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 #ifdef WINDOWS
  32 # pragma comment(lib, "libgnutls.lib")
  33 # pragma comment(lib, "libgcrypt.lib")
  34 # pragma comment(lib, "libgpg-error.lib")
  35 # pragma comment(lib, "user32.lib")
  36 # pragma comment(lib, "advapi32.lib")
  37 # pragma comment(lib, "libgcc.lib")
  38 # pragma comment(lib, "libmingwex.lib")
  39 # pragma comment(lib, "gdi32.lib")
  40 #endif
  41
  42 /* $ModDesc: Provides SSL support for clients */
  43 /* $CompileFlags: pkgconfincludes("gnutls","/gnutls/gnutls.h","") */
  44 /* $LinkerFlags: rpath("pkg-config --libs gnutls") pkgconflibs("gnutls","/libgnutls.so","-lgnutls") -lgcrypt */
  45
  46 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING_READ, ISSL_HANDSHAKING_WRITE, ISSL_HANDSHAKEN, ISSL_CLOSING, ISSL_CLOSED };
  47
  48 static std::vector<gnutls_x509_crt_t> x509_certs;
  49 static gnutls_x509_privkey_t x509_key;
  50 static int cert_callback (gnutls_session_t session, const gnutls_datum_t * req_ca_rdn, int nreqs,
  51         const gnutls_pk_algorithm_t * sign_algos, int sign_algos_length, gnutls_retr_st * st) {
  52
  53         st->type = GNUTLS_CRT_X509;
  54         st->ncerts = x509_certs.size();
  55         st->cert.x509 = &x509_certs[0];
  56         st->key.x509 = x509_key;
  57         st->deinit_all = 0;
  58
  59         return 0;
  60 }
  61
  62 static ssize_t gnutls_pull_wrapper(gnutls_transport_ptr_t user_wrap, void* buffer, size_t size)
  63 {
  64         StreamSocket* user = reinterpret_cast<StreamSocket*>(user_wrap);
  65         if (user->GetEventMask() & FD_READ_WILL_BLOCK)
  66         {
  67                 errno = EAGAIN;
  68                 return -1;
  69         }
  70         int rv = ServerInstance->SE->Recv(user, reinterpret_cast<char *>(buffer), size, 0);
  71         if (rv < (int)size)
  72                 ServerInstance->SE->ChangeEventMask(user, FD_READ_WILL_BLOCK);
  73         return rv;
  74 }
  75
  76 static ssize_t gnutls_push_wrapper(gnutls_transport_ptr_t user_wrap, const void* buffer, size_t size)
  77 {
  78         StreamSocket* user = reinterpret_cast<StreamSocket*>(user_wrap);
  79         if (user->GetEventMask() & FD_WRITE_WILL_BLOCK)
  80         {
  81                 errno = EAGAIN;
  82                 return -1;
  83         }
  84         int rv = ServerInstance->SE->Send(user, reinterpret_cast<const char *>(buffer), size, 0);
  85         if (rv < (int)size)
  86                 ServerInstance->SE->ChangeEventMask(user, FD_WRITE_WILL_BLOCK);
  87         return rv;
  88 }
  89
  90 class RandGen : public HandlerBase2<void, char*, size_t>
  91 {
  92  public:
  93         RandGen() {}
  94         void Call(char* buffer, size_t len)
  95         {
  96                 gcry_randomize(buffer, len, GCRY_STRONG_RANDOM);
  97         }
  98 };
  99
 100 /** Represents an SSL user's extra data
 101  */
 102 class issl_session
 103 {
 104 public:
 105         gnutls_session_t sess;
 106         issl_status status;
 107         reference<ssl_cert> cert;
 108         issl_session() : sess(NULL) {}
 109 };
 110
 111 class CommandStartTLS : public SplitCommand
 112 {
 113  public:
 114         bool enabled;
 115         CommandStartTLS (Module* mod) : SplitCommand(mod, "STARTTLS")
 116         {
 117                 enabled = true;
 118                 works_before_reg = true;
 119         }
 120
 121         CmdResult HandleLocal(const std::vector<std::string> &parameters, LocalUser *user)
 122         {
 123                 if (!enabled)
 124                 {
 125                         user->WriteNumeric(691, "%s :STARTTLS is not enabled", user->nick.c_str());
 126                         return CMD_FAILURE;
 127                 }
 128
 129                 if (user->registered == REG_ALL)
 130                 {
 131                         user->WriteNumeric(691, "%s :STARTTLS is not permitted after client registration is complete", user->nick.c_str());
 132                 }
 133                 else
 134                 {
 135                         if (!user->eh.GetIOHook())
 136                         {
 137                                 user->WriteNumeric(670, "%s :STARTTLS successful, go ahead with TLS handshake", user->nick.c_str());
 138                                 /* We need to flush the write buffer prior to adding the IOHook,
 139                                  * otherwise we'll be sending this line inside the SSL session - which
 140                                  * won't start its handshake until the client gets this line. Currently,
 141                                  * we assume the write will not block here; this is usually safe, as
 142                                  * STARTTLS is sent very early on in the registration phase, where the
 143                                  * user hasn't built up much sendq. Handling a blocked write here would
 144                                  * be very annoying.
 145                                  */
 146                                 user->eh.DoWrite();
 147                                 user->eh.AddIOHook(creator);
 148                                 creator->OnStreamSocketAccept(&user->eh, NULL, NULL);
 149                         }
 150                         else
 151                                 user->WriteNumeric(691, "%s :STARTTLS failure", user->nick.c_str());
 152                 }
 153
 154                 return CMD_FAILURE;
 155         }
 156 };
 157
 158 class ModuleSSLGnuTLS : public Module
 159 {
 160         issl_session* sessions;
 161
 162         gnutls_certificate_credentials x509_cred;
 163         gnutls_dh_params dh_params;
 164         gnutls_digest_algorithm_t hash;
 165
 166         std::string sslports;
 167         int dh_bits;
 168
 169         bool cred_alloc;
 170         bool dh_alloc;
 171
 172         RandGen randhandler;
 173         CommandStartTLS starttls;
 174
 175         GenericCap capHandler;
 176         ServiceProvider iohook;
 177  public:
 178
 179         ModuleSSLGnuTLS()
 180                 : starttls(this), capHandler(this, "tls"), iohook(this, "ssl/gnutls", SERVICE_IOHOOK)
 181         {
 182                 sessions = new issl_session[ServerInstance->SE->GetMaxFds()];
 183
 184                 gnutls_global_init(); // This must be called once in the program
 185                 gnutls_x509_privkey_init(&x509_key);
 186
 187                 cred_alloc = false;
 188                 dh_alloc = false;
 189         }
 190
 191         void init()
 192         {
 193                 // Needs the flag as it ignores a plain /rehash
 194                 OnModuleRehash(NULL,"ssl");
 195
 196                 ServerInstance->GenRandom = &randhandler;
 197
 198                 // Void return, guess we assume success
 199                 gnutls_certificate_set_dh_params(x509_cred, dh_params);
 200                 Implementation eventlist[] = { I_On005Numeric, I_OnRehash, I_OnModuleRehash, I_OnUserConnect,
 201                         I_OnEvent, I_OnHookIO };
 202                 ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
 203
 204                 ServerInstance->Modules->AddService(iohook);
 205                 ServerInstance->AddCommand(&starttls);
 206         }
 207
 208         void OnRehash(User* user)
 209         {
 210                 sslports.clear();
 211
 212                 ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
 213                 starttls.enabled = Conf->getBool("starttls", true);
 214
 215                 if (Conf->getBool("showports", true))
 216                 {
 217                         sslports = Conf->getString("advertisedports");
 218                         if (!sslports.empty())
 219                                 return;
 220
 221                         for (size_t i = 0; i < ServerInstance->ports.size(); i++)
 222                         {
 223                                 ListenSocket* port = ServerInstance->ports[i];
 224                                 if (port->bind_tag->getString("ssl") != "gnutls")
 225                                         continue;
 226
 227                                 const std::string& portid = port->bind_desc;
 228                                 ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT, "m_ssl_gnutls.so: Enabling SSL for port %s", portid.c_str());
 229
 230                                 if (port->bind_tag->getString("type", "clients") == "clients" && port->bind_addr != "127.0.0.1")
 231                                         sslports.append(portid).append(";");
 232                         }
 233
 234                         if (!sslports.empty())
 235                                 sslports.erase(sslports.end() - 1);
 236                 }
 237         }
 238
 239         void OnModuleRehash(User* user, const std::string &param)
 240         {
 241                 if(param != "ssl")
 242                         return;
 243
 244                 std::string keyfile;
 245                 std::string certfile;
 246                 std::string cafile;
 247                 std::string crlfile;
 248                 OnRehash(user);
 249
 250                 ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
 251
 252                 cafile = Conf->getString("cafile", "conf/ca.pem");
 253                 crlfile = Conf->getString("crlfile", "conf/crl.pem");
 254                 certfile = Conf->getString("certfile", "conf/cert.pem");
 255                 keyfile = Conf->getString("keyfile", "conf/key.pem");
 256                 dh_bits = Conf->getInt("dhbits");
 257                 std::string hashname = Conf->getString("hash", "md5");
 258
 259                 if((dh_bits != 768) && (dh_bits != 1024) && (dh_bits != 2048) && (dh_bits != 3072) && (dh_bits != 4096))
 260                         dh_bits = 1024;
 261
 262                 if (hashname == "md5")
 263                         hash = GNUTLS_DIG_MD5;
 264                 else if (hashname == "sha1")
 265                         hash = GNUTLS_DIG_SHA1;
 266                 else
 267                         throw ModuleException("Unknown hash type " + hashname);
 268
 269
 270                 int ret;
 271
 272                 if (dh_alloc)
 273                 {
 274                         gnutls_dh_params_deinit(dh_params);
 275                         dh_alloc = false;
 276                 }
 277
 278                 if (cred_alloc)
 279                 {
 280                         // Deallocate the old credentials
 281                         gnutls_certificate_free_credentials(x509_cred);
 282
 283                         for(unsigned int i=0; i < x509_certs.size(); i++)
 284                                 gnutls_x509_crt_deinit(x509_certs[i]);
 285                         x509_certs.clear();
 286                 }
 287
 288                 ret = gnutls_certificate_allocate_credentials(&x509_cred);
 289                 cred_alloc = (ret >= 0);
 290                 if (!cred_alloc)
 291                         ServerInstance->Logs->Log("m_ssl_gnutls",DEBUG, "m_ssl_gnutls.so: Failed to allocate certificate credentials: %s", gnutls_strerror(ret));
 292
 293                 if((ret =gnutls_certificate_set_x509_trust_file(x509_cred, cafile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 294                         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));
 295
 296                 if((ret = gnutls_certificate_set_x509_crl_file (x509_cred, crlfile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 297                         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));
 298
 299                 FileReader reader;
 300
 301                 reader.LoadFile(certfile);
 302                 std::string cert_string = reader.Contents();
 303                 gnutls_datum_t cert_datum = { (unsigned char*)cert_string.data(), cert_string.length() };
 304
 305                 reader.LoadFile(keyfile);
 306                 std::string key_string = reader.Contents();
 307                 gnutls_datum_t key_datum = { (unsigned char*)key_string.data(), key_string.length() };
 308
 309                 // If this fails, no SSL port will work. At all. So, do the smart thing - throw a ModuleException
 310                 unsigned int certcount = Conf->getInt("certcount", 3);
 311                 x509_certs.resize(certcount);
 312                 ret = gnutls_x509_crt_list_import(&x509_certs[0], &certcount, &cert_datum, GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 313                 if (ret < 0)
 314                         throw ModuleException("Unable to load GnuTLS server certificate (" + certfile + "): " + std::string(gnutls_strerror(ret)));
 315                 x509_certs.resize(certcount);
 316
 317                 if((ret = gnutls_x509_privkey_import(x509_key, &key_datum, GNUTLS_X509_FMT_PEM)) < 0)
 318                         throw ModuleException("Unable to load GnuTLS server private key (" + keyfile + "): " + std::string(gnutls_strerror(ret)));
 319
 320                 if((ret = gnutls_certificate_set_x509_key(x509_cred, &x509_certs[0], certcount, x509_key)) < 0)
 321                         throw ModuleException("Unable to set GnuTLS cert/key pair: " + std::string(gnutls_strerror(ret)));
 322
 323                 gnutls_certificate_client_set_retrieve_function (x509_cred, cert_callback);
 324
 325                 ret = gnutls_dh_params_init(&dh_params);
 326                 dh_alloc = (ret >= 0);
 327                 if (!dh_alloc)
 328                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to initialise DH parameters: %s", gnutls_strerror(ret));
 329
 330                 // This may be on a large (once a day or week) timer eventually.
 331                 GenerateDHParams();
 332         }
 333
 334         void GenerateDHParams()
 335         {
 336                 // Generate Diffie Hellman parameters - for use with DHE
 337                 // kx algorithms. These should be discarded and regenerated
 338                 // once a day, once a week or once a month. Depending on the
 339                 // security requirements.
 340
 341                 if (!dh_alloc)
 342                         return;
 343
 344                 int ret;
 345
 346                 if((ret = gnutls_dh_params_generate2(dh_params, dh_bits)) < 0)
 347                         ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to generate DH parameters (%d bits): %s", dh_bits, gnutls_strerror(ret));
 348         }
 349
 350         ~ModuleSSLGnuTLS()
 351         {
 352                 for(unsigned int i=0; i < x509_certs.size(); i++)
 353                         gnutls_x509_crt_deinit(x509_certs[i]);
 354
 355                 gnutls_x509_privkey_deinit(x509_key);
 356
 357                 if (dh_alloc)
 358                         gnutls_dh_params_deinit(dh_params);
 359                 if (cred_alloc)
 360                         gnutls_certificate_free_credentials(x509_cred);
 361
 362                 gnutls_global_deinit();
 363                 delete[] sessions;
 364                 ServerInstance->GenRandom = &ServerInstance->HandleGenRandom;
 365         }
 366
 367         void OnCleanup(int target_type, void* item)
 368         {
 369                 if(target_type == TYPE_USER)
 370                 {
 371                         LocalUser* user = IS_LOCAL(static_cast<User*>(item));
 372
 373                         if (user && user->eh.GetIOHook() == this)
 374                         {
 375                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 376                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 377                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 378                         }
 379                 }
 380         }
 381
 382         Version GetVersion()
 383         {
 384                 return Version("Provides SSL support for clients", VF_VENDOR);
 385         }
 386
 387
 388         void On005Numeric(std::string &output)
 389         {
 390                 if (!sslports.empty())
 391                         output.append(" SSL=" + sslports);
 392                 if (starttls.enabled)
 393                         output.append(" STARTTLS");
 394         }
 395
 396         void OnHookIO(StreamSocket* user, ListenSocket* lsb)
 397         {
 398                 if (!user->GetIOHook() && lsb->bind_tag->getString("ssl") == "gnutls")
 399                 {
 400                         /* Hook the user with our module */
 401                         user->AddIOHook(this);
 402                 }
 403         }
 404
 405         void OnRequest(Request& request)
 406         {
 407                 if (strcmp("GET_SSL_CERT", request.id) == 0)
 408                 {
 409                         SocketCertificateRequest& req = static_cast<SocketCertificateRequest&>(request);
 410                         int fd = req.sock->GetFd();
 411                         issl_session* session = &sessions[fd];
 412
 413                         req.cert = session->cert;
 414                 }
 415         }
 416
 417         void OnStreamSocketAccept(StreamSocket* user, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server)
 418         {
 419                 int fd = user->GetFd();
 420                 issl_session* session = &sessions[fd];
 421
 422                 /* For STARTTLS: Don't try and init a session on a socket that already has a session */
 423                 if (session->sess)
 424                         return;
 425
 426                 gnutls_init(&session->sess, GNUTLS_SERVER);
 427
 428                 gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
 429                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 430                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 431
 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                 gnutls_certificate_server_set_request(session->sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
 437
 438                 Handshake(session, user);
 439         }
 440
 441         void OnStreamSocketConnect(StreamSocket* user)
 442         {
 443                 issl_session* session = &sessions[user->GetFd()];
 444
 445                 gnutls_init(&session->sess, GNUTLS_CLIENT);
 446
 447                 gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
 448                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 449                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 450                 gnutls_transport_set_ptr(session->sess, reinterpret_cast<gnutls_transport_ptr_t>(user));
 451                 gnutls_transport_set_push_function(session->sess, gnutls_push_wrapper);
 452                 gnutls_transport_set_pull_function(session->sess, gnutls_pull_wrapper);
 453
 454                 Handshake(session, user);
 455         }
 456
 457         void OnStreamSocketClose(StreamSocket* user)
 458         {
 459                 CloseSession(&sessions[user->GetFd()]);
 460         }
 461
 462         int OnStreamSocketRead(StreamSocket* user, std::string& recvq)
 463         {
 464                 issl_session* session = &sessions[user->GetFd()];
 465
 466                 if (!session->sess)
 467                 {
 468                         CloseSession(session);
 469                         user->SetError("No SSL session");
 470                         return -1;
 471                 }
 472
 473                 if (session->status == ISSL_HANDSHAKING_READ || session->status == ISSL_HANDSHAKING_WRITE)
 474                 {
 475                         // The handshake isn't finished, try to finish it.
 476
 477                         if(!Handshake(session, user))
 478                         {
 479                                 if (session->status != ISSL_CLOSING)
 480                                         return 0;
 481                                 return -1;
 482                         }
 483                 }
 484
 485                 // If we resumed the handshake then session->status will be ISSL_HANDSHAKEN.
 486
 487                 if (session->status == ISSL_HANDSHAKEN)
 488                 {
 489                         char* buffer = ServerInstance->GetReadBuffer();
 490                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 491                         int ret = gnutls_record_recv(session->sess, buffer, bufsiz);
 492                         if (ret > 0)
 493                         {
 494                                 recvq.append(buffer, ret);
 495                                 return 1;
 496                         }
 497                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 498                         {
 499                                 return 0;
 500                         }
 501                         else if (ret == 0)
 502                         {
 503                                 user->SetError("SSL Connection closed");
 504                                 CloseSession(session);
 505                                 return -1;
 506                         }
 507                         else
 508                         {
 509                                 user->SetError(gnutls_strerror(ret));
 510                                 CloseSession(session);
 511                                 return -1;
 512                         }
 513                 }
 514                 else if (session->status == ISSL_CLOSING)
 515                         return -1;
 516
 517                 return 0;
 518         }
 519
 520         int OnStreamSocketWrite(StreamSocket* user, std::string& sendq)
 521         {
 522                 issl_session* session = &sessions[user->GetFd()];
 523
 524                 if (!session->sess)
 525                 {
 526                         CloseSession(session);
 527                         user->SetError("No SSL session");
 528                         return -1;
 529                 }
 530
 531                 if (session->status == ISSL_HANDSHAKING_WRITE || session->status == ISSL_HANDSHAKING_READ)
 532                 {
 533                         // The handshake isn't finished, try to finish it.
 534                         Handshake(session, user);
 535                         if (session->status != ISSL_CLOSING)
 536                                 return 0;
 537                         return -1;
 538                 }
 539
 540                 int ret = 0;
 541
 542                 if (session->status == ISSL_HANDSHAKEN)
 543                 {
 544                         ret = gnutls_record_send(session->sess, sendq.data(), sendq.length());
 545
 546                         if (ret == (int)sendq.length())
 547                         {
 548                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_WRITE);
 549                                 return 1;
 550                         }
 551                         else if (ret > 0)
 552                         {
 553                                 sendq = sendq.substr(ret);
 554                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 555                                 return 0;
 556                         }
 557                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED || ret == 0)
 558                         {
 559                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 560                                 return 0;
 561                         }
 562                         else // (ret < 0)
 563                         {
 564                                 user->SetError(gnutls_strerror(ret));
 565                                 CloseSession(session);
 566                                 return -1;
 567                         }
 568                 }
 569
 570                 return 0;
 571         }
 572
 573         bool Handshake(issl_session* session, StreamSocket* user)
 574         {
 575                 int ret = gnutls_handshake(session->sess);
 576
 577                 if (ret < 0)
 578                 {
 579                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 580                         {
 581                                 // Handshake needs resuming later, read() or write() would have blocked.
 582
 583                                 if(gnutls_record_get_direction(session->sess) == 0)
 584                                 {
 585                                         // gnutls_handshake() wants to read() again.
 586                                         session->status = ISSL_HANDSHAKING_READ;
 587                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 588                                 }
 589                                 else
 590                                 {
 591                                         // gnutls_handshake() wants to write() again.
 592                                         session->status = ISSL_HANDSHAKING_WRITE;
 593                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 594                                 }
 595                         }
 596                         else
 597                         {
 598                                 user->SetError(std::string("Handshake Failed - ") + gnutls_strerror(ret));
 599                                 CloseSession(session);
 600                                 session->status = ISSL_CLOSING;
 601                         }
 602
 603                         return false;
 604                 }
 605                 else
 606                 {
 607                         // Change the seesion state
 608                         session->status = ISSL_HANDSHAKEN;
 609
 610                         VerifyCertificate(session,user);
 611
 612                         // Finish writing, if any left
 613                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 614
 615                         return true;
 616                 }
 617         }
 618
 619         void OnUserConnect(LocalUser* user)
 620         {
 621                 if (user->eh.GetIOHook() == this)
 622                 {
 623                         if (sessions[user->eh.GetFd()].sess)
 624                         {
 625                                 ssl_cert* cert = sessions[user->eh.GetFd()].cert;
 626                                 std::string cipher = gnutls_kx_get_name(gnutls_kx_get(sessions[user->eh.GetFd()].sess));
 627                                 cipher.append("-").append(gnutls_cipher_get_name(gnutls_cipher_get(sessions[user->eh.GetFd()].sess))).append("-");
 628                                 cipher.append(gnutls_mac_get_name(gnutls_mac_get(sessions[user->eh.GetFd()].sess)));
 629                                 if (cert->fingerprint.empty())
 630                                         user->WriteServ("NOTICE %s :*** You are connected using SSL cipher \"%s\"", user->nick.c_str(), cipher.c_str());
 631                                 else
 632                                         user->WriteServ("NOTICE %s :*** You are connected using SSL cipher \"%s\""
 633                                                 " and your SSL fingerprint is %s", user->nick.c_str(), cipher.c_str(), cert->fingerprint.c_str());
 634                         }
 635                 }
 636         }
 637
 638         void CloseSession(issl_session* session)
 639         {
 640                 if (session->sess)
 641                 {
 642                         gnutls_bye(session->sess, GNUTLS_SHUT_WR);
 643                         gnutls_deinit(session->sess);
 644                 }
 645                 session->sess = NULL;
 646                 session->cert = NULL;
 647                 session->status = ISSL_NONE;
 648         }
 649
 650         void VerifyCertificate(issl_session* session, StreamSocket* user)
 651         {
 652                 if (!session->sess || !user)
 653                         return;
 654
 655                 unsigned int status;
 656                 const gnutls_datum_t* cert_list;
 657                 int ret;
 658                 unsigned int cert_list_size;
 659                 gnutls_x509_crt_t cert;
 660                 char name[MAXBUF];
 661                 unsigned char digest[MAXBUF];
 662                 size_t digest_size = sizeof(digest);
 663                 size_t name_size = sizeof(name);
 664                 ssl_cert* certinfo = new ssl_cert;
 665                 session->cert = certinfo;
 666
 667                 /* This verification function uses the trusted CAs in the credentials
 668                  * structure. So you must have installed one or more CA certificates.
 669                  */
 670                 ret = gnutls_certificate_verify_peers2(session->sess, &status);
 671
 672                 if (ret < 0)
 673                 {
 674                         certinfo->error = std::string(gnutls_strerror(ret));
 675                         return;
 676                 }
 677
 678                 certinfo->invalid = (status & GNUTLS_CERT_INVALID);
 679                 certinfo->unknownsigner = (status & GNUTLS_CERT_SIGNER_NOT_FOUND);
 680                 certinfo->revoked = (status & GNUTLS_CERT_REVOKED);
 681                 certinfo->trusted = !(status & GNUTLS_CERT_SIGNER_NOT_CA);
 682
 683                 /* Up to here the process is the same for X.509 certificates and
 684                  * OpenPGP keys. From now on X.509 certificates are assumed. This can
 685                  * be easily extended to work with openpgp keys as well.
 686                  */
 687                 if (gnutls_certificate_type_get(session->sess) != GNUTLS_CRT_X509)
 688                 {
 689                         certinfo->error = "No X509 keys sent";
 690                         return;
 691                 }
 692
 693                 ret = gnutls_x509_crt_init(&cert);
 694                 if (ret < 0)
 695                 {
 696                         certinfo->error = gnutls_strerror(ret);
 697                         return;
 698                 }
 699
 700                 cert_list_size = 0;
 701                 cert_list = gnutls_certificate_get_peers(session->sess, &cert_list_size);
 702                 if (cert_list == NULL)
 703                 {
 704                         certinfo->error = "No certificate was found";
 705                         goto info_done_dealloc;
 706                 }
 707
 708                 /* This is not a real world example, since we only check the first
 709                  * certificate in the given chain.
 710                  */
 711
 712                 ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
 713                 if (ret < 0)
 714                 {
 715                         certinfo->error = gnutls_strerror(ret);
 716                         goto info_done_dealloc;
 717                 }
 718
 719                 gnutls_x509_crt_get_dn(cert, name, &name_size);
 720                 certinfo->dn = name;
 721
 722                 gnutls_x509_crt_get_issuer_dn(cert, name, &name_size);
 723                 certinfo->issuer = name;
 724
 725                 if ((ret = gnutls_x509_crt_get_fingerprint(cert, hash, digest, &digest_size)) < 0)
 726                 {
 727                         certinfo->error = gnutls_strerror(ret);
 728                 }
 729                 else
 730                 {
 731                         certinfo->fingerprint = irc::hex(digest, digest_size);
 732                 }
 733
 734                 /* Beware here we do not check for errors.
 735                  */
 736                 if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
 737                 {
 738                         certinfo->error = "Not activated, or expired certificate";
 739                 }
 740
 741 info_done_dealloc:
 742                 gnutls_x509_crt_deinit(cert);
 743         }
 744
 745         void OnEvent(Event& ev)
 746         {
 747                 if (starttls.enabled)
 748                         capHandler.HandleEvent(ev);
 749         }
 750 };
 751
 752 MODULE_INIT(ModuleSSLGnuTLS)