
 770         }
 771
 772         virtual void OnBufferFlushed(User* user)
 773         {
 774                 if (user->GetIOHook() == this)
 775                 {
 776                         issl_session* session = &sessions[user->GetFd()];
 777                         if (session && session->outbuf.size())
 778                                 OnRawSocketWrite(user->GetFd(), NULL, 0);
 779                 }
 780         }
 781
 782         void CloseSession(issl_session* session)
 783         {
 784                 if(session->sess)
 785                 {
 786                         gnutls_bye(session->sess, GNUTLS_SHUT_WR);
 787                         gnutls_deinit(session->sess);
 788                 }
 789
 790                 if(session->inbuf)
 791                 {
 792                         delete[] session->inbuf;
 793                 }
 794
 795                 session->outbuf.clear();
 796                 session->inbuf = NULL;
 797                 session->sess = NULL;
 798                 session->status = ISSL_NONE;
 799         }
 800
 801         void VerifyCertificate(issl_session* session, Extensible* user)
 802         {
 803                 if (!session->sess || !user)
 804                         return;
 805
 806                 unsigned int status;
 807                 const gnutls_datum_t* cert_list;
 808                 int ret;
 809                 unsigned int cert_list_size;
 810                 gnutls_x509_crt_t cert;
 811                 char name[MAXBUF];
 812                 unsigned char digest[MAXBUF];
 813                 size_t digest_size = sizeof(digest);
 814                 size_t name_size = sizeof(name);
 815                 ssl_cert* certinfo = new ssl_cert;
 816
 817                 user->Extend("ssl_cert",certinfo);
 818
 819                 /* This verification function uses the trusted CAs in the credentials
 820                  * structure. So you must have installed one or more CA certificates.
 821                  */
 822                 ret = gnutls_certificate_verify_peers2(session->sess, &status);
 823
 824                 if (ret < 0)
 825                 {
 826                         certinfo->data.insert(std::make_pair("error",std::string(gnutls_strerror(ret))));
 827                         return;
 828                 }
 829
 830                 if (status & GNUTLS_CERT_INVALID)
 831                 {
 832                         certinfo->data.insert(std::make_pair("invalid",ConvToStr(1)));
 833                 }
 834                 else
 835                 {
 836                         certinfo->data.insert(std::make_pair("invalid",ConvToStr(0)));
 837                 }
 838                 if (status & GNUTLS_CERT_SIGNER_NOT_FOUND)
 839                 {
 840                         certinfo->data.insert(std::make_pair("unknownsigner",ConvToStr(1)));
 841                 }
 842                 else
 843                 {
 844                         certinfo->data.insert(std::make_pair("unknownsigner",ConvToStr(0)));
 845                 }
 846                 if (status & GNUTLS_CERT_REVOKED)
 847                 {
 848                         certinfo->data.insert(std::make_pair("revoked",ConvToStr(1)));
 849                 }
 850                 else
 851                 {
 852                         certinfo->data.insert(std::make_pair("revoked",ConvToStr(0)));
 853                 }
 854                 if (status & GNUTLS_CERT_SIGNER_NOT_CA)
 855                 {
 856                         certinfo->data.insert(std::make_pair("trusted",ConvToStr(0)));
 857                 }
 858                 else
 859                 {
 860                         certinfo->data.insert(std::make_pair("trusted",ConvToStr(1)));
 861                 }
 862
 863                 /* Up to here the process is the same for X.509 certificates and
 864                  * OpenPGP keys. From now on X.509 certificates are assumed. This can
 865                  * be easily extended to work with openpgp keys as well.
 866                  */
 867                 if (gnutls_certificate_type_get(session->sess) != GNUTLS_CRT_X509)
 868                 {
 869                         certinfo->data.insert(std::make_pair("error","No X509 keys sent"));
 870                         return;
 871                 }
 872
 873                 ret = gnutls_x509_crt_init(&cert);
 874                 if (ret < 0)
 875                 {
 876                         certinfo->data.insert(std::make_pair("error",gnutls_strerror(ret)));
 877                         return;
 878                 }
 879
 880                 cert_list_size = 0;
 881                 cert_list = gnutls_certificate_get_peers(session->sess, &cert_list_size);
 882                 if (cert_list == NULL)
 883                 {
 884                         certinfo->data.insert(std::make_pair("error","No certificate was found"));
 885                         return;
 886                 }
 887
 888                 /* This is not a real world example, since we only check the first
 889                  * certificate in the given chain.
 890                  */
 891
 892                 ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
 893                 if (ret < 0)
 894                 {
 895                         certinfo->data.insert(std::make_pair("error",gnutls_strerror(ret)));
 896                         return;
 897                 }
 898
 899                 gnutls_x509_crt_get_dn(cert, name, &name_size);
 900
 901                 certinfo->data.insert(std::make_pair("dn",name));
 902
 903                 gnutls_x509_crt_get_issuer_dn(cert, name, &name_size);
 904
 905                 certinfo->data.insert(std::make_pair("issuer",name));
 906
 907                 if ((ret = gnutls_x509_crt_get_fingerprint(cert, GNUTLS_DIG_MD5, digest, &digest_size)) < 0)
 908                 {
 909                         certinfo->data.insert(std::make_pair("error",gnutls_strerror(ret)));
 910                 }
 911                 else
 912                 {
 913                         certinfo->data.insert(std::make_pair("fingerprint",irc::hex(digest, digest_size)));
 914                 }
 915
 916                 /* Beware here we do not check for errors.
 917                  */
 918                 if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
 919                 {
 920                         certinfo->data.insert(std::make_pair("error","Not activated, or expired certificate"));
 921                 }
 922
 923                 gnutls_x509_crt_deinit(cert);
 924
 925                 return;
 926         }
 927
 928         void OnEvent(Event* ev)
 929         {
 930                 GenericCapHandler(ev, "tls", "tls");
 931         }
 932
 933         void Prioritize()
 934         {
 935                 Module* server = ServerInstance->Modules->Find("m_spanningtree.so");
 936                 ServerInstance->Modules->SetPriority(this, I_OnPostConnect, PRIO_AFTER, &server);
 937         }
 938 };
 939
 940 MODULE_INIT(ModuleSSLGnuTLS)