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 std::vector<gnutls_x509_crt_t> x509_certs;
  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 = x509_certs.size();
  38         st->cert.x509 = &x509_certs[0];
  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_privkey_init(&x509_key);
 168
 169                 cred_alloc = false;
 170         }
 171
 172         void init()
 173         {
 174                 // Needs the flag as it ignores a plain /rehash
 175                 OnModuleRehash(NULL,"ssl");
 176
 177                 ServerInstance->GenRandom = &randhandler;
 178
 179                 // Void return, guess we assume success
 180                 gnutls_certificate_set_dh_params(x509_cred, dh_params);
 181                 Implementation eventlist[] = { I_On005Numeric, I_OnRehash, I_OnModuleRehash, I_OnUserConnect,
 182                         I_OnEvent, I_OnHookIO };
 183                 ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
 184
 185                 ServerInstance->Modules->AddService(iohook);
 186                 ServerInstance->AddCommand(&starttls);
 187         }
 188
 189         void OnRehash(User* user)
 190         {
 191                 sslports.clear();
 192
 193                 ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
 194                 starttls.enabled = Conf->getBool("starttls", true);
 195
 196                 if (Conf->getBool("showports", true))
 197                 {
 198                         for (size_t i = 0; i < ServerInstance->ports.size(); i++)
 199                         {
 200                                 ListenSocket* port = ServerInstance->ports[i];
 201                                 if (port->bind_tag->getString("ssl") != "gnutls")
 202                                         continue;
 203
 204                                 const std::string& portid = port->bind_desc;
 205                                 ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT, "m_ssl_gnutls.so: Enabling SSL for port %s", portid.c_str());
 206
 207                                 if (port->bind_tag->getString("type", "clients") == "clients" && port->bind_addr != "127.0.0.1")
 208                                         sslports.append(portid).append(";");
 209                         }
 210
 211                         if (!sslports.empty())
 212                                 sslports.erase(sslports.end() - 1);
 213                 }
 214         }
 215
 216         void OnModuleRehash(User* user, const std::string &param)
 217         {
 218                 if(param != "ssl")
 219                         return;
 220
 221                 std::string keyfile;
 222                 std::string certfile;
 223                 std::string cafile;
 224                 std::string crlfile;
 225                 OnRehash(user);
 226
 227                 ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
 228
 229                 cafile = Conf->getString("cafile", "conf/ca.pem");
 230                 crlfile = Conf->getString("crlfile", "conf/crl.pem");
 231                 certfile = Conf->getString("certfile", "conf/cert.pem");
 232                 keyfile = Conf->getString("keyfile", "conf/key.pem");
 233                 dh_bits = Conf->getInt("dhbits");
 234                 std::string hashname = Conf->getString("hash", "md5");
 235
 236                 if((dh_bits != 768) && (dh_bits != 1024) && (dh_bits != 2048) && (dh_bits != 3072) && (dh_bits != 4096))
 237                         dh_bits = 1024;
 238
 239                 if (hashname == "md5")
 240                         hash = GNUTLS_DIG_MD5;
 241                 else if (hashname == "sha1")
 242                         hash = GNUTLS_DIG_SHA1;
 243                 else
 244                         throw ModuleException("Unknown hash type " + hashname);
 245
 246
 247                 int ret;
 248
 249                 if (cred_alloc)
 250                 {
 251                         // Deallocate the old credentials
 252                         gnutls_dh_params_deinit(dh_params);
 253                         gnutls_certificate_free_credentials(x509_cred);
 254
 255                         for(unsigned int i=0; i < x509_certs.size(); i++)
 256                                 gnutls_x509_crt_deinit(x509_certs[i]);
 257                         x509_certs.clear();
 258                 }
 259                 else
 260                         cred_alloc = true;
 261
 262                 if((ret = gnutls_certificate_allocate_credentials(&x509_cred)) < 0)
 263                         ServerInstance->Logs->Log("m_ssl_gnutls",DEBUG, "m_ssl_gnutls.so: Failed to allocate certificate credentials: %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",DEBUG, "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",DEBUG, "m_ssl_gnutls.so: Failed to set X.509 CRL file '%s': %s", crlfile.c_str(), gnutls_strerror(ret));
 270
 271                 FileReader reader;
 272
 273                 reader.LoadFile(certfile);
 274                 std::string cert_string = reader.Contents();
 275                 gnutls_datum_t cert_datum = { (unsigned char*)cert_string.data(), cert_string.length() };
 276
 277                 reader.LoadFile(keyfile);
 278                 std::string key_string = reader.Contents();
 279                 gnutls_datum_t key_datum = { (unsigned char*)key_string.data(), key_string.length() };
 280
 281                 // If this fails, no SSL port will work. At all. So, do the smart thing - throw a ModuleException
 282                 unsigned int certcount = Conf->getInt("certcount", 3);
 283                 x509_certs.resize(certcount);
 284                 ret = gnutls_x509_crt_list_import(&x509_certs[0], &certcount, &cert_datum, GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 285                 if (ret < 0)
 286                         throw ModuleException("Unable to load GnuTLS server certificate (" + certfile + "): " + std::string(gnutls_strerror(ret)));
 287                 x509_certs.resize(certcount);
 288
 289                 if((ret = gnutls_x509_privkey_import(x509_key, &key_datum, GNUTLS_X509_FMT_PEM)) < 0)
 290                         throw ModuleException("Unable to load GnuTLS server private key (" + keyfile + "): " + std::string(gnutls_strerror(ret)));
 291
 292                 if((ret = gnutls_certificate_set_x509_key(x509_cred, &x509_certs[0], certcount, x509_key)) < 0)
 293                         throw ModuleException("Unable to set GnuTLS cert/key pair: " + std::string(gnutls_strerror(ret)));
 294
 295                 gnutls_certificate_client_set_retrieve_function (x509_cred, cert_callback);
 296
 297                 if((ret = gnutls_dh_params_init(&dh_params)) < 0)
 298                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to initialise DH parameters: %s", gnutls_strerror(ret));
 299
 300                 // This may be on a large (once a day or week) timer eventually.
 301                 GenerateDHParams();
 302         }
 303
 304         void GenerateDHParams()
 305         {
 306                 // Generate Diffie Hellman parameters - for use with DHE
 307                 // kx algorithms. These should be discarded and regenerated
 308                 // once a day, once a week or once a month. Depending on the
 309                 // security requirements.
 310
 311                 int ret;
 312
 313                 if((ret = gnutls_dh_params_generate2(dh_params, dh_bits)) < 0)
 314                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to generate DH parameters (%d bits): %s", dh_bits, gnutls_strerror(ret));
 315         }
 316
 317         ~ModuleSSLGnuTLS()
 318         {
 319                 for(unsigned int i=0; i < x509_certs.size(); i++)
 320                         gnutls_x509_crt_deinit(x509_certs[i]);
 321                 x509_certs.clear();
 322                 gnutls_x509_privkey_deinit(x509_key);
 323                 if (cred_alloc)
 324                 {
 325                         gnutls_dh_params_deinit(dh_params);
 326                         gnutls_certificate_free_credentials(x509_cred);
 327                 }
 328                 gnutls_global_deinit();
 329                 delete[] sessions;
 330                 ServerInstance->GenRandom = &ServerInstance->HandleGenRandom;
 331         }
 332
 333         void OnCleanup(int target_type, void* item)
 334         {
 335                 if(target_type == TYPE_USER)
 336                 {
 337                         LocalUser* user = IS_LOCAL(static_cast<User*>(item));
 338
 339                         if (user && user->eh.GetIOHook() == this)
 340                         {
 341                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 342                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 343                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 344                         }
 345                 }
 346         }
 347
 348         Version GetVersion()
 349         {
 350                 return Version("Provides SSL support for clients", VF_VENDOR);
 351         }
 352
 353
 354         void On005Numeric(std::string &output)
 355         {
 356                 if (!sslports.empty())
 357                         output.append(" SSL=" + sslports);
 358                 if (starttls.enabled)
 359                         output.append(" STARTTLS");
 360         }
 361
 362         void OnHookIO(StreamSocket* user, ListenSocket* lsb)
 363         {
 364                 if (!user->GetIOHook() && lsb->bind_tag->getString("ssl") == "gnutls")
 365                 {
 366                         /* Hook the user with our module */
 367                         user->AddIOHook(this);
 368                 }
 369         }
 370
 371         void OnRequest(Request& request)
 372         {
 373                 if (strcmp("GET_SSL_CERT", request.id) == 0)
 374                 {
 375                         SocketCertificateRequest& req = static_cast<SocketCertificateRequest&>(request);
 376                         int fd = req.sock->GetFd();
 377                         issl_session* session = &sessions[fd];
 378
 379                         req.cert = session->cert;
 380                 }
 381         }
 382
 383         void OnStreamSocketAccept(StreamSocket* user, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server)
 384         {
 385                 int fd = user->GetFd();
 386                 issl_session* session = &sessions[fd];
 387
 388                 /* For STARTTLS: Don't try and init a session on a socket that already has a session */
 389                 if (session->sess)
 390                         return;
 391
 392                 gnutls_init(&session->sess, GNUTLS_SERVER);
 393
 394                 gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
 395                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 396                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 397
 398                 gnutls_transport_set_ptr(session->sess, reinterpret_cast<gnutls_transport_ptr_t>(user));
 399                 gnutls_transport_set_push_function(session->sess, gnutls_push_wrapper);
 400                 gnutls_transport_set_pull_function(session->sess, gnutls_pull_wrapper);
 401
 402                 gnutls_certificate_server_set_request(session->sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
 403
 404                 Handshake(session, user);
 405         }
 406
 407         void OnStreamSocketConnect(StreamSocket* user)
 408         {
 409                 issl_session* session = &sessions[user->GetFd()];
 410
 411                 gnutls_init(&session->sess, GNUTLS_CLIENT);
 412
 413                 gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
 414                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 415                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 416                 gnutls_transport_set_ptr(session->sess, reinterpret_cast<gnutls_transport_ptr_t>(user));
 417                 gnutls_transport_set_push_function(session->sess, gnutls_push_wrapper);
 418                 gnutls_transport_set_pull_function(session->sess, gnutls_pull_wrapper);
 419
 420                 Handshake(session, user);
 421         }
 422
 423         void OnStreamSocketClose(StreamSocket* user)
 424         {
 425                 CloseSession(&sessions[user->GetFd()]);
 426         }
 427
 428         int OnStreamSocketRead(StreamSocket* user, std::string& recvq)
 429         {
 430                 issl_session* session = &sessions[user->GetFd()];
 431
 432                 if (!session->sess)
 433                 {
 434                         CloseSession(session);
 435                         user->SetError("No SSL session");
 436                         return -1;
 437                 }
 438
 439                 if (session->status == ISSL_HANDSHAKING_READ || session->status == ISSL_HANDSHAKING_WRITE)
 440                 {
 441                         // The handshake isn't finished, try to finish it.
 442
 443                         if(!Handshake(session, user))
 444                         {
 445                                 if (session->status != ISSL_CLOSING)
 446                                         return 0;
 447                                 return -1;
 448                         }
 449                 }
 450
 451                 // If we resumed the handshake then session->status will be ISSL_HANDSHAKEN.
 452
 453                 if (session->status == ISSL_HANDSHAKEN)
 454                 {
 455                         char* buffer = ServerInstance->GetReadBuffer();
 456                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 457                         int ret = gnutls_record_recv(session->sess, buffer, bufsiz);
 458                         if (ret > 0)
 459                         {
 460                                 recvq.append(buffer, ret);
 461                                 return 1;
 462                         }
 463                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 464                         {
 465                                 return 0;
 466                         }
 467                         else if (ret == 0)
 468                         {
 469                                 user->SetError("SSL Connection closed");
 470                                 CloseSession(session);
 471                                 return -1;
 472                         }
 473                         else
 474                         {
 475                                 user->SetError(gnutls_strerror(ret));
 476                                 CloseSession(session);
 477                                 return -1;
 478                         }
 479                 }
 480                 else if (session->status == ISSL_CLOSING)
 481                         return -1;
 482
 483                 return 0;
 484         }
 485
 486         int OnStreamSocketWrite(StreamSocket* user, std::string& sendq)
 487         {
 488                 issl_session* session = &sessions[user->GetFd()];
 489
 490                 if (!session->sess)
 491                 {
 492                         CloseSession(session);
 493                         user->SetError("No SSL session");
 494                         return -1;
 495                 }
 496
 497                 if (session->status == ISSL_HANDSHAKING_WRITE || session->status == ISSL_HANDSHAKING_READ)
 498                 {
 499                         // The handshake isn't finished, try to finish it.
 500                         Handshake(session, user);
 501                         if (session->status != ISSL_CLOSING)
 502                                 return 0;
 503                         return -1;
 504                 }
 505
 506                 int ret = 0;
 507
 508                 if (session->status == ISSL_HANDSHAKEN)
 509                 {
 510                         ret = gnutls_record_send(session->sess, sendq.data(), sendq.length());
 511
 512                         if (ret == (int)sendq.length())
 513                         {
 514                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_WRITE);
 515                                 return 1;
 516                         }
 517                         else if (ret > 0)
 518                         {
 519                                 sendq = sendq.substr(ret);
 520                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 521                                 return 0;
 522                         }
 523                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED || ret == 0)
 524                         {
 525                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 526                                 return 0;
 527                         }
 528                         else // (ret < 0)
 529                         {
 530                                 user->SetError(gnutls_strerror(ret));
 531                                 CloseSession(session);
 532                                 return -1;
 533                         }
 534                 }
 535
 536                 return 0;
 537         }
 538
 539         bool Handshake(issl_session* session, StreamSocket* user)
 540         {
 541                 int ret = gnutls_handshake(session->sess);
 542
 543                 if (ret < 0)
 544                 {
 545                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 546                         {
 547                                 // Handshake needs resuming later, read() or write() would have blocked.
 548
 549                                 if(gnutls_record_get_direction(session->sess) == 0)
 550                                 {
 551                                         // gnutls_handshake() wants to read() again.
 552                                         session->status = ISSL_HANDSHAKING_READ;
 553                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 554                                 }
 555                                 else
 556                                 {
 557                                         // gnutls_handshake() wants to write() again.
 558                                         session->status = ISSL_HANDSHAKING_WRITE;
 559                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 560                                 }
 561                         }
 562                         else
 563                         {
 564                                 user->SetError(std::string("Handshake Failed - ") + gnutls_strerror(ret));
 565                                 CloseSession(session);
 566                                 session->status = ISSL_CLOSING;
 567                         }
 568
 569                         return false;
 570                 }
 571                 else
 572                 {
 573                         // Change the seesion state
 574                         session->status = ISSL_HANDSHAKEN;
 575
 576                         VerifyCertificate(session,user);
 577
 578                         // Finish writing, if any left
 579                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 580
 581                         return true;
 582                 }
 583         }
 584
 585         void OnUserConnect(LocalUser* user)
 586         {
 587                 if (user->eh.GetIOHook() == this)
 588                 {
 589                         if (sessions[user->eh.GetFd()].sess)
 590                         {
 591                                 ssl_cert* cert = sessions[user->eh.GetFd()].cert;
 592                                 std::string cipher = gnutls_kx_get_name(gnutls_kx_get(sessions[user->eh.GetFd()].sess));
 593                                 cipher.append("-").append(gnutls_cipher_get_name(gnutls_cipher_get(sessions[user->eh.GetFd()].sess))).append("-");
 594                                 cipher.append(gnutls_mac_get_name(gnutls_mac_get(sessions[user->eh.GetFd()].sess)));
 595                                 if (cert->fingerprint.empty())
 596                                         user->WriteServ("NOTICE %s :*** You are connected using SSL cipher \"%s\"", user->nick.c_str(), cipher.c_str());
 597                                 else
 598                                         user->WriteServ("NOTICE %s :*** You are connected using SSL cipher \"%s\""
 599                                                 " and your SSL fingerprint is %s", user->nick.c_str(), cipher.c_str(), cert->fingerprint.c_str());
 600                         }
 601                 }
 602         }
 603
 604         void CloseSession(issl_session* session)
 605         {
 606                 if (session->sess)
 607                 {
 608                         gnutls_bye(session->sess, GNUTLS_SHUT_WR);
 609                         gnutls_deinit(session->sess);
 610                 }
 611                 session->sess = NULL;
 612                 session->cert = NULL;
 613                 session->status = ISSL_NONE;
 614         }
 615
 616         void VerifyCertificate(issl_session* session, StreamSocket* user)
 617         {
 618                 if (!session->sess || !user || session->cert)
 619                         return;
 620
 621                 unsigned int status;
 622                 const gnutls_datum_t* cert_list;
 623                 int ret;
 624                 unsigned int cert_list_size;
 625                 gnutls_x509_crt_t cert;
 626                 char name[MAXBUF];
 627                 unsigned char digest[MAXBUF];
 628                 size_t digest_size = sizeof(digest);
 629                 size_t name_size = sizeof(name);
 630                 ssl_cert* certinfo = new ssl_cert;
 631                 session->cert = certinfo;
 632
 633                 /* This verification function uses the trusted CAs in the credentials
 634                  * structure. So you must have installed one or more CA certificates.
 635                  */
 636                 ret = gnutls_certificate_verify_peers2(session->sess, &status);
 637
 638                 if (ret < 0)
 639                 {
 640                         certinfo->error = std::string(gnutls_strerror(ret));
 641                         return;
 642                 }
 643
 644                 certinfo->invalid = (status & GNUTLS_CERT_INVALID);
 645                 certinfo->unknownsigner = (status & GNUTLS_CERT_SIGNER_NOT_FOUND);
 646                 certinfo->revoked = (status & GNUTLS_CERT_REVOKED);
 647                 certinfo->trusted = !(status & GNUTLS_CERT_SIGNER_NOT_CA);
 648
 649                 /* Up to here the process is the same for X.509 certificates and
 650                  * OpenPGP keys. From now on X.509 certificates are assumed. This can
 651                  * be easily extended to work with openpgp keys as well.
 652                  */
 653                 if (gnutls_certificate_type_get(session->sess) != GNUTLS_CRT_X509)
 654                 {
 655                         certinfo->error = "No X509 keys sent";
 656                         return;
 657                 }
 658
 659                 ret = gnutls_x509_crt_init(&cert);
 660                 if (ret < 0)
 661                 {
 662                         certinfo->error = gnutls_strerror(ret);
 663                         return;
 664                 }
 665
 666                 cert_list_size = 0;
 667                 cert_list = gnutls_certificate_get_peers(session->sess, &cert_list_size);
 668                 if (cert_list == NULL)
 669                 {
 670                         certinfo->error = "No certificate was found";
 671                         goto info_done_dealloc;
 672                 }
 673
 674                 /* This is not a real world example, since we only check the first
 675                  * certificate in the given chain.
 676                  */
 677
 678                 ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
 679                 if (ret < 0)
 680                 {
 681                         certinfo->error = gnutls_strerror(ret);
 682                         goto info_done_dealloc;
 683                 }
 684
 685                 gnutls_x509_crt_get_dn(cert, name, &name_size);
 686                 certinfo->dn = name;
 687
 688                 gnutls_x509_crt_get_issuer_dn(cert, name, &name_size);
 689                 certinfo->issuer = name;
 690
 691                 if ((ret = gnutls_x509_crt_get_fingerprint(cert, hash, digest, &digest_size)) < 0)
 692                 {
 693                         certinfo->error = gnutls_strerror(ret);
 694                 }
 695                 else
 696                 {
 697                         certinfo->fingerprint = irc::hex(digest, digest_size);
 698                 }
 699
 700                 /* Beware here we do not check for errors.
 701                  */
 702                 if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
 703                 {
 704                         certinfo->error = "Not activated, or expired certificate";
 705                 }
 706
 707 info_done_dealloc:
 708                 gnutls_x509_crt_deinit(cert);
 709         }
 710
 711         void OnEvent(Event& ev)
 712         {
 713                 if (starttls.enabled)
 714                         capHandler.HandleEvent(ev);
 715         }
 716 };
 717
 718 MODULE_INIT(ModuleSSLGnuTLS)