src/modules/extra/m_ssl_openssl.cpp

   1 /*
   2  * InspIRCd -- Internet Relay Chat Daemon
   3  *
   4  *   Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
   5  *   Copyright (C) 2008 Pippijn van Steenhoven <pip88nl@gmail.com>
   6  *   Copyright (C) 2006-2008 Craig Edwards <craigedwards@brainbox.cc>
   7  *   Copyright (C) 2008 Thomas Stagner <aquanight@inspircd.org>
   8  *   Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
   9  *   Copyright (C) 2006 Oliver Lupton <oliverlupton@gmail.com>
  10  *
  11  * This file is part of InspIRCd.  InspIRCd is free software: you can
  12  * redistribute it and/or modify it under the terms of the GNU General Public
  13  * License as published by the Free Software Foundation, version 2.
  14  *
  15  * This program is distributed in the hope that it will be useful, but WITHOUT
  16  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  17  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  18  * details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  22  */
  23
  24
  25 #include "inspircd.h"
  26 #include "iohook.h"
  27 #include "modules/ssl.h"
  28
  29 // Ignore OpenSSL deprecation warnings on OS X Lion and newer.
  30 #if defined __APPLE__
  31 # pragma GCC diagnostic ignored "-Wdeprecated-declarations"
  32 #endif
  33
  34 // Fix warnings about the use of `long long` on C++03.
  35 #if defined __clang__
  36 # pragma clang diagnostic ignored "-Wc++11-long-long"
  37 #elif defined __GNUC__
  38 # pragma GCC diagnostic ignored "-Wlong-long"
  39 #endif
  40
  41 #include <openssl/ssl.h>
  42 #include <openssl/err.h>
  43
  44 #ifdef _WIN32
  45 # pragma comment(lib, "ssleay32.lib")
  46 # pragma comment(lib, "libeay32.lib")
  47 #endif
  48
  49 /* $CompileFlags: pkgconfversion("openssl","0.9.7") pkgconfincludes("openssl","/openssl/ssl.h","") */
  50 /* $LinkerFlags: rpath("pkg-config --libs openssl") pkgconflibs("openssl","/libssl.so","-lssl -lcrypto") */
  51
  52 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING, ISSL_OPEN };
  53
  54 static bool SelfSigned = false;
  55 static int exdataindex;
  56
  57 char* get_error()
  58 {
  59         return ERR_error_string(ERR_get_error(), NULL);
  60 }
  61
  62 static int OnVerify(int preverify_ok, X509_STORE_CTX* ctx);
  63 static void StaticSSLInfoCallback(const SSL* ssl, int where, int rc);
  64
  65 namespace OpenSSL
  66 {
  67         class Exception : public ModuleException
  68         {
  69          public:
  70                 Exception(const std::string& reason)
  71                         : ModuleException(reason) { }
  72         };
  73
  74         class DHParams
  75         {
  76                 DH* dh;
  77
  78          public:
  79                 DHParams(const std::string& filename)
  80                 {
  81                         BIO* dhpfile = BIO_new_file(filename.c_str(), "r");
  82                         if (dhpfile == NULL)
  83                                 throw Exception("Couldn't open DH file " + filename);
  84
  85                         dh = PEM_read_bio_DHparams(dhpfile, NULL, NULL, NULL);
  86                         BIO_free(dhpfile);
  87
  88                         if (!dh)
  89                                 throw Exception("Couldn't read DH params from file " + filename);
  90                 }
  91
  92                 ~DHParams()
  93                 {
  94                         DH_free(dh);
  95                 }
  96
  97                 DH* get()
  98                 {
  99                         return dh;
 100                 }
 101         };
 102
 103         class Context
 104         {
 105                 SSL_CTX* const ctx;
 106                 long ctx_options;
 107
 108          public:
 109                 Context(SSL_CTX* context)
 110                         : ctx(context)
 111                 {
 112                         // Sane default options for OpenSSL see https://www.openssl.org/docs/ssl/SSL_CTX_set_options.html
 113                         // and when choosing a cipher, use the server's preferences instead of the client preferences.
 114                         long opts = SSL_OP_NO_SSLv2 | SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION | SSL_OP_CIPHER_SERVER_PREFERENCE | SSL_OP_SINGLE_DH_USE;
 115                         // Only turn options on if they exist
 116 #ifdef SSL_OP_SINGLE_ECDH_USE
 117                         opts |= SSL_OP_SINGLE_ECDH_USE;
 118 #endif
 119 #ifdef SSL_OP_NO_TICKET
 120                         opts |= SSL_OP_NO_TICKET;
 121 #endif
 122
 123                         ctx_options = SSL_CTX_set_options(ctx, opts);
 124                         SSL_CTX_set_mode(ctx, SSL_MODE_ENABLE_PARTIAL_WRITE | SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
 125                         SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, OnVerify);
 126                         SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_OFF);
 127                         SSL_CTX_set_info_callback(ctx, StaticSSLInfoCallback);
 128                 }
 129
 130                 ~Context()
 131                 {
 132                         SSL_CTX_free(ctx);
 133                 }
 134
 135                 bool SetDH(DHParams& dh)
 136                 {
 137                         ERR_clear_error();
 138                         return (SSL_CTX_set_tmp_dh(ctx, dh.get()) >= 0);
 139                 }
 140
 141 #ifdef INSPIRCD_OPENSSL_ENABLE_ECDH
 142                 void SetECDH(const std::string& curvename)
 143                 {
 144                         int nid = OBJ_sn2nid(curvename.c_str());
 145                         if (nid == 0)
 146                                 throw Exception("Unknown curve: " + curvename);
 147
 148                         EC_KEY* eckey = EC_KEY_new_by_curve_name(nid);
 149                         if (!eckey)
 150                                 throw Exception("Unable to create EC key object");
 151
 152                         ERR_clear_error();
 153                         bool ret = (SSL_CTX_set_tmp_ecdh(ctx, eckey) >= 0);
 154                         EC_KEY_free(eckey);
 155                         if (!ret)
 156                                 throw Exception("Couldn't set ECDH parameters");
 157                 }
 158 #endif
 159
 160                 bool SetCiphers(const std::string& ciphers)
 161                 {
 162                         ERR_clear_error();
 163                         return SSL_CTX_set_cipher_list(ctx, ciphers.c_str());
 164                 }
 165
 166                 bool SetCerts(const std::string& filename)
 167                 {
 168                         ERR_clear_error();
 169                         return SSL_CTX_use_certificate_chain_file(ctx, filename.c_str());
 170                 }
 171
 172                 bool SetPrivateKey(const std::string& filename)
 173                 {
 174                         ERR_clear_error();
 175                         return SSL_CTX_use_PrivateKey_file(ctx, filename.c_str(), SSL_FILETYPE_PEM);
 176                 }
 177
 178                 bool SetCA(const std::string& filename)
 179                 {
 180                         ERR_clear_error();
 181                         return SSL_CTX_load_verify_locations(ctx, filename.c_str(), 0);
 182                 }
 183
 184                 long GetDefaultContextOptions() const
 185                 {
 186                         return ctx_options;
 187                 }
 188
 189                 long SetRawContextOptions(long setoptions, long clearoptions)
 190                 {
 191                         // Clear everything
 192                         SSL_CTX_clear_options(ctx, SSL_CTX_get_options(ctx));
 193
 194                         // Set the default options and what is in the conf
 195                         SSL_CTX_set_options(ctx, ctx_options | setoptions);
 196                         return SSL_CTX_clear_options(ctx, clearoptions);
 197                 }
 198
 199                 SSL* CreateSession()
 200                 {
 201                         return SSL_new(ctx);
 202                 }
 203         };
 204
 205         class Profile : public refcountbase
 206         {
 207                 /** Name of this profile
 208                  */
 209                 const std::string name;
 210
 211                 /** DH parameters in use
 212                  */
 213                 DHParams dh;
 214
 215                 /** OpenSSL makes us have two contexts, one for servers and one for clients
 216                  */
 217                 Context ctx;
 218                 Context clictx;
 219
 220                 /** Digest to use when generating fingerprints
 221                  */
 222                 const EVP_MD* digest;
 223
 224                 /** Last error, set by error_callback()
 225                  */
 226                 std::string lasterr;
 227
 228                 /** True if renegotiations are allowed, false if not
 229                  */
 230                 const bool allowrenego;
 231
 232                 static int error_callback(const char* str, size_t len, void* u)
 233                 {
 234                         Profile* profile = reinterpret_cast<Profile*>(u);
 235                         profile->lasterr = std::string(str, len - 1);
 236                         return 0;
 237                 }
 238
 239                 /** Set raw OpenSSL context (SSL_CTX) options from a config tag
 240                  * @param ctxname Name of the context, client or server
 241                  * @param tag Config tag defining this profile
 242                  * @param context Context object to manipulate
 243                  */
 244                 void SetContextOptions(const std::string& ctxname, ConfigTag* tag, Context& context)
 245                 {
 246                         long setoptions = tag->getInt(ctxname + "setoptions");
 247                         long clearoptions = tag->getInt(ctxname + "clearoptions");
 248 #ifdef SSL_OP_NO_COMPRESSION
 249                         if (!tag->getBool("compression", true))
 250                                 setoptions |= SSL_OP_NO_COMPRESSION;
 251 #endif
 252                         if (!tag->getBool("sslv3", true))
 253                                 setoptions |= SSL_OP_NO_SSLv3;
 254                         if (!tag->getBool("tlsv1", true))
 255                                 setoptions |= SSL_OP_NO_TLSv1;
 256
 257                         if (!setoptions && !clearoptions)
 258                                 return; // Nothing to do
 259
 260                         ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Setting %s %s context options, default: %ld set: %ld clear: %ld", name.c_str(), ctxname.c_str(), ctx.GetDefaultContextOptions(), setoptions, clearoptions);
 261                         long final = context.SetRawContextOptions(setoptions, clearoptions);
 262                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "%s %s context options: %ld", name.c_str(), ctxname.c_str(), final);
 263                 }
 264
 265          public:
 266                 Profile(const std::string& profilename, ConfigTag* tag)
 267                         : name(profilename)
 268                         , dh(ServerInstance->Config->Paths.PrependConfig(tag->getString("dhfile", "dh.pem")))
 269                         , ctx(SSL_CTX_new(SSLv23_server_method()))
 270                         , clictx(SSL_CTX_new(SSLv23_client_method()))
 271                         , allowrenego(tag->getBool("renegotiation", true))
 272                 {
 273                         if ((!ctx.SetDH(dh)) || (!clictx.SetDH(dh)))
 274                                 throw Exception("Couldn't set DH parameters");
 275
 276                         std::string hash = tag->getString("hash", "md5");
 277                         digest = EVP_get_digestbyname(hash.c_str());
 278                         if (digest == NULL)
 279                                 throw Exception("Unknown hash type " + hash);
 280
 281                         std::string ciphers = tag->getString("ciphers");
 282                         if (!ciphers.empty())
 283                         {
 284                                 if ((!ctx.SetCiphers(ciphers)) || (!clictx.SetCiphers(ciphers)))
 285                                 {
 286                                         ERR_print_errors_cb(error_callback, this);
 287                                         throw Exception("Can't set cipher list to \"" + ciphers + "\" " + lasterr);
 288                                 }
 289                         }
 290
 291 #ifdef INSPIRCD_OPENSSL_ENABLE_ECDH
 292                         std::string curvename = tag->getString("ecdhcurve", "prime256v1");
 293                         if (!curvename.empty())
 294                                 ctx.SetECDH(curvename);
 295 #endif
 296
 297                         SetContextOptions("server", tag, ctx);
 298                         SetContextOptions("client", tag, clictx);
 299
 300                         /* Load our keys and certificates
 301                          * NOTE: OpenSSL's error logging API sucks, don't blame us for this clusterfuck.
 302                          */
 303                         std::string filename = ServerInstance->Config->Paths.PrependConfig(tag->getString("certfile", "cert.pem"));
 304                         if ((!ctx.SetCerts(filename)) || (!clictx.SetCerts(filename)))
 305                         {
 306                                 ERR_print_errors_cb(error_callback, this);
 307                                 throw Exception("Can't read certificate file: " + lasterr);
 308                         }
 309
 310                         filename = ServerInstance->Config->Paths.PrependConfig(tag->getString("keyfile", "key.pem"));
 311                         if ((!ctx.SetPrivateKey(filename)) || (!clictx.SetPrivateKey(filename)))
 312                         {
 313                                 ERR_print_errors_cb(error_callback, this);
 314                                 throw Exception("Can't read key file: " + lasterr);
 315                         }
 316
 317                         // Load the CAs we trust
 318                         filename = ServerInstance->Config->Paths.PrependConfig(tag->getString("cafile", "ca.pem"));
 319                         if ((!ctx.SetCA(filename)) || (!clictx.SetCA(filename)))
 320                         {
 321                                 ERR_print_errors_cb(error_callback, this);
 322                                 ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Can't read CA list from %s. This is only a problem if you want to verify client certificates, otherwise it's safe to ignore this message. Error: %s", filename.c_str(), lasterr.c_str());
 323                         }
 324                 }
 325
 326                 const std::string& GetName() const { return name; }
 327                 SSL* CreateServerSession() { return ctx.CreateSession(); }
 328                 SSL* CreateClientSession() { return clictx.CreateSession(); }
 329                 const EVP_MD* GetDigest() { return digest; }
 330                 bool AllowRenegotiation() const { return allowrenego; }
 331         };
 332 }
 333
 334 static int OnVerify(int preverify_ok, X509_STORE_CTX *ctx)
 335 {
 336         /* XXX: This will allow self signed certificates.
 337          * In the future if we want an option to not allow this,
 338          * we can just return preverify_ok here, and openssl
 339          * will boot off self-signed and invalid peer certs.
 340          */
 341         int ve = X509_STORE_CTX_get_error(ctx);
 342
 343         SelfSigned = (ve == X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT);
 344
 345         return 1;
 346 }
 347
 348 class OpenSSLIOHook : public SSLIOHook
 349 {
 350  private:
 351         SSL* sess;
 352         issl_status status;
 353         const bool outbound;
 354         bool data_to_write;
 355         reference<OpenSSL::Profile> profile;
 356
 357         // Returns 1 if handshake succeeded, 0 if it is still in progress, -1 if it failed
 358         int Handshake(StreamSocket* user)
 359         {
 360                 int ret;
 361
 362                 ERR_clear_error();
 363                 if (outbound)
 364                         ret = SSL_connect(sess);
 365                 else
 366                         ret = SSL_accept(sess);
 367
 368                 if (ret < 0)
 369                 {
 370                         int err = SSL_get_error(sess, ret);
 371
 372                         if (err == SSL_ERROR_WANT_READ)
 373                         {
 374                                 SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 375                                 this->status = ISSL_HANDSHAKING;
 376                                 return 0;
 377                         }
 378                         else if (err == SSL_ERROR_WANT_WRITE)
 379                         {
 380                                 SocketEngine::ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 381                                 this->status = ISSL_HANDSHAKING;
 382                                 return 0;
 383                         }
 384                         else
 385                         {
 386                                 CloseSession();
 387                                 return -1;
 388                         }
 389                 }
 390                 else if (ret > 0)
 391                 {
 392                         // Handshake complete.
 393                         VerifyCertificate();
 394
 395                         status = ISSL_OPEN;
 396
 397                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 398
 399                         return 1;
 400                 }
 401                 else if (ret == 0)
 402                 {
 403                         CloseSession();
 404                 }
 405                 return -1;
 406         }
 407
 408         void CloseSession()
 409         {
 410                 if (sess)
 411                 {
 412                         SSL_shutdown(sess);
 413                         SSL_free(sess);
 414                 }
 415                 sess = NULL;
 416                 certificate = NULL;
 417                 status = ISSL_NONE;
 418         }
 419
 420         void VerifyCertificate()
 421         {
 422                 X509* cert;
 423                 ssl_cert* certinfo = new ssl_cert;
 424                 this->certificate = certinfo;
 425                 unsigned int n;
 426                 unsigned char md[EVP_MAX_MD_SIZE];
 427
 428                 cert = SSL_get_peer_certificate(sess);
 429
 430                 if (!cert)
 431                 {
 432                         certinfo->error = "Could not get peer certificate: "+std::string(get_error());
 433                         return;
 434                 }
 435
 436                 certinfo->invalid = (SSL_get_verify_result(sess) != X509_V_OK);
 437
 438                 if (!SelfSigned)
 439                 {
 440                         certinfo->unknownsigner = false;
 441                         certinfo->trusted = true;
 442                 }
 443                 else
 444                 {
 445                         certinfo->unknownsigner = true;
 446                         certinfo->trusted = false;
 447                 }
 448
 449                 char buf[512];
 450                 X509_NAME_oneline(X509_get_subject_name(cert), buf, sizeof(buf));
 451                 certinfo->dn = buf;
 452                 // Make sure there are no chars in the string that we consider invalid
 453                 if (certinfo->dn.find_first_of("\r\n") != std::string::npos)
 454                         certinfo->dn.clear();
 455
 456                 X509_NAME_oneline(X509_get_issuer_name(cert), buf, sizeof(buf));
 457                 certinfo->issuer = buf;
 458                 if (certinfo->issuer.find_first_of("\r\n") != std::string::npos)
 459                         certinfo->issuer.clear();
 460
 461                 if (!X509_digest(cert, profile->GetDigest(), md, &n))
 462                 {
 463                         certinfo->error = "Out of memory generating fingerprint";
 464                 }
 465                 else
 466                 {
 467                         certinfo->fingerprint = BinToHex(md, n);
 468                 }
 469
 470                 if ((ASN1_UTCTIME_cmp_time_t(X509_get_notAfter(cert), ServerInstance->Time()) == -1) || (ASN1_UTCTIME_cmp_time_t(X509_get_notBefore(cert), ServerInstance->Time()) == 0))
 471                 {
 472                         certinfo->error = "Not activated, or expired certificate";
 473                 }
 474
 475                 X509_free(cert);
 476         }
 477
 478 #ifdef INSPIRCD_OPENSSL_ENABLE_RENEGO_DETECTION
 479         void SSLInfoCallback(int where, int rc)
 480         {
 481                 if ((where & SSL_CB_HANDSHAKE_START) && (status == ISSL_OPEN))
 482                 {
 483                         if (profile->AllowRenegotiation())
 484                                 return;
 485
 486                         // The other side is trying to renegotiate, kill the connection and change status
 487                         // to ISSL_NONE so CheckRenego() closes the session
 488                         status = ISSL_NONE;
 489                         SocketEngine::Shutdown(SSL_get_fd(sess), 2);
 490                 }
 491         }
 492
 493         bool CheckRenego(StreamSocket* sock)
 494         {
 495                 if (status != ISSL_NONE)
 496                         return true;
 497
 498                 ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Session %p killed, attempted to renegotiate", (void*)sess);
 499                 CloseSession();
 500                 sock->SetError("Renegotiation is not allowed");
 501                 return false;
 502         }
 503 #endif
 504
 505         // Returns 1 if application I/O should proceed, 0 if it must wait for the underlying protocol to progress, -1 on fatal error
 506         int PrepareIO(StreamSocket* sock)
 507         {
 508                 if (status == ISSL_OPEN)
 509                         return 1;
 510                 else if (status == ISSL_HANDSHAKING)
 511                 {
 512                         // The handshake isn't finished, try to finish it
 513                         return Handshake(sock);
 514                 }
 515
 516                 CloseSession();
 517                 return -1;
 518         }
 519
 520         // Calls our private SSLInfoCallback()
 521         friend void StaticSSLInfoCallback(const SSL* ssl, int where, int rc);
 522
 523  public:
 524         OpenSSLIOHook(IOHookProvider* hookprov, StreamSocket* sock, bool is_outbound, SSL* session, const reference<OpenSSL::Profile>& sslprofile)
 525                 : SSLIOHook(hookprov)
 526                 , sess(session)
 527                 , status(ISSL_NONE)
 528                 , outbound(is_outbound)
 529                 , data_to_write(false)
 530                 , profile(sslprofile)
 531         {
 532                 if (sess == NULL)
 533                         return;
 534                 if (SSL_set_fd(sess, sock->GetFd()) == 0)
 535                         throw ModuleException("Can't set fd with SSL_set_fd: " + ConvToStr(sock->GetFd()));
 536
 537                 SSL_set_ex_data(sess, exdataindex, this);
 538                 sock->AddIOHook(this);
 539                 Handshake(sock);
 540         }
 541
 542         void OnStreamSocketClose(StreamSocket* user) CXX11_OVERRIDE
 543         {
 544                 CloseSession();
 545         }
 546
 547         int OnStreamSocketRead(StreamSocket* user, std::string& recvq) CXX11_OVERRIDE
 548         {
 549                 // Finish handshake if needed
 550                 int prepret = PrepareIO(user);
 551                 if (prepret <= 0)
 552                         return prepret;
 553
 554                 // If we resumed the handshake then this->status will be ISSL_OPEN
 555                 {
 556                         ERR_clear_error();
 557                         char* buffer = ServerInstance->GetReadBuffer();
 558                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 559                         int ret = SSL_read(sess, buffer, bufsiz);
 560
 561 #ifdef INSPIRCD_OPENSSL_ENABLE_RENEGO_DETECTION
 562                         if (!CheckRenego(user))
 563                                 return -1;
 564 #endif
 565
 566                         if (ret > 0)
 567                         {
 568                                 recvq.append(buffer, ret);
 569                                 if (data_to_write)
 570                                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_SINGLE_WRITE);
 571                                 return 1;
 572                         }
 573                         else if (ret == 0)
 574                         {
 575                                 // Client closed connection.
 576                                 CloseSession();
 577                                 user->SetError("Connection closed");
 578                                 return -1;
 579                         }
 580                         else // if (ret < 0)
 581                         {
 582                                 int err = SSL_get_error(sess, ret);
 583
 584                                 if (err == SSL_ERROR_WANT_READ)
 585                                 {
 586                                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ);
 587                                         return 0;
 588                                 }
 589                                 else if (err == SSL_ERROR_WANT_WRITE)
 590                                 {
 591                                         SocketEngine::ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 592                                         return 0;
 593                                 }
 594                                 else
 595                                 {
 596                                         CloseSession();
 597                                         return -1;
 598                                 }
 599                         }
 600                 }
 601         }
 602
 603         int OnStreamSocketWrite(StreamSocket* user, std::string& buffer) CXX11_OVERRIDE
 604         {
 605                 // Finish handshake if needed
 606                 int prepret = PrepareIO(user);
 607                 if (prepret <= 0)
 608                         return prepret;
 609
 610                 data_to_write = true;
 611
 612                 // Session is ready for transferring application data
 613                 {
 614                         ERR_clear_error();
 615                         int ret = SSL_write(sess, buffer.data(), buffer.size());
 616
 617 #ifdef INSPIRCD_OPENSSL_ENABLE_RENEGO_DETECTION
 618                         if (!CheckRenego(user))
 619                                 return -1;
 620 #endif
 621
 622                         if (ret == (int)buffer.length())
 623                         {
 624                                 data_to_write = false;
 625                                 SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 626                                 return 1;
 627                         }
 628                         else if (ret > 0)
 629                         {
 630                                 buffer.erase(0, ret);
 631                                 SocketEngine::ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 632                                 return 0;
 633                         }
 634                         else if (ret == 0)
 635                         {
 636                                 CloseSession();
 637                                 return -1;
 638                         }
 639                         else // if (ret < 0)
 640                         {
 641                                 int err = SSL_get_error(sess, ret);
 642
 643                                 if (err == SSL_ERROR_WANT_WRITE)
 644                                 {
 645                                         SocketEngine::ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 646                                         return 0;
 647                                 }
 648                                 else if (err == SSL_ERROR_WANT_READ)
 649                                 {
 650                                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ);
 651                                         return 0;
 652                                 }
 653                                 else
 654                                 {
 655                                         CloseSession();
 656                                         return -1;
 657                                 }
 658                         }
 659                 }
 660         }
 661
 662         void TellCiphersAndFingerprint(LocalUser* user)
 663         {
 664                 if (sess)
 665                 {
 666                         std::string text = "*** You are connected using SSL cipher '";
 667                         GetCiphersuite(text);
 668                         text += '\'';
 669                         const std::string& fingerprint = certificate->fingerprint;
 670                         if (!fingerprint.empty())
 671                                 text += " and your SSL certificate fingerprint is " + fingerprint;
 672
 673                         user->WriteNotice(text);
 674                 }
 675         }
 676
 677         void GetCiphersuite(std::string& out) const
 678         {
 679                 out.append(SSL_get_version(sess)).push_back('-');
 680                 out.append(SSL_get_cipher(sess));
 681         }
 682 };
 683
 684 static void StaticSSLInfoCallback(const SSL* ssl, int where, int rc)
 685 {
 686 #ifdef INSPIRCD_OPENSSL_ENABLE_RENEGO_DETECTION
 687         OpenSSLIOHook* hook = static_cast<OpenSSLIOHook*>(SSL_get_ex_data(ssl, exdataindex));
 688         hook->SSLInfoCallback(where, rc);
 689 #endif
 690 }
 691
 692 class OpenSSLIOHookProvider : public refcountbase, public IOHookProvider
 693 {
 694         reference<OpenSSL::Profile> profile;
 695
 696  public:
 697         OpenSSLIOHookProvider(Module* mod, reference<OpenSSL::Profile>& prof)
 698                 : IOHookProvider(mod, "ssl/" + prof->GetName(), IOHookProvider::IOH_SSL)
 699                 , profile(prof)
 700         {
 701                 ServerInstance->Modules->AddService(*this);
 702         }
 703
 704         ~OpenSSLIOHookProvider()
 705         {
 706                 ServerInstance->Modules->DelService(*this);
 707         }
 708
 709         void OnAccept(StreamSocket* sock, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server) CXX11_OVERRIDE
 710         {
 711                 new OpenSSLIOHook(this, sock, false, profile->CreateServerSession(), profile);
 712         }
 713
 714         void OnConnect(StreamSocket* sock) CXX11_OVERRIDE
 715         {
 716                 new OpenSSLIOHook(this, sock, true, profile->CreateClientSession(), profile);
 717         }
 718 };
 719
 720 class ModuleSSLOpenSSL : public Module
 721 {
 722         typedef std::vector<reference<OpenSSLIOHookProvider> > ProfileList;
 723
 724         ProfileList profiles;
 725
 726         void ReadProfiles()
 727         {
 728                 ProfileList newprofiles;
 729                 ConfigTagList tags = ServerInstance->Config->ConfTags("sslprofile");
 730                 if (tags.first == tags.second)
 731                 {
 732                         // Create a default profile named "openssl"
 733                         const std::string defname = "openssl";
 734                         ConfigTag* tag = ServerInstance->Config->ConfValue(defname);
 735                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "No <sslprofile> tags found, using settings from the <openssl> tag");
 736
 737                         try
 738                         {
 739                                 reference<OpenSSL::Profile> profile(new OpenSSL::Profile(defname, tag));
 740                                 newprofiles.push_back(new OpenSSLIOHookProvider(this, profile));
 741                         }
 742                         catch (OpenSSL::Exception& ex)
 743                         {
 744                                 throw ModuleException("Error while initializing the default SSL profile - " + ex.GetReason());
 745                         }
 746                 }
 747
 748                 for (ConfigIter i = tags.first; i != tags.second; ++i)
 749                 {
 750                         ConfigTag* tag = i->second;
 751                         if (tag->getString("provider") != "openssl")
 752                                 continue;
 753
 754                         std::string name = tag->getString("name");
 755                         if (name.empty())
 756                         {
 757                                 ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Ignoring <sslprofile> tag without name at " + tag->getTagLocation());
 758                                 continue;
 759                         }
 760
 761                         reference<OpenSSL::Profile> profile;
 762                         try
 763                         {
 764                                 profile = new OpenSSL::Profile(name, tag);
 765                         }
 766                         catch (CoreException& ex)
 767                         {
 768                                 throw ModuleException("Error while initializing SSL profile \"" + name + "\" at " + tag->getTagLocation() + " - " + ex.GetReason());
 769                         }
 770
 771                         newprofiles.push_back(new OpenSSLIOHookProvider(this, profile));
 772                 }
 773
 774                 profiles.swap(newprofiles);
 775         }
 776
 777  public:
 778         ModuleSSLOpenSSL()
 779         {
 780                 // Initialize OpenSSL
 781                 SSL_library_init();
 782                 SSL_load_error_strings();
 783         }
 784
 785         void init() CXX11_OVERRIDE
 786         {
 787                 // Register application specific data
 788                 char exdatastr[] = "inspircd";
 789                 exdataindex = SSL_get_ex_new_index(0, exdatastr, NULL, NULL, NULL);
 790                 if (exdataindex < 0)
 791                         throw ModuleException("Failed to register application specific data");
 792
 793                 ReadProfiles();
 794         }
 795
 796         void OnModuleRehash(User* user, const std::string &param) CXX11_OVERRIDE
 797         {
 798                 if (param != "ssl")
 799                         return;
 800
 801                 try
 802                 {
 803                         ReadProfiles();
 804                 }
 805                 catch (ModuleException& ex)
 806                 {
 807                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, ex.GetReason() + " Not applying settings.");
 808                 }
 809         }
 810
 811         void OnUserConnect(LocalUser* user) CXX11_OVERRIDE
 812         {
 813                 IOHook* hook = user->eh.GetIOHook();
 814                 if (hook && hook->prov->creator == this)
 815                         static_cast<OpenSSLIOHook*>(hook)->TellCiphersAndFingerprint(user);
 816         }
 817
 818         void OnCleanup(int target_type, void* item) CXX11_OVERRIDE
 819         {
 820                 if (target_type == TYPE_USER)
 821                 {
 822                         LocalUser* user = IS_LOCAL((User*)item);
 823
 824                         if (user && user->eh.GetIOHook() && user->eh.GetIOHook()->prov->creator == this)
 825                         {
 826                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 827                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 828                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 829                         }
 830                 }
 831         }
 832
 833         Version GetVersion() CXX11_OVERRIDE
 834         {
 835                 return Version("Provides SSL support for clients", VF_VENDOR);
 836         }
 837 };
 838
 839 MODULE_INIT(ModuleSSLOpenSSL)