src/modules/extra/m_ssl_gnutls.cpp

   1 /*
   2  * InspIRCd -- Internet Relay Chat Daemon
   3  *
   4  *   Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
   5  *   Copyright (C) 2008 John Brooks <john.brooks@dereferenced.net>
   6  *   Copyright (C) 2006-2008 Craig Edwards <craigedwards@brainbox.cc>
   7  *   Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
   8  *   Copyright (C) 2006 Oliver Lupton <oliverlupton@gmail.com>
   9  *
  10  * This file is part of InspIRCd.  InspIRCd is free software: you can
  11  * redistribute it and/or modify it under the terms of the GNU General Public
  12  * License as published by the Free Software Foundation, version 2.
  13  *
  14  * This program is distributed in the hope that it will be useful, but WITHOUT
  15  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  16  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  17  * details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21  */
  22
  23
  24 #include "inspircd.h"
  25 #include <gnutls/gnutls.h>
  26 #include <gnutls/x509.h>
  27 #include <gcrypt.h>
  28 #include "ssl.h"
  29 #include "m_cap.h"
  30
  31 /* $ModDesc: Provides SSL support for clients */
  32 /* $CompileFlags: pkgconfincludes("gnutls","/gnutls/gnutls.h","") */
  33 /* $LinkerFlags: rpath("pkg-config --libs gnutls") pkgconflibs("gnutls","/libgnutls.so","-lgnutls") -lgcrypt */
  34
  35 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING_READ, ISSL_HANDSHAKING_WRITE, ISSL_HANDSHAKEN, ISSL_CLOSING, ISSL_CLOSED };
  36
  37 static std::vector<gnutls_x509_crt_t> x509_certs;
  38 static gnutls_x509_privkey_t x509_key;
  39 static int cert_callback (gnutls_session_t session, const gnutls_datum_t * req_ca_rdn, int nreqs,
  40         const gnutls_pk_algorithm_t * sign_algos, int sign_algos_length, gnutls_retr_st * st) {
  41
  42         st->type = GNUTLS_CRT_X509;
  43         st->ncerts = x509_certs.size();
  44         st->cert.x509 = &x509_certs[0];
  45         st->key.x509 = x509_key;
  46         st->deinit_all = 0;
  47
  48         return 0;
  49 }
  50
  51 static ssize_t gnutls_pull_wrapper(gnutls_transport_ptr_t user_wrap, void* buffer, size_t size)
  52 {
  53         StreamSocket* user = reinterpret_cast<StreamSocket*>(user_wrap);
  54         if (user->GetEventMask() & FD_READ_WILL_BLOCK)
  55         {
  56                 errno = EAGAIN;
  57                 return -1;
  58         }
  59         int rv = ServerInstance->SE->Recv(user, reinterpret_cast<char *>(buffer), size, 0);
  60         if (rv < (int)size)
  61                 ServerInstance->SE->ChangeEventMask(user, FD_READ_WILL_BLOCK);
  62         return rv;
  63 }
  64
  65 static ssize_t gnutls_push_wrapper(gnutls_transport_ptr_t user_wrap, const void* buffer, size_t size)
  66 {
  67         StreamSocket* user = reinterpret_cast<StreamSocket*>(user_wrap);
  68         if (user->GetEventMask() & FD_WRITE_WILL_BLOCK)
  69         {
  70                 errno = EAGAIN;
  71                 return -1;
  72         }
  73         int rv = ServerInstance->SE->Send(user, reinterpret_cast<const char *>(buffer), size, 0);
  74         if (rv < (int)size)
  75                 ServerInstance->SE->ChangeEventMask(user, FD_WRITE_WILL_BLOCK);
  76         return rv;
  77 }
  78
  79 class RandGen : public HandlerBase2<void, char*, size_t>
  80 {
  81  public:
  82         RandGen() {}
  83         void Call(char* buffer, size_t len)
  84         {
  85                 gcry_randomize(buffer, len, GCRY_STRONG_RANDOM);
  86         }
  87 };
  88
  89 /** Represents an SSL user's extra data
  90  */
  91 class issl_session
  92 {
  93 public:
  94         gnutls_session_t sess;
  95         issl_status status;
  96         reference<ssl_cert> cert;
  97         issl_session() : sess(NULL) {}
  98 };
  99
 100 class CommandStartTLS : public SplitCommand
 101 {
 102  public:
 103         bool enabled;
 104         CommandStartTLS (Module* mod) : SplitCommand(mod, "STARTTLS")
 105         {
 106                 enabled = true;
 107                 works_before_reg = true;
 108         }
 109
 110         CmdResult HandleLocal(const std::vector<std::string> &parameters, LocalUser *user)
 111         {
 112                 if (!enabled)
 113                 {
 114                         user->WriteNumeric(691, "%s :STARTTLS is not enabled", user->nick.c_str());
 115                         return CMD_FAILURE;
 116                 }
 117
 118                 if (user->registered == REG_ALL)
 119                 {
 120                         user->WriteNumeric(691, "%s :STARTTLS is not permitted after client registration is complete", user->nick.c_str());
 121                 }
 122                 else
 123                 {
 124                         if (!user->eh.GetIOHook())
 125                         {
 126                                 user->WriteNumeric(670, "%s :STARTTLS successful, go ahead with TLS handshake", user->nick.c_str());
 127                                 /* We need to flush the write buffer prior to adding the IOHook,
 128                                  * otherwise we'll be sending this line inside the SSL session - which
 129                                  * won't start its handshake until the client gets this line. Currently,
 130                                  * we assume the write will not block here; this is usually safe, as
 131                                  * STARTTLS is sent very early on in the registration phase, where the
 132                                  * user hasn't built up much sendq. Handling a blocked write here would
 133                                  * be very annoying.
 134                                  */
 135                                 user->eh.DoWrite();
 136                                 user->eh.AddIOHook(creator);
 137                                 creator->OnStreamSocketAccept(&user->eh, NULL, NULL);
 138                         }
 139                         else
 140                                 user->WriteNumeric(691, "%s :STARTTLS failure", user->nick.c_str());
 141                 }
 142
 143                 return CMD_FAILURE;
 144         }
 145 };
 146
 147 class ModuleSSLGnuTLS : public Module
 148 {
 149         issl_session* sessions;
 150
 151         gnutls_certificate_credentials x509_cred;
 152         gnutls_dh_params dh_params;
 153         gnutls_digest_algorithm_t hash;
 154
 155         std::string sslports;
 156         int dh_bits;
 157
 158         bool cred_alloc;
 159         bool dh_alloc;
 160
 161         RandGen randhandler;
 162         CommandStartTLS starttls;
 163
 164         GenericCap capHandler;
 165         ServiceProvider iohook;
 166  public:
 167
 168         ModuleSSLGnuTLS()
 169                 : starttls(this), capHandler(this, "tls"), iohook(this, "ssl/gnutls", SERVICE_IOHOOK)
 170         {
 171                 sessions = new issl_session[ServerInstance->SE->GetMaxFds()];
 172
 173                 gnutls_global_init(); // This must be called once in the program
 174                 gnutls_x509_privkey_init(&x509_key);
 175
 176                 cred_alloc = false;
 177                 dh_alloc = false;
 178         }
 179
 180         void init()
 181         {
 182                 // Needs the flag as it ignores a plain /rehash
 183                 OnModuleRehash(NULL,"ssl");
 184
 185                 ServerInstance->GenRandom = &randhandler;
 186
 187                 // Void return, guess we assume success
 188                 gnutls_certificate_set_dh_params(x509_cred, dh_params);
 189                 Implementation eventlist[] = { I_On005Numeric, I_OnRehash, I_OnModuleRehash, I_OnUserConnect,
 190                         I_OnEvent, I_OnHookIO };
 191                 ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
 192
 193                 ServerInstance->Modules->AddService(iohook);
 194                 ServerInstance->AddCommand(&starttls);
 195         }
 196
 197         void OnRehash(User* user)
 198         {
 199                 sslports.clear();
 200
 201                 ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
 202                 starttls.enabled = Conf->getBool("starttls", true);
 203
 204                 if (Conf->getBool("showports", true))
 205                 {
 206                         for (size_t i = 0; i < ServerInstance->ports.size(); i++)
 207                         {
 208                                 ListenSocket* port = ServerInstance->ports[i];
 209                                 if (port->bind_tag->getString("ssl") != "gnutls")
 210                                         continue;
 211
 212                                 const std::string& portid = port->bind_desc;
 213                                 ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT, "m_ssl_gnutls.so: Enabling SSL for port %s", portid.c_str());
 214
 215                                 if (port->bind_tag->getString("type", "clients") == "clients" && port->bind_addr != "127.0.0.1")
 216                                         sslports.append(portid).append(";");
 217                         }
 218
 219                         if (!sslports.empty())
 220                                 sslports.erase(sslports.end() - 1);
 221                 }
 222         }
 223
 224         void OnModuleRehash(User* user, const std::string &param)
 225         {
 226                 if(param != "ssl")
 227                         return;
 228
 229                 std::string keyfile;
 230                 std::string certfile;
 231                 std::string cafile;
 232                 std::string crlfile;
 233                 OnRehash(user);
 234
 235                 ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
 236
 237                 cafile = Conf->getString("cafile", "conf/ca.pem");
 238                 crlfile = Conf->getString("crlfile", "conf/crl.pem");
 239                 certfile = Conf->getString("certfile", "conf/cert.pem");
 240                 keyfile = Conf->getString("keyfile", "conf/key.pem");
 241                 dh_bits = Conf->getInt("dhbits");
 242                 std::string hashname = Conf->getString("hash", "md5");
 243
 244                 if((dh_bits != 768) && (dh_bits != 1024) && (dh_bits != 2048) && (dh_bits != 3072) && (dh_bits != 4096))
 245                         dh_bits = 1024;
 246
 247                 if (hashname == "md5")
 248                         hash = GNUTLS_DIG_MD5;
 249                 else if (hashname == "sha1")
 250                         hash = GNUTLS_DIG_SHA1;
 251                 else
 252                         throw ModuleException("Unknown hash type " + hashname);
 253
 254
 255                 int ret;
 256
 257                 if (dh_alloc)
 258                 {
 259                         gnutls_dh_params_deinit(dh_params);
 260                         dh_alloc = false;
 261                 }
 262
 263                 if (cred_alloc)
 264                 {
 265                         // Deallocate the old credentials
 266                         gnutls_certificate_free_credentials(x509_cred);
 267
 268                         for(unsigned int i=0; i < x509_certs.size(); i++)
 269                                 gnutls_x509_crt_deinit(x509_certs[i]);
 270                         x509_certs.clear();
 271                 }
 272
 273                 ret = gnutls_certificate_allocate_credentials(&x509_cred);
 274                 cred_alloc = (ret >= 0);
 275                 if (!cred_alloc)
 276                         ServerInstance->Logs->Log("m_ssl_gnutls",DEBUG, "m_ssl_gnutls.so: Failed to allocate certificate credentials: %s", gnutls_strerror(ret));
 277
 278                 if((ret =gnutls_certificate_set_x509_trust_file(x509_cred, cafile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 279                         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));
 280
 281                 if((ret = gnutls_certificate_set_x509_crl_file (x509_cred, crlfile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 282                         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));
 283
 284                 FileReader reader;
 285
 286                 reader.LoadFile(certfile);
 287                 std::string cert_string = reader.Contents();
 288                 gnutls_datum_t cert_datum = { (unsigned char*)cert_string.data(), cert_string.length() };
 289
 290                 reader.LoadFile(keyfile);
 291                 std::string key_string = reader.Contents();
 292                 gnutls_datum_t key_datum = { (unsigned char*)key_string.data(), key_string.length() };
 293
 294                 // If this fails, no SSL port will work. At all. So, do the smart thing - throw a ModuleException
 295                 unsigned int certcount = Conf->getInt("certcount", 3);
 296                 x509_certs.resize(certcount);
 297                 ret = gnutls_x509_crt_list_import(&x509_certs[0], &certcount, &cert_datum, GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 298                 if (ret < 0)
 299                         throw ModuleException("Unable to load GnuTLS server certificate (" + certfile + "): " + std::string(gnutls_strerror(ret)));
 300                 x509_certs.resize(certcount);
 301
 302                 if((ret = gnutls_x509_privkey_import(x509_key, &key_datum, GNUTLS_X509_FMT_PEM)) < 0)
 303                         throw ModuleException("Unable to load GnuTLS server private key (" + keyfile + "): " + std::string(gnutls_strerror(ret)));
 304
 305                 if((ret = gnutls_certificate_set_x509_key(x509_cred, &x509_certs[0], certcount, x509_key)) < 0)
 306                         throw ModuleException("Unable to set GnuTLS cert/key pair: " + std::string(gnutls_strerror(ret)));
 307
 308                 gnutls_certificate_client_set_retrieve_function (x509_cred, cert_callback);
 309
 310                 ret = gnutls_dh_params_init(&dh_params);
 311                 dh_alloc = (ret >= 0);
 312                 if (!dh_alloc)
 313                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to initialise DH parameters: %s", gnutls_strerror(ret));
 314
 315                 // This may be on a large (once a day or week) timer eventually.
 316                 GenerateDHParams();
 317         }
 318
 319         void GenerateDHParams()
 320         {
 321                 // Generate Diffie Hellman parameters - for use with DHE
 322                 // kx algorithms. These should be discarded and regenerated
 323                 // once a day, once a week or once a month. Depending on the
 324                 // security requirements.
 325
 326                 if (!dh_alloc)
 327                         return;
 328
 329                 int ret;
 330
 331                 if((ret = gnutls_dh_params_generate2(dh_params, dh_bits)) < 0)
 332                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to generate DH parameters (%d bits): %s", dh_bits, gnutls_strerror(ret));
 333         }
 334
 335         ~ModuleSSLGnuTLS()
 336         {
 337                 for(unsigned int i=0; i < x509_certs.size(); i++)
 338                         gnutls_x509_crt_deinit(x509_certs[i]);
 339
 340                 gnutls_x509_privkey_deinit(x509_key);
 341
 342                 if (dh_alloc)
 343                         gnutls_dh_params_deinit(dh_params);
 344                 if (cred_alloc)
 345                         gnutls_certificate_free_credentials(x509_cred);
 346
 347                 gnutls_global_deinit();
 348                 delete[] sessions;
 349                 ServerInstance->GenRandom = &ServerInstance->HandleGenRandom;
 350         }
 351
 352         void OnCleanup(int target_type, void* item)
 353         {
 354                 if(target_type == TYPE_USER)
 355                 {
 356                         LocalUser* user = IS_LOCAL(static_cast<User*>(item));
 357
 358                         if (user && user->eh.GetIOHook() == this)
 359                         {
 360                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 361                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 362                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 363                         }
 364                 }
 365         }
 366
 367         Version GetVersion()
 368         {
 369                 return Version("Provides SSL support for clients", VF_VENDOR);
 370         }
 371
 372
 373         void On005Numeric(std::string &output)
 374         {
 375                 if (!sslports.empty())
 376                         output.append(" SSL=" + sslports);
 377                 if (starttls.enabled)
 378                         output.append(" STARTTLS");
 379         }
 380
 381         void OnHookIO(StreamSocket* user, ListenSocket* lsb)
 382         {
 383                 if (!user->GetIOHook() && lsb->bind_tag->getString("ssl") == "gnutls")
 384                 {
 385                         /* Hook the user with our module */
 386                         user->AddIOHook(this);
 387                 }
 388         }
 389
 390         void OnRequest(Request& request)
 391         {
 392                 if (strcmp("GET_SSL_CERT", request.id) == 0)
 393                 {
 394                         SocketCertificateRequest& req = static_cast<SocketCertificateRequest&>(request);
 395                         int fd = req.sock->GetFd();
 396                         issl_session* session = &sessions[fd];
 397
 398                         req.cert = session->cert;
 399                 }
 400         }
 401
 402         void OnStreamSocketAccept(StreamSocket* user, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server)
 403         {
 404                 int fd = user->GetFd();
 405                 issl_session* session = &sessions[fd];
 406
 407                 /* For STARTTLS: Don't try and init a session on a socket that already has a session */
 408                 if (session->sess)
 409                         return;
 410
 411                 gnutls_init(&session->sess, GNUTLS_SERVER);
 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
 417                 gnutls_transport_set_ptr(session->sess, reinterpret_cast<gnutls_transport_ptr_t>(user));
 418                 gnutls_transport_set_push_function(session->sess, gnutls_push_wrapper);
 419                 gnutls_transport_set_pull_function(session->sess, gnutls_pull_wrapper);
 420
 421                 gnutls_certificate_server_set_request(session->sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
 422
 423                 Handshake(session, user);
 424         }
 425
 426         void OnStreamSocketConnect(StreamSocket* user)
 427         {
 428                 issl_session* session = &sessions[user->GetFd()];
 429
 430                 gnutls_init(&session->sess, GNUTLS_CLIENT);
 431
 432                 gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
 433                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 434                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 435                 gnutls_transport_set_ptr(session->sess, reinterpret_cast<gnutls_transport_ptr_t>(user));
 436                 gnutls_transport_set_push_function(session->sess, gnutls_push_wrapper);
 437                 gnutls_transport_set_pull_function(session->sess, gnutls_pull_wrapper);
 438
 439                 Handshake(session, user);
 440         }
 441
 442         void OnStreamSocketClose(StreamSocket* user)
 443         {
 444                 CloseSession(&sessions[user->GetFd()]);
 445         }
 446
 447         int OnStreamSocketRead(StreamSocket* user, std::string& recvq)
 448         {
 449                 issl_session* session = &sessions[user->GetFd()];
 450
 451                 if (!session->sess)
 452                 {
 453                         CloseSession(session);
 454                         user->SetError("No SSL session");
 455                         return -1;
 456                 }
 457
 458                 if (session->status == ISSL_HANDSHAKING_READ || session->status == ISSL_HANDSHAKING_WRITE)
 459                 {
 460                         // The handshake isn't finished, try to finish it.
 461
 462                         if(!Handshake(session, user))
 463                         {
 464                                 if (session->status != ISSL_CLOSING)
 465                                         return 0;
 466                                 return -1;
 467                         }
 468                 }
 469
 470                 // If we resumed the handshake then session->status will be ISSL_HANDSHAKEN.
 471
 472                 if (session->status == ISSL_HANDSHAKEN)
 473                 {
 474                         char* buffer = ServerInstance->GetReadBuffer();
 475                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 476                         int ret = gnutls_record_recv(session->sess, buffer, bufsiz);
 477                         if (ret > 0)
 478                         {
 479                                 recvq.append(buffer, ret);
 480                                 return 1;
 481                         }
 482                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 483                         {
 484                                 return 0;
 485                         }
 486                         else if (ret == 0)
 487                         {
 488                                 user->SetError("SSL Connection closed");
 489                                 CloseSession(session);
 490                                 return -1;
 491                         }
 492                         else
 493                         {
 494                                 user->SetError(gnutls_strerror(ret));
 495                                 CloseSession(session);
 496                                 return -1;
 497                         }
 498                 }
 499                 else if (session->status == ISSL_CLOSING)
 500                         return -1;
 501
 502                 return 0;
 503         }
 504
 505         int OnStreamSocketWrite(StreamSocket* user, std::string& sendq)
 506         {
 507                 issl_session* session = &sessions[user->GetFd()];
 508
 509                 if (!session->sess)
 510                 {
 511                         CloseSession(session);
 512                         user->SetError("No SSL session");
 513                         return -1;
 514                 }
 515
 516                 if (session->status == ISSL_HANDSHAKING_WRITE || session->status == ISSL_HANDSHAKING_READ)
 517                 {
 518                         // The handshake isn't finished, try to finish it.
 519                         Handshake(session, user);
 520                         if (session->status != ISSL_CLOSING)
 521                                 return 0;
 522                         return -1;
 523                 }
 524
 525                 int ret = 0;
 526
 527                 if (session->status == ISSL_HANDSHAKEN)
 528                 {
 529                         ret = gnutls_record_send(session->sess, sendq.data(), sendq.length());
 530
 531                         if (ret == (int)sendq.length())
 532                         {
 533                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_WRITE);
 534                                 return 1;
 535                         }
 536                         else if (ret > 0)
 537                         {
 538                                 sendq = sendq.substr(ret);
 539                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 540                                 return 0;
 541                         }
 542                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED || ret == 0)
 543                         {
 544                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 545                                 return 0;
 546                         }
 547                         else // (ret < 0)
 548                         {
 549                                 user->SetError(gnutls_strerror(ret));
 550                                 CloseSession(session);
 551                                 return -1;
 552                         }
 553                 }
 554
 555                 return 0;
 556         }
 557
 558         bool Handshake(issl_session* session, StreamSocket* user)
 559         {
 560                 int ret = gnutls_handshake(session->sess);
 561
 562                 if (ret < 0)
 563                 {
 564                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 565                         {
 566                                 // Handshake needs resuming later, read() or write() would have blocked.
 567
 568                                 if(gnutls_record_get_direction(session->sess) == 0)
 569                                 {
 570                                         // gnutls_handshake() wants to read() again.
 571                                         session->status = ISSL_HANDSHAKING_READ;
 572                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 573                                 }
 574                                 else
 575                                 {
 576                                         // gnutls_handshake() wants to write() again.
 577                                         session->status = ISSL_HANDSHAKING_WRITE;
 578                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 579                                 }
 580                         }
 581                         else
 582                         {
 583                                 user->SetError(std::string("Handshake Failed - ") + gnutls_strerror(ret));
 584                                 CloseSession(session);
 585                                 session->status = ISSL_CLOSING;
 586                         }
 587
 588                         return false;
 589                 }
 590                 else
 591                 {
 592                         // Change the seesion state
 593                         session->status = ISSL_HANDSHAKEN;
 594
 595                         VerifyCertificate(session,user);
 596
 597                         // Finish writing, if any left
 598                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 599
 600                         return true;
 601                 }
 602         }
 603
 604         void OnUserConnect(LocalUser* user)
 605         {
 606                 if (user->eh.GetIOHook() == this)
 607                 {
 608                         if (sessions[user->eh.GetFd()].sess)
 609                         {
 610                                 ssl_cert* cert = sessions[user->eh.GetFd()].cert;
 611                                 std::string cipher = gnutls_kx_get_name(gnutls_kx_get(sessions[user->eh.GetFd()].sess));
 612                                 cipher.append("-").append(gnutls_cipher_get_name(gnutls_cipher_get(sessions[user->eh.GetFd()].sess))).append("-");
 613                                 cipher.append(gnutls_mac_get_name(gnutls_mac_get(sessions[user->eh.GetFd()].sess)));
 614                                 if (cert->fingerprint.empty())
 615                                         user->WriteServ("NOTICE %s :*** You are connected using SSL cipher \"%s\"", user->nick.c_str(), cipher.c_str());
 616                                 else
 617                                         user->WriteServ("NOTICE %s :*** You are connected using SSL cipher \"%s\""
 618                                                 " and your SSL fingerprint is %s", user->nick.c_str(), cipher.c_str(), cert->fingerprint.c_str());
 619                         }
 620                 }
 621         }
 622
 623         void CloseSession(issl_session* session)
 624         {
 625                 if (session->sess)
 626                 {
 627                         gnutls_bye(session->sess, GNUTLS_SHUT_WR);
 628                         gnutls_deinit(session->sess);
 629                 }
 630                 session->sess = NULL;
 631                 session->cert = NULL;
 632                 session->status = ISSL_NONE;
 633         }
 634
 635         void VerifyCertificate(issl_session* session, StreamSocket* user)
 636         {
 637                 if (!session->sess || !user)
 638                         return;
 639
 640                 unsigned int status;
 641                 const gnutls_datum_t* cert_list;
 642                 int ret;
 643                 unsigned int cert_list_size;
 644                 gnutls_x509_crt_t cert;
 645                 char name[MAXBUF];
 646                 unsigned char digest[MAXBUF];
 647                 size_t digest_size = sizeof(digest);
 648                 size_t name_size = sizeof(name);
 649                 ssl_cert* certinfo = new ssl_cert;
 650                 session->cert = certinfo;
 651
 652                 /* This verification function uses the trusted CAs in the credentials
 653                  * structure. So you must have installed one or more CA certificates.
 654                  */
 655                 ret = gnutls_certificate_verify_peers2(session->sess, &status);
 656
 657                 if (ret < 0)
 658                 {
 659                         certinfo->error = std::string(gnutls_strerror(ret));
 660                         return;
 661                 }
 662
 663                 certinfo->invalid = (status & GNUTLS_CERT_INVALID);
 664                 certinfo->unknownsigner = (status & GNUTLS_CERT_SIGNER_NOT_FOUND);
 665                 certinfo->revoked = (status & GNUTLS_CERT_REVOKED);
 666                 certinfo->trusted = !(status & GNUTLS_CERT_SIGNER_NOT_CA);
 667
 668                 /* Up to here the process is the same for X.509 certificates and
 669                  * OpenPGP keys. From now on X.509 certificates are assumed. This can
 670                  * be easily extended to work with openpgp keys as well.
 671                  */
 672                 if (gnutls_certificate_type_get(session->sess) != GNUTLS_CRT_X509)
 673                 {
 674                         certinfo->error = "No X509 keys sent";
 675                         return;
 676                 }
 677
 678                 ret = gnutls_x509_crt_init(&cert);
 679                 if (ret < 0)
 680                 {
 681                         certinfo->error = gnutls_strerror(ret);
 682                         return;
 683                 }
 684
 685                 cert_list_size = 0;
 686                 cert_list = gnutls_certificate_get_peers(session->sess, &cert_list_size);
 687                 if (cert_list == NULL)
 688                 {
 689                         certinfo->error = "No certificate was found";
 690                         goto info_done_dealloc;
 691                 }
 692
 693                 /* This is not a real world example, since we only check the first
 694                  * certificate in the given chain.
 695                  */
 696
 697                 ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
 698                 if (ret < 0)
 699                 {
 700                         certinfo->error = gnutls_strerror(ret);
 701                         goto info_done_dealloc;
 702                 }
 703
 704                 gnutls_x509_crt_get_dn(cert, name, &name_size);
 705                 certinfo->dn = name;
 706
 707                 gnutls_x509_crt_get_issuer_dn(cert, name, &name_size);
 708                 certinfo->issuer = name;
 709
 710                 if ((ret = gnutls_x509_crt_get_fingerprint(cert, hash, digest, &digest_size)) < 0)
 711                 {
 712                         certinfo->error = gnutls_strerror(ret);
 713                 }
 714                 else
 715                 {
 716                         certinfo->fingerprint = irc::hex(digest, digest_size);
 717                 }
 718
 719                 /* Beware here we do not check for errors.
 720                  */
 721                 if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
 722                 {
 723                         certinfo->error = "Not activated, or expired certificate";
 724                 }
 725
 726 info_done_dealloc:
 727                 gnutls_x509_crt_deinit(cert);
 728         }
 729
 730         void OnEvent(Event& ev)
 731         {
 732                 if (starttls.enabled)
 733                         capHandler.HandleEvent(ev);
 734         }
 735 };
 736
 737 MODULE_INIT(ModuleSSLGnuTLS)