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         CommandStartTLS (Module* mod) : SplitCommand(mod, "STARTTLS")
  98         {
  99                 works_before_reg = true;
 100         }
 101
 102         CmdResult HandleLocal(const std::vector<std::string> &parameters, LocalUser *user)
 103         {
 104                 if (user->registered == REG_ALL)
 105                 {
 106                         user->WriteNumeric(691, "%s :STARTTLS is not permitted after client registration is complete", user->nick.c_str());
 107                 }
 108                 else
 109                 {
 110                         if (!user->eh.GetIOHook())
 111                         {
 112                                 user->WriteNumeric(670, "%s :STARTTLS successful, go ahead with TLS handshake", user->nick.c_str());
 113                                 /* We need to flush the write buffer prior to adding the IOHook,
 114                                  * otherwise we'll be sending this line inside the SSL session - which
 115                                  * won't start its handshake until the client gets this line. Currently,
 116                                  * we assume the write will not block here; this is usually safe, as
 117                                  * STARTTLS is sent very early on in the registration phase, where the
 118                                  * user hasn't built up much sendq. Handling a blocked write here would
 119                                  * be very annoying.
 120                                  */
 121                                 user->eh.DoWrite();
 122                                 user->eh.AddIOHook(creator);
 123                                 creator->OnStreamSocketAccept(&user->eh, NULL, NULL);
 124                         }
 125                         else
 126                                 user->WriteNumeric(691, "%s :STARTTLS failure", user->nick.c_str());
 127                 }
 128
 129                 return CMD_FAILURE;
 130         }
 131 };
 132
 133 class ModuleSSLGnuTLS : public Module
 134 {
 135         issl_session* sessions;
 136
 137         gnutls_certificate_credentials x509_cred;
 138         gnutls_dh_params dh_params;
 139         gnutls_digest_algorithm_t hash;
 140
 141         std::string sslports;
 142         int dh_bits;
 143
 144         bool cred_alloc;
 145
 146         RandGen randhandler;
 147         CommandStartTLS starttls;
 148
 149         GenericCap capHandler;
 150         ServiceProvider iohook;
 151  public:
 152
 153         ModuleSSLGnuTLS()
 154                 : starttls(this), capHandler(this, "tls"), iohook(this, "ssl/gnutls", SERVICE_IOHOOK)
 155         {
 156                 sessions = new issl_session[ServerInstance->SE->GetMaxFds()];
 157
 158                 gnutls_global_init(); // This must be called once in the program
 159                 gnutls_x509_crt_init(&x509_cert);
 160                 gnutls_x509_privkey_init(&x509_key);
 161
 162                 cred_alloc = false;
 163         }
 164
 165         void init()
 166         {
 167                 // Needs the flag as it ignores a plain /rehash
 168                 OnModuleRehash(NULL,"ssl");
 169
 170                 ServerInstance->GenRandom = &randhandler;
 171
 172                 // Void return, guess we assume success
 173                 gnutls_certificate_set_dh_params(x509_cred, dh_params);
 174                 Implementation eventlist[] = { I_On005Numeric, I_OnRehash, I_OnModuleRehash, I_OnUserConnect,
 175                         I_OnEvent, I_OnHookIO };
 176                 ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
 177
 178                 ServerInstance->Modules->AddService(iohook);
 179                 ServerInstance->AddCommand(&starttls);
 180         }
 181
 182         void OnRehash(User* user)
 183         {
 184                 sslports.clear();
 185
 186                 ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
 187
 188                 if (Conf->getBool("showports", true))
 189                 {
 190                         for (size_t i = 0; i < ServerInstance->ports.size(); i++)
 191                         {
 192                                 ListenSocket* port = ServerInstance->ports[i];
 193                                 if (port->bind_tag->getString("ssl") != "gnutls")
 194                                         continue;
 195
 196                                 const std::string& portid = port->bind_desc;
 197                                 ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT, "m_ssl_gnutls.so: Enabling SSL for port %s", portid.c_str());
 198
 199                                 if (port->bind_tag->getString("type", "clients") == "clients" && port->bind_addr != "127.0.0.1")
 200                                         sslports.append(portid).append(";");
 201                         }
 202
 203                         if (!sslports.empty())
 204                                 sslports.erase(sslports.end() - 1);
 205                 }
 206         }
 207
 208         void OnModuleRehash(User* user, const std::string &param)
 209         {
 210                 if(param != "ssl")
 211                         return;
 212
 213                 std::string keyfile;
 214                 std::string certfile;
 215                 std::string cafile;
 216                 std::string crlfile;
 217                 OnRehash(user);
 218
 219                 ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
 220
 221                 cafile = Conf->getString("cafile", "conf/ca.pem");
 222                 crlfile = Conf->getString("crlfile", "conf/crl.pem");
 223                 certfile = Conf->getString("certfile", "conf/cert.pem");
 224                 keyfile = Conf->getString("keyfile", "conf/key.pem");
 225                 dh_bits = Conf->getInt("dhbits");
 226                 std::string hashname = Conf->getString("hash", "md5");
 227
 228                 if((dh_bits != 768) && (dh_bits != 1024) && (dh_bits != 2048) && (dh_bits != 3072) && (dh_bits != 4096))
 229                         dh_bits = 1024;
 230
 231                 if (hashname == "md5")
 232                         hash = GNUTLS_DIG_MD5;
 233                 else if (hashname == "sha1")
 234                         hash = GNUTLS_DIG_SHA1;
 235                 else
 236                         throw ModuleException("Unknown hash type " + hashname);
 237
 238
 239                 int ret;
 240
 241                 if (cred_alloc)
 242                 {
 243                         // Deallocate the old credentials
 244                         gnutls_dh_params_deinit(dh_params);
 245                         gnutls_certificate_free_credentials(x509_cred);
 246                 }
 247                 else
 248                         cred_alloc = true;
 249
 250                 if((ret = gnutls_certificate_allocate_credentials(&x509_cred)) < 0)
 251                         ServerInstance->Logs->Log("m_ssl_gnutls",DEBUG, "m_ssl_gnutls.so: Failed to allocate certificate credentials: %s", gnutls_strerror(ret));
 252
 253                 if((ret =gnutls_certificate_set_x509_trust_file(x509_cred, cafile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 254                         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));
 255
 256                 if((ret = gnutls_certificate_set_x509_crl_file (x509_cred, crlfile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 257                         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));
 258
 259                 FileReader reader;
 260
 261                 reader.LoadFile(certfile);
 262                 std::string cert_string = reader.Contents();
 263                 gnutls_datum_t cert_datum = { (unsigned char*)cert_string.data(), cert_string.length() };
 264
 265                 reader.LoadFile(keyfile);
 266                 std::string key_string = reader.Contents();
 267                 gnutls_datum_t key_datum = { (unsigned char*)key_string.data(), key_string.length() };
 268
 269                 // If this fails, no SSL port will work. At all. So, do the smart thing - throw a ModuleException
 270                 if((ret = gnutls_x509_crt_import(x509_cert, &cert_datum, GNUTLS_X509_FMT_PEM)) < 0)
 271                         throw ModuleException("Unable to load GnuTLS server certificate (" + certfile + "): " + std::string(gnutls_strerror(ret)));
 272
 273                 if((ret = gnutls_x509_privkey_import(x509_key, &key_datum, GNUTLS_X509_FMT_PEM)) < 0)
 274                         throw ModuleException("Unable to load GnuTLS server private key (" + keyfile + "): " + std::string(gnutls_strerror(ret)));
 275
 276                 if((ret = gnutls_certificate_set_x509_key(x509_cred, &x509_cert, 1, x509_key)) < 0)
 277                         throw ModuleException("Unable to set GnuTLS cert/key pair: " + std::string(gnutls_strerror(ret)));
 278
 279                 gnutls_certificate_client_set_retrieve_function (x509_cred, cert_callback);
 280
 281                 if((ret = gnutls_dh_params_init(&dh_params)) < 0)
 282                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to initialise DH parameters: %s", gnutls_strerror(ret));
 283
 284                 // This may be on a large (once a day or week) timer eventually.
 285                 GenerateDHParams();
 286         }
 287
 288         void GenerateDHParams()
 289         {
 290                 // Generate Diffie Hellman parameters - for use with DHE
 291                 // kx algorithms. These should be discarded and regenerated
 292                 // once a day, once a week or once a month. Depending on the
 293                 // security requirements.
 294
 295                 int ret;
 296
 297                 if((ret = gnutls_dh_params_generate2(dh_params, dh_bits)) < 0)
 298                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to generate DH parameters (%d bits): %s", dh_bits, gnutls_strerror(ret));
 299         }
 300
 301         ~ModuleSSLGnuTLS()
 302         {
 303                 gnutls_x509_crt_deinit(x509_cert);
 304                 gnutls_x509_privkey_deinit(x509_key);
 305                 if (cred_alloc)
 306                 {
 307                         gnutls_dh_params_deinit(dh_params);
 308                         gnutls_certificate_free_credentials(x509_cred);
 309                 }
 310                 gnutls_global_deinit();
 311                 delete[] sessions;
 312                 ServerInstance->GenRandom = &ServerInstance->HandleGenRandom;
 313         }
 314
 315         void OnCleanup(int target_type, void* item)
 316         {
 317                 if(target_type == TYPE_USER)
 318                 {
 319                         LocalUser* user = IS_LOCAL(static_cast<User*>(item));
 320
 321                         if (user && user->eh.GetIOHook() == this)
 322                         {
 323                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 324                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 325                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 326                         }
 327                 }
 328         }
 329
 330         Version GetVersion()
 331         {
 332                 return Version("Provides SSL support for clients", VF_VENDOR);
 333         }
 334
 335
 336         void On005Numeric(std::string &output)
 337         {
 338                 if (!sslports.empty())
 339                         output.append(" SSL=" + sslports);
 340                 output.append(" STARTTLS");
 341         }
 342
 343         void OnHookIO(StreamSocket* user, ListenSocket* lsb)
 344         {
 345                 if (!user->GetIOHook() && lsb->bind_tag->getString("ssl") == "gnutls")
 346                 {
 347                         /* Hook the user with our module */
 348                         user->AddIOHook(this);
 349                 }
 350         }
 351
 352         void OnRequest(Request& request)
 353         {
 354                 if (strcmp("GET_SSL_CERT", request.id) == 0)
 355                 {
 356                         SocketCertificateRequest& req = static_cast<SocketCertificateRequest&>(request);
 357                         int fd = req.sock->GetFd();
 358                         issl_session* session = &sessions[fd];
 359
 360                         req.cert = session->cert;
 361                 }
 362         }
 363
 364         void OnStreamSocketAccept(StreamSocket* user, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server)
 365         {
 366                 int fd = user->GetFd();
 367                 issl_session* session = &sessions[fd];
 368
 369                 /* For STARTTLS: Don't try and init a session on a socket that already has a session */
 370                 if (session->sess)
 371                         return;
 372
 373                 gnutls_init(&session->sess, GNUTLS_SERVER);
 374
 375                 gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
 376                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 377                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 378
 379                 gnutls_transport_set_ptr(session->sess, reinterpret_cast<gnutls_transport_ptr_t>(user));
 380                 gnutls_transport_set_push_function(session->sess, gnutls_push_wrapper);
 381                 gnutls_transport_set_pull_function(session->sess, gnutls_pull_wrapper);
 382
 383                 gnutls_certificate_server_set_request(session->sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
 384
 385                 Handshake(session, user);
 386         }
 387
 388         void OnStreamSocketConnect(StreamSocket* user)
 389         {
 390                 issl_session* session = &sessions[user->GetFd()];
 391
 392                 gnutls_init(&session->sess, GNUTLS_CLIENT);
 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                 gnutls_transport_set_ptr(session->sess, reinterpret_cast<gnutls_transport_ptr_t>(user));
 398                 gnutls_transport_set_push_function(session->sess, gnutls_push_wrapper);
 399                 gnutls_transport_set_pull_function(session->sess, gnutls_pull_wrapper);
 400
 401                 Handshake(session, user);
 402         }
 403
 404         void OnStreamSocketClose(StreamSocket* user)
 405         {
 406                 CloseSession(&sessions[user->GetFd()]);
 407         }
 408
 409         int OnStreamSocketRead(StreamSocket* user, std::string& recvq)
 410         {
 411                 issl_session* session = &sessions[user->GetFd()];
 412
 413                 if (!session->sess)
 414                 {
 415                         CloseSession(session);
 416                         user->SetError("No SSL session");
 417                         return -1;
 418                 }
 419
 420                 if (session->status == ISSL_HANDSHAKING_READ || session->status == ISSL_HANDSHAKING_WRITE)
 421                 {
 422                         // The handshake isn't finished, try to finish it.
 423
 424                         if(!Handshake(session, user))
 425                         {
 426                                 if (session->status != ISSL_CLOSING)
 427                                         return 0;
 428                                 return -1;
 429                         }
 430                 }
 431
 432                 // If we resumed the handshake then session->status will be ISSL_HANDSHAKEN.
 433
 434                 if (session->status == ISSL_HANDSHAKEN)
 435                 {
 436                         char* buffer = ServerInstance->GetReadBuffer();
 437                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 438                         int ret = gnutls_record_recv(session->sess, buffer, bufsiz);
 439                         if (ret > 0)
 440                         {
 441                                 recvq.append(buffer, ret);
 442                                 return 1;
 443                         }
 444                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 445                         {
 446                                 return 0;
 447                         }
 448                         else if (ret == 0)
 449                         {
 450                                 user->SetError("SSL Connection closed");
 451                                 CloseSession(session);
 452                                 return -1;
 453                         }
 454                         else
 455                         {
 456                                 user->SetError(gnutls_strerror(ret));
 457                                 CloseSession(session);
 458                                 return -1;
 459                         }
 460                 }
 461                 else if (session->status == ISSL_CLOSING)
 462                         return -1;
 463
 464                 return 0;
 465         }
 466
 467         int OnStreamSocketWrite(StreamSocket* user, std::string& sendq)
 468         {
 469                 issl_session* session = &sessions[user->GetFd()];
 470
 471                 if (!session->sess)
 472                 {
 473                         CloseSession(session);
 474                         user->SetError("No SSL session");
 475                         return -1;
 476                 }
 477
 478                 if (session->status == ISSL_HANDSHAKING_WRITE || session->status == ISSL_HANDSHAKING_READ)
 479                 {
 480                         // The handshake isn't finished, try to finish it.
 481                         Handshake(session, user);
 482                         if (session->status != ISSL_CLOSING)
 483                                 return 0;
 484                         return -1;
 485                 }
 486
 487                 int ret = 0;
 488
 489                 if (session->status == ISSL_HANDSHAKEN)
 490                 {
 491                         ret = gnutls_record_send(session->sess, sendq.data(), sendq.length());
 492
 493                         if (ret == (int)sendq.length())
 494                         {
 495                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_WRITE);
 496                                 return 1;
 497                         }
 498                         else if (ret > 0)
 499                         {
 500                                 sendq = sendq.substr(ret);
 501                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 502                                 return 0;
 503                         }
 504                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 505                         {
 506                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 507                                 return 0;
 508                         }
 509                         else if (ret == 0)
 510                         {
 511                                 CloseSession(session);
 512                                 user->SetError("SSL Connection closed");
 513                                 return -1;
 514                         }
 515                         else // (ret < 0)
 516                         {
 517                                 user->SetError(gnutls_strerror(ret));
 518                                 CloseSession(session);
 519                                 return -1;
 520                         }
 521                 }
 522
 523                 return 0;
 524         }
 525
 526         bool Handshake(issl_session* session, StreamSocket* user)
 527         {
 528                 int ret = gnutls_handshake(session->sess);
 529
 530                 if (ret < 0)
 531                 {
 532                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 533                         {
 534                                 // Handshake needs resuming later, read() or write() would have blocked.
 535
 536                                 if(gnutls_record_get_direction(session->sess) == 0)
 537                                 {
 538                                         // gnutls_handshake() wants to read() again.
 539                                         session->status = ISSL_HANDSHAKING_READ;
 540                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 541                                 }
 542                                 else
 543                                 {
 544                                         // gnutls_handshake() wants to write() again.
 545                                         session->status = ISSL_HANDSHAKING_WRITE;
 546                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 547                                 }
 548                         }
 549                         else
 550                         {
 551                                 user->SetError(std::string("Handshake Failed - ") + gnutls_strerror(ret));
 552                                 CloseSession(session);
 553                                 session->status = ISSL_CLOSING;
 554                         }
 555
 556                         return false;
 557                 }
 558                 else
 559                 {
 560                         // Change the seesion state
 561                         session->status = ISSL_HANDSHAKEN;
 562
 563                         VerifyCertificate(session,user);
 564
 565                         // Finish writing, if any left
 566                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 567
 568                         return true;
 569                 }
 570         }
 571
 572         void OnUserConnect(LocalUser* user)
 573         {
 574                 if (user->eh.GetIOHook() == this)
 575                 {
 576                         if (sessions[user->eh.GetFd()].sess)
 577                         {
 578                                 ssl_cert* cert = sessions[user->eh.GetFd()].cert;
 579                                 std::string cipher = gnutls_kx_get_name(gnutls_kx_get(sessions[user->eh.GetFd()].sess));
 580                                 cipher.append("-").append(gnutls_cipher_get_name(gnutls_cipher_get(sessions[user->eh.GetFd()].sess))).append("-");
 581                                 cipher.append(gnutls_mac_get_name(gnutls_mac_get(sessions[user->eh.GetFd()].sess)));
 582                                 if (cert->fingerprint.empty())
 583                                         user->WriteServ("NOTICE %s :*** You are connected using SSL cipher \"%s\"", user->nick.c_str(), cipher.c_str());
 584                                 else
 585                                         user->WriteServ("NOTICE %s :*** You are connected using SSL cipher \"%s\""
 586                                                 " and your SSL fingerprint is %s", user->nick.c_str(), cipher.c_str(), cert->fingerprint.c_str());
 587                         }
 588                 }
 589         }
 590
 591         void CloseSession(issl_session* session)
 592         {
 593                 if (session->sess)
 594                 {
 595                         gnutls_bye(session->sess, GNUTLS_SHUT_WR);
 596                         gnutls_deinit(session->sess);
 597                 }
 598                 session->sess = NULL;
 599                 session->cert = NULL;
 600                 session->status = ISSL_NONE;
 601         }
 602
 603         void VerifyCertificate(issl_session* session, StreamSocket* user)
 604         {
 605                 if (!session->sess || !user || session->cert)
 606                         return;
 607
 608                 unsigned int status;
 609                 const gnutls_datum_t* cert_list;
 610                 int ret;
 611                 unsigned int cert_list_size;
 612                 gnutls_x509_crt_t cert;
 613                 char name[MAXBUF];
 614                 unsigned char digest[MAXBUF];
 615                 size_t digest_size = sizeof(digest);
 616                 size_t name_size = sizeof(name);
 617                 ssl_cert* certinfo = new ssl_cert;
 618                 session->cert = certinfo;
 619
 620                 /* This verification function uses the trusted CAs in the credentials
 621                  * structure. So you must have installed one or more CA certificates.
 622                  */
 623                 ret = gnutls_certificate_verify_peers2(session->sess, &status);
 624
 625                 if (ret < 0)
 626                 {
 627                         certinfo->error = std::string(gnutls_strerror(ret));
 628                         return;
 629                 }
 630
 631                 certinfo->invalid = (status & GNUTLS_CERT_INVALID);
 632                 certinfo->unknownsigner = (status & GNUTLS_CERT_SIGNER_NOT_FOUND);
 633                 certinfo->revoked = (status & GNUTLS_CERT_REVOKED);
 634                 certinfo->trusted = !(status & GNUTLS_CERT_SIGNER_NOT_CA);
 635
 636                 /* Up to here the process is the same for X.509 certificates and
 637                  * OpenPGP keys. From now on X.509 certificates are assumed. This can
 638                  * be easily extended to work with openpgp keys as well.
 639                  */
 640                 if (gnutls_certificate_type_get(session->sess) != GNUTLS_CRT_X509)
 641                 {
 642                         certinfo->error = "No X509 keys sent";
 643                         return;
 644                 }
 645
 646                 ret = gnutls_x509_crt_init(&cert);
 647                 if (ret < 0)
 648                 {
 649                         certinfo->error = gnutls_strerror(ret);
 650                         return;
 651                 }
 652
 653                 cert_list_size = 0;
 654                 cert_list = gnutls_certificate_get_peers(session->sess, &cert_list_size);
 655                 if (cert_list == NULL)
 656                 {
 657                         certinfo->error = "No certificate was found";
 658                         goto info_done_dealloc;
 659                 }
 660
 661                 /* This is not a real world example, since we only check the first
 662                  * certificate in the given chain.
 663                  */
 664
 665                 ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
 666                 if (ret < 0)
 667                 {
 668                         certinfo->error = gnutls_strerror(ret);
 669                         goto info_done_dealloc;
 670                 }
 671
 672                 gnutls_x509_crt_get_dn(cert, name, &name_size);
 673                 certinfo->dn = name;
 674
 675                 gnutls_x509_crt_get_issuer_dn(cert, name, &name_size);
 676                 certinfo->issuer = name;
 677
 678                 if ((ret = gnutls_x509_crt_get_fingerprint(cert, hash, digest, &digest_size)) < 0)
 679                 {
 680                         certinfo->error = gnutls_strerror(ret);
 681                 }
 682                 else
 683                 {
 684                         certinfo->fingerprint = irc::hex(digest, digest_size);
 685                 }
 686
 687                 /* Beware here we do not check for errors.
 688                  */
 689                 if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
 690                 {
 691                         certinfo->error = "Not activated, or expired certificate";
 692                 }
 693
 694 info_done_dealloc:
 695                 gnutls_x509_crt_deinit(cert);
 696         }
 697
 698         void OnEvent(Event& ev)
 699         {
 700                 capHandler.HandleEvent(ev);
 701         }
 702 };
 703
 704 MODULE_INIT(ModuleSSLGnuTLS)