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 <gcrypt.h>
  26 #include <gnutls/gnutls.h>
  27 #include <gnutls/x509.h>
  28 #include "modules/ssl.h"
  29 #include "modules/cap.h"
  30
  31 #ifdef _WIN32
  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","") exec("libgcrypt-config --cflags") */
  44 /* $LinkerFlags: rpath("pkg-config --libs gnutls") pkgconflibs("gnutls","/libgnutls.so","-lgnutls") exec("libgcrypt-config --libs") */
  45 /* $NoPedantic */
  46
  47 // These don't exist in older GnuTLS versions
  48 #if ((GNUTLS_VERSION_MAJOR > 2) || (GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR > 1) || (GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR == 1 && GNUTLS_VERSION_MICRO >= 7))
  49 #define GNUTLS_NEW_PRIO_API
  50 #endif
  51
  52 #if(GNUTLS_VERSION_MAJOR < 2)
  53 typedef gnutls_certificate_credentials_t gnutls_certificate_credentials;
  54 typedef gnutls_dh_params_t gnutls_dh_params;
  55 #endif
  56
  57 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING_READ, ISSL_HANDSHAKING_WRITE, ISSL_HANDSHAKEN, ISSL_CLOSING, ISSL_CLOSED };
  58
  59 static std::vector<gnutls_x509_crt_t> x509_certs;
  60 static gnutls_x509_privkey_t x509_key;
  61 #if(GNUTLS_VERSION_MAJOR < 2 || ( GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR < 12 ) )
  62 static int cert_callback (gnutls_session_t session, const gnutls_datum_t * req_ca_rdn, int nreqs,
  63         const gnutls_pk_algorithm_t * sign_algos, int sign_algos_length, gnutls_retr_st * st) {
  64
  65         st->type = GNUTLS_CRT_X509;
  66 #else
  67 static int cert_callback (gnutls_session_t session, const gnutls_datum_t * req_ca_rdn, int nreqs,
  68         const gnutls_pk_algorithm_t * sign_algos, int sign_algos_length, gnutls_retr2_st * st) {
  69         st->cert_type = GNUTLS_CRT_X509;
  70         st->key_type = GNUTLS_PRIVKEY_X509;
  71 #endif
  72         st->ncerts = x509_certs.size();
  73         st->cert.x509 = &x509_certs[0];
  74         st->key.x509 = x509_key;
  75         st->deinit_all = 0;
  76
  77         return 0;
  78 }
  79
  80 class RandGen : public HandlerBase2<void, char*, size_t>
  81 {
  82  public:
  83         RandGen() {}
  84         void Call(char* buffer, size_t len)
  85         {
  86                 gcry_randomize(buffer, len, GCRY_STRONG_RANDOM);
  87         }
  88 };
  89
  90 /** Represents an SSL user's extra data
  91  */
  92 class issl_session
  93 {
  94 public:
  95         StreamSocket* socket;
  96         gnutls_session_t sess;
  97         issl_status status;
  98         reference<ssl_cert> cert;
  99
 100         issl_session() : socket(NULL), sess(NULL) {}
 101 };
 102
 103 class GnuTLSIOHook : public IOHook
 104 {
 105  private:
 106         void InitSession(StreamSocket* user, bool me_server)
 107         {
 108                 issl_session* session = &sessions[user->GetFd()];
 109
 110                 gnutls_init(&session->sess, me_server ? GNUTLS_SERVER : GNUTLS_CLIENT);
 111                 session->socket = user;
 112
 113                 #ifdef GNUTLS_NEW_PRIO_API
 114                 gnutls_priority_set(session->sess, priority);
 115                 #endif
 116                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 117                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 118                 gnutls_transport_set_ptr(session->sess, reinterpret_cast<gnutls_transport_ptr_t>(session));
 119                 gnutls_transport_set_push_function(session->sess, gnutls_push_wrapper);
 120                 gnutls_transport_set_pull_function(session->sess, gnutls_pull_wrapper);
 121
 122                 if (me_server)
 123                         gnutls_certificate_server_set_request(session->sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
 124
 125                 Handshake(session, user);
 126         }
 127
 128         void CloseSession(issl_session* session)
 129         {
 130                 if (session->sess)
 131                 {
 132                         gnutls_bye(session->sess, GNUTLS_SHUT_WR);
 133                         gnutls_deinit(session->sess);
 134                 }
 135                 session->socket = NULL;
 136                 session->sess = NULL;
 137                 session->cert = NULL;
 138                 session->status = ISSL_NONE;
 139         }
 140
 141         bool Handshake(issl_session* session, StreamSocket* user)
 142         {
 143                 int ret = gnutls_handshake(session->sess);
 144
 145                 if (ret < 0)
 146                 {
 147                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 148                         {
 149                                 // Handshake needs resuming later, read() or write() would have blocked.
 150
 151                                 if(gnutls_record_get_direction(session->sess) == 0)
 152                                 {
 153                                         // gnutls_handshake() wants to read() again.
 154                                         session->status = ISSL_HANDSHAKING_READ;
 155                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 156                                 }
 157                                 else
 158                                 {
 159                                         // gnutls_handshake() wants to write() again.
 160                                         session->status = ISSL_HANDSHAKING_WRITE;
 161                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 162                                 }
 163                         }
 164                         else
 165                         {
 166                                 user->SetError("Handshake Failed - " + std::string(gnutls_strerror(ret)));
 167                                 CloseSession(session);
 168                                 session->status = ISSL_CLOSING;
 169                         }
 170
 171                         return false;
 172                 }
 173                 else
 174                 {
 175                         // Change the seesion state
 176                         session->status = ISSL_HANDSHAKEN;
 177
 178                         VerifyCertificate(session,user);
 179
 180                         // Finish writing, if any left
 181                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 182
 183                         return true;
 184                 }
 185         }
 186
 187         void VerifyCertificate(issl_session* session, StreamSocket* user)
 188         {
 189                 if (!session->sess || !user)
 190                         return;
 191
 192                 unsigned int status;
 193                 const gnutls_datum_t* cert_list;
 194                 int ret;
 195                 unsigned int cert_list_size;
 196                 gnutls_x509_crt_t cert;
 197                 char str[512];
 198                 unsigned char digest[512];
 199                 size_t digest_size = sizeof(digest);
 200                 size_t name_size = sizeof(str);
 201                 ssl_cert* certinfo = new ssl_cert;
 202                 session->cert = certinfo;
 203
 204                 /* This verification function uses the trusted CAs in the credentials
 205                  * structure. So you must have installed one or more CA certificates.
 206                  */
 207                 ret = gnutls_certificate_verify_peers2(session->sess, &status);
 208
 209                 if (ret < 0)
 210                 {
 211                         certinfo->error = std::string(gnutls_strerror(ret));
 212                         return;
 213                 }
 214
 215                 certinfo->invalid = (status & GNUTLS_CERT_INVALID);
 216                 certinfo->unknownsigner = (status & GNUTLS_CERT_SIGNER_NOT_FOUND);
 217                 certinfo->revoked = (status & GNUTLS_CERT_REVOKED);
 218                 certinfo->trusted = !(status & GNUTLS_CERT_SIGNER_NOT_CA);
 219
 220                 /* Up to here the process is the same for X.509 certificates and
 221                  * OpenPGP keys. From now on X.509 certificates are assumed. This can
 222                  * be easily extended to work with openpgp keys as well.
 223                  */
 224                 if (gnutls_certificate_type_get(session->sess) != GNUTLS_CRT_X509)
 225                 {
 226                         certinfo->error = "No X509 keys sent";
 227                         return;
 228                 }
 229
 230                 ret = gnutls_x509_crt_init(&cert);
 231                 if (ret < 0)
 232                 {
 233                         certinfo->error = gnutls_strerror(ret);
 234                         return;
 235                 }
 236
 237                 cert_list_size = 0;
 238                 cert_list = gnutls_certificate_get_peers(session->sess, &cert_list_size);
 239                 if (cert_list == NULL)
 240                 {
 241                         certinfo->error = "No certificate was found";
 242                         goto info_done_dealloc;
 243                 }
 244
 245                 /* This is not a real world example, since we only check the first
 246                  * certificate in the given chain.
 247                  */
 248
 249                 ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
 250                 if (ret < 0)
 251                 {
 252                         certinfo->error = gnutls_strerror(ret);
 253                         goto info_done_dealloc;
 254                 }
 255
 256                 gnutls_x509_crt_get_dn(cert, str, &name_size);
 257                 certinfo->dn = str;
 258
 259                 gnutls_x509_crt_get_issuer_dn(cert, str, &name_size);
 260                 certinfo->issuer = str;
 261
 262                 if ((ret = gnutls_x509_crt_get_fingerprint(cert, hash, digest, &digest_size)) < 0)
 263                 {
 264                         certinfo->error = gnutls_strerror(ret);
 265                 }
 266                 else
 267                 {
 268                         certinfo->fingerprint = BinToHex(digest, digest_size);
 269                 }
 270
 271                 /* Beware here we do not check for errors.
 272                  */
 273                 if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
 274                 {
 275                         certinfo->error = "Not activated, or expired certificate";
 276                 }
 277
 278 info_done_dealloc:
 279                 gnutls_x509_crt_deinit(cert);
 280         }
 281
 282         static const char* UnknownIfNULL(const char* str)
 283         {
 284                 return str ? str : "UNKNOWN";
 285         }
 286
 287         static ssize_t gnutls_pull_wrapper(gnutls_transport_ptr_t session_wrap, void* buffer, size_t size)
 288         {
 289                 issl_session* session = reinterpret_cast<issl_session*>(session_wrap);
 290                 if (session->socket->GetEventMask() & FD_READ_WILL_BLOCK)
 291                 {
 292 #ifdef _WIN32
 293                         gnutls_transport_set_errno(session->sess, EAGAIN);
 294 #else
 295                         errno = EAGAIN;
 296 #endif
 297                         return -1;
 298                 }
 299
 300                 int rv = ServerInstance->SE->Recv(session->socket, reinterpret_cast<char *>(buffer), size, 0);
 301
 302 #ifdef _WIN32
 303                 if (rv < 0)
 304                 {
 305                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 306                          * and then set errno appropriately.
 307                          * The gnutls library may also have a different errno variable than us, see
 308                          * gnutls_transport_set_errno(3).
 309                          */
 310                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 311                 }
 312 #endif
 313
 314                 if (rv < (int)size)
 315                         ServerInstance->SE->ChangeEventMask(session->socket, FD_READ_WILL_BLOCK);
 316                 return rv;
 317         }
 318
 319         static ssize_t gnutls_push_wrapper(gnutls_transport_ptr_t session_wrap, const void* buffer, size_t size)
 320         {
 321                 issl_session* session = reinterpret_cast<issl_session*>(session_wrap);
 322                 if (session->socket->GetEventMask() & FD_WRITE_WILL_BLOCK)
 323                 {
 324 #ifdef _WIN32
 325                         gnutls_transport_set_errno(session->sess, EAGAIN);
 326 #else
 327                         errno = EAGAIN;
 328 #endif
 329                         return -1;
 330                 }
 331
 332                 int rv = ServerInstance->SE->Send(session->socket, reinterpret_cast<const char *>(buffer), size, 0);
 333
 334 #ifdef _WIN32
 335                 if (rv < 0)
 336                 {
 337                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 338                          * and then set errno appropriately.
 339                          * The gnutls library may also have a different errno variable than us, see
 340                          * gnutls_transport_set_errno(3).
 341                          */
 342                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 343                 }
 344 #endif
 345
 346                 if (rv < (int)size)
 347                         ServerInstance->SE->ChangeEventMask(session->socket, FD_WRITE_WILL_BLOCK);
 348                 return rv;
 349         }
 350
 351  public:
 352         issl_session* sessions;
 353         gnutls_certificate_credentials_t x509_cred;
 354
 355         gnutls_digest_algorithm_t hash;
 356         #ifdef GNUTLS_NEW_PRIO_API
 357         gnutls_priority_t priority;
 358         #endif
 359         int dh_bits;
 360
 361         GnuTLSIOHook(Module* parent)
 362                 : IOHook(parent, "ssl/gnutls")
 363         {
 364                 sessions = new issl_session[ServerInstance->SE->GetMaxFds()];
 365         }
 366
 367         ~GnuTLSIOHook()
 368         {
 369                 delete[] sessions;
 370         }
 371
 372         void OnStreamSocketAccept(StreamSocket* user, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server) CXX11_OVERRIDE
 373         {
 374                 issl_session* session = &sessions[user->GetFd()];
 375
 376                 /* For STARTTLS: Don't try and init a session on a socket that already has a session */
 377                 if (session->sess)
 378                         return;
 379
 380                 InitSession(user, true);
 381         }
 382
 383         void OnStreamSocketConnect(StreamSocket* user) CXX11_OVERRIDE
 384         {
 385                 InitSession(user, false);
 386         }
 387
 388         void OnStreamSocketClose(StreamSocket* user) CXX11_OVERRIDE
 389         {
 390                 CloseSession(&sessions[user->GetFd()]);
 391         }
 392
 393         int OnStreamSocketRead(StreamSocket* user, std::string& recvq) CXX11_OVERRIDE
 394         {
 395                 issl_session* session = &sessions[user->GetFd()];
 396
 397                 if (!session->sess)
 398                 {
 399                         CloseSession(session);
 400                         user->SetError("No SSL session");
 401                         return -1;
 402                 }
 403
 404                 if (session->status == ISSL_HANDSHAKING_READ || session->status == ISSL_HANDSHAKING_WRITE)
 405                 {
 406                         // The handshake isn't finished, try to finish it.
 407
 408                         if(!Handshake(session, user))
 409                         {
 410                                 if (session->status != ISSL_CLOSING)
 411                                         return 0;
 412                                 return -1;
 413                         }
 414                 }
 415
 416                 // If we resumed the handshake then session->status will be ISSL_HANDSHAKEN.
 417
 418                 if (session->status == ISSL_HANDSHAKEN)
 419                 {
 420                         char* buffer = ServerInstance->GetReadBuffer();
 421                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 422                         int ret = gnutls_record_recv(session->sess, buffer, bufsiz);
 423                         if (ret > 0)
 424                         {
 425                                 recvq.append(buffer, ret);
 426                                 return 1;
 427                         }
 428                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 429                         {
 430                                 return 0;
 431                         }
 432                         else if (ret == 0)
 433                         {
 434                                 user->SetError("Connection closed");
 435                                 CloseSession(session);
 436                                 return -1;
 437                         }
 438                         else
 439                         {
 440                                 user->SetError(gnutls_strerror(ret));
 441                                 CloseSession(session);
 442                                 return -1;
 443                         }
 444                 }
 445                 else if (session->status == ISSL_CLOSING)
 446                         return -1;
 447
 448                 return 0;
 449         }
 450
 451         int OnStreamSocketWrite(StreamSocket* user, std::string& sendq) CXX11_OVERRIDE
 452         {
 453                 issl_session* session = &sessions[user->GetFd()];
 454
 455                 if (!session->sess)
 456                 {
 457                         CloseSession(session);
 458                         user->SetError("No SSL session");
 459                         return -1;
 460                 }
 461
 462                 if (session->status == ISSL_HANDSHAKING_WRITE || session->status == ISSL_HANDSHAKING_READ)
 463                 {
 464                         // The handshake isn't finished, try to finish it.
 465                         Handshake(session, user);
 466                         if (session->status != ISSL_CLOSING)
 467                                 return 0;
 468                         return -1;
 469                 }
 470
 471                 int ret = 0;
 472
 473                 if (session->status == ISSL_HANDSHAKEN)
 474                 {
 475                         ret = gnutls_record_send(session->sess, sendq.data(), sendq.length());
 476
 477                         if (ret == (int)sendq.length())
 478                         {
 479                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_WRITE);
 480                                 return 1;
 481                         }
 482                         else if (ret > 0)
 483                         {
 484                                 sendq = sendq.substr(ret);
 485                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 486                                 return 0;
 487                         }
 488                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED || ret == 0)
 489                         {
 490                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 491                                 return 0;
 492                         }
 493                         else // (ret < 0)
 494                         {
 495                                 user->SetError(gnutls_strerror(ret));
 496                                 CloseSession(session);
 497                                 return -1;
 498                         }
 499                 }
 500
 501                 return 0;
 502         }
 503
 504         void TellCiphersAndFingerprint(LocalUser* user)
 505         {
 506                 const gnutls_session_t& sess = sessions[user->eh.GetFd()].sess;
 507                 if (sess)
 508                 {
 509                         std::string text = "*** You are connected using SSL cipher '";
 510
 511                         text += UnknownIfNULL(gnutls_kx_get_name(gnutls_kx_get(sess)));
 512                         text.append("-").append(UnknownIfNULL(gnutls_cipher_get_name(gnutls_cipher_get(sess)))).append("-");
 513                         text.append(UnknownIfNULL(gnutls_mac_get_name(gnutls_mac_get(sess)))).append("'");
 514
 515                         ssl_cert* cert = sessions[user->eh.GetFd()].cert;
 516                         if (!cert->fingerprint.empty())
 517                                 text += " and your SSL fingerprint is " + cert->fingerprint;
 518
 519                         user->WriteNotice(text);
 520                 }
 521         }
 522 };
 523
 524 class CommandStartTLS : public SplitCommand
 525 {
 526         IOHook& hook;
 527
 528  public:
 529         bool enabled;
 530         CommandStartTLS(Module* mod, IOHook& Hook)
 531                 : SplitCommand(mod, "STARTTLS")
 532                 , hook(Hook)
 533         {
 534                 enabled = true;
 535                 works_before_reg = true;
 536         }
 537
 538         CmdResult HandleLocal(const std::vector<std::string> &parameters, LocalUser *user)
 539         {
 540                 if (!enabled)
 541                 {
 542                         user->WriteNumeric(691, "%s :STARTTLS is not enabled", user->nick.c_str());
 543                         return CMD_FAILURE;
 544                 }
 545
 546                 if (user->registered == REG_ALL)
 547                 {
 548                         user->WriteNumeric(691, "%s :STARTTLS is not permitted after client registration is complete", user->nick.c_str());
 549                 }
 550                 else
 551                 {
 552                         if (!user->eh.GetIOHook())
 553                         {
 554                                 user->WriteNumeric(670, "%s :STARTTLS successful, go ahead with TLS handshake", user->nick.c_str());
 555                                 /* We need to flush the write buffer prior to adding the IOHook,
 556                                  * otherwise we'll be sending this line inside the SSL session - which
 557                                  * won't start its handshake until the client gets this line. Currently,
 558                                  * we assume the write will not block here; this is usually safe, as
 559                                  * STARTTLS is sent very early on in the registration phase, where the
 560                                  * user hasn't built up much sendq. Handling a blocked write here would
 561                                  * be very annoying.
 562                                  */
 563                                 user->eh.DoWrite();
 564                                 user->eh.AddIOHook(&hook);
 565                                 hook.OnStreamSocketAccept(&user->eh, NULL, NULL);
 566                         }
 567                         else
 568                                 user->WriteNumeric(691, "%s :STARTTLS failure", user->nick.c_str());
 569                 }
 570
 571                 return CMD_FAILURE;
 572         }
 573 };
 574
 575 class ModuleSSLGnuTLS : public Module
 576 {
 577         GnuTLSIOHook iohook;
 578
 579         gnutls_dh_params_t dh_params;
 580
 581         std::string sslports;
 582
 583         bool cred_alloc;
 584         bool dh_alloc;
 585
 586         RandGen randhandler;
 587         CommandStartTLS starttls;
 588
 589         GenericCap capHandler;
 590
 591  public:
 592         ModuleSSLGnuTLS()
 593                 : iohook(this), starttls(this, iohook), capHandler(this, "tls")
 594         {
 595                 gcry_control (GCRYCTL_INITIALIZATION_FINISHED, 0);
 596
 597                 gnutls_global_init(); // This must be called once in the program
 598                 gnutls_x509_privkey_init(&x509_key);
 599
 600                 #ifdef GNUTLS_NEW_PRIO_API
 601                 // Init this here so it's always initialized, avoids an extra boolean
 602                 gnutls_priority_init(&iohook.priority, "NORMAL", NULL);
 603                 #endif
 604
 605                 cred_alloc = false;
 606                 dh_alloc = false;
 607         }
 608
 609         void init() CXX11_OVERRIDE
 610         {
 611                 // Needs the flag as it ignores a plain /rehash
 612                 OnModuleRehash(NULL,"ssl");
 613
 614                 ServerInstance->GenRandom = &randhandler;
 615
 616                 // Void return, guess we assume success
 617                 gnutls_certificate_set_dh_params(iohook.x509_cred, dh_params);
 618                 Implementation eventlist[] = { I_On005Numeric, I_OnRehash, I_OnModuleRehash, I_OnUserConnect,
 619                         I_OnEvent, I_OnHookIO };
 620                 ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
 621
 622                 ServerInstance->Modules->AddService(iohook);
 623                 ServerInstance->Modules->AddService(starttls);
 624         }
 625
 626         void OnRehash(User* user) CXX11_OVERRIDE
 627         {
 628                 sslports.clear();
 629
 630                 ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
 631                 starttls.enabled = Conf->getBool("starttls", true);
 632
 633                 if (Conf->getBool("showports", true))
 634                 {
 635                         sslports = Conf->getString("advertisedports");
 636                         if (!sslports.empty())
 637                                 return;
 638
 639                         for (size_t i = 0; i < ServerInstance->ports.size(); i++)
 640                         {
 641                                 ListenSocket* port = ServerInstance->ports[i];
 642                                 if (port->bind_tag->getString("ssl") != "gnutls")
 643                                         continue;
 644
 645                                 const std::string& portid = port->bind_desc;
 646                                 ServerInstance->Logs->Log("m_ssl_gnutls", LOG_DEFAULT, "m_ssl_gnutls.so: Enabling SSL for port %s", portid.c_str());
 647
 648                                 if (port->bind_tag->getString("type", "clients") == "clients" && port->bind_addr != "127.0.0.1")
 649                                 {
 650                                         /*
 651                                          * Found an SSL port for clients that is not bound to 127.0.0.1 and handled by us, display
 652                                          * the IP:port in ISUPPORT.
 653                                          *
 654                                          * We used to advertise all ports seperated by a ';' char that matched the above criteria,
 655                                          * but this resulted in too long ISUPPORT lines if there were lots of ports to be displayed.
 656                                          * To solve this by default we now only display the first IP:port found and let the user
 657                                          * configure the exact value for the 005 token, if necessary.
 658                                          */
 659                                         sslports = portid;
 660                                         break;
 661                                 }
 662                         }
 663                 }
 664         }
 665
 666         void OnModuleRehash(User* user, const std::string &param) CXX11_OVERRIDE
 667         {
 668                 if(param != "ssl")
 669                         return;
 670
 671                 std::string keyfile;
 672                 std::string certfile;
 673                 std::string cafile;
 674                 std::string crlfile;
 675                 OnRehash(user);
 676
 677                 ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
 678
 679                 cafile = Conf->getString("cafile", CONFIG_PATH "/ca.pem");
 680                 crlfile = Conf->getString("crlfile", CONFIG_PATH "/crl.pem");
 681                 certfile = Conf->getString("certfile", CONFIG_PATH "/cert.pem");
 682                 keyfile = Conf->getString("keyfile", CONFIG_PATH "/key.pem");
 683                 int dh_bits = Conf->getInt("dhbits");
 684                 std::string hashname = Conf->getString("hash", "md5");
 685
 686                 // The GnuTLS manual states that the gnutls_set_default_priority()
 687                 // call we used previously when initializing the session is the same
 688                 // as setting the "NORMAL" priority string.
 689                 // Thus if the setting below is not in the config we will behave exactly
 690                 // the same as before, when the priority setting wasn't available.
 691                 std::string priorities = Conf->getString("priority", "NORMAL");
 692
 693                 if((dh_bits != 768) && (dh_bits != 1024) && (dh_bits != 2048) && (dh_bits != 3072) && (dh_bits != 4096))
 694                         dh_bits = 1024;
 695
 696                 iohook.dh_bits = dh_bits;
 697
 698                 if (hashname == "md5")
 699                         iohook.hash = GNUTLS_DIG_MD5;
 700                 else if (hashname == "sha1")
 701                         iohook.hash = GNUTLS_DIG_SHA1;
 702                 else
 703                         throw ModuleException("Unknown hash type " + hashname);
 704
 705
 706                 int ret;
 707
 708                 if (dh_alloc)
 709                 {
 710                         gnutls_dh_params_deinit(dh_params);
 711                         dh_alloc = false;
 712                         dh_params = NULL;
 713                 }
 714
 715                 if (cred_alloc)
 716                 {
 717                         // Deallocate the old credentials
 718                         gnutls_certificate_free_credentials(iohook.x509_cred);
 719
 720                         for(unsigned int i=0; i < x509_certs.size(); i++)
 721                                 gnutls_x509_crt_deinit(x509_certs[i]);
 722                         x509_certs.clear();
 723                 }
 724
 725                 ret = gnutls_certificate_allocate_credentials(&iohook.x509_cred);
 726                 cred_alloc = (ret >= 0);
 727                 if (!cred_alloc)
 728                         ServerInstance->Logs->Log("m_ssl_gnutls", LOG_DEBUG, "m_ssl_gnutls.so: Failed to allocate certificate credentials: %s", gnutls_strerror(ret));
 729
 730                 if((ret =gnutls_certificate_set_x509_trust_file(iohook.x509_cred, cafile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 731                         ServerInstance->Logs->Log("m_ssl_gnutls", LOG_DEBUG, "m_ssl_gnutls.so: Failed to set X.509 trust file '%s': %s", cafile.c_str(), gnutls_strerror(ret));
 732
 733                 if((ret = gnutls_certificate_set_x509_crl_file (iohook.x509_cred, crlfile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 734                         ServerInstance->Logs->Log("m_ssl_gnutls", LOG_DEBUG, "m_ssl_gnutls.so: Failed to set X.509 CRL file '%s': %s", crlfile.c_str(), gnutls_strerror(ret));
 735
 736                 FileReader reader;
 737
 738                 reader.Load(certfile);
 739                 std::string cert_string = reader.GetString();
 740                 gnutls_datum_t cert_datum = { (unsigned char*)cert_string.data(), static_cast<unsigned int>(cert_string.length()) };
 741
 742                 reader.Load(keyfile);
 743                 std::string key_string = reader.GetString();
 744                 gnutls_datum_t key_datum = { (unsigned char*)key_string.data(), static_cast<unsigned int>(key_string.length()) };
 745
 746                 // If this fails, no SSL port will work. At all. So, do the smart thing - throw a ModuleException
 747                 unsigned int certcount = 3;
 748                 x509_certs.resize(certcount);
 749                 ret = gnutls_x509_crt_list_import(&x509_certs[0], &certcount, &cert_datum, GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 750                 if (ret == GNUTLS_E_SHORT_MEMORY_BUFFER)
 751                 {
 752                         // the buffer wasn't big enough to hold all certs but gnutls updated certcount to the number of available certs, try again with a bigger buffer
 753                         x509_certs.resize(certcount);
 754                         ret = gnutls_x509_crt_list_import(&x509_certs[0], &certcount, &cert_datum, GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 755                 }
 756
 757                 if (ret <= 0)
 758                 {
 759                         // clear the vector so we won't call gnutls_x509_crt_deinit() on the (uninited) certs later
 760                         x509_certs.clear();
 761                         throw ModuleException("Unable to load GnuTLS server certificate (" + certfile + "): " + ((ret < 0) ? (std::string(gnutls_strerror(ret))) : "No certs could be read"));
 762                 }
 763                 x509_certs.resize(ret);
 764
 765                 if((ret = gnutls_x509_privkey_import(x509_key, &key_datum, GNUTLS_X509_FMT_PEM)) < 0)
 766                         throw ModuleException("Unable to load GnuTLS server private key (" + keyfile + "): " + std::string(gnutls_strerror(ret)));
 767
 768                 if((ret = gnutls_certificate_set_x509_key(iohook.x509_cred, &x509_certs[0], certcount, x509_key)) < 0)
 769                         throw ModuleException("Unable to set GnuTLS cert/key pair: " + std::string(gnutls_strerror(ret)));
 770
 771                 #ifdef GNUTLS_NEW_PRIO_API
 772                 // It's safe to call this every time as we cannot have this uninitialized, see constructor and below.
 773                 gnutls_priority_deinit(iohook.priority);
 774
 775                 // Try to set the priorities for ciphers, kex methods etc. to the user supplied string
 776                 // If the user did not supply anything then the string is already set to "NORMAL"
 777                 const char* priocstr = priorities.c_str();
 778                 const char* prioerror;
 779
 780                 if ((ret = gnutls_priority_init(&iohook.priority, priocstr, &prioerror)) < 0)
 781                 {
 782                         // gnutls did not understand the user supplied string, log and fall back to the default priorities
 783                         ServerInstance->Logs->Log("m_ssl_gnutls", LOG_DEFAULT, "m_ssl_gnutls.so: Failed to set priorities to \"%s\": %s Syntax error at position %u, falling back to default (NORMAL)", priorities.c_str(), gnutls_strerror(ret), (unsigned int) (prioerror - priocstr));
 784                         gnutls_priority_init(&iohook.priority, "NORMAL", NULL);
 785                 }
 786
 787                 #else
 788                 if (priorities != "NORMAL")
 789                         ServerInstance->Logs->Log("m_ssl_gnutls", LOG_DEFAULT, "m_ssl_gnutls.so: You've set <gnutls:priority> to a value other than the default, but this is only supported with GnuTLS v2.1.7 or newer. Your GnuTLS version is older than that so the option will have no effect.");
 790                 #endif
 791
 792                 #if(GNUTLS_VERSION_MAJOR < 2 || ( GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR < 12 ) )
 793                 gnutls_certificate_client_set_retrieve_function (iohook.x509_cred, cert_callback);
 794                 #else
 795                 gnutls_certificate_set_retrieve_function (iohook.x509_cred, cert_callback);
 796                 #endif
 797                 ret = gnutls_dh_params_init(&dh_params);
 798                 dh_alloc = (ret >= 0);
 799                 if (!dh_alloc)
 800                 {
 801                         ServerInstance->Logs->Log("m_ssl_gnutls", LOG_DEFAULT, "m_ssl_gnutls.so: Failed to initialise DH parameters: %s", gnutls_strerror(ret));
 802                         return;
 803                 }
 804
 805                 std::string dhfile = Conf->getString("dhfile");
 806                 if (!dhfile.empty())
 807                 {
 808                         // Try to load DH params from file
 809                         reader.Load(dhfile);
 810                         std::string dhstring = reader.GetString();
 811                         gnutls_datum_t dh_datum = { (unsigned char*)dhstring.data(), static_cast<unsigned int>(dhstring.length()) };
 812
 813                         if ((ret = gnutls_dh_params_import_pkcs3(dh_params, &dh_datum, GNUTLS_X509_FMT_PEM)) < 0)
 814                         {
 815                                 // File unreadable or GnuTLS was unhappy with the contents, generate the DH primes now
 816                                 ServerInstance->Logs->Log("m_ssl_gnutls", LOG_DEFAULT, "m_ssl_gnutls.so: Generating DH parameters because I failed to load them from file '%s': %s", dhfile.c_str(), gnutls_strerror(ret));
 817                                 GenerateDHParams();
 818                         }
 819                 }
 820                 else
 821                 {
 822                         GenerateDHParams();
 823                 }
 824         }
 825
 826         void GenerateDHParams()
 827         {
 828                 // Generate Diffie Hellman parameters - for use with DHE
 829                 // kx algorithms. These should be discarded and regenerated
 830                 // once a day, once a week or once a month. Depending on the
 831                 // security requirements.
 832
 833                 if (!dh_alloc)
 834                         return;
 835
 836                 int ret;
 837
 838                 if((ret = gnutls_dh_params_generate2(dh_params, iohook.dh_bits)) < 0)
 839                         ServerInstance->Logs->Log("m_ssl_gnutls", LOG_DEFAULT, "m_ssl_gnutls.so: Failed to generate DH parameters (%d bits): %s", iohook.dh_bits, gnutls_strerror(ret));
 840         }
 841
 842         ~ModuleSSLGnuTLS()
 843         {
 844                 for(unsigned int i=0; i < x509_certs.size(); i++)
 845                         gnutls_x509_crt_deinit(x509_certs[i]);
 846
 847                 gnutls_x509_privkey_deinit(x509_key);
 848                 #ifdef GNUTLS_NEW_PRIO_API
 849                 gnutls_priority_deinit(iohook.priority);
 850                 #endif
 851
 852                 if (dh_alloc)
 853                         gnutls_dh_params_deinit(dh_params);
 854                 if (cred_alloc)
 855                         gnutls_certificate_free_credentials(iohook.x509_cred);
 856
 857                 gnutls_global_deinit();
 858                 ServerInstance->GenRandom = &ServerInstance->HandleGenRandom;
 859         }
 860
 861         void OnCleanup(int target_type, void* item) CXX11_OVERRIDE
 862         {
 863                 if(target_type == TYPE_USER)
 864                 {
 865                         LocalUser* user = IS_LOCAL(static_cast<User*>(item));
 866
 867                         if (user && user->eh.GetIOHook() == &iohook)
 868                         {
 869                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 870                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 871                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 872                         }
 873                 }
 874         }
 875
 876         Version GetVersion() CXX11_OVERRIDE
 877         {
 878                 return Version("Provides SSL support for clients", VF_VENDOR);
 879         }
 880
 881         void On005Numeric(std::map<std::string, std::string>& tokens) CXX11_OVERRIDE
 882         {
 883                 if (!sslports.empty())
 884                         tokens["SSL"] = sslports;
 885                 if (starttls.enabled)
 886                         tokens["STARTTLS"];
 887         }
 888
 889         void OnHookIO(StreamSocket* user, ListenSocket* lsb) CXX11_OVERRIDE
 890         {
 891                 if (!user->GetIOHook() && lsb->bind_tag->getString("ssl") == "gnutls")
 892                 {
 893                         /* Hook the user with our module */
 894                         user->AddIOHook(&iohook);
 895                 }
 896         }
 897
 898         void OnRequest(Request& request) CXX11_OVERRIDE
 899         {
 900                 if (strcmp("GET_SSL_CERT", request.id) == 0)
 901                 {
 902                         SocketCertificateRequest& req = static_cast<SocketCertificateRequest&>(request);
 903                         int fd = req.sock->GetFd();
 904                         issl_session* session = &iohook.sessions[fd];
 905
 906                         req.cert = session->cert;
 907                 }
 908         }
 909
 910         void OnUserConnect(LocalUser* user) CXX11_OVERRIDE
 911         {
 912                 if (user->eh.GetIOHook() == &iohook)
 913                         iohook.TellCiphersAndFingerprint(user);
 914         }
 915
 916         void OnEvent(Event& ev) CXX11_OVERRIDE
 917         {
 918                 if (starttls.enabled)
 919                         capHandler.HandleEvent(ev);
 920         }
 921 };
 922
 923 MODULE_INIT(ModuleSSLGnuTLS)