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                 int ret;
 327
 328                 if((ret = gnutls_dh_params_generate2(dh_params, dh_bits)) < 0)
 329                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to generate DH parameters (%d bits): %s", dh_bits, gnutls_strerror(ret));
 330         }
 331
 332         ~ModuleSSLGnuTLS()
 333         {
 334                 for(unsigned int i=0; i < x509_certs.size(); i++)
 335                         gnutls_x509_crt_deinit(x509_certs[i]);
 336
 337                 gnutls_x509_privkey_deinit(x509_key);
 338
 339                 if (dh_alloc)
 340                         gnutls_dh_params_deinit(dh_params);
 341                 if (cred_alloc)
 342                         gnutls_certificate_free_credentials(x509_cred);
 343
 344                 gnutls_global_deinit();
 345                 delete[] sessions;
 346                 ServerInstance->GenRandom = &ServerInstance->HandleGenRandom;
 347         }
 348
 349         void OnCleanup(int target_type, void* item)
 350         {
 351                 if(target_type == TYPE_USER)
 352                 {
 353                         LocalUser* user = IS_LOCAL(static_cast<User*>(item));
 354
 355                         if (user && user->eh.GetIOHook() == this)
 356                         {
 357                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 358                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 359                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 360                         }
 361                 }
 362         }
 363
 364         Version GetVersion()
 365         {
 366                 return Version("Provides SSL support for clients", VF_VENDOR);
 367         }
 368
 369
 370         void On005Numeric(std::string &output)
 371         {
 372                 if (!sslports.empty())
 373                         output.append(" SSL=" + sslports);
 374                 if (starttls.enabled)
 375                         output.append(" STARTTLS");
 376         }
 377
 378         void OnHookIO(StreamSocket* user, ListenSocket* lsb)
 379         {
 380                 if (!user->GetIOHook() && lsb->bind_tag->getString("ssl") == "gnutls")
 381                 {
 382                         /* Hook the user with our module */
 383                         user->AddIOHook(this);
 384                 }
 385         }
 386
 387         void OnRequest(Request& request)
 388         {
 389                 if (strcmp("GET_SSL_CERT", request.id) == 0)
 390                 {
 391                         SocketCertificateRequest& req = static_cast<SocketCertificateRequest&>(request);
 392                         int fd = req.sock->GetFd();
 393                         issl_session* session = &sessions[fd];
 394
 395                         req.cert = session->cert;
 396                 }
 397         }
 398
 399         void OnStreamSocketAccept(StreamSocket* user, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server)
 400         {
 401                 int fd = user->GetFd();
 402                 issl_session* session = &sessions[fd];
 403
 404                 /* For STARTTLS: Don't try and init a session on a socket that already has a session */
 405                 if (session->sess)
 406                         return;
 407
 408                 gnutls_init(&session->sess, GNUTLS_SERVER);
 409
 410                 gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
 411                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 412                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 413
 414                 gnutls_transport_set_ptr(session->sess, reinterpret_cast<gnutls_transport_ptr_t>(user));
 415                 gnutls_transport_set_push_function(session->sess, gnutls_push_wrapper);
 416                 gnutls_transport_set_pull_function(session->sess, gnutls_pull_wrapper);
 417
 418                 gnutls_certificate_server_set_request(session->sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
 419
 420                 Handshake(session, user);
 421         }
 422
 423         void OnStreamSocketConnect(StreamSocket* user)
 424         {
 425                 issl_session* session = &sessions[user->GetFd()];
 426
 427                 gnutls_init(&session->sess, GNUTLS_CLIENT);
 428
 429                 gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
 430                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 431                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 432                 gnutls_transport_set_ptr(session->sess, reinterpret_cast<gnutls_transport_ptr_t>(user));
 433                 gnutls_transport_set_push_function(session->sess, gnutls_push_wrapper);
 434                 gnutls_transport_set_pull_function(session->sess, gnutls_pull_wrapper);
 435
 436                 Handshake(session, user);
 437         }
 438
 439         void OnStreamSocketClose(StreamSocket* user)
 440         {
 441                 CloseSession(&sessions[user->GetFd()]);
 442         }
 443
 444         int OnStreamSocketRead(StreamSocket* user, std::string& recvq)
 445         {
 446                 issl_session* session = &sessions[user->GetFd()];
 447
 448                 if (!session->sess)
 449                 {
 450                         CloseSession(session);
 451                         user->SetError("No SSL session");
 452                         return -1;
 453                 }
 454
 455                 if (session->status == ISSL_HANDSHAKING_READ || session->status == ISSL_HANDSHAKING_WRITE)
 456                 {
 457                         // The handshake isn't finished, try to finish it.
 458
 459                         if(!Handshake(session, user))
 460                         {
 461                                 if (session->status != ISSL_CLOSING)
 462                                         return 0;
 463                                 return -1;
 464                         }
 465                 }
 466
 467                 // If we resumed the handshake then session->status will be ISSL_HANDSHAKEN.
 468
 469                 if (session->status == ISSL_HANDSHAKEN)
 470                 {
 471                         char* buffer = ServerInstance->GetReadBuffer();
 472                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 473                         int ret = gnutls_record_recv(session->sess, buffer, bufsiz);
 474                         if (ret > 0)
 475                         {
 476                                 recvq.append(buffer, ret);
 477                                 return 1;
 478                         }
 479                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 480                         {
 481                                 return 0;
 482                         }
 483                         else if (ret == 0)
 484                         {
 485                                 user->SetError("SSL Connection closed");
 486                                 CloseSession(session);
 487                                 return -1;
 488                         }
 489                         else
 490                         {
 491                                 user->SetError(gnutls_strerror(ret));
 492                                 CloseSession(session);
 493                                 return -1;
 494                         }
 495                 }
 496                 else if (session->status == ISSL_CLOSING)
 497                         return -1;
 498
 499                 return 0;
 500         }
 501
 502         int OnStreamSocketWrite(StreamSocket* user, std::string& sendq)
 503         {
 504                 issl_session* session = &sessions[user->GetFd()];
 505
 506                 if (!session->sess)
 507                 {
 508                         CloseSession(session);
 509                         user->SetError("No SSL session");
 510                         return -1;
 511                 }
 512
 513                 if (session->status == ISSL_HANDSHAKING_WRITE || session->status == ISSL_HANDSHAKING_READ)
 514                 {
 515                         // The handshake isn't finished, try to finish it.
 516                         Handshake(session, user);
 517                         if (session->status != ISSL_CLOSING)
 518                                 return 0;
 519                         return -1;
 520                 }
 521
 522                 int ret = 0;
 523
 524                 if (session->status == ISSL_HANDSHAKEN)
 525                 {
 526                         ret = gnutls_record_send(session->sess, sendq.data(), sendq.length());
 527
 528                         if (ret == (int)sendq.length())
 529                         {
 530                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_WRITE);
 531                                 return 1;
 532                         }
 533                         else if (ret > 0)
 534                         {
 535                                 sendq = sendq.substr(ret);
 536                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 537                                 return 0;
 538                         }
 539                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED || ret == 0)
 540                         {
 541                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 542                                 return 0;
 543                         }
 544                         else // (ret < 0)
 545                         {
 546                                 user->SetError(gnutls_strerror(ret));
 547                                 CloseSession(session);
 548                                 return -1;
 549                         }
 550                 }
 551
 552                 return 0;
 553         }
 554
 555         bool Handshake(issl_session* session, StreamSocket* user)
 556         {
 557                 int ret = gnutls_handshake(session->sess);
 558
 559                 if (ret < 0)
 560                 {
 561                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 562                         {
 563                                 // Handshake needs resuming later, read() or write() would have blocked.
 564
 565                                 if(gnutls_record_get_direction(session->sess) == 0)
 566                                 {
 567                                         // gnutls_handshake() wants to read() again.
 568                                         session->status = ISSL_HANDSHAKING_READ;
 569                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 570                                 }
 571                                 else
 572                                 {
 573                                         // gnutls_handshake() wants to write() again.
 574                                         session->status = ISSL_HANDSHAKING_WRITE;
 575                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 576                                 }
 577                         }
 578                         else
 579                         {
 580                                 user->SetError(std::string("Handshake Failed - ") + gnutls_strerror(ret));
 581                                 CloseSession(session);
 582                                 session->status = ISSL_CLOSING;
 583                         }
 584
 585                         return false;
 586                 }
 587                 else
 588                 {
 589                         // Change the seesion state
 590                         session->status = ISSL_HANDSHAKEN;
 591
 592                         VerifyCertificate(session,user);
 593
 594                         // Finish writing, if any left
 595                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 596
 597                         return true;
 598                 }
 599         }
 600
 601         void OnUserConnect(LocalUser* user)
 602         {
 603                 if (user->eh.GetIOHook() == this)
 604                 {
 605                         if (sessions[user->eh.GetFd()].sess)
 606                         {
 607                                 ssl_cert* cert = sessions[user->eh.GetFd()].cert;
 608                                 std::string cipher = gnutls_kx_get_name(gnutls_kx_get(sessions[user->eh.GetFd()].sess));
 609                                 cipher.append("-").append(gnutls_cipher_get_name(gnutls_cipher_get(sessions[user->eh.GetFd()].sess))).append("-");
 610                                 cipher.append(gnutls_mac_get_name(gnutls_mac_get(sessions[user->eh.GetFd()].sess)));
 611                                 if (cert->fingerprint.empty())
 612                                         user->WriteServ("NOTICE %s :*** You are connected using SSL cipher \"%s\"", user->nick.c_str(), cipher.c_str());
 613                                 else
 614                                         user->WriteServ("NOTICE %s :*** You are connected using SSL cipher \"%s\""
 615                                                 " and your SSL fingerprint is %s", user->nick.c_str(), cipher.c_str(), cert->fingerprint.c_str());
 616                         }
 617                 }
 618         }
 619
 620         void CloseSession(issl_session* session)
 621         {
 622                 if (session->sess)
 623                 {
 624                         gnutls_bye(session->sess, GNUTLS_SHUT_WR);
 625                         gnutls_deinit(session->sess);
 626                 }
 627                 session->sess = NULL;
 628                 session->cert = NULL;
 629                 session->status = ISSL_NONE;
 630         }
 631
 632         void VerifyCertificate(issl_session* session, StreamSocket* user)
 633         {
 634                 if (!session->sess || !user)
 635                         return;
 636
 637                 unsigned int status;
 638                 const gnutls_datum_t* cert_list;
 639                 int ret;
 640                 unsigned int cert_list_size;
 641                 gnutls_x509_crt_t cert;
 642                 char name[MAXBUF];
 643                 unsigned char digest[MAXBUF];
 644                 size_t digest_size = sizeof(digest);
 645                 size_t name_size = sizeof(name);
 646                 ssl_cert* certinfo = new ssl_cert;
 647                 session->cert = certinfo;
 648
 649                 /* This verification function uses the trusted CAs in the credentials
 650                  * structure. So you must have installed one or more CA certificates.
 651                  */
 652                 ret = gnutls_certificate_verify_peers2(session->sess, &status);
 653
 654                 if (ret < 0)
 655                 {
 656                         certinfo->error = std::string(gnutls_strerror(ret));
 657                         return;
 658                 }
 659
 660                 certinfo->invalid = (status & GNUTLS_CERT_INVALID);
 661                 certinfo->unknownsigner = (status & GNUTLS_CERT_SIGNER_NOT_FOUND);
 662                 certinfo->revoked = (status & GNUTLS_CERT_REVOKED);
 663                 certinfo->trusted = !(status & GNUTLS_CERT_SIGNER_NOT_CA);
 664
 665                 /* Up to here the process is the same for X.509 certificates and
 666                  * OpenPGP keys. From now on X.509 certificates are assumed. This can
 667                  * be easily extended to work with openpgp keys as well.
 668                  */
 669                 if (gnutls_certificate_type_get(session->sess) != GNUTLS_CRT_X509)
 670                 {
 671                         certinfo->error = "No X509 keys sent";
 672                         return;
 673                 }
 674
 675                 ret = gnutls_x509_crt_init(&cert);
 676                 if (ret < 0)
 677                 {
 678                         certinfo->error = gnutls_strerror(ret);
 679                         return;
 680                 }
 681
 682                 cert_list_size = 0;
 683                 cert_list = gnutls_certificate_get_peers(session->sess, &cert_list_size);
 684                 if (cert_list == NULL)
 685                 {
 686                         certinfo->error = "No certificate was found";
 687                         goto info_done_dealloc;
 688                 }
 689
 690                 /* This is not a real world example, since we only check the first
 691                  * certificate in the given chain.
 692                  */
 693
 694                 ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
 695                 if (ret < 0)
 696                 {
 697                         certinfo->error = gnutls_strerror(ret);
 698                         goto info_done_dealloc;
 699                 }
 700
 701                 gnutls_x509_crt_get_dn(cert, name, &name_size);
 702                 certinfo->dn = name;
 703
 704                 gnutls_x509_crt_get_issuer_dn(cert, name, &name_size);
 705                 certinfo->issuer = name;
 706
 707                 if ((ret = gnutls_x509_crt_get_fingerprint(cert, hash, digest, &digest_size)) < 0)
 708                 {
 709                         certinfo->error = gnutls_strerror(ret);
 710                 }
 711                 else
 712                 {
 713                         certinfo->fingerprint = irc::hex(digest, digest_size);
 714                 }
 715
 716                 /* Beware here we do not check for errors.
 717                  */
 718                 if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
 719                 {
 720                         certinfo->error = "Not activated, or expired certificate";
 721                 }
 722
 723 info_done_dealloc:
 724                 gnutls_x509_crt_deinit(cert);
 725         }
 726
 727         void OnEvent(Event& ev)
 728         {
 729                 if (starttls.enabled)
 730                         capHandler.HandleEvent(ev);
 731         }
 732 };
 733
 734 MODULE_INIT(ModuleSSLGnuTLS)