src/modules/extra/m_ssl_gnutls.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2008 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         /* Command 'dalinfo', takes no parameters and needs no special modes */
  67         CommandStartTLS (InspIRCd* Instance, Module* mod) : Command(Instance,"STARTTLS", 0, 0, true), Caller(mod)
  68         {
  69                 this->source = "m_ssl_gnutls.so";
  70         }
  71
  72         CmdResult Handle (const std::vector<std::string> &parameters, User *user)
  73         {
  74                 if (user->registered == REG_ALL)
  75                 {
  76                         ServerInstance->Users->QuitUser(user, "STARTTLS not allowed after client registration");
  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(671, "%s :STARTTLS failure", user->nick.c_str());
  88                 }
  89
  90                 return CMD_FAILURE;
  91         }
  92 };
  93
  94 class ModuleSSLGnuTLS : public Module
  95 {
  96
  97         ConfigReader* Conf;
  98
  99         char* dummy;
 100
 101         std::vector<std::string> listenports;
 102
 103         int inbufsize;
 104         issl_session* sessions;
 105
 106         gnutls_certificate_credentials x509_cred;
 107         gnutls_dh_params dh_params;
 108
 109         std::string keyfile;
 110         std::string certfile;
 111         std::string cafile;
 112         std::string crlfile;
 113         std::string sslports;
 114         int dh_bits;
 115
 116         int clientactive;
 117         bool cred_alloc;
 118
 119         CommandStartTLS* starttls;
 120
 121  public:
 122
 123         ModuleSSLGnuTLS(InspIRCd* Me)
 124                 : Module(Me)
 125         {
 126                 ServerInstance->Modules->PublishInterface("BufferedSocketHook", this);
 127
 128                 sessions = new issl_session[ServerInstance->SE->GetMaxFds()];
 129
 130                 // Not rehashable...because I cba to reduce all the sizes of existing buffers.
 131                 inbufsize = ServerInstance->Config->NetBufferSize;
 132
 133                 gnutls_global_init(); // This must be called once in the program
 134
 135                 cred_alloc = false;
 136                 // Needs the flag as it ignores a plain /rehash
 137                 OnRehash(NULL,"ssl");
 138
 139                 // Void return, guess we assume success
 140                 gnutls_certificate_set_dh_params(x509_cred, dh_params);
 141                 Implementation eventlist[] = { I_On005Numeric, I_OnRawSocketConnect, I_OnRawSocketAccept, I_OnRawSocketClose, I_OnRawSocketRead, I_OnRawSocketWrite, I_OnCleanup,
 142                         I_OnBufferFlushed, I_OnRequest, I_OnSyncUserMetaData, I_OnDecodeMetaData, I_OnUnloadModule, I_OnRehash, I_OnWhois, I_OnPostConnect, I_OnEvent, I_OnHookUserIO };
 143                 ServerInstance->Modules->Attach(eventlist, this, 17);
 144
 145                 starttls = new CommandStartTLS(ServerInstance, this);
 146                 ServerInstance->AddCommand(starttls);
 147         }
 148
 149         virtual void OnRehash(User* user, const std::string &param)
 150         {
 151                 Conf = new ConfigReader(ServerInstance);
 152
 153                 listenports.clear();
 154                 clientactive = 0;
 155                 sslports.clear();
 156
 157                 for(int index = 0; index < Conf->Enumerate("bind"); index++)
 158                 {
 159                         // For each <bind> tag
 160                         std::string x = Conf->ReadValue("bind", "type", index);
 161                         if(((x.empty()) || (x == "clients")) && (Conf->ReadValue("bind", "ssl", index) == "gnutls"))
 162                         {
 163                                 // Get the port we're meant to be listening on with SSL
 164                                 std::string port = Conf->ReadValue("bind", "port", index);
 165                                 std::string addr = Conf->ReadValue("bind", "address", index);
 166
 167                                 irc::portparser portrange(port, false);
 168                                 long portno = -1;
 169                                 while ((portno = portrange.GetToken()))
 170                                 {
 171                                         clientactive++;
 172                                         try
 173                                         {
 174                                                 listenports.push_back(addr + ":" + ConvToStr(portno));
 175
 176                                                 for (size_t i = 0; i < ServerInstance->Config->ports.size(); i++)
 177                                                         if ((ServerInstance->Config->ports[i]->GetPort() == portno) && (ServerInstance->Config->ports[i]->GetIP() == addr))
 178                                                                 ServerInstance->Config->ports[i]->SetDescription("ssl");
 179                                                 ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Enabling SSL for port %ld", portno);
 180
 181                                                 sslports.append((addr.empty() ? "*" : addr)).append(":").append(ConvToStr(portno)).append(";");
 182                                         }
 183                                         catch (ModuleException &e)
 184                                         {
 185                                                 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());
 186                                         }
 187                                 }
 188                         }
 189                 }
 190
 191                 if (!sslports.empty())
 192                         sslports.erase(sslports.end() - 1);
 193
 194                 if(param != "ssl")
 195                 {
 196                         delete Conf;
 197                         return;
 198                 }
 199
 200                 std::string confdir(ServerInstance->ConfigFileName);
 201                 // +1 so we the path ends with a /
 202                 confdir = confdir.substr(0, confdir.find_last_of('/') + 1);
 203
 204                 cafile  = Conf->ReadValue("gnutls", "cafile", 0);
 205                 crlfile = Conf->ReadValue("gnutls", "crlfile", 0);
 206                 certfile        = Conf->ReadValue("gnutls", "certfile", 0);
 207                 keyfile = Conf->ReadValue("gnutls", "keyfile", 0);
 208                 dh_bits = Conf->ReadInteger("gnutls", "dhbits", 0, false);
 209
 210                 // Set all the default values needed.
 211                 if (cafile.empty())
 212                         cafile = "ca.pem";
 213
 214                 if (crlfile.empty())
 215                         crlfile = "crl.pem";
 216
 217                 if (certfile.empty())
 218                         certfile = "cert.pem";
 219
 220                 if (keyfile.empty())
 221                         keyfile = "key.pem";
 222
 223                 if((dh_bits != 768) && (dh_bits != 1024) && (dh_bits != 2048) && (dh_bits != 3072) && (dh_bits != 4096))
 224                         dh_bits = 1024;
 225
 226                 // Prepend relative paths with the path to the config directory.
 227                 if ((cafile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(cafile)))
 228                         cafile = confdir + cafile;
 229
 230                 if ((crlfile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(crlfile)))
 231                         crlfile = confdir + crlfile;
 232
 233                 if ((certfile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(certfile)))
 234                         certfile = confdir + certfile;
 235
 236                 if ((keyfile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(keyfile)))
 237                         keyfile = confdir + keyfile;
 238
 239                 int ret;
 240
 241                 if (cred_alloc)
 242                 {
 243                         // Deallocate the old credentials
 244                         gnutls_dh_params_deinit(dh_params);
 245                         gnutls_certificate_free_credentials(x509_cred);
 246                 }
 247                 else
 248                         cred_alloc = true;
 249
 250                 if((ret = gnutls_certificate_allocate_credentials(&x509_cred)) < 0)
 251                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to allocate certificate credentials: %s", gnutls_strerror(ret));
 252
 253                 if((ret = gnutls_dh_params_init(&dh_params)) < 0)
 254                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to initialise DH parameters: %s", gnutls_strerror(ret));
 255
 256                 if((ret =gnutls_certificate_set_x509_trust_file(x509_cred, cafile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 257                         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));
 258
 259                 if((ret = gnutls_certificate_set_x509_crl_file (x509_cred, crlfile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 260                         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));
 261
 262                 if((ret = gnutls_certificate_set_x509_key_file (x509_cred, certfile.c_str(), keyfile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 263                 {
 264                         // If this fails, no SSL port will work. At all. So, do the smart thing - throw a ModuleException
 265                         throw ModuleException("Unable to load GnuTLS server certificate (" + std::string(certfile) + ", key: " + keyfile + "): " + std::string(gnutls_strerror(ret)));
 266                 }
 267
 268                 // This may be on a large (once a day or week) timer eventually.
 269                 GenerateDHParams();
 270
 271                 delete Conf;
 272         }
 273
 274         void GenerateDHParams()
 275         {
 276                 // Generate Diffie Hellman parameters - for use with DHE
 277                 // kx algorithms. These should be discarded and regenerated
 278                 // once a day, once a week or once a month. Depending on the
 279                 // security requirements.
 280
 281                 int ret;
 282
 283                 if((ret = gnutls_dh_params_generate2(dh_params, dh_bits)) < 0)
 284                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to generate DH parameters (%d bits): %s", dh_bits, gnutls_strerror(ret));
 285         }
 286
 287         virtual ~ModuleSSLGnuTLS()
 288         {
 289                 gnutls_dh_params_deinit(dh_params);
 290                 gnutls_certificate_free_credentials(x509_cred);
 291                 gnutls_global_deinit();
 292                 ServerInstance->Modules->UnpublishInterface("BufferedSocketHook", this);
 293                 delete[] sessions;
 294         }
 295
 296         virtual void OnCleanup(int target_type, void* item)
 297         {
 298                 if(target_type == TYPE_USER)
 299                 {
 300                         User* user = (User*)item;
 301
 302                         if (user->GetIOHook() == this)
 303                         {
 304                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 305                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 306                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 307                                 user->DelIOHook();
 308                         }
 309                         if (user->GetExt("ssl_cert", dummy))
 310                         {
 311                                 ssl_cert* tofree;
 312                                 user->GetExt("ssl_cert", tofree);
 313                                 delete tofree;
 314                                 user->Shrink("ssl_cert");
 315                         }
 316                 }
 317         }
 318
 319         virtual void OnUnloadModule(Module* mod, const std::string &name)
 320         {
 321                 if(mod == this)
 322                 {
 323                         for(unsigned int i = 0; i < listenports.size(); i++)
 324                         {
 325                                 for (size_t j = 0; j < ServerInstance->Config->ports.size(); j++)
 326                                         if (listenports[i] == (ServerInstance->Config->ports[j]->GetIP()+":"+ConvToStr(ServerInstance->Config->ports[j]->GetPort())))
 327                                                 ServerInstance->Config->ports[j]->SetDescription("plaintext");
 328                         }
 329                 }
 330         }
 331
 332         virtual Version GetVersion()
 333         {
 334                 return Version("$Id$", VF_VENDOR, API_VERSION);
 335         }
 336
 337
 338         virtual void On005Numeric(std::string &output)
 339         {
 340                 output.append(" SSL=" + sslports);
 341         }
 342
 343         virtual void OnHookUserIO(User* user, const std::string &targetip)
 344         {
 345                 if (!user->GetIOHook() && isin(targetip,user->GetPort(),listenports))
 346                 {
 347                         /* Hook the user with our module */
 348                         user->AddIOHook(this);
 349                 }
 350         }
 351
 352         virtual const char* OnRequest(Request* request)
 353         {
 354                 ISHRequest* ISR = (ISHRequest*)request;
 355                 if (strcmp("IS_NAME", request->GetId()) == 0)
 356                 {
 357                         return "gnutls";
 358                 }
 359                 else if (strcmp("IS_HOOK", request->GetId()) == 0)
 360                 {
 361                         const char* ret = "OK";
 362                         try
 363                         {
 364                                 ret = ISR->Sock->AddIOHook((Module*)this) ? "OK" : NULL;
 365                         }
 366                         catch (ModuleException &e)
 367                         {
 368                                 return NULL;
 369                         }
 370                         return ret;
 371                 }
 372                 else if (strcmp("IS_UNHOOK", request->GetId()) == 0)
 373                 {
 374                         return ISR->Sock->DelIOHook() ? "OK" : NULL;
 375                 }
 376                 else if (strcmp("IS_HSDONE", request->GetId()) == 0)
 377                 {
 378                         if (ISR->Sock->GetFd() < 0)
 379                                 return "OK";
 380
 381                         issl_session* session = &sessions[ISR->Sock->GetFd()];
 382                         return (session->status == ISSL_HANDSHAKING_READ || session->status == ISSL_HANDSHAKING_WRITE) ? NULL : "OK";
 383                 }
 384                 else if (strcmp("IS_ATTACH", request->GetId()) == 0)
 385                 {
 386                         if (ISR->Sock->GetFd() > -1)
 387                         {
 388                                 issl_session* session = &sessions[ISR->Sock->GetFd()];
 389                                 if (session->sess)
 390                                 {
 391                                         if ((Extensible*)ServerInstance->FindDescriptor(ISR->Sock->GetFd()) == (Extensible*)(ISR->Sock))
 392                                         {
 393                                                 VerifyCertificate(session, (BufferedSocket*)ISR->Sock);
 394                                                 return "OK";
 395                                         }
 396                                 }
 397                         }
 398                 }
 399                 return NULL;
 400         }
 401
 402
 403         virtual void OnRawSocketAccept(int fd, const std::string &ip, int localport)
 404         {
 405                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 406                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 407                         return;
 408
 409                 issl_session* session = &sessions[fd];
 410
 411                 /* For STARTTLS: Don't try and init a session on a socket that already has a session */
 412                 if (session->sess)
 413                         return;
 414
 415                 session->fd = fd;
 416                 session->inbuf = new char[inbufsize];
 417                 session->inbufoffset = 0;
 418
 419                 gnutls_init(&session->sess, GNUTLS_SERVER);
 420
 421                 gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
 422                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 423                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 424
 425                 /* This is an experimental change to avoid a warning on 64bit systems about casting between integer and pointer of different sizes
 426                  * This needs testing, but it's easy enough to rollback if need be
 427                  * Old: gnutls_transport_set_ptr(session->sess, (gnutls_transport_ptr_t) fd); // Give gnutls the fd for the socket.
 428                  * New: gnutls_transport_set_ptr(session->sess, &fd); // Give gnutls the fd for the socket.
 429                  *
 430                  * With testing this seems to...not work :/
 431                  */
 432
 433                 gnutls_transport_set_ptr(session->sess, (gnutls_transport_ptr_t) fd); // Give gnutls the fd for the socket.
 434
 435                 gnutls_certificate_server_set_request(session->sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
 436
 437                 Handshake(session);
 438         }
 439
 440         virtual void OnRawSocketConnect(int fd)
 441         {
 442                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 443                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 444                         return;
 445
 446                 issl_session* session = &sessions[fd];
 447
 448                 session->fd = fd;
 449                 session->inbuf = new char[inbufsize];
 450                 session->inbufoffset = 0;
 451
 452                 gnutls_init(&session->sess, GNUTLS_CLIENT);
 453
 454                 gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
 455                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 456                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 457                 gnutls_transport_set_ptr(session->sess, (gnutls_transport_ptr_t) fd); // Give gnutls the fd for the socket.
 458
 459                 Handshake(session);
 460         }
 461
 462         virtual void OnRawSocketClose(int fd)
 463         {
 464                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 465                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds()))
 466                         return;
 467
 468                 CloseSession(&sessions[fd]);
 469
 470                 EventHandler* user = ServerInstance->SE->GetRef(fd);
 471
 472                 if ((user) && (user->GetExt("ssl_cert", dummy)))
 473                 {
 474                         ssl_cert* tofree;
 475                         user->GetExt("ssl_cert", tofree);
 476                         delete tofree;
 477                         user->Shrink("ssl_cert");
 478                 }
 479         }
 480
 481         virtual int OnRawSocketRead(int fd, char* buffer, unsigned int count, int &readresult)
 482         {
 483                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 484                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 485                         return 0;
 486
 487                 issl_session* session = &sessions[fd];
 488
 489                 if (!session->sess)
 490                 {
 491                         readresult = 0;
 492                         CloseSession(session);
 493                         return 1;
 494                 }
 495
 496                 if (session->status == ISSL_HANDSHAKING_READ)
 497                 {
 498                         // The handshake isn't finished, try to finish it.
 499
 500                         if(!Handshake(session))
 501                         {
 502                                 // Couldn't resume handshake.
 503                                 return -1;
 504                         }
 505                 }
 506                 else if (session->status == ISSL_HANDSHAKING_WRITE)
 507                 {
 508                         errno = EAGAIN;
 509                         MakePollWrite(session);
 510                         return -1;
 511                 }
 512
 513                 // If we resumed the handshake then session->status will be ISSL_HANDSHAKEN.
 514
 515                 if (session->status == ISSL_HANDSHAKEN)
 516                 {
 517                         // Is this right? Not sure if the unencrypted data is garaunteed to be the same length.
 518                         // Read into the inbuffer, offset from the beginning by the amount of data we have that insp hasn't taken yet.
 519                         int ret = gnutls_record_recv(session->sess, session->inbuf + session->inbufoffset, inbufsize - session->inbufoffset);
 520
 521                         if (ret == 0)
 522                         {
 523                                 // Client closed connection.
 524                                 readresult = 0;
 525                                 CloseSession(session);
 526                                 return 1;
 527                         }
 528                         else if (ret < 0)
 529                         {
 530                                 if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 531                                 {
 532                                         errno = EAGAIN;
 533                                         return -1;
 534                                 }
 535                                 else
 536                                 {
 537                                         ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT,
 538                                                         "m_ssl_gnutls.so: Error while reading on fd %d: %s",
 539                                                         session->fd, gnutls_strerror(ret));
 540                                         readresult = 0;
 541                                         CloseSession(session);
 542                                 }
 543                         }
 544                         else
 545                         {
 546                                 // Read successfully 'ret' bytes into inbuf + inbufoffset
 547                                 // There are 'ret' + 'inbufoffset' bytes of data in 'inbuf'
 548                                 // 'buffer' is 'count' long
 549
 550                                 unsigned int length = ret + session->inbufoffset;
 551
 552                                 if(count <= length)
 553                                 {
 554                                         memcpy(buffer, session->inbuf, count);
 555                                         // Move the stuff left in inbuf to the beginning of it
 556                                         memmove(session->inbuf, session->inbuf + count, (length - count));
 557                                         // Now we need to set session->inbufoffset to the amount of data still waiting to be handed to insp.
 558                                         session->inbufoffset = length - count;
 559                                         // Insp uses readresult as the count of how much data there is in buffer, so:
 560                                         readresult = count;
 561                                 }
 562                                 else
 563                                 {
 564                                         // There's not as much in the inbuf as there is space in the buffer, so just copy the whole thing.
 565                                         memcpy(buffer, session->inbuf, length);
 566                                         // Zero the offset, as there's nothing there..
 567                                         session->inbufoffset = 0;
 568                                         // As above
 569                                         readresult = length;
 570                                 }
 571                         }
 572                 }
 573                 else if(session->status == ISSL_CLOSING)
 574                         readresult = 0;
 575
 576                 return 1;
 577         }
 578
 579         virtual int OnRawSocketWrite(int fd, const char* buffer, int count)
 580         {
 581                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 582                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 583                         return 0;
 584
 585                 issl_session* session = &sessions[fd];
 586                 const char* sendbuffer = buffer;
 587
 588                 if (!session->sess)
 589                 {
 590                         CloseSession(session);
 591                         return 1;
 592                 }
 593
 594                 session->outbuf.append(sendbuffer, count);
 595                 sendbuffer = session->outbuf.c_str();
 596                 count = session->outbuf.size();
 597
 598                 if (session->status == ISSL_HANDSHAKING_WRITE)
 599                 {
 600                         // The handshake isn't finished, try to finish it.
 601                         Handshake(session);
 602                         errno = EAGAIN;
 603                         return -1;
 604                 }
 605
 606                 int ret = 0;
 607
 608                 if (session->status == ISSL_HANDSHAKEN)
 609                 {
 610                         ret = gnutls_record_send(session->sess, sendbuffer, count);
 611
 612                         if (ret == 0)
 613                         {
 614                                 CloseSession(session);
 615                         }
 616                         else if (ret < 0)
 617                         {
 618                                 if(ret != GNUTLS_E_AGAIN && ret != GNUTLS_E_INTERRUPTED)
 619                                 {
 620                                         ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT,
 621                                                         "m_ssl_gnutls.so: Error while writing to fd %d: %s",
 622                                                         session->fd, gnutls_strerror(ret));
 623                                         CloseSession(session);
 624                                 }
 625                                 else
 626                                 {
 627                                         errno = EAGAIN;
 628                                 }
 629                         }
 630                         else
 631                         {
 632                                 session->outbuf = session->outbuf.substr(ret);
 633                         }
 634                 }
 635
 636                 MakePollWrite(session);
 637
 638                 /* Who's smart idea was it to return 1 when we havent written anything?
 639                  * This fucks the buffer up in BufferedSocket :p
 640                  */
 641                 return ret < 1 ? 0 : ret;
 642         }
 643
 644         // :kenny.chatspike.net 320 Om Epy|AFK :is a Secure Connection
 645         virtual void OnWhois(User* source, User* dest)
 646         {
 647                 if (!clientactive)
 648                         return;
 649
 650                 // Bugfix, only send this numeric for *our* SSL users
 651                 if (dest->GetExt("ssl", dummy) || ((IS_LOCAL(dest) && (dest->GetIOHook() == this))))
 652                 {
 653                         ServerInstance->SendWhoisLine(source, dest, 320, "%s %s :is using a secure connection", source->nick.c_str(), dest->nick.c_str());
 654                 }
 655         }
 656
 657         virtual void OnSyncUserMetaData(User* user, Module* proto, void* opaque, const std::string &extname, bool displayable)
 658         {
 659                 // check if the linking module wants to know about OUR metadata
 660                 if(extname == "ssl")
 661                 {
 662                         // check if this user has an swhois field to send
 663                         if(user->GetExt(extname, dummy))
 664                         {
 665                                 // call this function in the linking module, let it format the data how it
 666                                 // sees fit, and send it on its way. We dont need or want to know how.
 667                                 proto->ProtoSendMetaData(opaque, TYPE_USER, user, extname, displayable ? "Enabled" : "ON");
 668                         }
 669                 }
 670         }
 671
 672         virtual void OnDecodeMetaData(int target_type, void* target, const std::string &extname, const std::string &extdata)
 673         {
 674                 // check if its our metadata key, and its associated with a user
 675                 if ((target_type == TYPE_USER) && (extname == "ssl"))
 676                 {
 677                         User* dest = (User*)target;
 678                         // if they dont already have an ssl flag, accept the remote server's
 679                         if (!dest->GetExt(extname, dummy))
 680                         {
 681                                 dest->Extend(extname, "ON");
 682                         }
 683                 }
 684         }
 685
 686         bool Handshake(issl_session* session)
 687         {
 688                 int ret = gnutls_handshake(session->sess);
 689
 690                 if (ret < 0)
 691                 {
 692                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 693                         {
 694                                 // Handshake needs resuming later, read() or write() would have blocked.
 695
 696                                 if(gnutls_record_get_direction(session->sess) == 0)
 697                                 {
 698                                         // gnutls_handshake() wants to read() again.
 699                                         session->status = ISSL_HANDSHAKING_READ;
 700                                 }
 701                                 else
 702                                 {
 703                                         // gnutls_handshake() wants to write() again.
 704                                         session->status = ISSL_HANDSHAKING_WRITE;
 705                                         MakePollWrite(session);
 706                                 }
 707                         }
 708                         else
 709                         {
 710                                 // Handshake failed.
 711                                 ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT,
 712                                                 "m_ssl_gnutls.so: Handshake failed on fd %d: %s",
 713                                                 session->fd, gnutls_strerror(ret));
 714                                 CloseSession(session);
 715                                 session->status = ISSL_CLOSING;
 716                         }
 717
 718                         return false;
 719                 }
 720                 else
 721                 {
 722                         // Handshake complete.
 723                         // This will do for setting the ssl flag...it could be done earlier if it's needed. But this seems neater.
 724                         User* extendme = ServerInstance->FindDescriptor(session->fd);
 725                         if (extendme)
 726                         {
 727                                 if (!extendme->GetExt("ssl", dummy))
 728                                         extendme->Extend("ssl", "ON");
 729                         }
 730
 731                         // Change the seesion state
 732                         session->status = ISSL_HANDSHAKEN;
 733
 734                         // Finish writing, if any left
 735                         MakePollWrite(session);
 736
 737                         return true;
 738                 }
 739         }
 740
 741         virtual void OnPostConnect(User* user)
 742         {
 743                 // This occurs AFTER OnUserConnect so we can be sure the
 744                 // protocol module has propagated the NICK message.
 745                 if ((user->GetExt("ssl", dummy)) && (IS_LOCAL(user)))
 746                 {
 747                         // Tell whatever protocol module we're using that we need to inform other servers of this metadata NOW.
 748                         ServerInstance->PI->SendMetaData(user, TYPE_USER, "SSL", "on");
 749
 750                         VerifyCertificate(&sessions[user->GetFd()],user);
 751                         if (sessions[user->GetFd()].sess)
 752                         {
 753                                 std::string cipher = gnutls_kx_get_name(gnutls_kx_get(sessions[user->GetFd()].sess));
 754                                 cipher.append("-").append(gnutls_cipher_get_name(gnutls_cipher_get(sessions[user->GetFd()].sess))).append("-");
 755                                 cipher.append(gnutls_mac_get_name(gnutls_mac_get(sessions[user->GetFd()].sess)));
 756                                 user->WriteServ("NOTICE %s :*** You are connected using SSL cipher \"%s\"", user->nick.c_str(), cipher.c_str());
 757                         }
 758                 }
 759         }
 760
 761         void MakePollWrite(issl_session* session)
 762         {
 763                 //OnRawSocketWrite(session->fd, NULL, 0);
 764                 EventHandler* eh = ServerInstance->FindDescriptor(session->fd);
 765                 if (eh)
 766                         ServerInstance->SE->WantWrite(eh);
 767         }
 768
 769         virtual void OnBufferFlushed(User* user)
 770         {
 771                 if (user->GetExt("ssl"))
 772                 {
 773                         issl_session* session = &sessions[user->GetFd()];
 774                         if (session && session->outbuf.size())
 775                                 OnRawSocketWrite(user->GetFd(), NULL, 0);
 776                 }
 777         }
 778
 779         void CloseSession(issl_session* session)
 780         {
 781                 if(session->sess)
 782                 {
 783                         gnutls_bye(session->sess, GNUTLS_SHUT_WR);
 784                         gnutls_deinit(session->sess);
 785                 }
 786
 787                 if(session->inbuf)
 788                 {
 789                         delete[] session->inbuf;
 790                 }
 791
 792                 session->outbuf.clear();
 793                 session->inbuf = NULL;
 794                 session->sess = NULL;
 795                 session->status = ISSL_NONE;
 796         }
 797
 798         void VerifyCertificate(issl_session* session, Extensible* user)
 799         {
 800                 if (!session->sess || !user)
 801                         return;
 802
 803                 unsigned int status;
 804                 const gnutls_datum_t* cert_list;
 805                 int ret;
 806                 unsigned int cert_list_size;
 807                 gnutls_x509_crt_t cert;
 808                 char name[MAXBUF];
 809                 unsigned char digest[MAXBUF];
 810                 size_t digest_size = sizeof(digest);
 811                 size_t name_size = sizeof(name);
 812                 ssl_cert* certinfo = new ssl_cert;
 813
 814                 user->Extend("ssl_cert",certinfo);
 815
 816                 /* This verification function uses the trusted CAs in the credentials
 817                  * structure. So you must have installed one or more CA certificates.
 818                  */
 819                 ret = gnutls_certificate_verify_peers2(session->sess, &status);
 820
 821                 if (ret < 0)
 822                 {
 823                         certinfo->data.insert(std::make_pair("error",std::string(gnutls_strerror(ret))));
 824                         return;
 825                 }
 826
 827                 if (status & GNUTLS_CERT_INVALID)
 828                 {
 829                         certinfo->data.insert(std::make_pair("invalid",ConvToStr(1)));
 830                 }
 831                 else
 832                 {
 833                         certinfo->data.insert(std::make_pair("invalid",ConvToStr(0)));
 834                 }
 835                 if (status & GNUTLS_CERT_SIGNER_NOT_FOUND)
 836                 {
 837                         certinfo->data.insert(std::make_pair("unknownsigner",ConvToStr(1)));
 838                 }
 839                 else
 840                 {
 841                         certinfo->data.insert(std::make_pair("unknownsigner",ConvToStr(0)));
 842                 }
 843                 if (status & GNUTLS_CERT_REVOKED)
 844                 {
 845                         certinfo->data.insert(std::make_pair("revoked",ConvToStr(1)));
 846                 }
 847                 else
 848                 {
 849                         certinfo->data.insert(std::make_pair("revoked",ConvToStr(0)));
 850                 }
 851                 if (status & GNUTLS_CERT_SIGNER_NOT_CA)
 852                 {
 853                         certinfo->data.insert(std::make_pair("trusted",ConvToStr(0)));
 854                 }
 855                 else
 856                 {
 857                         certinfo->data.insert(std::make_pair("trusted",ConvToStr(1)));
 858                 }
 859
 860                 /* Up to here the process is the same for X.509 certificates and
 861                  * OpenPGP keys. From now on X.509 certificates are assumed. This can
 862                  * be easily extended to work with openpgp keys as well.
 863                  */
 864                 if (gnutls_certificate_type_get(session->sess) != GNUTLS_CRT_X509)
 865                 {
 866                         certinfo->data.insert(std::make_pair("error","No X509 keys sent"));
 867                         return;
 868                 }
 869
 870                 ret = gnutls_x509_crt_init(&cert);
 871                 if (ret < 0)
 872                 {
 873                         certinfo->data.insert(std::make_pair("error",gnutls_strerror(ret)));
 874                         return;
 875                 }
 876
 877                 cert_list_size = 0;
 878                 cert_list = gnutls_certificate_get_peers(session->sess, &cert_list_size);
 879                 if (cert_list == NULL)
 880                 {
 881                         certinfo->data.insert(std::make_pair("error","No certificate was found"));
 882                         return;
 883                 }
 884
 885                 /* This is not a real world example, since we only check the first
 886                  * certificate in the given chain.
 887                  */
 888
 889                 ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
 890                 if (ret < 0)
 891                 {
 892                         certinfo->data.insert(std::make_pair("error",gnutls_strerror(ret)));
 893                         return;
 894                 }
 895
 896                 gnutls_x509_crt_get_dn(cert, name, &name_size);
 897
 898                 certinfo->data.insert(std::make_pair("dn",name));
 899
 900                 gnutls_x509_crt_get_issuer_dn(cert, name, &name_size);
 901
 902                 certinfo->data.insert(std::make_pair("issuer",name));
 903
 904                 if ((ret = gnutls_x509_crt_get_fingerprint(cert, GNUTLS_DIG_MD5, digest, &digest_size)) < 0)
 905                 {
 906                         certinfo->data.insert(std::make_pair("error",gnutls_strerror(ret)));
 907                 }
 908                 else
 909                 {
 910                         certinfo->data.insert(std::make_pair("fingerprint",irc::hex(digest, digest_size)));
 911                 }
 912
 913                 /* Beware here we do not check for errors.
 914                  */
 915                 if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
 916                 {
 917                         certinfo->data.insert(std::make_pair("error","Not activated, or expired certificate"));
 918                 }
 919
 920                 gnutls_x509_crt_deinit(cert);
 921
 922                 return;
 923         }
 924
 925         void OnEvent(Event* ev)
 926         {
 927                 GenericCapHandler(ev, "tls", "tls");
 928         }
 929
 930         void Prioritize()
 931         {
 932                 Module* server = ServerInstance->Modules->Find("m_spanningtree.so");
 933                 ServerInstance->Modules->SetPriority(this, I_OnPostConnect, PRIO_AFTER, &server);
 934         }
 935 };
 936
 937 MODULE_INIT(ModuleSSLGnuTLS)