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 "modules/ssl.h"
  28 #include "modules/cap.h"
  29
  30 #if ((GNUTLS_VERSION_MAJOR > 2) || (GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR > 9) || (GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR == 9 && GNUTLS_VERSION_PATCH >= 8))
  31 #define GNUTLS_HAS_MAC_GET_ID
  32 #include <gnutls/crypto.h>
  33 #endif
  34
  35 #if (GNUTLS_VERSION_MAJOR > 2 || GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR > 12)
  36 # define GNUTLS_HAS_RND
  37 #else
  38 # include <gcrypt.h>
  39 #endif
  40
  41 #ifdef _WIN32
  42 # pragma comment(lib, "libgnutls.lib")
  43 # pragma comment(lib, "libgcrypt.lib")
  44 # pragma comment(lib, "libgpg-error.lib")
  45 # pragma comment(lib, "user32.lib")
  46 # pragma comment(lib, "advapi32.lib")
  47 # pragma comment(lib, "libgcc.lib")
  48 # pragma comment(lib, "libmingwex.lib")
  49 # pragma comment(lib, "gdi32.lib")
  50 #endif
  51
  52 /* $CompileFlags: pkgconfincludes("gnutls","/gnutls/gnutls.h","") eval("print `libgcrypt-config --cflags | tr -d \r` if `pkg-config --modversion gnutls 2>/dev/null | tr -d \r` lt '2.12'") -Wno-pedantic */
  53 /* $LinkerFlags: rpath("pkg-config --libs gnutls") pkgconflibs("gnutls","/libgnutls.so","-lgnutls") eval("print `libgcrypt-config --libs | tr -d \r` if `pkg-config --modversion gnutls 2>/dev/null | tr -d \r` lt '2.12'") */
  54
  55 #ifndef GNUTLS_VERSION_MAJOR
  56 #define GNUTLS_VERSION_MAJOR LIBGNUTLS_VERSION_MAJOR
  57 #define GNUTLS_VERSION_MINOR LIBGNUTLS_VERSION_MINOR
  58 #define GNUTLS_VERSION_PATCH LIBGNUTLS_VERSION_PATCH
  59 #endif
  60
  61 // These don't exist in older GnuTLS versions
  62 #if ((GNUTLS_VERSION_MAJOR > 2) || (GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR > 1) || (GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR == 1 && GNUTLS_VERSION_PATCH >= 7))
  63 #define GNUTLS_NEW_PRIO_API
  64 #endif
  65
  66 #if(GNUTLS_VERSION_MAJOR < 2)
  67 typedef gnutls_certificate_credentials_t gnutls_certificate_credentials;
  68 typedef gnutls_dh_params_t gnutls_dh_params;
  69 #endif
  70
  71 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING_READ, ISSL_HANDSHAKING_WRITE, ISSL_HANDSHAKEN, ISSL_CLOSING, ISSL_CLOSED };
  72
  73 static std::vector<gnutls_x509_crt_t> x509_certs;
  74 static gnutls_x509_privkey_t x509_key;
  75 #if(GNUTLS_VERSION_MAJOR < 2 || ( GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR < 12 ) )
  76 static int cert_callback (gnutls_session_t session, const gnutls_datum_t * req_ca_rdn, int nreqs,
  77         const gnutls_pk_algorithm_t * sign_algos, int sign_algos_length, gnutls_retr_st * st) {
  78
  79         st->type = GNUTLS_CRT_X509;
  80 #else
  81 static int cert_callback (gnutls_session_t session, const gnutls_datum_t * req_ca_rdn, int nreqs,
  82         const gnutls_pk_algorithm_t * sign_algos, int sign_algos_length, gnutls_retr2_st * st) {
  83         st->cert_type = GNUTLS_CRT_X509;
  84         st->key_type = GNUTLS_PRIVKEY_X509;
  85 #endif
  86         st->ncerts = x509_certs.size();
  87         st->cert.x509 = &x509_certs[0];
  88         st->key.x509 = x509_key;
  89         st->deinit_all = 0;
  90
  91         return 0;
  92 }
  93
  94 class RandGen : public HandlerBase2<void, char*, size_t>
  95 {
  96  public:
  97         RandGen() {}
  98         void Call(char* buffer, size_t len)
  99         {
 100 #ifdef GNUTLS_HAS_RND
 101                 gnutls_rnd(GNUTLS_RND_RANDOM, buffer, len);
 102 #else
 103                 gcry_randomize(buffer, len, GCRY_STRONG_RANDOM);
 104 #endif
 105         }
 106 };
 107
 108 /** Represents an SSL user's extra data
 109  */
 110 class issl_session
 111 {
 112 public:
 113         StreamSocket* socket;
 114         gnutls_session_t sess;
 115         issl_status status;
 116         reference<ssl_cert> cert;
 117
 118         issl_session() : socket(NULL), sess(NULL) {}
 119 };
 120
 121 class GnuTLSIOHook : public SSLIOHook
 122 {
 123  private:
 124         void InitSession(StreamSocket* user, bool me_server)
 125         {
 126                 issl_session* session = &sessions[user->GetFd()];
 127
 128                 gnutls_init(&session->sess, me_server ? GNUTLS_SERVER : GNUTLS_CLIENT);
 129                 session->socket = user;
 130
 131                 #ifdef GNUTLS_NEW_PRIO_API
 132                 gnutls_priority_set(session->sess, priority);
 133                 #else
 134                 gnutls_set_default_priority(session->sess);
 135                 #endif
 136                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 137                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 138                 gnutls_transport_set_ptr(session->sess, reinterpret_cast<gnutls_transport_ptr_t>(session));
 139                 gnutls_transport_set_push_function(session->sess, gnutls_push_wrapper);
 140                 gnutls_transport_set_pull_function(session->sess, gnutls_pull_wrapper);
 141
 142                 if (me_server)
 143                         gnutls_certificate_server_set_request(session->sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
 144
 145                 Handshake(session, user);
 146         }
 147
 148         void CloseSession(issl_session* session)
 149         {
 150                 if (session->sess)
 151                 {
 152                         gnutls_bye(session->sess, GNUTLS_SHUT_WR);
 153                         gnutls_deinit(session->sess);
 154                 }
 155                 session->socket = NULL;
 156                 session->sess = NULL;
 157                 session->cert = NULL;
 158                 session->status = ISSL_NONE;
 159         }
 160
 161         bool Handshake(issl_session* session, StreamSocket* user)
 162         {
 163                 int ret = gnutls_handshake(session->sess);
 164
 165                 if (ret < 0)
 166                 {
 167                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 168                         {
 169                                 // Handshake needs resuming later, read() or write() would have blocked.
 170
 171                                 if(gnutls_record_get_direction(session->sess) == 0)
 172                                 {
 173                                         // gnutls_handshake() wants to read() again.
 174                                         session->status = ISSL_HANDSHAKING_READ;
 175                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 176                                 }
 177                                 else
 178                                 {
 179                                         // gnutls_handshake() wants to write() again.
 180                                         session->status = ISSL_HANDSHAKING_WRITE;
 181                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 182                                 }
 183                         }
 184                         else
 185                         {
 186                                 user->SetError("Handshake Failed - " + std::string(gnutls_strerror(ret)));
 187                                 CloseSession(session);
 188                                 session->status = ISSL_CLOSING;
 189                         }
 190
 191                         return false;
 192                 }
 193                 else
 194                 {
 195                         // Change the seesion state
 196                         session->status = ISSL_HANDSHAKEN;
 197
 198                         VerifyCertificate(session,user);
 199
 200                         // Finish writing, if any left
 201                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 202
 203                         return true;
 204                 }
 205         }
 206
 207         void VerifyCertificate(issl_session* session, StreamSocket* user)
 208         {
 209                 if (!session->sess || !user)
 210                         return;
 211
 212                 unsigned int status;
 213                 const gnutls_datum_t* cert_list;
 214                 int ret;
 215                 unsigned int cert_list_size;
 216                 gnutls_x509_crt_t cert;
 217                 char str[512];
 218                 unsigned char digest[512];
 219                 size_t digest_size = sizeof(digest);
 220                 size_t name_size = sizeof(str);
 221                 ssl_cert* certinfo = new ssl_cert;
 222                 session->cert = certinfo;
 223
 224                 /* This verification function uses the trusted CAs in the credentials
 225                  * structure. So you must have installed one or more CA certificates.
 226                  */
 227                 ret = gnutls_certificate_verify_peers2(session->sess, &status);
 228
 229                 if (ret < 0)
 230                 {
 231                         certinfo->error = std::string(gnutls_strerror(ret));
 232                         return;
 233                 }
 234
 235                 certinfo->invalid = (status & GNUTLS_CERT_INVALID);
 236                 certinfo->unknownsigner = (status & GNUTLS_CERT_SIGNER_NOT_FOUND);
 237                 certinfo->revoked = (status & GNUTLS_CERT_REVOKED);
 238                 certinfo->trusted = !(status & GNUTLS_CERT_SIGNER_NOT_CA);
 239
 240                 /* Up to here the process is the same for X.509 certificates and
 241                  * OpenPGP keys. From now on X.509 certificates are assumed. This can
 242                  * be easily extended to work with openpgp keys as well.
 243                  */
 244                 if (gnutls_certificate_type_get(session->sess) != GNUTLS_CRT_X509)
 245                 {
 246                         certinfo->error = "No X509 keys sent";
 247                         return;
 248                 }
 249
 250                 ret = gnutls_x509_crt_init(&cert);
 251                 if (ret < 0)
 252                 {
 253                         certinfo->error = gnutls_strerror(ret);
 254                         return;
 255                 }
 256
 257                 cert_list_size = 0;
 258                 cert_list = gnutls_certificate_get_peers(session->sess, &cert_list_size);
 259                 if (cert_list == NULL)
 260                 {
 261                         certinfo->error = "No certificate was found";
 262                         goto info_done_dealloc;
 263                 }
 264
 265                 /* This is not a real world example, since we only check the first
 266                  * certificate in the given chain.
 267                  */
 268
 269                 ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
 270                 if (ret < 0)
 271                 {
 272                         certinfo->error = gnutls_strerror(ret);
 273                         goto info_done_dealloc;
 274                 }
 275
 276                 gnutls_x509_crt_get_dn(cert, str, &name_size);
 277                 certinfo->dn = str;
 278
 279                 gnutls_x509_crt_get_issuer_dn(cert, str, &name_size);
 280                 certinfo->issuer = str;
 281
 282                 if ((ret = gnutls_x509_crt_get_fingerprint(cert, hash, digest, &digest_size)) < 0)
 283                 {
 284                         certinfo->error = gnutls_strerror(ret);
 285                 }
 286                 else
 287                 {
 288                         certinfo->fingerprint = BinToHex(digest, digest_size);
 289                 }
 290
 291                 /* Beware here we do not check for errors.
 292                  */
 293                 if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
 294                 {
 295                         certinfo->error = "Not activated, or expired certificate";
 296                 }
 297
 298 info_done_dealloc:
 299                 gnutls_x509_crt_deinit(cert);
 300         }
 301
 302         static const char* UnknownIfNULL(const char* str)
 303         {
 304                 return str ? str : "UNKNOWN";
 305         }
 306
 307         static ssize_t gnutls_pull_wrapper(gnutls_transport_ptr_t session_wrap, void* buffer, size_t size)
 308         {
 309                 issl_session* session = reinterpret_cast<issl_session*>(session_wrap);
 310                 if (session->socket->GetEventMask() & FD_READ_WILL_BLOCK)
 311                 {
 312 #ifdef _WIN32
 313                         gnutls_transport_set_errno(session->sess, EAGAIN);
 314 #else
 315                         errno = EAGAIN;
 316 #endif
 317                         return -1;
 318                 }
 319
 320                 int rv = ServerInstance->SE->Recv(session->socket, reinterpret_cast<char *>(buffer), size, 0);
 321
 322 #ifdef _WIN32
 323                 if (rv < 0)
 324                 {
 325                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 326                          * and then set errno appropriately.
 327                          * The gnutls library may also have a different errno variable than us, see
 328                          * gnutls_transport_set_errno(3).
 329                          */
 330                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 331                 }
 332 #endif
 333
 334                 if (rv < (int)size)
 335                         ServerInstance->SE->ChangeEventMask(session->socket, FD_READ_WILL_BLOCK);
 336                 return rv;
 337         }
 338
 339         static ssize_t gnutls_push_wrapper(gnutls_transport_ptr_t session_wrap, const void* buffer, size_t size)
 340         {
 341                 issl_session* session = reinterpret_cast<issl_session*>(session_wrap);
 342                 if (session->socket->GetEventMask() & FD_WRITE_WILL_BLOCK)
 343                 {
 344 #ifdef _WIN32
 345                         gnutls_transport_set_errno(session->sess, EAGAIN);
 346 #else
 347                         errno = EAGAIN;
 348 #endif
 349                         return -1;
 350                 }
 351
 352                 int rv = ServerInstance->SE->Send(session->socket, reinterpret_cast<const char *>(buffer), size, 0);
 353
 354 #ifdef _WIN32
 355                 if (rv < 0)
 356                 {
 357                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 358                          * and then set errno appropriately.
 359                          * The gnutls library may also have a different errno variable than us, see
 360                          * gnutls_transport_set_errno(3).
 361                          */
 362                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 363                 }
 364 #endif
 365
 366                 if (rv < (int)size)
 367                         ServerInstance->SE->ChangeEventMask(session->socket, FD_WRITE_WILL_BLOCK);
 368                 return rv;
 369         }
 370
 371  public:
 372         issl_session* sessions;
 373         gnutls_certificate_credentials_t x509_cred;
 374
 375         gnutls_digest_algorithm_t hash;
 376         #ifdef GNUTLS_NEW_PRIO_API
 377         gnutls_priority_t priority;
 378         #endif
 379         int dh_bits;
 380
 381         GnuTLSIOHook(Module* parent)
 382                 : SSLIOHook(parent, "ssl/gnutls")
 383         {
 384                 sessions = new issl_session[ServerInstance->SE->GetMaxFds()];
 385         }
 386
 387         ~GnuTLSIOHook()
 388         {
 389                 delete[] sessions;
 390         }
 391
 392         void OnStreamSocketAccept(StreamSocket* user, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server) CXX11_OVERRIDE
 393         {
 394                 issl_session* session = &sessions[user->GetFd()];
 395
 396                 /* For STARTTLS: Don't try and init a session on a socket that already has a session */
 397                 if (session->sess)
 398                         return;
 399
 400                 InitSession(user, true);
 401         }
 402
 403         void OnStreamSocketConnect(StreamSocket* user) CXX11_OVERRIDE
 404         {
 405                 InitSession(user, false);
 406         }
 407
 408         void OnStreamSocketClose(StreamSocket* user) CXX11_OVERRIDE
 409         {
 410                 CloseSession(&sessions[user->GetFd()]);
 411         }
 412
 413         int OnStreamSocketRead(StreamSocket* user, std::string& recvq) CXX11_OVERRIDE
 414         {
 415                 issl_session* session = &sessions[user->GetFd()];
 416
 417                 if (!session->sess)
 418                 {
 419                         CloseSession(session);
 420                         user->SetError("No SSL session");
 421                         return -1;
 422                 }
 423
 424                 if (session->status == ISSL_HANDSHAKING_READ || session->status == ISSL_HANDSHAKING_WRITE)
 425                 {
 426                         // The handshake isn't finished, try to finish it.
 427
 428                         if(!Handshake(session, user))
 429                         {
 430                                 if (session->status != ISSL_CLOSING)
 431                                         return 0;
 432                                 return -1;
 433                         }
 434                 }
 435
 436                 // If we resumed the handshake then session->status will be ISSL_HANDSHAKEN.
 437
 438                 if (session->status == ISSL_HANDSHAKEN)
 439                 {
 440                         char* buffer = ServerInstance->GetReadBuffer();
 441                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 442                         int ret = gnutls_record_recv(session->sess, buffer, bufsiz);
 443                         if (ret > 0)
 444                         {
 445                                 recvq.append(buffer, ret);
 446                                 return 1;
 447                         }
 448                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 449                         {
 450                                 return 0;
 451                         }
 452                         else if (ret == 0)
 453                         {
 454                                 user->SetError("Connection closed");
 455                                 CloseSession(session);
 456                                 return -1;
 457                         }
 458                         else
 459                         {
 460                                 user->SetError(gnutls_strerror(ret));
 461                                 CloseSession(session);
 462                                 return -1;
 463                         }
 464                 }
 465                 else if (session->status == ISSL_CLOSING)
 466                         return -1;
 467
 468                 return 0;
 469         }
 470
 471         int OnStreamSocketWrite(StreamSocket* user, std::string& sendq) CXX11_OVERRIDE
 472         {
 473                 issl_session* session = &sessions[user->GetFd()];
 474
 475                 if (!session->sess)
 476                 {
 477                         CloseSession(session);
 478                         user->SetError("No SSL session");
 479                         return -1;
 480                 }
 481
 482                 if (session->status == ISSL_HANDSHAKING_WRITE || session->status == ISSL_HANDSHAKING_READ)
 483                 {
 484                         // The handshake isn't finished, try to finish it.
 485                         Handshake(session, user);
 486                         if (session->status != ISSL_CLOSING)
 487                                 return 0;
 488                         return -1;
 489                 }
 490
 491                 int ret = 0;
 492
 493                 if (session->status == ISSL_HANDSHAKEN)
 494                 {
 495                         ret = gnutls_record_send(session->sess, sendq.data(), sendq.length());
 496
 497                         if (ret == (int)sendq.length())
 498                         {
 499                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_WRITE);
 500                                 return 1;
 501                         }
 502                         else if (ret > 0)
 503                         {
 504                                 sendq = sendq.substr(ret);
 505                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 506                                 return 0;
 507                         }
 508                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED || ret == 0)
 509                         {
 510                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 511                                 return 0;
 512                         }
 513                         else // (ret < 0)
 514                         {
 515                                 user->SetError(gnutls_strerror(ret));
 516                                 CloseSession(session);
 517                                 return -1;
 518                         }
 519                 }
 520
 521                 return 0;
 522         }
 523
 524         ssl_cert* GetCertificate(StreamSocket* sock) CXX11_OVERRIDE
 525         {
 526                 int fd = sock->GetFd();
 527                 issl_session* session = &sessions[fd];
 528                 return session->cert;
 529         }
 530
 531         void TellCiphersAndFingerprint(LocalUser* user)
 532         {
 533                 const gnutls_session_t& sess = sessions[user->eh.GetFd()].sess;
 534                 if (sess)
 535                 {
 536                         std::string text = "*** You are connected using SSL cipher '";
 537
 538                         text += UnknownIfNULL(gnutls_kx_get_name(gnutls_kx_get(sess)));
 539                         text.append("-").append(UnknownIfNULL(gnutls_cipher_get_name(gnutls_cipher_get(sess)))).append("-");
 540                         text.append(UnknownIfNULL(gnutls_mac_get_name(gnutls_mac_get(sess)))).append("'");
 541
 542                         ssl_cert* cert = sessions[user->eh.GetFd()].cert;
 543                         if (!cert->fingerprint.empty())
 544                                 text += " and your SSL fingerprint is " + cert->fingerprint;
 545
 546                         user->WriteNotice(text);
 547                 }
 548         }
 549 };
 550
 551 class CommandStartTLS : public SplitCommand
 552 {
 553         IOHook& hook;
 554
 555  public:
 556         bool enabled;
 557         CommandStartTLS(Module* mod, IOHook& Hook)
 558                 : SplitCommand(mod, "STARTTLS")
 559                 , hook(Hook)
 560         {
 561                 enabled = true;
 562                 works_before_reg = true;
 563         }
 564
 565         CmdResult HandleLocal(const std::vector<std::string> &parameters, LocalUser *user)
 566         {
 567                 if (!enabled)
 568                 {
 569                         user->WriteNumeric(691, ":STARTTLS is not enabled");
 570                         return CMD_FAILURE;
 571                 }
 572
 573                 if (user->registered == REG_ALL)
 574                 {
 575                         user->WriteNumeric(691, ":STARTTLS is not permitted after client registration is complete");
 576                 }
 577                 else
 578                 {
 579                         if (!user->eh.GetIOHook())
 580                         {
 581                                 user->WriteNumeric(670, ":STARTTLS successful, go ahead with TLS handshake");
 582                                 /* We need to flush the write buffer prior to adding the IOHook,
 583                                  * otherwise we'll be sending this line inside the SSL session - which
 584                                  * won't start its handshake until the client gets this line. Currently,
 585                                  * we assume the write will not block here; this is usually safe, as
 586                                  * STARTTLS is sent very early on in the registration phase, where the
 587                                  * user hasn't built up much sendq. Handling a blocked write here would
 588                                  * be very annoying.
 589                                  */
 590                                 user->eh.DoWrite();
 591                                 user->eh.AddIOHook(&hook);
 592                                 hook.OnStreamSocketAccept(&user->eh, NULL, NULL);
 593                         }
 594                         else
 595                                 user->WriteNumeric(691, ":STARTTLS failure");
 596                 }
 597
 598                 return CMD_FAILURE;
 599         }
 600 };
 601
 602 class ModuleSSLGnuTLS : public Module
 603 {
 604         GnuTLSIOHook iohook;
 605
 606         gnutls_dh_params_t dh_params;
 607
 608         std::string sslports;
 609
 610         bool cred_alloc;
 611         bool dh_alloc;
 612
 613         RandGen randhandler;
 614         CommandStartTLS starttls;
 615
 616         GenericCap capHandler;
 617
 618  public:
 619         ModuleSSLGnuTLS()
 620                 : iohook(this), starttls(this, iohook), capHandler(this, "tls")
 621         {
 622 #ifndef GNUTLS_HAS_RND
 623                 gcry_control (GCRYCTL_INITIALIZATION_FINISHED, 0);
 624 #endif
 625
 626                 gnutls_global_init(); // This must be called once in the program
 627                 gnutls_x509_privkey_init(&x509_key);
 628
 629                 #ifdef GNUTLS_NEW_PRIO_API
 630                 // Init this here so it's always initialized, avoids an extra boolean
 631                 gnutls_priority_init(&iohook.priority, "NORMAL", NULL);
 632                 #endif
 633
 634                 cred_alloc = false;
 635                 dh_alloc = false;
 636         }
 637
 638         void init() CXX11_OVERRIDE
 639         {
 640                 // Needs the flag as it ignores a plain /rehash
 641                 OnModuleRehash(NULL,"ssl");
 642
 643                 ServerInstance->GenRandom = &randhandler;
 644
 645                 // Void return, guess we assume success
 646                 gnutls_certificate_set_dh_params(iohook.x509_cred, dh_params);
 647         }
 648
 649         void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE
 650         {
 651                 sslports.clear();
 652
 653                 ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
 654                 starttls.enabled = Conf->getBool("starttls", true);
 655
 656                 if (Conf->getBool("showports", true))
 657                 {
 658                         sslports = Conf->getString("advertisedports");
 659                         if (!sslports.empty())
 660                                 return;
 661
 662                         for (size_t i = 0; i < ServerInstance->ports.size(); i++)
 663                         {
 664                                 ListenSocket* port = ServerInstance->ports[i];
 665                                 if (port->bind_tag->getString("ssl") != "gnutls")
 666                                         continue;
 667
 668                                 const std::string& portid = port->bind_desc;
 669                                 ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Enabling SSL for port %s", portid.c_str());
 670
 671                                 if (port->bind_tag->getString("type", "clients") == "clients" && port->bind_addr != "127.0.0.1")
 672                                 {
 673                                         /*
 674                                          * Found an SSL port for clients that is not bound to 127.0.0.1 and handled by us, display
 675                                          * the IP:port in ISUPPORT.
 676                                          *
 677                                          * We used to advertise all ports seperated by a ';' char that matched the above criteria,
 678                                          * but this resulted in too long ISUPPORT lines if there were lots of ports to be displayed.
 679                                          * To solve this by default we now only display the first IP:port found and let the user
 680                                          * configure the exact value for the 005 token, if necessary.
 681                                          */
 682                                         sslports = portid;
 683                                         break;
 684                                 }
 685                         }
 686                 }
 687         }
 688
 689         void OnModuleRehash(User* user, const std::string &param) CXX11_OVERRIDE
 690         {
 691                 if(param != "ssl")
 692                         return;
 693
 694                 std::string keyfile;
 695                 std::string certfile;
 696                 std::string cafile;
 697                 std::string crlfile;
 698
 699                 ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
 700
 701                 cafile = ServerInstance->Config->Paths.PrependConfig(Conf->getString("cafile", "ca.pem"));
 702                 crlfile = ServerInstance->Config->Paths.PrependConfig(Conf->getString("crlfile", "crl.pem"));
 703                 certfile = ServerInstance->Config->Paths.PrependConfig(Conf->getString("certfile", "cert.pem"));
 704                 keyfile = ServerInstance->Config->Paths.PrependConfig(Conf->getString("keyfile", "key.pem"));
 705                 int dh_bits = Conf->getInt("dhbits");
 706                 std::string hashname = Conf->getString("hash", "md5");
 707
 708                 // The GnuTLS manual states that the gnutls_set_default_priority()
 709                 // call we used previously when initializing the session is the same
 710                 // as setting the "NORMAL" priority string.
 711                 // Thus if the setting below is not in the config we will behave exactly
 712                 // the same as before, when the priority setting wasn't available.
 713                 std::string priorities = Conf->getString("priority", "NORMAL");
 714
 715                 if((dh_bits != 768) && (dh_bits != 1024) && (dh_bits != 2048) && (dh_bits != 3072) && (dh_bits != 4096))
 716                         dh_bits = 1024;
 717
 718                 iohook.dh_bits = dh_bits;
 719
 720                 // As older versions of gnutls can't do this, let's disable it where needed.
 721 #ifdef GNUTLS_HAS_MAC_GET_ID
 722                 // As gnutls_digest_algorithm_t and gnutls_mac_algorithm_t are mapped 1:1, we can do this
 723                 // There is no gnutls_dig_get_id() at the moment, but it may come later
 724                 iohook.hash = (gnutls_digest_algorithm_t)gnutls_mac_get_id(hashname.c_str());
 725                 if (iohook.hash == GNUTLS_DIG_UNKNOWN)
 726                         throw ModuleException("Unknown hash type " + hashname);
 727
 728                 // Check if the user is walking around with their head in the ass,
 729                 // giving us something that is a valid MAC but not digest
 730                 gnutls_hash_hd_t is_digest;
 731                 if (gnutls_hash_init(&is_digest, iohook.hash) < 0)
 732                         throw ModuleException("Unknown hash type " + hashname);
 733                 gnutls_hash_deinit(is_digest, NULL);
 734 #else
 735                 if (hashname == "md5")
 736                         iohook.hash = GNUTLS_DIG_MD5;
 737                 else if (hashname == "sha1")
 738                         iohook.hash = GNUTLS_DIG_SHA1;
 739                 else
 740                         throw ModuleException("Unknown hash type " + hashname);
 741 #endif
 742
 743                 int ret;
 744
 745                 if (dh_alloc)
 746                 {
 747                         gnutls_dh_params_deinit(dh_params);
 748                         dh_alloc = false;
 749                         dh_params = NULL;
 750                 }
 751
 752                 if (cred_alloc)
 753                 {
 754                         // Deallocate the old credentials
 755                         gnutls_certificate_free_credentials(iohook.x509_cred);
 756
 757                         for(unsigned int i=0; i < x509_certs.size(); i++)
 758                                 gnutls_x509_crt_deinit(x509_certs[i]);
 759                         x509_certs.clear();
 760                 }
 761
 762                 ret = gnutls_certificate_allocate_credentials(&iohook.x509_cred);
 763                 cred_alloc = (ret >= 0);
 764                 if (!cred_alloc)
 765                         ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Failed to allocate certificate credentials: %s", gnutls_strerror(ret));
 766
 767                 if((ret =gnutls_certificate_set_x509_trust_file(iohook.x509_cred, cafile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 768                         ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Failed to set X.509 trust file '%s': %s", cafile.c_str(), gnutls_strerror(ret));
 769
 770                 if((ret = gnutls_certificate_set_x509_crl_file (iohook.x509_cred, crlfile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 771                         ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Failed to set X.509 CRL file '%s': %s", crlfile.c_str(), gnutls_strerror(ret));
 772
 773                 FileReader reader;
 774
 775                 reader.Load(certfile);
 776                 std::string cert_string = reader.GetString();
 777                 gnutls_datum_t cert_datum = { (unsigned char*)cert_string.data(), static_cast<unsigned int>(cert_string.length()) };
 778
 779                 reader.Load(keyfile);
 780                 std::string key_string = reader.GetString();
 781                 gnutls_datum_t key_datum = { (unsigned char*)key_string.data(), static_cast<unsigned int>(key_string.length()) };
 782
 783                 // If this fails, no SSL port will work. At all. So, do the smart thing - throw a ModuleException
 784                 unsigned int certcount = 3;
 785                 x509_certs.resize(certcount);
 786                 ret = gnutls_x509_crt_list_import(&x509_certs[0], &certcount, &cert_datum, GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 787                 if (ret == GNUTLS_E_SHORT_MEMORY_BUFFER)
 788                 {
 789                         // 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
 790                         x509_certs.resize(certcount);
 791                         ret = gnutls_x509_crt_list_import(&x509_certs[0], &certcount, &cert_datum, GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 792                 }
 793
 794                 if (ret <= 0)
 795                 {
 796                         // clear the vector so we won't call gnutls_x509_crt_deinit() on the (uninited) certs later
 797                         x509_certs.clear();
 798                         throw ModuleException("Unable to load GnuTLS server certificate (" + certfile + "): " + ((ret < 0) ? (std::string(gnutls_strerror(ret))) : "No certs could be read"));
 799                 }
 800                 x509_certs.resize(ret);
 801
 802                 if((ret = gnutls_x509_privkey_import(x509_key, &key_datum, GNUTLS_X509_FMT_PEM)) < 0)
 803                         throw ModuleException("Unable to load GnuTLS server private key (" + keyfile + "): " + std::string(gnutls_strerror(ret)));
 804
 805                 if((ret = gnutls_certificate_set_x509_key(iohook.x509_cred, &x509_certs[0], certcount, x509_key)) < 0)
 806                         throw ModuleException("Unable to set GnuTLS cert/key pair: " + std::string(gnutls_strerror(ret)));
 807
 808                 #ifdef GNUTLS_NEW_PRIO_API
 809                 // It's safe to call this every time as we cannot have this uninitialized, see constructor and below.
 810                 gnutls_priority_deinit(iohook.priority);
 811
 812                 // Try to set the priorities for ciphers, kex methods etc. to the user supplied string
 813                 // If the user did not supply anything then the string is already set to "NORMAL"
 814                 const char* priocstr = priorities.c_str();
 815                 const char* prioerror;
 816
 817                 if ((ret = gnutls_priority_init(&iohook.priority, priocstr, &prioerror)) < 0)
 818                 {
 819                         // gnutls did not understand the user supplied string, log and fall back to the default priorities
 820                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "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));
 821                         gnutls_priority_init(&iohook.priority, "NORMAL", NULL);
 822                 }
 823
 824                 #else
 825                 if (priorities != "NORMAL")
 826                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "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.");
 827                 #endif
 828
 829                 #if(GNUTLS_VERSION_MAJOR < 2 || ( GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR < 12 ) )
 830                 gnutls_certificate_client_set_retrieve_function (iohook.x509_cred, cert_callback);
 831                 #else
 832                 gnutls_certificate_set_retrieve_function (iohook.x509_cred, cert_callback);
 833                 #endif
 834                 ret = gnutls_dh_params_init(&dh_params);
 835                 dh_alloc = (ret >= 0);
 836                 if (!dh_alloc)
 837                 {
 838                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Failed to initialise DH parameters: %s", gnutls_strerror(ret));
 839                         return;
 840                 }
 841
 842                 std::string dhfile = Conf->getString("dhfile");
 843                 if (!dhfile.empty())
 844                 {
 845                         // Try to load DH params from file
 846                         reader.Load(dhfile);
 847                         std::string dhstring = reader.GetString();
 848                         gnutls_datum_t dh_datum = { (unsigned char*)dhstring.data(), static_cast<unsigned int>(dhstring.length()) };
 849
 850                         if ((ret = gnutls_dh_params_import_pkcs3(dh_params, &dh_datum, GNUTLS_X509_FMT_PEM)) < 0)
 851                         {
 852                                 // File unreadable or GnuTLS was unhappy with the contents, generate the DH primes now
 853                                 ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Generating DH parameters because I failed to load them from file '%s': %s", dhfile.c_str(), gnutls_strerror(ret));
 854                                 GenerateDHParams();
 855                         }
 856                 }
 857                 else
 858                 {
 859                         GenerateDHParams();
 860                 }
 861         }
 862
 863         void GenerateDHParams()
 864         {
 865                 // Generate Diffie Hellman parameters - for use with DHE
 866                 // kx algorithms. These should be discarded and regenerated
 867                 // once a day, once a week or once a month. Depending on the
 868                 // security requirements.
 869
 870                 if (!dh_alloc)
 871                         return;
 872
 873                 int ret;
 874
 875                 if((ret = gnutls_dh_params_generate2(dh_params, iohook.dh_bits)) < 0)
 876                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Failed to generate DH parameters (%d bits): %s", iohook.dh_bits, gnutls_strerror(ret));
 877         }
 878
 879         ~ModuleSSLGnuTLS()
 880         {
 881                 for(unsigned int i=0; i < x509_certs.size(); i++)
 882                         gnutls_x509_crt_deinit(x509_certs[i]);
 883
 884                 gnutls_x509_privkey_deinit(x509_key);
 885                 #ifdef GNUTLS_NEW_PRIO_API
 886                 gnutls_priority_deinit(iohook.priority);
 887                 #endif
 888
 889                 if (dh_alloc)
 890                         gnutls_dh_params_deinit(dh_params);
 891                 if (cred_alloc)
 892                         gnutls_certificate_free_credentials(iohook.x509_cred);
 893
 894                 gnutls_global_deinit();
 895                 ServerInstance->GenRandom = &ServerInstance->HandleGenRandom;
 896         }
 897
 898         void OnCleanup(int target_type, void* item) CXX11_OVERRIDE
 899         {
 900                 if(target_type == TYPE_USER)
 901                 {
 902                         LocalUser* user = IS_LOCAL(static_cast<User*>(item));
 903
 904                         if (user && user->eh.GetIOHook() == &iohook)
 905                         {
 906                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 907                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 908                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 909                         }
 910                 }
 911         }
 912
 913         Version GetVersion() CXX11_OVERRIDE
 914         {
 915                 return Version("Provides SSL support for clients", VF_VENDOR);
 916         }
 917
 918         void On005Numeric(std::map<std::string, std::string>& tokens) CXX11_OVERRIDE
 919         {
 920                 if (!sslports.empty())
 921                         tokens["SSL"] = sslports;
 922                 if (starttls.enabled)
 923                         tokens["STARTTLS"];
 924         }
 925
 926         void OnHookIO(StreamSocket* user, ListenSocket* lsb) CXX11_OVERRIDE
 927         {
 928                 if (!user->GetIOHook() && lsb->bind_tag->getString("ssl") == "gnutls")
 929                 {
 930                         /* Hook the user with our module */
 931                         user->AddIOHook(&iohook);
 932                 }
 933         }
 934
 935         void OnUserConnect(LocalUser* user) CXX11_OVERRIDE
 936         {
 937                 if (user->eh.GetIOHook() == &iohook)
 938                         iohook.TellCiphersAndFingerprint(user);
 939         }
 940
 941         void OnEvent(Event& ev) CXX11_OVERRIDE
 942         {
 943                 if (starttls.enabled)
 944                         capHandler.HandleEvent(ev);
 945         }
 946 };
 947
 948 MODULE_INIT(ModuleSSLGnuTLS)