src/modules/extra/m_ssl_gnutls.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2010 InspIRCd Development Team
   6  * See: http://wiki.inspircd.org/Credits
   7  *
   8  * This program is free but copyrighted software; see
   9  *          the file COPYING for details.
  10  *
  11  * ---------------------------------------------------
  12  */
  13
  14 #include "inspircd.h"
  15 #include <gnutls/gnutls.h>
  16 #include <gnutls/x509.h>
  17 #include <gcrypt.h>
  18 #include "ssl.h"
  19 #include "m_cap.h"
  20
  21 #ifdef WINDOWS
  22 #pragma comment(lib, "libgnutls-13.lib")
  23 #endif
  24
  25 /* $ModDesc: Provides SSL support for clients */
  26 /* $CompileFlags: pkgconfincludes("gnutls","/gnutls/gnutls.h","") */
  27 /* $LinkerFlags: rpath("pkg-config --libs gnutls") pkgconflibs("gnutls","/libgnutls.so","-lgnutls") */
  28
  29 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING_READ, ISSL_HANDSHAKING_WRITE, ISSL_HANDSHAKEN, ISSL_CLOSING, ISSL_CLOSED };
  30
  31 static gnutls_x509_crt_t x509_cert;
  32 static gnutls_x509_privkey_t x509_key;
  33 static int cert_callback (gnutls_session_t session, const gnutls_datum_t * req_ca_rdn, int nreqs,
  34         const gnutls_pk_algorithm_t * sign_algos, int sign_algos_length, gnutls_retr_st * st) {
  35
  36         st->type = GNUTLS_CRT_X509;
  37         st->ncerts = 1;
  38         st->cert.x509 = &x509_cert;
  39         st->key.x509 = x509_key;
  40         st->deinit_all = 0;
  41
  42         return 0;
  43 }
  44
  45 static ssize_t gnutls_pull_wrapper(gnutls_transport_ptr_t user_wrap, void* buffer, size_t size)
  46 {
  47         StreamSocket* user = reinterpret_cast<StreamSocket*>(user_wrap);
  48         if (user->GetEventMask() & FD_READ_WILL_BLOCK)
  49         {
  50                 errno = EAGAIN;
  51                 return -1;
  52         }
  53         int rv = recv(user->GetFd(), buffer, size, 0);
  54         if (rv < (int)size)
  55                 ServerInstance->SE->ChangeEventMask(user, FD_READ_WILL_BLOCK);
  56         return rv;
  57 }
  58
  59 static ssize_t gnutls_push_wrapper(gnutls_transport_ptr_t user_wrap, const void* buffer, size_t size)
  60 {
  61         StreamSocket* user = reinterpret_cast<StreamSocket*>(user_wrap);
  62         if (user->GetEventMask() & FD_WRITE_WILL_BLOCK)
  63         {
  64                 errno = EAGAIN;
  65                 return -1;
  66         }
  67         int rv = send(user->GetFd(), buffer, size, 0);
  68         if (rv < (int)size)
  69                 ServerInstance->SE->ChangeEventMask(user, FD_WRITE_WILL_BLOCK);
  70         return rv;
  71 }
  72
  73 class RandGen : public HandlerBase2<void, char*, size_t>
  74 {
  75  public:
  76         RandGen() {}
  77         void Call(char* buffer, size_t len)
  78         {
  79                 gcry_randomize(buffer, len, GCRY_STRONG_RANDOM);
  80         }
  81 };
  82
  83 /** Represents an SSL user's extra data
  84  */
  85 class issl_session
  86 {
  87 public:
  88         gnutls_session_t sess;
  89         issl_status status;
  90         reference<ssl_cert> cert;
  91         issl_session() : sess(NULL) {}
  92 };
  93
  94 class CommandStartTLS : public SplitCommand
  95 {
  96  public:
  97         bool enabled;
  98         CommandStartTLS (Module* mod) : SplitCommand(mod, "STARTTLS")
  99         {
 100                 enabled = true;
 101                 works_before_reg = true;
 102         }
 103
 104         CmdResult HandleLocal(const std::vector<std::string> &parameters, LocalUser *user)
 105         {
 106                 if (!enabled)
 107                 {
 108                         user->WriteNumeric(691, "%s :STARTTLS is not enabled", user->nick.c_str());
 109                         return CMD_FAILURE;
 110                 }
 111
 112                 if (user->registered == REG_ALL)
 113                 {
 114                         user->WriteNumeric(691, "%s :STARTTLS is not permitted after client registration is complete", user->nick.c_str());
 115                 }
 116                 else
 117                 {
 118                         if (!user->eh.GetIOHook())
 119                         {
 120                                 user->WriteNumeric(670, "%s :STARTTLS successful, go ahead with TLS handshake", user->nick.c_str());
 121                                 /* We need to flush the write buffer prior to adding the IOHook,
 122                                  * otherwise we'll be sending this line inside the SSL session - which
 123                                  * won't start its handshake until the client gets this line. Currently,
 124                                  * we assume the write will not block here; this is usually safe, as
 125                                  * STARTTLS is sent very early on in the registration phase, where the
 126                                  * user hasn't built up much sendq. Handling a blocked write here would
 127                                  * be very annoying.
 128                                  */
 129                                 user->eh.DoWrite();
 130                                 user->eh.AddIOHook(creator);
 131                                 creator->OnStreamSocketAccept(&user->eh, NULL, NULL);
 132                         }
 133                         else
 134                                 user->WriteNumeric(691, "%s :STARTTLS failure", user->nick.c_str());
 135                 }
 136
 137                 return CMD_FAILURE;
 138         }
 139 };
 140
 141 class ModuleSSLGnuTLS : public Module
 142 {
 143         issl_session* sessions;
 144
 145         gnutls_certificate_credentials x509_cred;
 146         gnutls_dh_params dh_params;
 147         gnutls_digest_algorithm_t hash;
 148
 149         std::string sslports;
 150         int dh_bits;
 151
 152         bool cred_alloc;
 153
 154         RandGen randhandler;
 155         CommandStartTLS starttls;
 156
 157         GenericCap capHandler;
 158         ServiceProvider iohook;
 159  public:
 160
 161         ModuleSSLGnuTLS()
 162                 : starttls(this), capHandler(this, "tls"), iohook(this, "ssl/gnutls", SERVICE_IOHOOK)
 163         {
 164                 sessions = new issl_session[ServerInstance->SE->GetMaxFds()];
 165
 166                 gnutls_global_init(); // This must be called once in the program
 167                 gnutls_x509_crt_init(&x509_cert);
 168                 gnutls_x509_privkey_init(&x509_key);
 169
 170                 cred_alloc = false;
 171         }
 172
 173         void init()
 174         {
 175                 // Needs the flag as it ignores a plain /rehash
 176                 OnModuleRehash(NULL,"ssl");
 177
 178                 ServerInstance->GenRandom = &randhandler;
 179
 180                 // Void return, guess we assume success
 181                 gnutls_certificate_set_dh_params(x509_cred, dh_params);
 182                 Implementation eventlist[] = { I_On005Numeric, I_OnRehash, I_OnModuleRehash, I_OnUserConnect,
 183                         I_OnEvent, I_OnHookIO };
 184                 ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
 185
 186                 ServerInstance->Modules->AddService(iohook);
 187                 ServerInstance->AddCommand(&starttls);
 188         }
 189
 190         void OnRehash(User* user)
 191         {
 192                 sslports.clear();
 193
 194                 ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
 195                 starttls.enabled = Conf->getBool("starttls", true);
 196
 197                 if (Conf->getBool("showports", true))
 198                 {
 199                         for (size_t i = 0; i < ServerInstance->ports.size(); i++)
 200                         {
 201                                 ListenSocket* port = ServerInstance->ports[i];
 202                                 if (port->bind_tag->getString("ssl") != "gnutls")
 203                                         continue;
 204
 205                                 const std::string& portid = port->bind_desc;
 206                                 ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT, "m_ssl_gnutls.so: Enabling SSL for port %s", portid.c_str());
 207
 208                                 if (port->bind_tag->getString("type", "clients") == "clients" && port->bind_addr != "127.0.0.1")
 209                                         sslports.append(portid).append(";");
 210                         }
 211
 212                         if (!sslports.empty())
 213                                 sslports.erase(sslports.end() - 1);
 214                 }
 215         }
 216
 217         void OnModuleRehash(User* user, const std::string &param)
 218         {
 219                 if(param != "ssl")
 220                         return;
 221
 222                 std::string keyfile;
 223                 std::string certfile;
 224                 std::string cafile;
 225                 std::string crlfile;
 226                 OnRehash(user);
 227
 228                 ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
 229
 230                 cafile = Conf->getString("cafile", "conf/ca.pem");
 231                 crlfile = Conf->getString("crlfile", "conf/crl.pem");
 232                 certfile = Conf->getString("certfile", "conf/cert.pem");
 233                 keyfile = Conf->getString("keyfile", "conf/key.pem");
 234                 dh_bits = Conf->getInt("dhbits");
 235                 std::string hashname = Conf->getString("hash", "md5");
 236
 237                 if((dh_bits != 768) && (dh_bits != 1024) && (dh_bits != 2048) && (dh_bits != 3072) && (dh_bits != 4096))
 238                         dh_bits = 1024;
 239
 240                 if (hashname == "md5")
 241                         hash = GNUTLS_DIG_MD5;
 242                 else if (hashname == "sha1")
 243                         hash = GNUTLS_DIG_SHA1;
 244                 else
 245                         throw ModuleException("Unknown hash type " + hashname);
 246
 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",DEBUG, "m_ssl_gnutls.so: Failed to allocate certificate credentials: %s", gnutls_strerror(ret));
 261
 262                 if((ret =gnutls_certificate_set_x509_trust_file(x509_cred, cafile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 263                         ServerInstance->Logs->Log("m_ssl_gnutls",DEBUG, "m_ssl_gnutls.so: Failed to set X.509 trust file '%s': %s", cafile.c_str(), gnutls_strerror(ret));
 264
 265                 if((ret = gnutls_certificate_set_x509_crl_file (x509_cred, crlfile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 266                         ServerInstance->Logs->Log("m_ssl_gnutls",DEBUG, "m_ssl_gnutls.so: Failed to set X.509 CRL file '%s': %s", crlfile.c_str(), gnutls_strerror(ret));
 267
 268                 FileReader reader;
 269
 270                 reader.LoadFile(certfile);
 271                 std::string cert_string = reader.Contents();
 272                 gnutls_datum_t cert_datum = { (unsigned char*)cert_string.data(), cert_string.length() };
 273
 274                 reader.LoadFile(keyfile);
 275                 std::string key_string = reader.Contents();
 276                 gnutls_datum_t key_datum = { (unsigned char*)key_string.data(), key_string.length() };
 277
 278                 // If this fails, no SSL port will work. At all. So, do the smart thing - throw a ModuleException
 279                 if((ret = gnutls_x509_crt_import(x509_cert, &cert_datum, GNUTLS_X509_FMT_PEM)) < 0)
 280                         throw ModuleException("Unable to load GnuTLS server certificate (" + certfile + "): " + std::string(gnutls_strerror(ret)));
 281
 282                 if((ret = gnutls_x509_privkey_import(x509_key, &key_datum, GNUTLS_X509_FMT_PEM)) < 0)
 283                         throw ModuleException("Unable to load GnuTLS server private key (" + keyfile + "): " + std::string(gnutls_strerror(ret)));
 284
 285                 if((ret = gnutls_certificate_set_x509_key(x509_cred, &x509_cert, 1, x509_key)) < 0)
 286                         throw ModuleException("Unable to set GnuTLS cert/key pair: " + std::string(gnutls_strerror(ret)));
 287
 288                 gnutls_certificate_client_set_retrieve_function (x509_cred, cert_callback);
 289
 290                 if((ret = gnutls_dh_params_init(&dh_params)) < 0)
 291                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to initialise DH parameters: %s", gnutls_strerror(ret));
 292
 293                 // This may be on a large (once a day or week) timer eventually.
 294                 GenerateDHParams();
 295         }
 296
 297         void GenerateDHParams()
 298         {
 299                 // Generate Diffie Hellman parameters - for use with DHE
 300                 // kx algorithms. These should be discarded and regenerated
 301                 // once a day, once a week or once a month. Depending on the
 302                 // security requirements.
 303
 304                 int ret;
 305
 306                 if((ret = gnutls_dh_params_generate2(dh_params, dh_bits)) < 0)
 307                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to generate DH parameters (%d bits): %s", dh_bits, gnutls_strerror(ret));
 308         }
 309
 310         ~ModuleSSLGnuTLS()
 311         {
 312                 gnutls_x509_crt_deinit(x509_cert);
 313                 gnutls_x509_privkey_deinit(x509_key);
 314                 if (cred_alloc)
 315                 {
 316                         gnutls_dh_params_deinit(dh_params);
 317                         gnutls_certificate_free_credentials(x509_cred);
 318                 }
 319                 gnutls_global_deinit();
 320                 delete[] sessions;
 321                 ServerInstance->GenRandom = &ServerInstance->HandleGenRandom;
 322         }
 323
 324         void OnCleanup(int target_type, void* item)
 325         {
 326                 if(target_type == TYPE_USER)
 327                 {
 328                         LocalUser* user = IS_LOCAL(static_cast<User*>(item));
 329
 330                         if (user && user->eh.GetIOHook() == this)
 331                         {
 332                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 333                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 334                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 335                         }
 336                 }
 337         }
 338
 339         Version GetVersion()
 340         {
 341                 return Version("Provides SSL support for clients", VF_VENDOR);
 342         }
 343
 344
 345         void On005Numeric(std::string &output)
 346         {
 347                 if (!sslports.empty())
 348                         output.append(" SSL=" + sslports);
 349                 if (starttls.enabled)
 350                         output.append(" STARTTLS");
 351         }
 352
 353         void OnHookIO(StreamSocket* user, ListenSocket* lsb)
 354         {
 355                 if (!user->GetIOHook() && lsb->bind_tag->getString("ssl") == "gnutls")
 356                 {
 357                         /* Hook the user with our module */
 358                         user->AddIOHook(this);
 359                 }
 360         }
 361
 362         void OnRequest(Request& request)
 363         {
 364                 if (strcmp("GET_SSL_CERT", request.id) == 0)
 365                 {
 366                         SocketCertificateRequest& req = static_cast<SocketCertificateRequest&>(request);
 367                         int fd = req.sock->GetFd();
 368                         issl_session* session = &sessions[fd];
 369
 370                         req.cert = session->cert;
 371                 }
 372         }
 373
 374         void OnStreamSocketAccept(StreamSocket* user, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server)
 375         {
 376                 int fd = user->GetFd();
 377                 issl_session* session = &sessions[fd];
 378
 379                 /* For STARTTLS: Don't try and init a session on a socket that already has a session */
 380                 if (session->sess)
 381                         return;
 382
 383                 gnutls_init(&session->sess, GNUTLS_SERVER);
 384
 385                 gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
 386                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 387                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 388
 389                 gnutls_transport_set_ptr(session->sess, reinterpret_cast<gnutls_transport_ptr_t>(user));
 390                 gnutls_transport_set_push_function(session->sess, gnutls_push_wrapper);
 391                 gnutls_transport_set_pull_function(session->sess, gnutls_pull_wrapper);
 392
 393                 gnutls_certificate_server_set_request(session->sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
 394
 395                 Handshake(session, user);
 396         }
 397
 398         void OnStreamSocketConnect(StreamSocket* user)
 399         {
 400                 issl_session* session = &sessions[user->GetFd()];
 401
 402                 gnutls_init(&session->sess, GNUTLS_CLIENT);
 403
 404                 gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
 405                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 406                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 407                 gnutls_transport_set_ptr(session->sess, reinterpret_cast<gnutls_transport_ptr_t>(user));
 408                 gnutls_transport_set_push_function(session->sess, gnutls_push_wrapper);
 409                 gnutls_transport_set_pull_function(session->sess, gnutls_pull_wrapper);
 410
 411                 Handshake(session, user);
 412         }
 413
 414         void OnStreamSocketClose(StreamSocket* user)
 415         {
 416                 CloseSession(&sessions[user->GetFd()]);
 417         }
 418
 419         int OnStreamSocketRead(StreamSocket* user, std::string& recvq)
 420         {
 421                 issl_session* session = &sessions[user->GetFd()];
 422
 423                 if (!session->sess)
 424                 {
 425                         CloseSession(session);
 426                         user->SetError("No SSL session");
 427                         return -1;
 428                 }
 429
 430                 if (session->status == ISSL_HANDSHAKING_READ || session->status == ISSL_HANDSHAKING_WRITE)
 431                 {
 432                         // The handshake isn't finished, try to finish it.
 433
 434                         if(!Handshake(session, user))
 435                         {
 436                                 if (session->status != ISSL_CLOSING)
 437                                         return 0;
 438                                 return -1;
 439                         }
 440                 }
 441
 442                 // If we resumed the handshake then session->status will be ISSL_HANDSHAKEN.
 443
 444                 if (session->status == ISSL_HANDSHAKEN)
 445                 {
 446                         char* buffer = ServerInstance->GetReadBuffer();
 447                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 448                         int ret = gnutls_record_recv(session->sess, buffer, bufsiz);
 449                         if (ret > 0)
 450                         {
 451                                 recvq.append(buffer, ret);
 452                                 return 1;
 453                         }
 454                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 455                         {
 456                                 return 0;
 457                         }
 458                         else if (ret == 0)
 459                         {
 460                                 user->SetError("SSL Connection closed");
 461                                 CloseSession(session);
 462                                 return -1;
 463                         }
 464                         else
 465                         {
 466                                 user->SetError(gnutls_strerror(ret));
 467                                 CloseSession(session);
 468                                 return -1;
 469                         }
 470                 }
 471                 else if (session->status == ISSL_CLOSING)
 472                         return -1;
 473
 474                 return 0;
 475         }
 476
 477         int OnStreamSocketWrite(StreamSocket* user, std::string& sendq)
 478         {
 479                 issl_session* session = &sessions[user->GetFd()];
 480
 481                 if (!session->sess)
 482                 {
 483                         CloseSession(session);
 484                         user->SetError("No SSL session");
 485                         return -1;
 486                 }
 487
 488                 if (session->status == ISSL_HANDSHAKING_WRITE || session->status == ISSL_HANDSHAKING_READ)
 489                 {
 490                         // The handshake isn't finished, try to finish it.
 491                         Handshake(session, user);
 492                         if (session->status != ISSL_CLOSING)
 493                                 return 0;
 494                         return -1;
 495                 }
 496
 497                 int ret = 0;
 498
 499                 if (session->status == ISSL_HANDSHAKEN)
 500                 {
 501                         ret = gnutls_record_send(session->sess, sendq.data(), sendq.length());
 502
 503                         if (ret == (int)sendq.length())
 504                         {
 505                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_WRITE);
 506                                 return 1;
 507                         }
 508                         else if (ret > 0)
 509                         {
 510                                 sendq = sendq.substr(ret);
 511                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 512                                 return 0;
 513                         }
 514                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 515                         {
 516                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 517                                 return 0;
 518                         }
 519                         else if (ret == 0)
 520                         {
 521                                 CloseSession(session);
 522                                 user->SetError("SSL Connection closed");
 523                                 return -1;
 524                         }
 525                         else // (ret < 0)
 526                         {
 527                                 user->SetError(gnutls_strerror(ret));
 528                                 CloseSession(session);
 529                                 return -1;
 530                         }
 531                 }
 532
 533                 return 0;
 534         }
 535
 536         bool Handshake(issl_session* session, StreamSocket* user)
 537         {
 538                 int ret = gnutls_handshake(session->sess);
 539
 540                 if (ret < 0)
 541                 {
 542                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 543                         {
 544                                 // Handshake needs resuming later, read() or write() would have blocked.
 545
 546                                 if(gnutls_record_get_direction(session->sess) == 0)
 547                                 {
 548                                         // gnutls_handshake() wants to read() again.
 549                                         session->status = ISSL_HANDSHAKING_READ;
 550                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 551                                 }
 552                                 else
 553                                 {
 554                                         // gnutls_handshake() wants to write() again.
 555                                         session->status = ISSL_HANDSHAKING_WRITE;
 556                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 557                                 }
 558                         }
 559                         else
 560                         {
 561                                 user->SetError(std::string("Handshake Failed - ") + gnutls_strerror(ret));
 562                                 CloseSession(session);
 563                                 session->status = ISSL_CLOSING;
 564                         }
 565
 566                         return false;
 567                 }
 568                 else
 569                 {
 570                         // Change the seesion state
 571                         session->status = ISSL_HANDSHAKEN;
 572
 573                         VerifyCertificate(session,user);
 574
 575                         // Finish writing, if any left
 576                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 577
 578                         return true;
 579                 }
 580         }
 581
 582         void OnUserConnect(LocalUser* user)
 583         {
 584                 if (user->eh.GetIOHook() == this)
 585                 {
 586                         if (sessions[user->eh.GetFd()].sess)
 587                         {
 588                                 ssl_cert* cert = sessions[user->eh.GetFd()].cert;
 589                                 std::string cipher = gnutls_kx_get_name(gnutls_kx_get(sessions[user->eh.GetFd()].sess));
 590                                 cipher.append("-").append(gnutls_cipher_get_name(gnutls_cipher_get(sessions[user->eh.GetFd()].sess))).append("-");
 591                                 cipher.append(gnutls_mac_get_name(gnutls_mac_get(sessions[user->eh.GetFd()].sess)));
 592                                 if (cert->fingerprint.empty())
 593                                         user->WriteServ("NOTICE %s :*** You are connected using SSL cipher \"%s\"", user->nick.c_str(), cipher.c_str());
 594                                 else
 595                                         user->WriteServ("NOTICE %s :*** You are connected using SSL cipher \"%s\""
 596                                                 " and your SSL fingerprint is %s", user->nick.c_str(), cipher.c_str(), cert->fingerprint.c_str());
 597                         }
 598                 }
 599         }
 600
 601         void CloseSession(issl_session* session)
 602         {
 603                 if (session->sess)
 604                 {
 605                         gnutls_bye(session->sess, GNUTLS_SHUT_WR);
 606                         gnutls_deinit(session->sess);
 607                 }
 608                 session->sess = NULL;
 609                 session->cert = NULL;
 610                 session->status = ISSL_NONE;
 611         }
 612
 613         void VerifyCertificate(issl_session* session, StreamSocket* user)
 614         {
 615                 if (!session->sess || !user || session->cert)
 616                         return;
 617
 618                 unsigned int status;
 619                 const gnutls_datum_t* cert_list;
 620                 int ret;
 621                 unsigned int cert_list_size;
 622                 gnutls_x509_crt_t cert;
 623                 char name[MAXBUF];
 624                 unsigned char digest[MAXBUF];
 625                 size_t digest_size = sizeof(digest);
 626                 size_t name_size = sizeof(name);
 627                 ssl_cert* certinfo = new ssl_cert;
 628                 session->cert = certinfo;
 629
 630                 /* This verification function uses the trusted CAs in the credentials
 631                  * structure. So you must have installed one or more CA certificates.
 632                  */
 633                 ret = gnutls_certificate_verify_peers2(session->sess, &status);
 634
 635                 if (ret < 0)
 636                 {
 637                         certinfo->error = std::string(gnutls_strerror(ret));
 638                         return;
 639                 }
 640
 641                 certinfo->invalid = (status & GNUTLS_CERT_INVALID);
 642                 certinfo->unknownsigner = (status & GNUTLS_CERT_SIGNER_NOT_FOUND);
 643                 certinfo->revoked = (status & GNUTLS_CERT_REVOKED);
 644                 certinfo->trusted = !(status & GNUTLS_CERT_SIGNER_NOT_CA);
 645
 646                 /* Up to here the process is the same for X.509 certificates and
 647                  * OpenPGP keys. From now on X.509 certificates are assumed. This can
 648                  * be easily extended to work with openpgp keys as well.
 649                  */
 650                 if (gnutls_certificate_type_get(session->sess) != GNUTLS_CRT_X509)
 651                 {
 652                         certinfo->error = "No X509 keys sent";
 653                         return;
 654                 }
 655
 656                 ret = gnutls_x509_crt_init(&cert);
 657                 if (ret < 0)
 658                 {
 659                         certinfo->error = gnutls_strerror(ret);
 660                         return;
 661                 }
 662
 663                 cert_list_size = 0;
 664                 cert_list = gnutls_certificate_get_peers(session->sess, &cert_list_size);
 665                 if (cert_list == NULL)
 666                 {
 667                         certinfo->error = "No certificate was found";
 668                         goto info_done_dealloc;
 669                 }
 670
 671                 /* This is not a real world example, since we only check the first
 672                  * certificate in the given chain.
 673                  */
 674
 675                 ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
 676                 if (ret < 0)
 677                 {
 678                         certinfo->error = gnutls_strerror(ret);
 679                         goto info_done_dealloc;
 680                 }
 681
 682                 gnutls_x509_crt_get_dn(cert, name, &name_size);
 683                 certinfo->dn = name;
 684
 685                 gnutls_x509_crt_get_issuer_dn(cert, name, &name_size);
 686                 certinfo->issuer = name;
 687
 688                 if ((ret = gnutls_x509_crt_get_fingerprint(cert, hash, digest, &digest_size)) < 0)
 689                 {
 690                         certinfo->error = gnutls_strerror(ret);
 691                 }
 692                 else
 693                 {
 694                         certinfo->fingerprint = irc::hex(digest, digest_size);
 695                 }
 696
 697                 /* Beware here we do not check for errors.
 698                  */
 699                 if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
 700                 {
 701                         certinfo->error = "Not activated, or expired certificate";
 702                 }
 703
 704 info_done_dealloc:
 705                 gnutls_x509_crt_deinit(cert);
 706         }
 707
 708         void OnEvent(Event& ev)
 709         {
 710                 if (starttls.enabled)
 711                         capHandler.HandleEvent(ev);
 712         }
 713 };
 714
 715 MODULE_INIT(ModuleSSLGnuTLS)