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 SSLIOHook
 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                 : SSLIOHook(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         ssl_cert* GetCertificate(StreamSocket* sock) CXX11_OVERRIDE
 505         {
 506                 int fd = sock->GetFd();
 507                 issl_session* session = &sessions[fd];
 508                 return session->cert;
 509         }
 510
 511         void TellCiphersAndFingerprint(LocalUser* user)
 512         {
 513                 const gnutls_session_t& sess = sessions[user->eh.GetFd()].sess;
 514                 if (sess)
 515                 {
 516                         std::string text = "*** You are connected using SSL cipher '";
 517
 518                         text += UnknownIfNULL(gnutls_kx_get_name(gnutls_kx_get(sess)));
 519                         text.append("-").append(UnknownIfNULL(gnutls_cipher_get_name(gnutls_cipher_get(sess)))).append("-");
 520                         text.append(UnknownIfNULL(gnutls_mac_get_name(gnutls_mac_get(sess)))).append("'");
 521
 522                         ssl_cert* cert = sessions[user->eh.GetFd()].cert;
 523                         if (!cert->fingerprint.empty())
 524                                 text += " and your SSL fingerprint is " + cert->fingerprint;
 525
 526                         user->WriteNotice(text);
 527                 }
 528         }
 529 };
 530
 531 class CommandStartTLS : public SplitCommand
 532 {
 533         IOHook& hook;
 534
 535  public:
 536         bool enabled;
 537         CommandStartTLS(Module* mod, IOHook& Hook)
 538                 : SplitCommand(mod, "STARTTLS")
 539                 , hook(Hook)
 540         {
 541                 enabled = true;
 542                 works_before_reg = true;
 543         }
 544
 545         CmdResult HandleLocal(const std::vector<std::string> &parameters, LocalUser *user)
 546         {
 547                 if (!enabled)
 548                 {
 549                         user->WriteNumeric(691, "%s :STARTTLS is not enabled", user->nick.c_str());
 550                         return CMD_FAILURE;
 551                 }
 552
 553                 if (user->registered == REG_ALL)
 554                 {
 555                         user->WriteNumeric(691, "%s :STARTTLS is not permitted after client registration is complete", user->nick.c_str());
 556                 }
 557                 else
 558                 {
 559                         if (!user->eh.GetIOHook())
 560                         {
 561                                 user->WriteNumeric(670, "%s :STARTTLS successful, go ahead with TLS handshake", user->nick.c_str());
 562                                 /* We need to flush the write buffer prior to adding the IOHook,
 563                                  * otherwise we'll be sending this line inside the SSL session - which
 564                                  * won't start its handshake until the client gets this line. Currently,
 565                                  * we assume the write will not block here; this is usually safe, as
 566                                  * STARTTLS is sent very early on in the registration phase, where the
 567                                  * user hasn't built up much sendq. Handling a blocked write here would
 568                                  * be very annoying.
 569                                  */
 570                                 user->eh.DoWrite();
 571                                 user->eh.AddIOHook(&hook);
 572                                 hook.OnStreamSocketAccept(&user->eh, NULL, NULL);
 573                         }
 574                         else
 575                                 user->WriteNumeric(691, "%s :STARTTLS failure", user->nick.c_str());
 576                 }
 577
 578                 return CMD_FAILURE;
 579         }
 580 };
 581
 582 class ModuleSSLGnuTLS : public Module
 583 {
 584         GnuTLSIOHook iohook;
 585
 586         gnutls_dh_params_t dh_params;
 587
 588         std::string sslports;
 589
 590         bool cred_alloc;
 591         bool dh_alloc;
 592
 593         RandGen randhandler;
 594         CommandStartTLS starttls;
 595
 596         GenericCap capHandler;
 597
 598  public:
 599         ModuleSSLGnuTLS()
 600                 : iohook(this), starttls(this, iohook), capHandler(this, "tls")
 601         {
 602                 gcry_control (GCRYCTL_INITIALIZATION_FINISHED, 0);
 603
 604                 gnutls_global_init(); // This must be called once in the program
 605                 gnutls_x509_privkey_init(&x509_key);
 606
 607                 #ifdef GNUTLS_NEW_PRIO_API
 608                 // Init this here so it's always initialized, avoids an extra boolean
 609                 gnutls_priority_init(&iohook.priority, "NORMAL", NULL);
 610                 #endif
 611
 612                 cred_alloc = false;
 613                 dh_alloc = false;
 614         }
 615
 616         void init() CXX11_OVERRIDE
 617         {
 618                 // Needs the flag as it ignores a plain /rehash
 619                 OnModuleRehash(NULL,"ssl");
 620
 621                 ServerInstance->GenRandom = &randhandler;
 622
 623                 // Void return, guess we assume success
 624                 gnutls_certificate_set_dh_params(iohook.x509_cred, dh_params);
 625                 Implementation eventlist[] = { I_On005Numeric, I_OnRehash, I_OnModuleRehash, I_OnUserConnect,
 626                         I_OnEvent, I_OnHookIO };
 627                 ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
 628
 629                 ServerInstance->Modules->AddService(iohook);
 630                 ServerInstance->Modules->AddService(starttls);
 631         }
 632
 633         void OnRehash(User* user) CXX11_OVERRIDE
 634         {
 635                 sslports.clear();
 636
 637                 ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
 638                 starttls.enabled = Conf->getBool("starttls", true);
 639
 640                 if (Conf->getBool("showports", true))
 641                 {
 642                         sslports = Conf->getString("advertisedports");
 643                         if (!sslports.empty())
 644                                 return;
 645
 646                         for (size_t i = 0; i < ServerInstance->ports.size(); i++)
 647                         {
 648                                 ListenSocket* port = ServerInstance->ports[i];
 649                                 if (port->bind_tag->getString("ssl") != "gnutls")
 650                                         continue;
 651
 652                                 const std::string& portid = port->bind_desc;
 653                                 ServerInstance->Logs->Log("m_ssl_gnutls", LOG_DEFAULT, "m_ssl_gnutls.so: Enabling SSL for port %s", portid.c_str());
 654
 655                                 if (port->bind_tag->getString("type", "clients") == "clients" && port->bind_addr != "127.0.0.1")
 656                                 {
 657                                         /*
 658                                          * Found an SSL port for clients that is not bound to 127.0.0.1 and handled by us, display
 659                                          * the IP:port in ISUPPORT.
 660                                          *
 661                                          * We used to advertise all ports seperated by a ';' char that matched the above criteria,
 662                                          * but this resulted in too long ISUPPORT lines if there were lots of ports to be displayed.
 663                                          * To solve this by default we now only display the first IP:port found and let the user
 664                                          * configure the exact value for the 005 token, if necessary.
 665                                          */
 666                                         sslports = portid;
 667                                         break;
 668                                 }
 669                         }
 670                 }
 671         }
 672
 673         void OnModuleRehash(User* user, const std::string &param) CXX11_OVERRIDE
 674         {
 675                 if(param != "ssl")
 676                         return;
 677
 678                 std::string keyfile;
 679                 std::string certfile;
 680                 std::string cafile;
 681                 std::string crlfile;
 682                 OnRehash(user);
 683
 684                 ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
 685
 686                 cafile = Conf->getString("cafile", CONFIG_PATH "/ca.pem");
 687                 crlfile = Conf->getString("crlfile", CONFIG_PATH "/crl.pem");
 688                 certfile = Conf->getString("certfile", CONFIG_PATH "/cert.pem");
 689                 keyfile = Conf->getString("keyfile", CONFIG_PATH "/key.pem");
 690                 int dh_bits = Conf->getInt("dhbits");
 691                 std::string hashname = Conf->getString("hash", "md5");
 692
 693                 // The GnuTLS manual states that the gnutls_set_default_priority()
 694                 // call we used previously when initializing the session is the same
 695                 // as setting the "NORMAL" priority string.
 696                 // Thus if the setting below is not in the config we will behave exactly
 697                 // the same as before, when the priority setting wasn't available.
 698                 std::string priorities = Conf->getString("priority", "NORMAL");
 699
 700                 if((dh_bits != 768) && (dh_bits != 1024) && (dh_bits != 2048) && (dh_bits != 3072) && (dh_bits != 4096))
 701                         dh_bits = 1024;
 702
 703                 iohook.dh_bits = dh_bits;
 704
 705                 if (hashname == "md5")
 706                         iohook.hash = GNUTLS_DIG_MD5;
 707                 else if (hashname == "sha1")
 708                         iohook.hash = GNUTLS_DIG_SHA1;
 709                 else
 710                         throw ModuleException("Unknown hash type " + hashname);
 711
 712
 713                 int ret;
 714
 715                 if (dh_alloc)
 716                 {
 717                         gnutls_dh_params_deinit(dh_params);
 718                         dh_alloc = false;
 719                         dh_params = NULL;
 720                 }
 721
 722                 if (cred_alloc)
 723                 {
 724                         // Deallocate the old credentials
 725                         gnutls_certificate_free_credentials(iohook.x509_cred);
 726
 727                         for(unsigned int i=0; i < x509_certs.size(); i++)
 728                                 gnutls_x509_crt_deinit(x509_certs[i]);
 729                         x509_certs.clear();
 730                 }
 731
 732                 ret = gnutls_certificate_allocate_credentials(&iohook.x509_cred);
 733                 cred_alloc = (ret >= 0);
 734                 if (!cred_alloc)
 735                         ServerInstance->Logs->Log("m_ssl_gnutls", LOG_DEBUG, "m_ssl_gnutls.so: Failed to allocate certificate credentials: %s", gnutls_strerror(ret));
 736
 737                 if((ret =gnutls_certificate_set_x509_trust_file(iohook.x509_cred, cafile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 738                         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));
 739
 740                 if((ret = gnutls_certificate_set_x509_crl_file (iohook.x509_cred, crlfile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 741                         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));
 742
 743                 FileReader reader;
 744
 745                 reader.Load(certfile);
 746                 std::string cert_string = reader.GetString();
 747                 gnutls_datum_t cert_datum = { (unsigned char*)cert_string.data(), static_cast<unsigned int>(cert_string.length()) };
 748
 749                 reader.Load(keyfile);
 750                 std::string key_string = reader.GetString();
 751                 gnutls_datum_t key_datum = { (unsigned char*)key_string.data(), static_cast<unsigned int>(key_string.length()) };
 752
 753                 // If this fails, no SSL port will work. At all. So, do the smart thing - throw a ModuleException
 754                 unsigned int certcount = 3;
 755                 x509_certs.resize(certcount);
 756                 ret = gnutls_x509_crt_list_import(&x509_certs[0], &certcount, &cert_datum, GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 757                 if (ret == GNUTLS_E_SHORT_MEMORY_BUFFER)
 758                 {
 759                         // 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
 760                         x509_certs.resize(certcount);
 761                         ret = gnutls_x509_crt_list_import(&x509_certs[0], &certcount, &cert_datum, GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 762                 }
 763
 764                 if (ret <= 0)
 765                 {
 766                         // clear the vector so we won't call gnutls_x509_crt_deinit() on the (uninited) certs later
 767                         x509_certs.clear();
 768                         throw ModuleException("Unable to load GnuTLS server certificate (" + certfile + "): " + ((ret < 0) ? (std::string(gnutls_strerror(ret))) : "No certs could be read"));
 769                 }
 770                 x509_certs.resize(ret);
 771
 772                 if((ret = gnutls_x509_privkey_import(x509_key, &key_datum, GNUTLS_X509_FMT_PEM)) < 0)
 773                         throw ModuleException("Unable to load GnuTLS server private key (" + keyfile + "): " + std::string(gnutls_strerror(ret)));
 774
 775                 if((ret = gnutls_certificate_set_x509_key(iohook.x509_cred, &x509_certs[0], certcount, x509_key)) < 0)
 776                         throw ModuleException("Unable to set GnuTLS cert/key pair: " + std::string(gnutls_strerror(ret)));
 777
 778                 #ifdef GNUTLS_NEW_PRIO_API
 779                 // It's safe to call this every time as we cannot have this uninitialized, see constructor and below.
 780                 gnutls_priority_deinit(iohook.priority);
 781
 782                 // Try to set the priorities for ciphers, kex methods etc. to the user supplied string
 783                 // If the user did not supply anything then the string is already set to "NORMAL"
 784                 const char* priocstr = priorities.c_str();
 785                 const char* prioerror;
 786
 787                 if ((ret = gnutls_priority_init(&iohook.priority, priocstr, &prioerror)) < 0)
 788                 {
 789                         // gnutls did not understand the user supplied string, log and fall back to the default priorities
 790                         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));
 791                         gnutls_priority_init(&iohook.priority, "NORMAL", NULL);
 792                 }
 793
 794                 #else
 795                 if (priorities != "NORMAL")
 796                         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.");
 797                 #endif
 798
 799                 #if(GNUTLS_VERSION_MAJOR < 2 || ( GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR < 12 ) )
 800                 gnutls_certificate_client_set_retrieve_function (iohook.x509_cred, cert_callback);
 801                 #else
 802                 gnutls_certificate_set_retrieve_function (iohook.x509_cred, cert_callback);
 803                 #endif
 804                 ret = gnutls_dh_params_init(&dh_params);
 805                 dh_alloc = (ret >= 0);
 806                 if (!dh_alloc)
 807                 {
 808                         ServerInstance->Logs->Log("m_ssl_gnutls", LOG_DEFAULT, "m_ssl_gnutls.so: Failed to initialise DH parameters: %s", gnutls_strerror(ret));
 809                         return;
 810                 }
 811
 812                 std::string dhfile = Conf->getString("dhfile");
 813                 if (!dhfile.empty())
 814                 {
 815                         // Try to load DH params from file
 816                         reader.Load(dhfile);
 817                         std::string dhstring = reader.GetString();
 818                         gnutls_datum_t dh_datum = { (unsigned char*)dhstring.data(), static_cast<unsigned int>(dhstring.length()) };
 819
 820                         if ((ret = gnutls_dh_params_import_pkcs3(dh_params, &dh_datum, GNUTLS_X509_FMT_PEM)) < 0)
 821                         {
 822                                 // File unreadable or GnuTLS was unhappy with the contents, generate the DH primes now
 823                                 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));
 824                                 GenerateDHParams();
 825                         }
 826                 }
 827                 else
 828                 {
 829                         GenerateDHParams();
 830                 }
 831         }
 832
 833         void GenerateDHParams()
 834         {
 835                 // Generate Diffie Hellman parameters - for use with DHE
 836                 // kx algorithms. These should be discarded and regenerated
 837                 // once a day, once a week or once a month. Depending on the
 838                 // security requirements.
 839
 840                 if (!dh_alloc)
 841                         return;
 842
 843                 int ret;
 844
 845                 if((ret = gnutls_dh_params_generate2(dh_params, iohook.dh_bits)) < 0)
 846                         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));
 847         }
 848
 849         ~ModuleSSLGnuTLS()
 850         {
 851                 for(unsigned int i=0; i < x509_certs.size(); i++)
 852                         gnutls_x509_crt_deinit(x509_certs[i]);
 853
 854                 gnutls_x509_privkey_deinit(x509_key);
 855                 #ifdef GNUTLS_NEW_PRIO_API
 856                 gnutls_priority_deinit(iohook.priority);
 857                 #endif
 858
 859                 if (dh_alloc)
 860                         gnutls_dh_params_deinit(dh_params);
 861                 if (cred_alloc)
 862                         gnutls_certificate_free_credentials(iohook.x509_cred);
 863
 864                 gnutls_global_deinit();
 865                 ServerInstance->GenRandom = &ServerInstance->HandleGenRandom;
 866         }
 867
 868         void OnCleanup(int target_type, void* item) CXX11_OVERRIDE
 869         {
 870                 if(target_type == TYPE_USER)
 871                 {
 872                         LocalUser* user = IS_LOCAL(static_cast<User*>(item));
 873
 874                         if (user && user->eh.GetIOHook() == &iohook)
 875                         {
 876                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 877                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 878                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 879                         }
 880                 }
 881         }
 882
 883         Version GetVersion() CXX11_OVERRIDE
 884         {
 885                 return Version("Provides SSL support for clients", VF_VENDOR);
 886         }
 887
 888         void On005Numeric(std::map<std::string, std::string>& tokens) CXX11_OVERRIDE
 889         {
 890                 if (!sslports.empty())
 891                         tokens["SSL"] = sslports;
 892                 if (starttls.enabled)
 893                         tokens["STARTTLS"];
 894         }
 895
 896         void OnHookIO(StreamSocket* user, ListenSocket* lsb) CXX11_OVERRIDE
 897         {
 898                 if (!user->GetIOHook() && lsb->bind_tag->getString("ssl") == "gnutls")
 899                 {
 900                         /* Hook the user with our module */
 901                         user->AddIOHook(&iohook);
 902                 }
 903         }
 904
 905         void OnUserConnect(LocalUser* user) CXX11_OVERRIDE
 906         {
 907                 if (user->eh.GetIOHook() == &iohook)
 908                         iohook.TellCiphersAndFingerprint(user);
 909         }
 910
 911         void OnEvent(Event& ev) CXX11_OVERRIDE
 912         {
 913                 if (starttls.enabled)
 914                         capHandler.HandleEvent(ev);
 915         }
 916 };
 917
 918 MODULE_INIT(ModuleSSLGnuTLS)