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
  16 #include <gnutls/gnutls.h>
  17 #include <gnutls/x509.h>
  18
  19 #include "inspircd_config.h"
  20 #include "configreader.h"
  21 #include "users.h"
  22 #include "channels.h"
  23 #include "modules.h"
  24 #include "socket.h"
  25 #include "hashcomp.h"
  26 #include "transport.h"
  27 #include "m_cap.h"
  28
  29 #ifdef WINDOWS
  30 #pragma comment(lib, "libgnutls-13.lib")
  31 #endif
  32
  33 /* $ModDesc: Provides SSL support for clients */
  34 /* $CompileFlags: exec("libgnutls-config --cflags") */
  35 /* $LinkerFlags: rpath("libgnutls-config --libs") exec("libgnutls-config --libs") */
  36 /* $ModDep: transport.h */
  37 /* $CopyInstall: conf/key.pem $(CONPATH) */
  38 /* $CopyInstall: conf/cert.pem $(CONPATH) */
  39
  40 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING_READ, ISSL_HANDSHAKING_WRITE, ISSL_HANDSHAKEN, ISSL_CLOSING, ISSL_CLOSED };
  41
  42 bool isin(const std::string &host, int port, const std::vector<std::string> &portlist)
  43 {
  44         if (std::find(portlist.begin(), portlist.end(), "*:" + ConvToStr(port)) != portlist.end())
  45                 return true;
  46
  47         if (std::find(portlist.begin(), portlist.end(), ":" + ConvToStr(port)) != portlist.end())
  48                 return true;
  49
  50         return std::find(portlist.begin(), portlist.end(), host + ":" + ConvToStr(port)) != portlist.end();
  51 }
  52
  53 /** Represents an SSL user's extra data
  54  */
  55 class issl_session : public classbase
  56 {
  57 public:
  58         issl_session()
  59         {
  60                 sess = NULL;
  61         }
  62
  63         gnutls_session_t sess;
  64         issl_status status;
  65         std::string outbuf;
  66         int inbufoffset;
  67         char* inbuf;
  68         int fd;
  69 };
  70
  71 class CommandStartTLS : public Command
  72 {
  73         Module* Caller;
  74  public:
  75         /* Command 'dalinfo', takes no parameters and needs no special modes */
  76         CommandStartTLS (InspIRCd* Instance, Module* mod) : Command(Instance,"STARTTLS", 0, 0, true), Caller(mod)
  77         {
  78                 this->source = "m_ssl_gnutls.so";
  79         }
  80
  81         CmdResult Handle (const std::vector<std::string> &parameters, User *user)
  82         {
  83                 if (user->registered == REG_ALL)
  84                 {
  85                         ServerInstance->Users->QuitUser(user, "STARTTLS not allowed after client registration");
  86                 }
  87                 else
  88                 {
  89                         if (!user->GetIOHook())
  90                         {
  91                                 user->WriteNumeric(670, "%s :STARTTLS successful, go ahead with TLS handshake", user->nick.c_str());
  92                                 user->AddIOHook(Caller);
  93                                 Caller->OnRawSocketAccept(user->GetFd(), user->GetIPString(), user->GetPort());
  94                         }
  95                         else
  96                                 user->WriteNumeric(671, "%s :STARTTLS failure", user->nick.c_str());
  97                 }
  98
  99                 return CMD_FAILURE;
 100         }
 101 };
 102
 103 class ModuleSSLGnuTLS : public Module
 104 {
 105
 106         ConfigReader* Conf;
 107
 108         char* dummy;
 109
 110         std::vector<std::string> listenports;
 111
 112         int inbufsize;
 113         issl_session* sessions;
 114
 115         gnutls_certificate_credentials x509_cred;
 116         gnutls_dh_params dh_params;
 117
 118         std::string keyfile;
 119         std::string certfile;
 120         std::string cafile;
 121         std::string crlfile;
 122         std::string sslports;
 123         int dh_bits;
 124
 125         int clientactive;
 126         bool cred_alloc;
 127
 128         CommandStartTLS* starttls;
 129
 130  public:
 131
 132         ModuleSSLGnuTLS(InspIRCd* Me)
 133                 : Module(Me)
 134         {
 135                 ServerInstance->Modules->PublishInterface("BufferedSocketHook", this);
 136
 137                 sessions = new issl_session[ServerInstance->SE->GetMaxFds()];
 138
 139                 // Not rehashable...because I cba to reduce all the sizes of existing buffers.
 140                 inbufsize = ServerInstance->Config->NetBufferSize;
 141
 142                 gnutls_global_init(); // This must be called once in the program
 143
 144                 cred_alloc = false;
 145                 // Needs the flag as it ignores a plain /rehash
 146                 OnRehash(NULL,"ssl");
 147
 148                 // Void return, guess we assume success
 149                 gnutls_certificate_set_dh_params(x509_cred, dh_params);
 150                 Implementation eventlist[] = { I_On005Numeric, I_OnRawSocketConnect, I_OnRawSocketAccept, I_OnRawSocketClose, I_OnRawSocketRead, I_OnRawSocketWrite, I_OnCleanup,
 151                         I_OnBufferFlushed, I_OnRequest, I_OnSyncUserMetaData, I_OnDecodeMetaData, I_OnUnloadModule, I_OnRehash, I_OnWhois, I_OnPostConnect, I_OnEvent, I_OnHookUserIO };
 152                 ServerInstance->Modules->Attach(eventlist, this, 17);
 153
 154                 starttls = new CommandStartTLS(ServerInstance, this);
 155                 ServerInstance->AddCommand(starttls);
 156         }
 157
 158         virtual void OnRehash(User* user, const std::string &param)
 159         {
 160                 Conf = new ConfigReader(ServerInstance);
 161
 162                 listenports.clear();
 163                 clientactive = 0;
 164                 sslports.clear();
 165
 166                 for(int index = 0; index < Conf->Enumerate("bind"); index++)
 167                 {
 168                         // For each <bind> tag
 169                         std::string x = Conf->ReadValue("bind", "type", index);
 170                         if(((x.empty()) || (x == "clients")) && (Conf->ReadValue("bind", "ssl", index) == "gnutls"))
 171                         {
 172                                 // Get the port we're meant to be listening on with SSL
 173                                 std::string port = Conf->ReadValue("bind", "port", index);
 174                                 std::string addr = Conf->ReadValue("bind", "address", index);
 175
 176                                 irc::portparser portrange(port, false);
 177                                 long portno = -1;
 178                                 while ((portno = portrange.GetToken()))
 179                                 {
 180                                         clientactive++;
 181                                         try
 182                                         {
 183                                                 listenports.push_back(addr + ":" + ConvToStr(portno));
 184
 185                                                 for (size_t i = 0; i < ServerInstance->Config->ports.size(); i++)
 186                                                         if ((ServerInstance->Config->ports[i]->GetPort() == portno) && (ServerInstance->Config->ports[i]->GetIP() == addr))
 187                                                                 ServerInstance->Config->ports[i]->SetDescription("ssl");
 188                                                 ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Enabling SSL for port %ld", portno);
 189
 190                                                 sslports.append((addr.empty() ? "*" : addr)).append(":").append(ConvToStr(portno)).append(";");
 191                                         }
 192                                         catch (ModuleException &e)
 193                                         {
 194                                                 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());
 195                                         }
 196                                 }
 197                         }
 198                 }
 199
 200                 if (!sslports.empty())
 201                         sslports.erase(sslports.end() - 1);
 202
 203                 if(param != "ssl")
 204                 {
 205                         delete Conf;
 206                         return;
 207                 }
 208
 209                 std::string confdir(ServerInstance->ConfigFileName);
 210                 // +1 so we the path ends with a /
 211                 confdir = confdir.substr(0, confdir.find_last_of('/') + 1);
 212
 213                 cafile  = Conf->ReadValue("gnutls", "cafile", 0);
 214                 crlfile = Conf->ReadValue("gnutls", "crlfile", 0);
 215                 certfile        = Conf->ReadValue("gnutls", "certfile", 0);
 216                 keyfile = Conf->ReadValue("gnutls", "keyfile", 0);
 217                 dh_bits = Conf->ReadInteger("gnutls", "dhbits", 0, false);
 218
 219                 // Set all the default values needed.
 220                 if (cafile.empty())
 221                         cafile = "ca.pem";
 222
 223                 if (crlfile.empty())
 224                         crlfile = "crl.pem";
 225
 226                 if (certfile.empty())
 227                         certfile = "cert.pem";
 228
 229                 if (keyfile.empty())
 230                         keyfile = "key.pem";
 231
 232                 if((dh_bits != 768) && (dh_bits != 1024) && (dh_bits != 2048) && (dh_bits != 3072) && (dh_bits != 4096))
 233                         dh_bits = 1024;
 234
 235                 // Prepend relative paths with the path to the config directory.
 236                 if ((cafile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(cafile)))
 237                         cafile = confdir + cafile;
 238
 239                 if ((crlfile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(crlfile)))
 240                         crlfile = confdir + crlfile;
 241
 242                 if ((certfile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(certfile)))
 243                         certfile = confdir + certfile;
 244
 245                 if ((keyfile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(keyfile)))
 246                         keyfile = confdir + keyfile;
 247
 248                 int ret;
 249
 250                 if (cred_alloc)
 251                 {
 252                         // Deallocate the old credentials
 253                         gnutls_dh_params_deinit(dh_params);
 254                         gnutls_certificate_free_credentials(x509_cred);
 255                 }
 256                 else
 257                         cred_alloc = true;
 258
 259                 if((ret = gnutls_certificate_allocate_credentials(&x509_cred)) < 0)
 260                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to allocate certificate credentials: %s", gnutls_strerror(ret));
 261
 262                 if((ret = gnutls_dh_params_init(&dh_params)) < 0)
 263                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to initialise DH parameters: %s", gnutls_strerror(ret));
 264
 265                 if((ret =gnutls_certificate_set_x509_trust_file(x509_cred, cafile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 266                         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));
 267
 268                 if((ret = gnutls_certificate_set_x509_crl_file (x509_cred, crlfile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 269                         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));
 270
 271                 if((ret = gnutls_certificate_set_x509_key_file (x509_cred, certfile.c_str(), keyfile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 272                 {
 273                         // If this fails, no SSL port will work. At all. So, do the smart thing - throw a ModuleException
 274                         throw ModuleException("Unable to load GnuTLS server certificate: " + std::string(gnutls_strerror(ret)));
 275                 }
 276
 277                 // This may be on a large (once a day or week) timer eventually.
 278                 GenerateDHParams();
 279
 280                 delete Conf;
 281         }
 282
 283         void GenerateDHParams()
 284         {
 285                 // Generate Diffie Hellman parameters - for use with DHE
 286                 // kx algorithms. These should be discarded and regenerated
 287                 // once a day, once a week or once a month. Depending on the
 288                 // security requirements.
 289
 290                 int ret;
 291
 292                 if((ret = gnutls_dh_params_generate2(dh_params, dh_bits)) < 0)
 293                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to generate DH parameters (%d bits): %s", dh_bits, gnutls_strerror(ret));
 294         }
 295
 296         virtual ~ModuleSSLGnuTLS()
 297         {
 298                 gnutls_dh_params_deinit(dh_params);
 299                 gnutls_certificate_free_credentials(x509_cred);
 300                 gnutls_global_deinit();
 301                 ServerInstance->Modules->UnpublishInterface("BufferedSocketHook", this);
 302                 delete[] sessions;
 303         }
 304
 305         virtual void OnCleanup(int target_type, void* item)
 306         {
 307                 if(target_type == TYPE_USER)
 308                 {
 309                         User* user = (User*)item;
 310
 311                         if (user->GetIOHook() == this)
 312                         {
 313                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 314                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 315                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 316                                 user->DelIOHook();
 317                         }
 318                         if (user->GetExt("ssl_cert", dummy))
 319                         {
 320                                 ssl_cert* tofree;
 321                                 user->GetExt("ssl_cert", tofree);
 322                                 delete tofree;
 323                                 user->Shrink("ssl_cert");
 324                         }
 325                 }
 326         }
 327
 328         virtual void OnUnloadModule(Module* mod, const std::string &name)
 329         {
 330                 if(mod == this)
 331                 {
 332                         for(unsigned int i = 0; i < listenports.size(); i++)
 333                         {
 334                                 for (size_t j = 0; j < ServerInstance->Config->ports.size(); j++)
 335                                         if (listenports[i] == (ServerInstance->Config->ports[j]->GetIP()+":"+ConvToStr(ServerInstance->Config->ports[j]->GetPort())))
 336                                                 ServerInstance->Config->ports[j]->SetDescription("plaintext");
 337                         }
 338                 }
 339         }
 340
 341         virtual Version GetVersion()
 342         {
 343                 return Version("$Id$", VF_VENDOR, API_VERSION);
 344         }
 345
 346
 347         virtual void On005Numeric(std::string &output)
 348         {
 349                 output.append(" SSL=" + sslports);
 350         }
 351
 352         virtual void OnHookUserIO(User* user, const std::string &targetip)
 353         {
 354                 if (!user->GetIOHook() && isin(targetip,user->GetPort(),listenports))
 355                 {
 356                         /* Hook the user with our module */
 357                         user->AddIOHook(this);
 358                 }
 359         }
 360
 361         virtual const char* OnRequest(Request* request)
 362         {
 363                 ISHRequest* ISR = (ISHRequest*)request;
 364                 if (strcmp("IS_NAME", request->GetId()) == 0)
 365                 {
 366                         return "gnutls";
 367                 }
 368                 else if (strcmp("IS_HOOK", request->GetId()) == 0)
 369                 {
 370                         const char* ret = "OK";
 371                         try
 372                         {
 373                                 ret = ISR->Sock->AddIOHook((Module*)this) ? "OK" : NULL;
 374                         }
 375                         catch (ModuleException &e)
 376                         {
 377                                 return NULL;
 378                         }
 379                         return ret;
 380                 }
 381                 else if (strcmp("IS_UNHOOK", request->GetId()) == 0)
 382                 {
 383                         return ISR->Sock->DelIOHook() ? "OK" : NULL;
 384                 }
 385                 else if (strcmp("IS_HSDONE", request->GetId()) == 0)
 386                 {
 387                         if (ISR->Sock->GetFd() < 0)
 388                                 return "OK";
 389
 390                         issl_session* session = &sessions[ISR->Sock->GetFd()];
 391                         return (session->status == ISSL_HANDSHAKING_READ || session->status == ISSL_HANDSHAKING_WRITE) ? NULL : "OK";
 392                 }
 393                 else if (strcmp("IS_ATTACH", request->GetId()) == 0)
 394                 {
 395                         if (ISR->Sock->GetFd() > -1)
 396                         {
 397                                 issl_session* session = &sessions[ISR->Sock->GetFd()];
 398                                 if (session->sess)
 399                                 {
 400                                         if ((Extensible*)ServerInstance->FindDescriptor(ISR->Sock->GetFd()) == (Extensible*)(ISR->Sock))
 401                                         {
 402                                                 VerifyCertificate(session, (BufferedSocket*)ISR->Sock);
 403                                                 return "OK";
 404                                         }
 405                                 }
 406                         }
 407                 }
 408                 return NULL;
 409         }
 410
 411
 412         virtual void OnRawSocketAccept(int fd, const std::string &ip, int localport)
 413         {
 414                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 415                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 416                         return;
 417
 418                 issl_session* session = &sessions[fd];
 419
 420                 /* For STARTTLS: Don't try and init a session on a socket that already has a session */
 421                 if (session->sess)
 422                         return;
 423
 424                 session->fd = fd;
 425                 session->inbuf = new char[inbufsize];
 426                 session->inbufoffset = 0;
 427
 428                 gnutls_init(&session->sess, GNUTLS_SERVER);
 429
 430                 gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
 431                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 432                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 433
 434                 /* This is an experimental change to avoid a warning on 64bit systems about casting between integer and pointer of different sizes
 435                  * This needs testing, but it's easy enough to rollback if need be
 436                  * Old: gnutls_transport_set_ptr(session->sess, (gnutls_transport_ptr_t) fd); // Give gnutls the fd for the socket.
 437                  * New: gnutls_transport_set_ptr(session->sess, &fd); // Give gnutls the fd for the socket.
 438                  *
 439                  * With testing this seems to...not work :/
 440                  */
 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);
 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                 session->fd = fd;
 458                 session->inbuf = new char[inbufsize];
 459                 session->inbufoffset = 0;
 460
 461                 gnutls_init(&session->sess, GNUTLS_CLIENT);
 462
 463                 gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
 464                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 465                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 466                 gnutls_transport_set_ptr(session->sess, (gnutls_transport_ptr_t) fd); // Give gnutls the fd for the socket.
 467
 468                 Handshake(session);
 469         }
 470
 471         virtual void OnRawSocketClose(int fd)
 472         {
 473                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 474                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds()))
 475                         return;
 476
 477                 CloseSession(&sessions[fd]);
 478
 479                 EventHandler* user = ServerInstance->SE->GetRef(fd);
 480
 481                 if ((user) && (user->GetExt("ssl_cert", dummy)))
 482                 {
 483                         ssl_cert* tofree;
 484                         user->GetExt("ssl_cert", tofree);
 485                         delete tofree;
 486                         user->Shrink("ssl_cert");
 487                 }
 488         }
 489
 490         virtual int OnRawSocketRead(int fd, char* buffer, unsigned int count, int &readresult)
 491         {
 492                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 493                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 494                         return 0;
 495
 496                 issl_session* session = &sessions[fd];
 497
 498                 if (!session->sess)
 499                 {
 500                         readresult = 0;
 501                         CloseSession(session);
 502                         return 1;
 503                 }
 504
 505                 if (session->status == ISSL_HANDSHAKING_READ)
 506                 {
 507                         // The handshake isn't finished, try to finish it.
 508
 509                         if(!Handshake(session))
 510                         {
 511                                 // Couldn't resume handshake.
 512                                 return -1;
 513                         }
 514                 }
 515                 else if (session->status == ISSL_HANDSHAKING_WRITE)
 516                 {
 517                         errno = EAGAIN;
 518                         MakePollWrite(session);
 519                         return -1;
 520                 }
 521
 522                 // If we resumed the handshake then session->status will be ISSL_HANDSHAKEN.
 523
 524                 if (session->status == ISSL_HANDSHAKEN)
 525                 {
 526                         // Is this right? Not sure if the unencrypted data is garaunteed to be the same length.
 527                         // Read into the inbuffer, offset from the beginning by the amount of data we have that insp hasn't taken yet.
 528                         int ret = gnutls_record_recv(session->sess, session->inbuf + session->inbufoffset, inbufsize - session->inbufoffset);
 529
 530                         if (ret == 0)
 531                         {
 532                                 // Client closed connection.
 533                                 readresult = 0;
 534                                 CloseSession(session);
 535                                 return 1;
 536                         }
 537                         else if (ret < 0)
 538                         {
 539                                 if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 540                                 {
 541                                         errno = EAGAIN;
 542                                         return -1;
 543                                 }
 544                                 else
 545                                 {
 546                                         readresult = 0;
 547                                         CloseSession(session);
 548                                 }
 549                         }
 550                         else
 551                         {
 552                                 // Read successfully 'ret' bytes into inbuf + inbufoffset
 553                                 // There are 'ret' + 'inbufoffset' bytes of data in 'inbuf'
 554                                 // 'buffer' is 'count' long
 555
 556                                 unsigned int length = ret + session->inbufoffset;
 557
 558                                 if(count <= length)
 559                                 {
 560                                         memcpy(buffer, session->inbuf, count);
 561                                         // Move the stuff left in inbuf to the beginning of it
 562                                         memmove(session->inbuf, session->inbuf + count, (length - count));
 563                                         // Now we need to set session->inbufoffset to the amount of data still waiting to be handed to insp.
 564                                         session->inbufoffset = length - count;
 565                                         // Insp uses readresult as the count of how much data there is in buffer, so:
 566                                         readresult = count;
 567                                 }
 568                                 else
 569                                 {
 570                                         // There's not as much in the inbuf as there is space in the buffer, so just copy the whole thing.
 571                                         memcpy(buffer, session->inbuf, length);
 572                                         // Zero the offset, as there's nothing there..
 573                                         session->inbufoffset = 0;
 574                                         // As above
 575                                         readresult = length;
 576                                 }
 577                         }
 578                 }
 579                 else if(session->status == ISSL_CLOSING)
 580                         readresult = 0;
 581
 582                 return 1;
 583         }
 584
 585         virtual int OnRawSocketWrite(int fd, const char* buffer, int count)
 586         {
 587                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 588                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 589                         return 0;
 590
 591                 issl_session* session = &sessions[fd];
 592                 const char* sendbuffer = buffer;
 593
 594                 if (!session->sess)
 595                 {
 596                         CloseSession(session);
 597                         return 1;
 598                 }
 599
 600                 session->outbuf.append(sendbuffer, count);
 601                 sendbuffer = session->outbuf.c_str();
 602                 count = session->outbuf.size();
 603
 604                 if (session->status == ISSL_HANDSHAKING_WRITE)
 605                 {
 606                         // The handshake isn't finished, try to finish it.
 607                         Handshake(session);
 608                         errno = EAGAIN;
 609                         return -1;
 610                 }
 611
 612                 int ret = 0;
 613
 614                 if (session->status == ISSL_HANDSHAKEN)
 615                 {
 616                         ret = gnutls_record_send(session->sess, sendbuffer, count);
 617
 618                         if (ret == 0)
 619                         {
 620                                 CloseSession(session);
 621                         }
 622                         else if (ret < 0)
 623                         {
 624                                 if(ret != GNUTLS_E_AGAIN && ret != GNUTLS_E_INTERRUPTED)
 625                                 {
 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) || ((IS_LOCAL(dest) && (dest->GetIOHook() == this))))
 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                                 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) < time(0)) || (gnutls_x509_crt_get_activation_time(cert) > time(0)))
 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)