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 = recv(user->GetFd(), 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 = send(user->GetFd(), 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
 160         RandGen randhandler;
 161         CommandStartTLS starttls;
 162
 163         GenericCap capHandler;
 164         ServiceProvider iohook;
 165  public:
 166
 167         ModuleSSLGnuTLS()
 168                 : starttls(this), capHandler(this, "tls"), iohook(this, "ssl/gnutls", SERVICE_IOHOOK)
 169         {
 170                 sessions = new issl_session[ServerInstance->SE->GetMaxFds()];
 171
 172                 gnutls_global_init(); // This must be called once in the program
 173                 gnutls_x509_privkey_init(&x509_key);
 174
 175                 cred_alloc = false;
 176         }
 177
 178         void init()
 179         {
 180                 // Needs the flag as it ignores a plain /rehash
 181                 OnModuleRehash(NULL,"ssl");
 182
 183                 ServerInstance->GenRandom = &randhandler;
 184
 185                 // Void return, guess we assume success
 186                 gnutls_certificate_set_dh_params(x509_cred, dh_params);
 187                 Implementation eventlist[] = { I_On005Numeric, I_OnRehash, I_OnModuleRehash, I_OnUserConnect,
 188                         I_OnEvent, I_OnHookIO };
 189                 ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
 190
 191                 ServerInstance->Modules->AddService(iohook);
 192                 ServerInstance->AddCommand(&starttls);
 193         }
 194
 195         void OnRehash(User* user)
 196         {
 197                 sslports.clear();
 198
 199                 ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
 200                 starttls.enabled = Conf->getBool("starttls", true);
 201
 202                 if (Conf->getBool("showports", true))
 203                 {
 204                         for (size_t i = 0; i < ServerInstance->ports.size(); i++)
 205                         {
 206                                 ListenSocket* port = ServerInstance->ports[i];
 207                                 if (port->bind_tag->getString("ssl") != "gnutls")
 208                                         continue;
 209
 210                                 const std::string& portid = port->bind_desc;
 211                                 ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT, "m_ssl_gnutls.so: Enabling SSL for port %s", portid.c_str());
 212
 213                                 if (port->bind_tag->getString("type", "clients") == "clients" && port->bind_addr != "127.0.0.1")
 214                                         sslports.append(portid).append(";");
 215                         }
 216
 217                         if (!sslports.empty())
 218                                 sslports.erase(sslports.end() - 1);
 219                 }
 220         }
 221
 222         void OnModuleRehash(User* user, const std::string &param)
 223         {
 224                 if(param != "ssl")
 225                         return;
 226
 227                 std::string keyfile;
 228                 std::string certfile;
 229                 std::string cafile;
 230                 std::string crlfile;
 231                 OnRehash(user);
 232
 233                 ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
 234
 235                 cafile = Conf->getString("cafile", "conf/ca.pem");
 236                 crlfile = Conf->getString("crlfile", "conf/crl.pem");
 237                 certfile = Conf->getString("certfile", "conf/cert.pem");
 238                 keyfile = Conf->getString("keyfile", "conf/key.pem");
 239                 dh_bits = Conf->getInt("dhbits");
 240                 std::string hashname = Conf->getString("hash", "md5");
 241
 242                 if((dh_bits != 768) && (dh_bits != 1024) && (dh_bits != 2048) && (dh_bits != 3072) && (dh_bits != 4096))
 243                         dh_bits = 1024;
 244
 245                 if (hashname == "md5")
 246                         hash = GNUTLS_DIG_MD5;
 247                 else if (hashname == "sha1")
 248                         hash = GNUTLS_DIG_SHA1;
 249                 else
 250                         throw ModuleException("Unknown hash type " + hashname);
 251
 252
 253                 int ret;
 254
 255                 if (cred_alloc)
 256                 {
 257                         // Deallocate the old credentials
 258                         gnutls_dh_params_deinit(dh_params);
 259                         gnutls_certificate_free_credentials(x509_cred);
 260
 261                         for(unsigned int i=0; i < x509_certs.size(); i++)
 262                                 gnutls_x509_crt_deinit(x509_certs[i]);
 263                         x509_certs.clear();
 264                 }
 265                 else
 266                         cred_alloc = true;
 267
 268                 if((ret = gnutls_certificate_allocate_credentials(&x509_cred)) < 0)
 269                         ServerInstance->Logs->Log("m_ssl_gnutls",DEBUG, "m_ssl_gnutls.so: Failed to allocate certificate credentials: %s", gnutls_strerror(ret));
 270
 271                 if((ret =gnutls_certificate_set_x509_trust_file(x509_cred, cafile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 272                         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));
 273
 274                 if((ret = gnutls_certificate_set_x509_crl_file (x509_cred, crlfile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 275                         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));
 276
 277                 FileReader reader;
 278
 279                 reader.LoadFile(certfile);
 280                 std::string cert_string = reader.Contents();
 281                 gnutls_datum_t cert_datum = { (unsigned char*)cert_string.data(), cert_string.length() };
 282
 283                 reader.LoadFile(keyfile);
 284                 std::string key_string = reader.Contents();
 285                 gnutls_datum_t key_datum = { (unsigned char*)key_string.data(), key_string.length() };
 286
 287                 // If this fails, no SSL port will work. At all. So, do the smart thing - throw a ModuleException
 288                 unsigned int certcount = Conf->getInt("certcount", 3);
 289                 x509_certs.resize(certcount);
 290                 ret = gnutls_x509_crt_list_import(&x509_certs[0], &certcount, &cert_datum, GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 291                 if (ret < 0)
 292                         throw ModuleException("Unable to load GnuTLS server certificate (" + certfile + "): " + std::string(gnutls_strerror(ret)));
 293                 x509_certs.resize(certcount);
 294
 295                 if((ret = gnutls_x509_privkey_import(x509_key, &key_datum, GNUTLS_X509_FMT_PEM)) < 0)
 296                         throw ModuleException("Unable to load GnuTLS server private key (" + keyfile + "): " + std::string(gnutls_strerror(ret)));
 297
 298                 if((ret = gnutls_certificate_set_x509_key(x509_cred, &x509_certs[0], certcount, x509_key)) < 0)
 299                         throw ModuleException("Unable to set GnuTLS cert/key pair: " + std::string(gnutls_strerror(ret)));
 300
 301                 gnutls_certificate_client_set_retrieve_function (x509_cred, cert_callback);
 302
 303                 if((ret = gnutls_dh_params_init(&dh_params)) < 0)
 304                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to initialise DH parameters: %s", gnutls_strerror(ret));
 305
 306                 // This may be on a large (once a day or week) timer eventually.
 307                 GenerateDHParams();
 308         }
 309
 310         void GenerateDHParams()
 311         {
 312                 // Generate Diffie Hellman parameters - for use with DHE
 313                 // kx algorithms. These should be discarded and regenerated
 314                 // once a day, once a week or once a month. Depending on the
 315                 // security requirements.
 316
 317                 int ret;
 318
 319                 if((ret = gnutls_dh_params_generate2(dh_params, dh_bits)) < 0)
 320                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to generate DH parameters (%d bits): %s", dh_bits, gnutls_strerror(ret));
 321         }
 322
 323         ~ModuleSSLGnuTLS()
 324         {
 325                 for(unsigned int i=0; i < x509_certs.size(); i++)
 326                         gnutls_x509_crt_deinit(x509_certs[i]);
 327                 x509_certs.clear();
 328                 gnutls_x509_privkey_deinit(x509_key);
 329                 if (cred_alloc)
 330                 {
 331                         gnutls_dh_params_deinit(dh_params);
 332                         gnutls_certificate_free_credentials(x509_cred);
 333                 }
 334                 gnutls_global_deinit();
 335                 delete[] sessions;
 336                 ServerInstance->GenRandom = &ServerInstance->HandleGenRandom;
 337         }
 338
 339         void OnCleanup(int target_type, void* item)
 340         {
 341                 if(target_type == TYPE_USER)
 342                 {
 343                         LocalUser* user = IS_LOCAL(static_cast<User*>(item));
 344
 345                         if (user && user->eh.GetIOHook() == this)
 346                         {
 347                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 348                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 349                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 350                         }
 351                 }
 352         }
 353
 354         Version GetVersion()
 355         {
 356                 return Version("Provides SSL support for clients", VF_VENDOR);
 357         }
 358
 359
 360         void On005Numeric(std::string &output)
 361         {
 362                 if (!sslports.empty())
 363                         output.append(" SSL=" + sslports);
 364                 if (starttls.enabled)
 365                         output.append(" STARTTLS");
 366         }
 367
 368         void OnHookIO(StreamSocket* user, ListenSocket* lsb)
 369         {
 370                 if (!user->GetIOHook() && lsb->bind_tag->getString("ssl") == "gnutls")
 371                 {
 372                         /* Hook the user with our module */
 373                         user->AddIOHook(this);
 374                 }
 375         }
 376
 377         void OnRequest(Request& request)
 378         {
 379                 if (strcmp("GET_SSL_CERT", request.id) == 0)
 380                 {
 381                         SocketCertificateRequest& req = static_cast<SocketCertificateRequest&>(request);
 382                         int fd = req.sock->GetFd();
 383                         issl_session* session = &sessions[fd];
 384
 385                         req.cert = session->cert;
 386                 }
 387         }
 388
 389         void OnStreamSocketAccept(StreamSocket* user, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server)
 390         {
 391                 int fd = user->GetFd();
 392                 issl_session* session = &sessions[fd];
 393
 394                 /* For STARTTLS: Don't try and init a session on a socket that already has a session */
 395                 if (session->sess)
 396                         return;
 397
 398                 gnutls_init(&session->sess, GNUTLS_SERVER);
 399
 400                 gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
 401                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 402                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 403
 404                 gnutls_transport_set_ptr(session->sess, reinterpret_cast<gnutls_transport_ptr_t>(user));
 405                 gnutls_transport_set_push_function(session->sess, gnutls_push_wrapper);
 406                 gnutls_transport_set_pull_function(session->sess, gnutls_pull_wrapper);
 407
 408                 gnutls_certificate_server_set_request(session->sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
 409
 410                 Handshake(session, user);
 411         }
 412
 413         void OnStreamSocketConnect(StreamSocket* user)
 414         {
 415                 issl_session* session = &sessions[user->GetFd()];
 416
 417                 gnutls_init(&session->sess, GNUTLS_CLIENT);
 418
 419                 gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
 420                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 421                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 422                 gnutls_transport_set_ptr(session->sess, reinterpret_cast<gnutls_transport_ptr_t>(user));
 423                 gnutls_transport_set_push_function(session->sess, gnutls_push_wrapper);
 424                 gnutls_transport_set_pull_function(session->sess, gnutls_pull_wrapper);
 425
 426                 Handshake(session, user);
 427         }
 428
 429         void OnStreamSocketClose(StreamSocket* user)
 430         {
 431                 CloseSession(&sessions[user->GetFd()]);
 432         }
 433
 434         int OnStreamSocketRead(StreamSocket* user, std::string& recvq)
 435         {
 436                 issl_session* session = &sessions[user->GetFd()];
 437
 438                 if (!session->sess)
 439                 {
 440                         CloseSession(session);
 441                         user->SetError("No SSL session");
 442                         return -1;
 443                 }
 444
 445                 if (session->status == ISSL_HANDSHAKING_READ || session->status == ISSL_HANDSHAKING_WRITE)
 446                 {
 447                         // The handshake isn't finished, try to finish it.
 448
 449                         if(!Handshake(session, user))
 450                         {
 451                                 if (session->status != ISSL_CLOSING)
 452                                         return 0;
 453                                 return -1;
 454                         }
 455                 }
 456
 457                 // If we resumed the handshake then session->status will be ISSL_HANDSHAKEN.
 458
 459                 if (session->status == ISSL_HANDSHAKEN)
 460                 {
 461                         char* buffer = ServerInstance->GetReadBuffer();
 462                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 463                         int ret = gnutls_record_recv(session->sess, buffer, bufsiz);
 464                         if (ret > 0)
 465                         {
 466                                 recvq.append(buffer, ret);
 467                                 return 1;
 468                         }
 469                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 470                         {
 471                                 return 0;
 472                         }
 473                         else if (ret == 0)
 474                         {
 475                                 user->SetError("SSL Connection closed");
 476                                 CloseSession(session);
 477                                 return -1;
 478                         }
 479                         else
 480                         {
 481                                 user->SetError(gnutls_strerror(ret));
 482                                 CloseSession(session);
 483                                 return -1;
 484                         }
 485                 }
 486                 else if (session->status == ISSL_CLOSING)
 487                         return -1;
 488
 489                 return 0;
 490         }
 491
 492         int OnStreamSocketWrite(StreamSocket* user, std::string& sendq)
 493         {
 494                 issl_session* session = &sessions[user->GetFd()];
 495
 496                 if (!session->sess)
 497                 {
 498                         CloseSession(session);
 499                         user->SetError("No SSL session");
 500                         return -1;
 501                 }
 502
 503                 if (session->status == ISSL_HANDSHAKING_WRITE || session->status == ISSL_HANDSHAKING_READ)
 504                 {
 505                         // The handshake isn't finished, try to finish it.
 506                         Handshake(session, user);
 507                         if (session->status != ISSL_CLOSING)
 508                                 return 0;
 509                         return -1;
 510                 }
 511
 512                 int ret = 0;
 513
 514                 if (session->status == ISSL_HANDSHAKEN)
 515                 {
 516                         ret = gnutls_record_send(session->sess, sendq.data(), sendq.length());
 517
 518                         if (ret == (int)sendq.length())
 519                         {
 520                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_WRITE);
 521                                 return 1;
 522                         }
 523                         else if (ret > 0)
 524                         {
 525                                 sendq = sendq.substr(ret);
 526                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 527                                 return 0;
 528                         }
 529                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED || ret == 0)
 530                         {
 531                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 532                                 return 0;
 533                         }
 534                         else // (ret < 0)
 535                         {
 536                                 user->SetError(gnutls_strerror(ret));
 537                                 CloseSession(session);
 538                                 return -1;
 539                         }
 540                 }
 541
 542                 return 0;
 543         }
 544
 545         bool Handshake(issl_session* session, StreamSocket* user)
 546         {
 547                 int ret = gnutls_handshake(session->sess);
 548
 549                 if (ret < 0)
 550                 {
 551                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 552                         {
 553                                 // Handshake needs resuming later, read() or write() would have blocked.
 554
 555                                 if(gnutls_record_get_direction(session->sess) == 0)
 556                                 {
 557                                         // gnutls_handshake() wants to read() again.
 558                                         session->status = ISSL_HANDSHAKING_READ;
 559                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 560                                 }
 561                                 else
 562                                 {
 563                                         // gnutls_handshake() wants to write() again.
 564                                         session->status = ISSL_HANDSHAKING_WRITE;
 565                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 566                                 }
 567                         }
 568                         else
 569                         {
 570                                 user->SetError(std::string("Handshake Failed - ") + gnutls_strerror(ret));
 571                                 CloseSession(session);
 572                                 session->status = ISSL_CLOSING;
 573                         }
 574
 575                         return false;
 576                 }
 577                 else
 578                 {
 579                         // Change the seesion state
 580                         session->status = ISSL_HANDSHAKEN;
 581
 582                         VerifyCertificate(session,user);
 583
 584                         // Finish writing, if any left
 585                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 586
 587                         return true;
 588                 }
 589         }
 590
 591         void OnUserConnect(LocalUser* user)
 592         {
 593                 if (user->eh.GetIOHook() == this)
 594                 {
 595                         if (sessions[user->eh.GetFd()].sess)
 596                         {
 597                                 ssl_cert* cert = sessions[user->eh.GetFd()].cert;
 598                                 std::string cipher = gnutls_kx_get_name(gnutls_kx_get(sessions[user->eh.GetFd()].sess));
 599                                 cipher.append("-").append(gnutls_cipher_get_name(gnutls_cipher_get(sessions[user->eh.GetFd()].sess))).append("-");
 600                                 cipher.append(gnutls_mac_get_name(gnutls_mac_get(sessions[user->eh.GetFd()].sess)));
 601                                 if (cert->fingerprint.empty())
 602                                         user->WriteServ("NOTICE %s :*** You are connected using SSL cipher \"%s\"", user->nick.c_str(), cipher.c_str());
 603                                 else
 604                                         user->WriteServ("NOTICE %s :*** You are connected using SSL cipher \"%s\""
 605                                                 " and your SSL fingerprint is %s", user->nick.c_str(), cipher.c_str(), cert->fingerprint.c_str());
 606                         }
 607                 }
 608         }
 609
 610         void CloseSession(issl_session* session)
 611         {
 612                 if (session->sess)
 613                 {
 614                         gnutls_bye(session->sess, GNUTLS_SHUT_WR);
 615                         gnutls_deinit(session->sess);
 616                 }
 617                 session->sess = NULL;
 618                 session->cert = NULL;
 619                 session->status = ISSL_NONE;
 620         }
 621
 622         void VerifyCertificate(issl_session* session, StreamSocket* user)
 623         {
 624                 if (!session->sess || !user)
 625                         return;
 626
 627                 unsigned int status;
 628                 const gnutls_datum_t* cert_list;
 629                 int ret;
 630                 unsigned int cert_list_size;
 631                 gnutls_x509_crt_t cert;
 632                 char name[MAXBUF];
 633                 unsigned char digest[MAXBUF];
 634                 size_t digest_size = sizeof(digest);
 635                 size_t name_size = sizeof(name);
 636                 ssl_cert* certinfo = new ssl_cert;
 637                 session->cert = certinfo;
 638
 639                 /* This verification function uses the trusted CAs in the credentials
 640                  * structure. So you must have installed one or more CA certificates.
 641                  */
 642                 ret = gnutls_certificate_verify_peers2(session->sess, &status);
 643
 644                 if (ret < 0)
 645                 {
 646                         certinfo->error = std::string(gnutls_strerror(ret));
 647                         return;
 648                 }
 649
 650                 certinfo->invalid = (status & GNUTLS_CERT_INVALID);
 651                 certinfo->unknownsigner = (status & GNUTLS_CERT_SIGNER_NOT_FOUND);
 652                 certinfo->revoked = (status & GNUTLS_CERT_REVOKED);
 653                 certinfo->trusted = !(status & GNUTLS_CERT_SIGNER_NOT_CA);
 654
 655                 /* Up to here the process is the same for X.509 certificates and
 656                  * OpenPGP keys. From now on X.509 certificates are assumed. This can
 657                  * be easily extended to work with openpgp keys as well.
 658                  */
 659                 if (gnutls_certificate_type_get(session->sess) != GNUTLS_CRT_X509)
 660                 {
 661                         certinfo->error = "No X509 keys sent";
 662                         return;
 663                 }
 664
 665                 ret = gnutls_x509_crt_init(&cert);
 666                 if (ret < 0)
 667                 {
 668                         certinfo->error = gnutls_strerror(ret);
 669                         return;
 670                 }
 671
 672                 cert_list_size = 0;
 673                 cert_list = gnutls_certificate_get_peers(session->sess, &cert_list_size);
 674                 if (cert_list == NULL)
 675                 {
 676                         certinfo->error = "No certificate was found";
 677                         goto info_done_dealloc;
 678                 }
 679
 680                 /* This is not a real world example, since we only check the first
 681                  * certificate in the given chain.
 682                  */
 683
 684                 ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
 685                 if (ret < 0)
 686                 {
 687                         certinfo->error = gnutls_strerror(ret);
 688                         goto info_done_dealloc;
 689                 }
 690
 691                 gnutls_x509_crt_get_dn(cert, name, &name_size);
 692                 certinfo->dn = name;
 693
 694                 gnutls_x509_crt_get_issuer_dn(cert, name, &name_size);
 695                 certinfo->issuer = name;
 696
 697                 if ((ret = gnutls_x509_crt_get_fingerprint(cert, hash, digest, &digest_size)) < 0)
 698                 {
 699                         certinfo->error = gnutls_strerror(ret);
 700                 }
 701                 else
 702                 {
 703                         certinfo->fingerprint = irc::hex(digest, digest_size);
 704                 }
 705
 706                 /* Beware here we do not check for errors.
 707                  */
 708                 if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
 709                 {
 710                         certinfo->error = "Not activated, or expired certificate";
 711                 }
 712
 713 info_done_dealloc:
 714                 gnutls_x509_crt_deinit(cert);
 715         }
 716
 717         void OnEvent(Event& ev)
 718         {
 719                 if (starttls.enabled)
 720                         capHandler.HandleEvent(ev);
 721         }
 722 };
 723
 724 MODULE_INIT(ModuleSSLGnuTLS)