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 #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))
  32 #define GNUTLS_HAS_MAC_GET_ID
  33 #include <gnutls/crypto.h>
  34 #endif
  35
  36 #ifdef _WIN32
  37 # pragma comment(lib, "libgnutls.lib")
  38 # pragma comment(lib, "libgcrypt.lib")
  39 # pragma comment(lib, "libgpg-error.lib")
  40 # pragma comment(lib, "user32.lib")
  41 # pragma comment(lib, "advapi32.lib")
  42 # pragma comment(lib, "libgcc.lib")
  43 # pragma comment(lib, "libmingwex.lib")
  44 # pragma comment(lib, "gdi32.lib")
  45 #endif
  46
  47 /* $CompileFlags: pkgconfincludes("gnutls","/gnutls/gnutls.h","") exec("libgcrypt-config --cflags") -Wno-pedantic */
  48 /* $LinkerFlags: rpath("pkg-config --libs gnutls") pkgconflibs("gnutls","/libgnutls.so","-lgnutls") exec("libgcrypt-config --libs") */
  49
  50 #ifndef GNUTLS_VERSION_MAJOR
  51 #define GNUTLS_VERSION_MAJOR LIBGNUTLS_VERSION_MAJOR
  52 #define GNUTLS_VERSION_MINOR LIBGNUTLS_VERSION_MINOR
  53 #define GNUTLS_VERSION_PATCH LIBGNUTLS_VERSION_PATCH
  54 #endif
  55
  56 // These don't exist in older GnuTLS versions
  57 #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))
  58 #define GNUTLS_NEW_PRIO_API
  59 #endif
  60
  61 #if(GNUTLS_VERSION_MAJOR < 2)
  62 typedef gnutls_certificate_credentials_t gnutls_certificate_credentials;
  63 typedef gnutls_dh_params_t gnutls_dh_params;
  64 #endif
  65
  66 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING_READ, ISSL_HANDSHAKING_WRITE, ISSL_HANDSHAKEN, ISSL_CLOSING, ISSL_CLOSED };
  67
  68 static std::vector<gnutls_x509_crt_t> x509_certs;
  69 static gnutls_x509_privkey_t x509_key;
  70 #if(GNUTLS_VERSION_MAJOR < 2 || ( GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR < 12 ) )
  71 static int cert_callback (gnutls_session_t session, const gnutls_datum_t * req_ca_rdn, int nreqs,
  72         const gnutls_pk_algorithm_t * sign_algos, int sign_algos_length, gnutls_retr_st * st) {
  73
  74         st->type = GNUTLS_CRT_X509;
  75 #else
  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_retr2_st * st) {
  78         st->cert_type = GNUTLS_CRT_X509;
  79         st->key_type = GNUTLS_PRIVKEY_X509;
  80 #endif
  81         st->ncerts = x509_certs.size();
  82         st->cert.x509 = &x509_certs[0];
  83         st->key.x509 = x509_key;
  84         st->deinit_all = 0;
  85
  86         return 0;
  87 }
  88
  89 class RandGen : public HandlerBase2<void, char*, size_t>
  90 {
  91  public:
  92         RandGen() {}
  93         void Call(char* buffer, size_t len)
  94         {
  95                 gcry_randomize(buffer, len, GCRY_STRONG_RANDOM);
  96         }
  97 };
  98
  99 /** Represents an SSL user's extra data
 100  */
 101 class issl_session
 102 {
 103 public:
 104         StreamSocket* socket;
 105         gnutls_session_t sess;
 106         issl_status status;
 107         reference<ssl_cert> cert;
 108
 109         issl_session() : socket(NULL), sess(NULL) {}
 110 };
 111
 112 class GnuTLSIOHook : public SSLIOHook
 113 {
 114  private:
 115         void InitSession(StreamSocket* user, bool me_server)
 116         {
 117                 issl_session* session = &sessions[user->GetFd()];
 118
 119                 gnutls_init(&session->sess, me_server ? GNUTLS_SERVER : GNUTLS_CLIENT);
 120                 session->socket = user;
 121
 122                 #ifdef GNUTLS_NEW_PRIO_API
 123                 gnutls_priority_set(session->sess, priority);
 124                 #else
 125                 gnutls_set_default_priority(session->sess);
 126                 #endif
 127                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 128                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 129                 gnutls_transport_set_ptr(session->sess, reinterpret_cast<gnutls_transport_ptr_t>(session));
 130                 gnutls_transport_set_push_function(session->sess, gnutls_push_wrapper);
 131                 gnutls_transport_set_pull_function(session->sess, gnutls_pull_wrapper);
 132
 133                 if (me_server)
 134                         gnutls_certificate_server_set_request(session->sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
 135
 136                 Handshake(session, user);
 137         }
 138
 139         void CloseSession(issl_session* session)
 140         {
 141                 if (session->sess)
 142                 {
 143                         gnutls_bye(session->sess, GNUTLS_SHUT_WR);
 144                         gnutls_deinit(session->sess);
 145                 }
 146                 session->socket = NULL;
 147                 session->sess = NULL;
 148                 session->cert = NULL;
 149                 session->status = ISSL_NONE;
 150         }
 151
 152         bool Handshake(issl_session* session, StreamSocket* user)
 153         {
 154                 int ret = gnutls_handshake(session->sess);
 155
 156                 if (ret < 0)
 157                 {
 158                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 159                         {
 160                                 // Handshake needs resuming later, read() or write() would have blocked.
 161
 162                                 if(gnutls_record_get_direction(session->sess) == 0)
 163                                 {
 164                                         // gnutls_handshake() wants to read() again.
 165                                         session->status = ISSL_HANDSHAKING_READ;
 166                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 167                                 }
 168                                 else
 169                                 {
 170                                         // gnutls_handshake() wants to write() again.
 171                                         session->status = ISSL_HANDSHAKING_WRITE;
 172                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 173                                 }
 174                         }
 175                         else
 176                         {
 177                                 user->SetError("Handshake Failed - " + std::string(gnutls_strerror(ret)));
 178                                 CloseSession(session);
 179                                 session->status = ISSL_CLOSING;
 180                         }
 181
 182                         return false;
 183                 }
 184                 else
 185                 {
 186                         // Change the seesion state
 187                         session->status = ISSL_HANDSHAKEN;
 188
 189                         VerifyCertificate(session,user);
 190
 191                         // Finish writing, if any left
 192                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 193
 194                         return true;
 195                 }
 196         }
 197
 198         void VerifyCertificate(issl_session* session, StreamSocket* user)
 199         {
 200                 if (!session->sess || !user)
 201                         return;
 202
 203                 unsigned int status;
 204                 const gnutls_datum_t* cert_list;
 205                 int ret;
 206                 unsigned int cert_list_size;
 207                 gnutls_x509_crt_t cert;
 208                 char str[512];
 209                 unsigned char digest[512];
 210                 size_t digest_size = sizeof(digest);
 211                 size_t name_size = sizeof(str);
 212                 ssl_cert* certinfo = new ssl_cert;
 213                 session->cert = certinfo;
 214
 215                 /* This verification function uses the trusted CAs in the credentials
 216                  * structure. So you must have installed one or more CA certificates.
 217                  */
 218                 ret = gnutls_certificate_verify_peers2(session->sess, &status);
 219
 220                 if (ret < 0)
 221                 {
 222                         certinfo->error = std::string(gnutls_strerror(ret));
 223                         return;
 224                 }
 225
 226                 certinfo->invalid = (status & GNUTLS_CERT_INVALID);
 227                 certinfo->unknownsigner = (status & GNUTLS_CERT_SIGNER_NOT_FOUND);
 228                 certinfo->revoked = (status & GNUTLS_CERT_REVOKED);
 229                 certinfo->trusted = !(status & GNUTLS_CERT_SIGNER_NOT_CA);
 230
 231                 /* Up to here the process is the same for X.509 certificates and
 232                  * OpenPGP keys. From now on X.509 certificates are assumed. This can
 233                  * be easily extended to work with openpgp keys as well.
 234                  */
 235                 if (gnutls_certificate_type_get(session->sess) != GNUTLS_CRT_X509)
 236                 {
 237                         certinfo->error = "No X509 keys sent";
 238                         return;
 239                 }
 240
 241                 ret = gnutls_x509_crt_init(&cert);
 242                 if (ret < 0)
 243                 {
 244                         certinfo->error = gnutls_strerror(ret);
 245                         return;
 246                 }
 247
 248                 cert_list_size = 0;
 249                 cert_list = gnutls_certificate_get_peers(session->sess, &cert_list_size);
 250                 if (cert_list == NULL)
 251                 {
 252                         certinfo->error = "No certificate was found";
 253                         goto info_done_dealloc;
 254                 }
 255
 256                 /* This is not a real world example, since we only check the first
 257                  * certificate in the given chain.
 258                  */
 259
 260                 ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
 261                 if (ret < 0)
 262                 {
 263                         certinfo->error = gnutls_strerror(ret);
 264                         goto info_done_dealloc;
 265                 }
 266
 267                 gnutls_x509_crt_get_dn(cert, str, &name_size);
 268                 certinfo->dn = str;
 269
 270                 gnutls_x509_crt_get_issuer_dn(cert, str, &name_size);
 271                 certinfo->issuer = str;
 272
 273                 if ((ret = gnutls_x509_crt_get_fingerprint(cert, hash, digest, &digest_size)) < 0)
 274                 {
 275                         certinfo->error = gnutls_strerror(ret);
 276                 }
 277                 else
 278                 {
 279                         certinfo->fingerprint = BinToHex(digest, digest_size);
 280                 }
 281
 282                 /* Beware here we do not check for errors.
 283                  */
 284                 if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
 285                 {
 286                         certinfo->error = "Not activated, or expired certificate";
 287                 }
 288
 289 info_done_dealloc:
 290                 gnutls_x509_crt_deinit(cert);
 291         }
 292
 293         static const char* UnknownIfNULL(const char* str)
 294         {
 295                 return str ? str : "UNKNOWN";
 296         }
 297
 298         static ssize_t gnutls_pull_wrapper(gnutls_transport_ptr_t session_wrap, void* buffer, size_t size)
 299         {
 300                 issl_session* session = reinterpret_cast<issl_session*>(session_wrap);
 301                 if (session->socket->GetEventMask() & FD_READ_WILL_BLOCK)
 302                 {
 303 #ifdef _WIN32
 304                         gnutls_transport_set_errno(session->sess, EAGAIN);
 305 #else
 306                         errno = EAGAIN;
 307 #endif
 308                         return -1;
 309                 }
 310
 311                 int rv = ServerInstance->SE->Recv(session->socket, reinterpret_cast<char *>(buffer), size, 0);
 312
 313 #ifdef _WIN32
 314                 if (rv < 0)
 315                 {
 316                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 317                          * and then set errno appropriately.
 318                          * The gnutls library may also have a different errno variable than us, see
 319                          * gnutls_transport_set_errno(3).
 320                          */
 321                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 322                 }
 323 #endif
 324
 325                 if (rv < (int)size)
 326                         ServerInstance->SE->ChangeEventMask(session->socket, FD_READ_WILL_BLOCK);
 327                 return rv;
 328         }
 329
 330         static ssize_t gnutls_push_wrapper(gnutls_transport_ptr_t session_wrap, const void* buffer, size_t size)
 331         {
 332                 issl_session* session = reinterpret_cast<issl_session*>(session_wrap);
 333                 if (session->socket->GetEventMask() & FD_WRITE_WILL_BLOCK)
 334                 {
 335 #ifdef _WIN32
 336                         gnutls_transport_set_errno(session->sess, EAGAIN);
 337 #else
 338                         errno = EAGAIN;
 339 #endif
 340                         return -1;
 341                 }
 342
 343                 int rv = ServerInstance->SE->Send(session->socket, reinterpret_cast<const char *>(buffer), size, 0);
 344
 345 #ifdef _WIN32
 346                 if (rv < 0)
 347                 {
 348                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 349                          * and then set errno appropriately.
 350                          * The gnutls library may also have a different errno variable than us, see
 351                          * gnutls_transport_set_errno(3).
 352                          */
 353                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 354                 }
 355 #endif
 356
 357                 if (rv < (int)size)
 358                         ServerInstance->SE->ChangeEventMask(session->socket, FD_WRITE_WILL_BLOCK);
 359                 return rv;
 360         }
 361
 362  public:
 363         issl_session* sessions;
 364         gnutls_certificate_credentials_t x509_cred;
 365
 366         gnutls_digest_algorithm_t hash;
 367         #ifdef GNUTLS_NEW_PRIO_API
 368         gnutls_priority_t priority;
 369         #endif
 370         int dh_bits;
 371
 372         GnuTLSIOHook(Module* parent)
 373                 : SSLIOHook(parent, "ssl/gnutls")
 374         {
 375                 sessions = new issl_session[ServerInstance->SE->GetMaxFds()];
 376         }
 377
 378         ~GnuTLSIOHook()
 379         {
 380                 delete[] sessions;
 381         }
 382
 383         void OnStreamSocketAccept(StreamSocket* user, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server) CXX11_OVERRIDE
 384         {
 385                 issl_session* session = &sessions[user->GetFd()];
 386
 387                 /* For STARTTLS: Don't try and init a session on a socket that already has a session */
 388                 if (session->sess)
 389                         return;
 390
 391                 InitSession(user, true);
 392         }
 393
 394         void OnStreamSocketConnect(StreamSocket* user) CXX11_OVERRIDE
 395         {
 396                 InitSession(user, false);
 397         }
 398
 399         void OnStreamSocketClose(StreamSocket* user) CXX11_OVERRIDE
 400         {
 401                 CloseSession(&sessions[user->GetFd()]);
 402         }
 403
 404         int OnStreamSocketRead(StreamSocket* user, std::string& recvq) CXX11_OVERRIDE
 405         {
 406                 issl_session* session = &sessions[user->GetFd()];
 407
 408                 if (!session->sess)
 409                 {
 410                         CloseSession(session);
 411                         user->SetError("No SSL session");
 412                         return -1;
 413                 }
 414
 415                 if (session->status == ISSL_HANDSHAKING_READ || session->status == ISSL_HANDSHAKING_WRITE)
 416                 {
 417                         // The handshake isn't finished, try to finish it.
 418
 419                         if(!Handshake(session, user))
 420                         {
 421                                 if (session->status != ISSL_CLOSING)
 422                                         return 0;
 423                                 return -1;
 424                         }
 425                 }
 426
 427                 // If we resumed the handshake then session->status will be ISSL_HANDSHAKEN.
 428
 429                 if (session->status == ISSL_HANDSHAKEN)
 430                 {
 431                         char* buffer = ServerInstance->GetReadBuffer();
 432                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 433                         int ret = gnutls_record_recv(session->sess, buffer, bufsiz);
 434                         if (ret > 0)
 435                         {
 436                                 recvq.append(buffer, ret);
 437                                 return 1;
 438                         }
 439                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 440                         {
 441                                 return 0;
 442                         }
 443                         else if (ret == 0)
 444                         {
 445                                 user->SetError("Connection closed");
 446                                 CloseSession(session);
 447                                 return -1;
 448                         }
 449                         else
 450                         {
 451                                 user->SetError(gnutls_strerror(ret));
 452                                 CloseSession(session);
 453                                 return -1;
 454                         }
 455                 }
 456                 else if (session->status == ISSL_CLOSING)
 457                         return -1;
 458
 459                 return 0;
 460         }
 461
 462         int OnStreamSocketWrite(StreamSocket* user, std::string& sendq) CXX11_OVERRIDE
 463         {
 464                 issl_session* session = &sessions[user->GetFd()];
 465
 466                 if (!session->sess)
 467                 {
 468                         CloseSession(session);
 469                         user->SetError("No SSL session");
 470                         return -1;
 471                 }
 472
 473                 if (session->status == ISSL_HANDSHAKING_WRITE || session->status == ISSL_HANDSHAKING_READ)
 474                 {
 475                         // The handshake isn't finished, try to finish it.
 476                         Handshake(session, user);
 477                         if (session->status != ISSL_CLOSING)
 478                                 return 0;
 479                         return -1;
 480                 }
 481
 482                 int ret = 0;
 483
 484                 if (session->status == ISSL_HANDSHAKEN)
 485                 {
 486                         ret = gnutls_record_send(session->sess, sendq.data(), sendq.length());
 487
 488                         if (ret == (int)sendq.length())
 489                         {
 490                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_WRITE);
 491                                 return 1;
 492                         }
 493                         else if (ret > 0)
 494                         {
 495                                 sendq = sendq.substr(ret);
 496                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 497                                 return 0;
 498                         }
 499                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED || ret == 0)
 500                         {
 501                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 502                                 return 0;
 503                         }
 504                         else // (ret < 0)
 505                         {
 506                                 user->SetError(gnutls_strerror(ret));
 507                                 CloseSession(session);
 508                                 return -1;
 509                         }
 510                 }
 511
 512                 return 0;
 513         }
 514
 515         ssl_cert* GetCertificate(StreamSocket* sock) CXX11_OVERRIDE
 516         {
 517                 int fd = sock->GetFd();
 518                 issl_session* session = &sessions[fd];
 519                 return session->cert;
 520         }
 521
 522         void TellCiphersAndFingerprint(LocalUser* user)
 523         {
 524                 const gnutls_session_t& sess = sessions[user->eh.GetFd()].sess;
 525                 if (sess)
 526                 {
 527                         std::string text = "*** You are connected using SSL cipher '";
 528
 529                         text += UnknownIfNULL(gnutls_kx_get_name(gnutls_kx_get(sess)));
 530                         text.append("-").append(UnknownIfNULL(gnutls_cipher_get_name(gnutls_cipher_get(sess)))).append("-");
 531                         text.append(UnknownIfNULL(gnutls_mac_get_name(gnutls_mac_get(sess)))).append("'");
 532
 533                         ssl_cert* cert = sessions[user->eh.GetFd()].cert;
 534                         if (!cert->fingerprint.empty())
 535                                 text += " and your SSL fingerprint is " + cert->fingerprint;
 536
 537                         user->WriteNotice(text);
 538                 }
 539         }
 540 };
 541
 542 class CommandStartTLS : public SplitCommand
 543 {
 544         IOHook& hook;
 545
 546  public:
 547         bool enabled;
 548         CommandStartTLS(Module* mod, IOHook& Hook)
 549                 : SplitCommand(mod, "STARTTLS")
 550                 , hook(Hook)
 551         {
 552                 enabled = true;
 553                 works_before_reg = true;
 554         }
 555
 556         CmdResult HandleLocal(const std::vector<std::string> &parameters, LocalUser *user)
 557         {
 558                 if (!enabled)
 559                 {
 560                         user->WriteNumeric(691, "%s :STARTTLS is not enabled", user->nick.c_str());
 561                         return CMD_FAILURE;
 562                 }
 563
 564                 if (user->registered == REG_ALL)
 565                 {
 566                         user->WriteNumeric(691, "%s :STARTTLS is not permitted after client registration is complete", user->nick.c_str());
 567                 }
 568                 else
 569                 {
 570                         if (!user->eh.GetIOHook())
 571                         {
 572                                 user->WriteNumeric(670, "%s :STARTTLS successful, go ahead with TLS handshake", user->nick.c_str());
 573                                 /* We need to flush the write buffer prior to adding the IOHook,
 574                                  * otherwise we'll be sending this line inside the SSL session - which
 575                                  * won't start its handshake until the client gets this line. Currently,
 576                                  * we assume the write will not block here; this is usually safe, as
 577                                  * STARTTLS is sent very early on in the registration phase, where the
 578                                  * user hasn't built up much sendq. Handling a blocked write here would
 579                                  * be very annoying.
 580                                  */
 581                                 user->eh.DoWrite();
 582                                 user->eh.AddIOHook(&hook);
 583                                 hook.OnStreamSocketAccept(&user->eh, NULL, NULL);
 584                         }
 585                         else
 586                                 user->WriteNumeric(691, "%s :STARTTLS failure", user->nick.c_str());
 587                 }
 588
 589                 return CMD_FAILURE;
 590         }
 591 };
 592
 593 class ModuleSSLGnuTLS : public Module
 594 {
 595         GnuTLSIOHook iohook;
 596
 597         gnutls_dh_params_t dh_params;
 598
 599         std::string sslports;
 600
 601         bool cred_alloc;
 602         bool dh_alloc;
 603
 604         RandGen randhandler;
 605         CommandStartTLS starttls;
 606
 607         GenericCap capHandler;
 608
 609  public:
 610         ModuleSSLGnuTLS()
 611                 : iohook(this), starttls(this, iohook), capHandler(this, "tls")
 612         {
 613                 gcry_control (GCRYCTL_INITIALIZATION_FINISHED, 0);
 614
 615                 gnutls_global_init(); // This must be called once in the program
 616                 gnutls_x509_privkey_init(&x509_key);
 617
 618                 #ifdef GNUTLS_NEW_PRIO_API
 619                 // Init this here so it's always initialized, avoids an extra boolean
 620                 gnutls_priority_init(&iohook.priority, "NORMAL", NULL);
 621                 #endif
 622
 623                 cred_alloc = false;
 624                 dh_alloc = false;
 625         }
 626
 627         void init() CXX11_OVERRIDE
 628         {
 629                 // Needs the flag as it ignores a plain /rehash
 630                 OnModuleRehash(NULL,"ssl");
 631
 632                 ServerInstance->GenRandom = &randhandler;
 633
 634                 // Void return, guess we assume success
 635                 gnutls_certificate_set_dh_params(iohook.x509_cred, dh_params);
 636
 637                 ServerInstance->Modules->AddService(iohook);
 638                 ServerInstance->Modules->AddService(starttls);
 639         }
 640
 641         void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE
 642         {
 643                 sslports.clear();
 644
 645                 ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
 646                 starttls.enabled = Conf->getBool("starttls", true);
 647
 648                 if (Conf->getBool("showports", true))
 649                 {
 650                         sslports = Conf->getString("advertisedports");
 651                         if (!sslports.empty())
 652                                 return;
 653
 654                         for (size_t i = 0; i < ServerInstance->ports.size(); i++)
 655                         {
 656                                 ListenSocket* port = ServerInstance->ports[i];
 657                                 if (port->bind_tag->getString("ssl") != "gnutls")
 658                                         continue;
 659
 660                                 const std::string& portid = port->bind_desc;
 661                                 ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Enabling SSL for port %s", portid.c_str());
 662
 663                                 if (port->bind_tag->getString("type", "clients") == "clients" && port->bind_addr != "127.0.0.1")
 664                                 {
 665                                         /*
 666                                          * Found an SSL port for clients that is not bound to 127.0.0.1 and handled by us, display
 667                                          * the IP:port in ISUPPORT.
 668                                          *
 669                                          * We used to advertise all ports seperated by a ';' char that matched the above criteria,
 670                                          * but this resulted in too long ISUPPORT lines if there were lots of ports to be displayed.
 671                                          * To solve this by default we now only display the first IP:port found and let the user
 672                                          * configure the exact value for the 005 token, if necessary.
 673                                          */
 674                                         sslports = portid;
 675                                         break;
 676                                 }
 677                         }
 678                 }
 679         }
 680
 681         void OnModuleRehash(User* user, const std::string &param) CXX11_OVERRIDE
 682         {
 683                 if(param != "ssl")
 684                         return;
 685
 686                 std::string keyfile;
 687                 std::string certfile;
 688                 std::string cafile;
 689                 std::string crlfile;
 690
 691                 ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
 692
 693                 cafile = ServerInstance->Config->Paths.PrependConfig(Conf->getString("cafile", "ca.pem"));
 694                 crlfile = ServerInstance->Config->Paths.PrependConfig(Conf->getString("crlfile", "crl.pem"));
 695                 certfile = ServerInstance->Config->Paths.PrependConfig(Conf->getString("certfile", "cert.pem"));
 696                 keyfile = ServerInstance->Config->Paths.PrependConfig(Conf->getString("keyfile", "key.pem"));
 697                 int dh_bits = Conf->getInt("dhbits");
 698                 std::string hashname = Conf->getString("hash", "md5");
 699
 700                 // The GnuTLS manual states that the gnutls_set_default_priority()
 701                 // call we used previously when initializing the session is the same
 702                 // as setting the "NORMAL" priority string.
 703                 // Thus if the setting below is not in the config we will behave exactly
 704                 // the same as before, when the priority setting wasn't available.
 705                 std::string priorities = Conf->getString("priority", "NORMAL");
 706
 707                 if((dh_bits != 768) && (dh_bits != 1024) && (dh_bits != 2048) && (dh_bits != 3072) && (dh_bits != 4096))
 708                         dh_bits = 1024;
 709
 710                 iohook.dh_bits = dh_bits;
 711
 712                 // As older versions of gnutls can't do this, let's disable it where needed.
 713 #ifdef GNUTLS_HAS_MAC_GET_ID
 714                 // As gnutls_digest_algorithm_t and gnutls_mac_algorithm_t are mapped 1:1, we can do this
 715                 // There is no gnutls_dig_get_id() at the moment, but it may come later
 716                 iohook.hash = (gnutls_digest_algorithm_t)gnutls_mac_get_id(hashname.c_str());
 717                 if (iohook.hash == GNUTLS_DIG_UNKNOWN)
 718                         throw ModuleException("Unknown hash type " + hashname);
 719
 720                 // Check if the user is walking around with their head in the ass,
 721                 // giving us something that is a valid MAC but not digest
 722                 gnutls_hash_hd_t is_digest;
 723                 if (gnutls_hash_init(&is_digest, iohook.hash) < 0)
 724                         throw ModuleException("Unknown hash type " + hashname);
 725                 gnutls_hash_deinit(is_digest, NULL);
 726 #else
 727                 if (hashname == "md5")
 728                         iohook.hash = GNUTLS_DIG_MD5;
 729                 else if (hashname == "sha1")
 730                         iohook.hash = GNUTLS_DIG_SHA1;
 731                 else
 732                         throw ModuleException("Unknown hash type " + hashname);
 733 #endif
 734
 735                 int ret;
 736
 737                 if (dh_alloc)
 738                 {
 739                         gnutls_dh_params_deinit(dh_params);
 740                         dh_alloc = false;
 741                         dh_params = NULL;
 742                 }
 743
 744                 if (cred_alloc)
 745                 {
 746                         // Deallocate the old credentials
 747                         gnutls_certificate_free_credentials(iohook.x509_cred);
 748
 749                         for(unsigned int i=0; i < x509_certs.size(); i++)
 750                                 gnutls_x509_crt_deinit(x509_certs[i]);
 751                         x509_certs.clear();
 752                 }
 753
 754                 ret = gnutls_certificate_allocate_credentials(&iohook.x509_cred);
 755                 cred_alloc = (ret >= 0);
 756                 if (!cred_alloc)
 757                         ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Failed to allocate certificate credentials: %s", gnutls_strerror(ret));
 758
 759                 if((ret =gnutls_certificate_set_x509_trust_file(iohook.x509_cred, cafile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 760                         ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Failed to set X.509 trust file '%s': %s", cafile.c_str(), gnutls_strerror(ret));
 761
 762                 if((ret = gnutls_certificate_set_x509_crl_file (iohook.x509_cred, crlfile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 763                         ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Failed to set X.509 CRL file '%s': %s", crlfile.c_str(), gnutls_strerror(ret));
 764
 765                 FileReader reader;
 766
 767                 reader.Load(certfile);
 768                 std::string cert_string = reader.GetString();
 769                 gnutls_datum_t cert_datum = { (unsigned char*)cert_string.data(), static_cast<unsigned int>(cert_string.length()) };
 770
 771                 reader.Load(keyfile);
 772                 std::string key_string = reader.GetString();
 773                 gnutls_datum_t key_datum = { (unsigned char*)key_string.data(), static_cast<unsigned int>(key_string.length()) };
 774
 775                 // If this fails, no SSL port will work. At all. So, do the smart thing - throw a ModuleException
 776                 unsigned int certcount = 3;
 777                 x509_certs.resize(certcount);
 778                 ret = gnutls_x509_crt_list_import(&x509_certs[0], &certcount, &cert_datum, GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 779                 if (ret == GNUTLS_E_SHORT_MEMORY_BUFFER)
 780                 {
 781                         // 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
 782                         x509_certs.resize(certcount);
 783                         ret = gnutls_x509_crt_list_import(&x509_certs[0], &certcount, &cert_datum, GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 784                 }
 785
 786                 if (ret <= 0)
 787                 {
 788                         // clear the vector so we won't call gnutls_x509_crt_deinit() on the (uninited) certs later
 789                         x509_certs.clear();
 790                         throw ModuleException("Unable to load GnuTLS server certificate (" + certfile + "): " + ((ret < 0) ? (std::string(gnutls_strerror(ret))) : "No certs could be read"));
 791                 }
 792                 x509_certs.resize(ret);
 793
 794                 if((ret = gnutls_x509_privkey_import(x509_key, &key_datum, GNUTLS_X509_FMT_PEM)) < 0)
 795                         throw ModuleException("Unable to load GnuTLS server private key (" + keyfile + "): " + std::string(gnutls_strerror(ret)));
 796
 797                 if((ret = gnutls_certificate_set_x509_key(iohook.x509_cred, &x509_certs[0], certcount, x509_key)) < 0)
 798                         throw ModuleException("Unable to set GnuTLS cert/key pair: " + std::string(gnutls_strerror(ret)));
 799
 800                 #ifdef GNUTLS_NEW_PRIO_API
 801                 // It's safe to call this every time as we cannot have this uninitialized, see constructor and below.
 802                 gnutls_priority_deinit(iohook.priority);
 803
 804                 // Try to set the priorities for ciphers, kex methods etc. to the user supplied string
 805                 // If the user did not supply anything then the string is already set to "NORMAL"
 806                 const char* priocstr = priorities.c_str();
 807                 const char* prioerror;
 808
 809                 if ((ret = gnutls_priority_init(&iohook.priority, priocstr, &prioerror)) < 0)
 810                 {
 811                         // gnutls did not understand the user supplied string, log and fall back to the default priorities
 812                         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));
 813                         gnutls_priority_init(&iohook.priority, "NORMAL", NULL);
 814                 }
 815
 816                 #else
 817                 if (priorities != "NORMAL")
 818                         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.");
 819                 #endif
 820
 821                 #if(GNUTLS_VERSION_MAJOR < 2 || ( GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR < 12 ) )
 822                 gnutls_certificate_client_set_retrieve_function (iohook.x509_cred, cert_callback);
 823                 #else
 824                 gnutls_certificate_set_retrieve_function (iohook.x509_cred, cert_callback);
 825                 #endif
 826                 ret = gnutls_dh_params_init(&dh_params);
 827                 dh_alloc = (ret >= 0);
 828                 if (!dh_alloc)
 829                 {
 830                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Failed to initialise DH parameters: %s", gnutls_strerror(ret));
 831                         return;
 832                 }
 833
 834                 std::string dhfile = Conf->getString("dhfile");
 835                 if (!dhfile.empty())
 836                 {
 837                         // Try to load DH params from file
 838                         reader.Load(dhfile);
 839                         std::string dhstring = reader.GetString();
 840                         gnutls_datum_t dh_datum = { (unsigned char*)dhstring.data(), static_cast<unsigned int>(dhstring.length()) };
 841
 842                         if ((ret = gnutls_dh_params_import_pkcs3(dh_params, &dh_datum, GNUTLS_X509_FMT_PEM)) < 0)
 843                         {
 844                                 // File unreadable or GnuTLS was unhappy with the contents, generate the DH primes now
 845                                 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));
 846                                 GenerateDHParams();
 847                         }
 848                 }
 849                 else
 850                 {
 851                         GenerateDHParams();
 852                 }
 853         }
 854
 855         void GenerateDHParams()
 856         {
 857                 // Generate Diffie Hellman parameters - for use with DHE
 858                 // kx algorithms. These should be discarded and regenerated
 859                 // once a day, once a week or once a month. Depending on the
 860                 // security requirements.
 861
 862                 if (!dh_alloc)
 863                         return;
 864
 865                 int ret;
 866
 867                 if((ret = gnutls_dh_params_generate2(dh_params, iohook.dh_bits)) < 0)
 868                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Failed to generate DH parameters (%d bits): %s", iohook.dh_bits, gnutls_strerror(ret));
 869         }
 870
 871         ~ModuleSSLGnuTLS()
 872         {
 873                 for(unsigned int i=0; i < x509_certs.size(); i++)
 874                         gnutls_x509_crt_deinit(x509_certs[i]);
 875
 876                 gnutls_x509_privkey_deinit(x509_key);
 877                 #ifdef GNUTLS_NEW_PRIO_API
 878                 gnutls_priority_deinit(iohook.priority);
 879                 #endif
 880
 881                 if (dh_alloc)
 882                         gnutls_dh_params_deinit(dh_params);
 883                 if (cred_alloc)
 884                         gnutls_certificate_free_credentials(iohook.x509_cred);
 885
 886                 gnutls_global_deinit();
 887                 ServerInstance->GenRandom = &ServerInstance->HandleGenRandom;
 888         }
 889
 890         void OnCleanup(int target_type, void* item) CXX11_OVERRIDE
 891         {
 892                 if(target_type == TYPE_USER)
 893                 {
 894                         LocalUser* user = IS_LOCAL(static_cast<User*>(item));
 895
 896                         if (user && user->eh.GetIOHook() == &iohook)
 897                         {
 898                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 899                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 900                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 901                         }
 902                 }
 903         }
 904
 905         Version GetVersion() CXX11_OVERRIDE
 906         {
 907                 return Version("Provides SSL support for clients", VF_VENDOR);
 908         }
 909
 910         void On005Numeric(std::map<std::string, std::string>& tokens) CXX11_OVERRIDE
 911         {
 912                 if (!sslports.empty())
 913                         tokens["SSL"] = sslports;
 914                 if (starttls.enabled)
 915                         tokens["STARTTLS"];
 916         }
 917
 918         void OnHookIO(StreamSocket* user, ListenSocket* lsb) CXX11_OVERRIDE
 919         {
 920                 if (!user->GetIOHook() && lsb->bind_tag->getString("ssl") == "gnutls")
 921                 {
 922                         /* Hook the user with our module */
 923                         user->AddIOHook(&iohook);
 924                 }
 925         }
 926
 927         void OnUserConnect(LocalUser* user) CXX11_OVERRIDE
 928         {
 929                 if (user->eh.GetIOHook() == &iohook)
 930                         iohook.TellCiphersAndFingerprint(user);
 931         }
 932
 933         void OnEvent(Event& ev) CXX11_OVERRIDE
 934         {
 935                 if (starttls.enabled)
 936                         capHandler.HandleEvent(ev);
 937         }
 938 };
 939
 940 MODULE_INIT(ModuleSSLGnuTLS)