src/modules/extra/m_ssl_openssl.cpp

   1 /*
   2  * InspIRCd -- Internet Relay Chat Daemon
   3  *
   4  *   Copyright (C) 2020 Matt Schatz <genius3000@g3k.solutions>
   5  *   Copyright (C) 2019 linuxdaemon <linuxdaemon.irc@gmail.com>
   6  *   Copyright (C) 2017 Wade Cline <wadecline@hotmail.com>
   7  *   Copyright (C) 2014, 2016 Adam <Adam@anope.org>
   8  *   Copyright (C) 2014 Julien Vehent <julien@linuxwall.info>
   9  *   Copyright (C) 2013-2014, 2016-2020 Sadie Powell <sadie@witchery.services>
  10  *   Copyright (C) 2012-2017 Attila Molnar <attilamolnar@hush.com>
  11  *   Copyright (C) 2012 Robby <robby@chatbelgie.be>
  12  *   Copyright (C) 2012 ChrisTX <xpipe@hotmail.de>
  13  *   Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
  14  *   Copyright (C) 2008 Robin Burchell <robin+git@viroteck.net>
  15  *   Copyright (C) 2007-2008, 2010 Craig Edwards <brain@inspircd.org>
  16  *   Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
  17  *
  18  * This file is part of InspIRCd.  InspIRCd is free software: you can
  19  * redistribute it and/or modify it under the terms of the GNU General Public
  20  * License as published by the Free Software Foundation, version 2.
  21  *
  22  * This program is distributed in the hope that it will be useful, but WITHOUT
  23  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  24  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  25  * details.
  26  *
  27  * You should have received a copy of the GNU General Public License
  28  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  29  */
  30
  31 /// $CompilerFlags: find_compiler_flags("openssl" "")
  32 /// $LinkerFlags: find_linker_flags("openssl" "-lssl -lcrypto")
  33
  34 /// $PackageInfo: require_system("arch") openssl pkgconf
  35 /// $PackageInfo: require_system("centos") openssl-devel pkgconfig
  36 /// $PackageInfo: require_system("darwin") openssl pkg-config
  37 /// $PackageInfo: require_system("debian") libssl-dev openssl pkg-config
  38 /// $PackageInfo: require_system("ubuntu") libssl-dev openssl pkg-config
  39
  40
  41 #include "inspircd.h"
  42 #include "iohook.h"
  43 #include "modules/ssl.h"
  44
  45 #ifdef __GNUC__
  46 # pragma GCC diagnostic push
  47 #endif
  48
  49 // Ignore OpenSSL deprecation warnings on OS X Lion and newer.
  50 #if defined __APPLE__
  51 # pragma GCC diagnostic ignored "-Wdeprecated-declarations"
  52 #endif
  53
  54 // LibreSSL lies about the version of OpenSSL it is compatible with and is a general pain
  55 // to support. Support for it was removed in the master branch at the same time that
  56 // support for OpenSSL pre-1.1 was.
  57 #if defined __GNUC__ && defined LIBRESSL_VERSION_NUMBER
  58 # warning LibreSSL support will be discontinued in the future. Consider using the ssl_gnutls or ssl_mbedtls modules instead.
  59 #endif
  60
  61 // Fix warnings about the use of `long long` on C++03.
  62 #if defined __clang__
  63 # pragma clang diagnostic ignored "-Wc++11-long-long"
  64 #elif defined __GNUC__
  65 # pragma GCC diagnostic ignored "-Wlong-long"
  66 #endif
  67
  68 #include <openssl/ssl.h>
  69 #include <openssl/err.h>
  70 #include <openssl/dh.h>
  71
  72 #ifdef __GNUC__
  73 # pragma GCC diagnostic pop
  74 #endif
  75
  76 #ifdef _WIN32
  77 # pragma comment(lib, "ssleay32.lib")
  78 # pragma comment(lib, "libeay32.lib")
  79 #endif
  80
  81 // Compatibility layer to allow OpenSSL 1.0 to use the 1.1 API.
  82 #if ((defined LIBRESSL_VERSION_NUMBER) || (OPENSSL_VERSION_NUMBER < 0x10100000L))
  83
  84 // BIO is opaque in OpenSSL 1.1 but the access API does not exist in 1.0.
  85 # define BIO_get_data(BIO) BIO->ptr
  86 # define BIO_set_data(BIO, VALUE) BIO->ptr = VALUE;
  87 # define BIO_set_init(BIO, VALUE) BIO->init = VALUE;
  88
  89 // These functions have been renamed in OpenSSL 1.1.
  90 # define OpenSSL_version SSLeay_version
  91 # define X509_getm_notAfter X509_get_notAfter
  92 # define X509_getm_notBefore X509_get_notBefore
  93 # define OPENSSL_init_ssl(OPTIONS, SETTINGS) \
  94         SSL_library_init(); \
  95         SSL_load_error_strings();
  96
  97 // These macros have been renamed in OpenSSL 1.1.
  98 # define OPENSSL_VERSION SSLEAY_VERSION
  99
 100 #else
 101 # define INSPIRCD_OPENSSL_OPAQUE_BIO
 102 #endif
 103
 104 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING, ISSL_OPEN };
 105
 106 static bool SelfSigned = false;
 107 static int exdataindex;
 108
 109 char* get_error()
 110 {
 111         return ERR_error_string(ERR_get_error(), NULL);
 112 }
 113
 114 static int OnVerify(int preverify_ok, X509_STORE_CTX* ctx);
 115 static void StaticSSLInfoCallback(const SSL* ssl, int where, int rc);
 116
 117 namespace OpenSSL
 118 {
 119         class Exception : public ModuleException
 120         {
 121          public:
 122                 Exception(const std::string& reason)
 123                         : ModuleException(reason) { }
 124         };
 125
 126         class DHParams
 127         {
 128                 DH* dh;
 129
 130          public:
 131                 DHParams(const std::string& filename)
 132                 {
 133                         BIO* dhpfile = BIO_new_file(filename.c_str(), "r");
 134                         if (dhpfile == NULL)
 135                                 throw Exception("Couldn't open DH file " + filename);
 136
 137                         dh = PEM_read_bio_DHparams(dhpfile, NULL, NULL, NULL);
 138                         BIO_free(dhpfile);
 139
 140                         if (!dh)
 141                                 throw Exception("Couldn't read DH params from file " + filename);
 142                 }
 143
 144                 ~DHParams()
 145                 {
 146                         DH_free(dh);
 147                 }
 148
 149                 DH* get()
 150                 {
 151                         return dh;
 152                 }
 153         };
 154
 155         class Context
 156         {
 157                 SSL_CTX* const ctx;
 158                 long ctx_options;
 159
 160          public:
 161                 Context(SSL_CTX* context)
 162                         : ctx(context)
 163                 {
 164                         // Sane default options for OpenSSL see https://www.openssl.org/docs/ssl/SSL_CTX_set_options.html
 165                         // and when choosing a cipher, use the server's preferences instead of the client preferences.
 166                         long opts = SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3 | SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION | SSL_OP_CIPHER_SERVER_PREFERENCE | SSL_OP_SINGLE_DH_USE;
 167                         // Only turn options on if they exist
 168 #ifdef SSL_OP_SINGLE_ECDH_USE
 169                         opts |= SSL_OP_SINGLE_ECDH_USE;
 170 #endif
 171 #ifdef SSL_OP_NO_TICKET
 172                         opts |= SSL_OP_NO_TICKET;
 173 #endif
 174
 175                         ctx_options = SSL_CTX_set_options(ctx, opts);
 176
 177                         long mode = SSL_MODE_ENABLE_PARTIAL_WRITE | SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER;
 178 #ifdef SSL_MODE_RELEASE_BUFFERS
 179                         mode |= SSL_MODE_RELEASE_BUFFERS;
 180 #endif
 181                         SSL_CTX_set_mode(ctx, mode);
 182                         SSL_CTX_set_verify(ctx, SSL_VERIFY_NONE, NULL);
 183                         SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_OFF);
 184                         SSL_CTX_set_info_callback(ctx, StaticSSLInfoCallback);
 185                 }
 186
 187                 ~Context()
 188                 {
 189                         SSL_CTX_free(ctx);
 190                 }
 191
 192                 bool SetDH(DHParams& dh)
 193                 {
 194                         ERR_clear_error();
 195                         return (SSL_CTX_set_tmp_dh(ctx, dh.get()) >= 0);
 196                 }
 197
 198 #ifndef OPENSSL_NO_ECDH
 199                 void SetECDH(const std::string& curvename)
 200                 {
 201                         int nid = OBJ_sn2nid(curvename.c_str());
 202                         if (nid == 0)
 203                                 throw Exception("Unknown curve: " + curvename);
 204
 205                         EC_KEY* eckey = EC_KEY_new_by_curve_name(nid);
 206                         if (!eckey)
 207                                 throw Exception("Unable to create EC key object");
 208
 209                         ERR_clear_error();
 210                         bool ret = (SSL_CTX_set_tmp_ecdh(ctx, eckey) >= 0);
 211                         EC_KEY_free(eckey);
 212                         if (!ret)
 213                                 throw Exception("Couldn't set ECDH parameters");
 214                 }
 215 #endif
 216
 217                 bool SetCiphers(const std::string& ciphers)
 218                 {
 219                         ERR_clear_error();
 220                         return SSL_CTX_set_cipher_list(ctx, ciphers.c_str());
 221                 }
 222
 223                 bool SetCerts(const std::string& filename)
 224                 {
 225                         ERR_clear_error();
 226                         return SSL_CTX_use_certificate_chain_file(ctx, filename.c_str());
 227                 }
 228
 229                 bool SetPrivateKey(const std::string& filename)
 230                 {
 231                         ERR_clear_error();
 232                         return SSL_CTX_use_PrivateKey_file(ctx, filename.c_str(), SSL_FILETYPE_PEM);
 233                 }
 234
 235                 bool SetCA(const std::string& filename)
 236                 {
 237                         ERR_clear_error();
 238                         return SSL_CTX_load_verify_locations(ctx, filename.c_str(), 0);
 239                 }
 240
 241                 void SetCRL(const std::string& crlfile, const std::string& crlpath, const std::string& crlmode)
 242                 {
 243                         if (crlfile.empty() && crlpath.empty())
 244                                 return;
 245
 246                         /* Set CRL mode */
 247                         unsigned long crlflags = X509_V_FLAG_CRL_CHECK;
 248                         if (stdalgo::string::equalsci(crlmode, "chain"))
 249                         {
 250                                 crlflags |= X509_V_FLAG_CRL_CHECK_ALL;
 251                         }
 252                         else if (!stdalgo::string::equalsci(crlmode, "leaf"))
 253                         {
 254                                 throw ModuleException("Unknown mode '" + crlmode + "'; expected either 'chain' (default) or 'leaf'");
 255                         }
 256
 257                         /* Load CRL files */
 258                         X509_STORE* store = SSL_CTX_get_cert_store(ctx);
 259                         if (!store)
 260                         {
 261                                 throw ModuleException("Unable to get X509_STORE from TLS (SSL) context; this should never happen");
 262                         }
 263                         ERR_clear_error();
 264                         if (!X509_STORE_load_locations(store,
 265                                 crlfile.empty() ? NULL : crlfile.c_str(),
 266                                 crlpath.empty() ? NULL : crlpath.c_str()))
 267                         {
 268                                 int err = ERR_get_error();
 269                                 throw ModuleException("Unable to load CRL file '" + crlfile + "' or CRL path '" + crlpath + "': '" + (err ? ERR_error_string(err, NULL) : "unknown") + "'");
 270                         }
 271
 272                         /* Set CRL mode */
 273                         if (X509_STORE_set_flags(store, crlflags) != 1)
 274                         {
 275                                 throw ModuleException("Unable to set X509 CRL flags");
 276                         }
 277                 }
 278
 279
 280                 long GetDefaultContextOptions() const
 281                 {
 282                         return ctx_options;
 283                 }
 284
 285                 long SetRawContextOptions(long setoptions, long clearoptions)
 286                 {
 287                         // Clear everything
 288                         SSL_CTX_clear_options(ctx, SSL_CTX_get_options(ctx));
 289
 290                         // Set the default options and what is in the conf
 291                         SSL_CTX_set_options(ctx, ctx_options | setoptions);
 292                         return SSL_CTX_clear_options(ctx, clearoptions);
 293                 }
 294
 295                 void SetVerifyCert()
 296                 {
 297                         SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, OnVerify);
 298                 }
 299
 300                 SSL* CreateServerSession()
 301                 {
 302                         SSL* sess = SSL_new(ctx);
 303                         SSL_set_accept_state(sess); // Act as server
 304                         return sess;
 305                 }
 306
 307                 SSL* CreateClientSession()
 308                 {
 309                         SSL* sess = SSL_new(ctx);
 310                         SSL_set_connect_state(sess); // Act as client
 311                         return sess;
 312                 }
 313         };
 314
 315         class Profile
 316         {
 317                 /** Name of this profile
 318                  */
 319                 const std::string name;
 320
 321                 /** DH parameters in use
 322                  */
 323                 DHParams dh;
 324
 325                 /** OpenSSL makes us have two contexts, one for servers and one for clients
 326                  */
 327                 Context ctx;
 328                 Context clictx;
 329
 330                 /** Digest to use when generating fingerprints
 331                  */
 332                 const EVP_MD* digest;
 333
 334                 /** Last error, set by error_callback()
 335                  */
 336                 std::string lasterr;
 337
 338                 /** True if renegotiations are allowed, false if not
 339                  */
 340                 const bool allowrenego;
 341
 342                 /** Rough max size of records to send
 343                  */
 344                 const unsigned int outrecsize;
 345
 346                 static int error_callback(const char* str, size_t len, void* u)
 347                 {
 348                         Profile* profile = reinterpret_cast<Profile*>(u);
 349                         profile->lasterr = std::string(str, len - 1);
 350                         return 0;
 351                 }
 352
 353                 /** Set raw OpenSSL context (SSL_CTX) options from a config tag
 354                  * @param ctxname Name of the context, client or server
 355                  * @param tag Config tag defining this profile
 356                  * @param context Context object to manipulate
 357                  */
 358                 void SetContextOptions(const std::string& ctxname, ConfigTag* tag, Context& context)
 359                 {
 360                         long setoptions = tag->getInt(ctxname + "setoptions", 0);
 361                         long clearoptions = tag->getInt(ctxname + "clearoptions", 0);
 362
 363 #ifdef SSL_OP_NO_COMPRESSION
 364                         // Disable compression by default
 365                         if (!tag->getBool("compression", false))
 366                                 setoptions |= SSL_OP_NO_COMPRESSION;
 367 #endif
 368
 369                         // Disable TLSv1.0 by default.
 370                         if (!tag->getBool("tlsv1", false))
 371                                 setoptions |= SSL_OP_NO_TLSv1;
 372
 373 #ifdef SSL_OP_NO_TLSv1_1
 374                         // Enable TLSv1.1 by default.
 375                         if (!tag->getBool("tlsv11", true))
 376                                 setoptions |= SSL_OP_NO_TLSv1_1;
 377 #endif
 378
 379 #ifdef SSL_OP_NO_TLSv1_2
 380                         // Enable TLSv1.2 by default.
 381                         if (!tag->getBool("tlsv12", true))
 382                                 setoptions |= SSL_OP_NO_TLSv1_2;
 383 #endif
 384
 385                         if (!setoptions && !clearoptions)
 386                                 return; // Nothing to do
 387
 388                         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);
 389                         long final = context.SetRawContextOptions(setoptions, clearoptions);
 390                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "%s %s context options: %ld", name.c_str(), ctxname.c_str(), final);
 391                 }
 392
 393          public:
 394                 Profile(const std::string& profilename, ConfigTag* tag)
 395                         : name(profilename)
 396                         , dh(ServerInstance->Config->Paths.PrependConfig(tag->getString("dhfile", "dhparams.pem", 1)))
 397                         , ctx(SSL_CTX_new(SSLv23_server_method()))
 398                         , clictx(SSL_CTX_new(SSLv23_client_method()))
 399                         , allowrenego(tag->getBool("renegotiation")) // Disallow by default
 400                         , outrecsize(tag->getUInt("outrecsize", 2048, 512, 16384))
 401                 {
 402                         if ((!ctx.SetDH(dh)) || (!clictx.SetDH(dh)))
 403                                 throw Exception("Couldn't set DH parameters");
 404
 405                         const std::string hash = tag->getString("hash", "md5", 1);
 406                         digest = EVP_get_digestbyname(hash.c_str());
 407                         if (digest == NULL)
 408                                 throw Exception("Unknown hash type " + hash);
 409
 410                         std::string ciphers = tag->getString("ciphers");
 411                         if (!ciphers.empty())
 412                         {
 413                                 if ((!ctx.SetCiphers(ciphers)) || (!clictx.SetCiphers(ciphers)))
 414                                 {
 415                                         ERR_print_errors_cb(error_callback, this);
 416                                         throw Exception("Can't set cipher list to \"" + ciphers + "\" " + lasterr);
 417                                 }
 418                         }
 419
 420 #ifndef OPENSSL_NO_ECDH
 421                         const std::string curvename = tag->getString("ecdhcurve", "prime256v1", 1);
 422                         if (!curvename.empty())
 423                                 ctx.SetECDH(curvename);
 424 #endif
 425
 426                         SetContextOptions("server", tag, ctx);
 427                         SetContextOptions("client", tag, clictx);
 428
 429                         /* Load our keys and certificates
 430                          * NOTE: OpenSSL's error logging API sucks, don't blame us for this clusterfuck.
 431                          */
 432                         std::string filename = ServerInstance->Config->Paths.PrependConfig(tag->getString("certfile", "cert.pem", 1));
 433                         if ((!ctx.SetCerts(filename)) || (!clictx.SetCerts(filename)))
 434                         {
 435                                 ERR_print_errors_cb(error_callback, this);
 436                                 throw Exception("Can't read certificate file: " + lasterr);
 437                         }
 438
 439                         filename = ServerInstance->Config->Paths.PrependConfig(tag->getString("keyfile", "key.pem", 1));
 440                         if ((!ctx.SetPrivateKey(filename)) || (!clictx.SetPrivateKey(filename)))
 441                         {
 442                                 ERR_print_errors_cb(error_callback, this);
 443                                 throw Exception("Can't read key file: " + lasterr);
 444                         }
 445
 446                         // Load the CAs we trust
 447                         filename = ServerInstance->Config->Paths.PrependConfig(tag->getString("cafile", "ca.pem", 1));
 448                         if ((!ctx.SetCA(filename)) || (!clictx.SetCA(filename)))
 449                         {
 450                                 ERR_print_errors_cb(error_callback, this);
 451                                 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());
 452                         }
 453
 454                         // Load the CRLs.
 455                         const std::string crlfile = tag->getString("crlfile");
 456                         const std::string crlpath = tag->getString("crlpath");
 457                         const std::string crlmode = tag->getString("crlmode", "chain", 1);
 458                         ctx.SetCRL(crlfile, crlpath, crlmode);
 459
 460                         clictx.SetVerifyCert();
 461                         if (tag->getBool("requestclientcert", true))
 462                                 ctx.SetVerifyCert();
 463                 }
 464
 465                 const std::string& GetName() const { return name; }
 466                 SSL* CreateServerSession() { return ctx.CreateServerSession(); }
 467                 SSL* CreateClientSession() { return clictx.CreateClientSession(); }
 468                 const EVP_MD* GetDigest() { return digest; }
 469                 bool AllowRenegotiation() const { return allowrenego; }
 470                 unsigned int GetOutgoingRecordSize() const { return outrecsize; }
 471         };
 472
 473         namespace BIOMethod
 474         {
 475                 static int create(BIO* bio)
 476                 {
 477                         BIO_set_init(bio, 1);
 478                         return 1;
 479                 }
 480
 481                 static int destroy(BIO* bio)
 482                 {
 483                         // XXX: Dummy function to avoid a memory leak in OpenSSL.
 484                         // The memory leak happens in BIO_free() (bio_lib.c) when the destroy func of the BIO is NULL.
 485                         // This is fixed in OpenSSL but some distros still ship the unpatched version hence we provide this workaround.
 486                         return 1;
 487                 }
 488
 489                 static long ctrl(BIO* bio, int cmd, long num, void* ptr)
 490                 {
 491                         if (cmd == BIO_CTRL_FLUSH)
 492                                 return 1;
 493                         return 0;
 494                 }
 495
 496                 static int read(BIO* bio, char* buf, int len);
 497                 static int write(BIO* bio, const char* buf, int len);
 498
 499 #ifdef INSPIRCD_OPENSSL_OPAQUE_BIO
 500                 static BIO_METHOD* alloc()
 501                 {
 502                         BIO_METHOD* meth = BIO_meth_new(100 | BIO_TYPE_SOURCE_SINK, "inspircd");
 503                         BIO_meth_set_write(meth, OpenSSL::BIOMethod::write);
 504                         BIO_meth_set_read(meth, OpenSSL::BIOMethod::read);
 505                         BIO_meth_set_ctrl(meth, OpenSSL::BIOMethod::ctrl);
 506                         BIO_meth_set_create(meth, OpenSSL::BIOMethod::create);
 507                         BIO_meth_set_destroy(meth, OpenSSL::BIOMethod::destroy);
 508                         return meth;
 509                 }
 510 #endif
 511         }
 512 }
 513
 514 // BIO_METHOD is opaque in OpenSSL 1.1 so we can't do this.
 515 // See OpenSSL::BIOMethod::alloc for the new method.
 516 #ifndef INSPIRCD_OPENSSL_OPAQUE_BIO
 517 static BIO_METHOD biomethods =
 518 {
 519         (100 | BIO_TYPE_SOURCE_SINK),
 520         "inspircd",
 521         OpenSSL::BIOMethod::write,
 522         OpenSSL::BIOMethod::read,
 523         NULL, // puts
 524         NULL, // gets
 525         OpenSSL::BIOMethod::ctrl,
 526         OpenSSL::BIOMethod::create,
 527         OpenSSL::BIOMethod::destroy, // destroy, does nothing, see function body for more info
 528         NULL // callback_ctrl
 529 };
 530 #else
 531 static BIO_METHOD* biomethods;
 532 #endif
 533
 534 static int OnVerify(int preverify_ok, X509_STORE_CTX *ctx)
 535 {
 536         /* XXX: This will allow self signed certificates.
 537          * In the future if we want an option to not allow this,
 538          * we can just return preverify_ok here, and openssl
 539          * will boot off self-signed and invalid peer certs.
 540          */
 541         int ve = X509_STORE_CTX_get_error(ctx);
 542
 543         SelfSigned = (ve == X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT);
 544
 545         return 1;
 546 }
 547
 548 class OpenSSLIOHook : public SSLIOHook
 549 {
 550  private:
 551         SSL* sess;
 552         issl_status status;
 553         bool data_to_write;
 554
 555         // Returns 1 if handshake succeeded, 0 if it is still in progress, -1 if it failed
 556         int Handshake(StreamSocket* user)
 557         {
 558                 ERR_clear_error();
 559                 int ret = SSL_do_handshake(sess);
 560                 if (ret < 0)
 561                 {
 562                         int err = SSL_get_error(sess, ret);
 563
 564                         if (err == SSL_ERROR_WANT_READ)
 565                         {
 566                                 SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 567                                 this->status = ISSL_HANDSHAKING;
 568                                 return 0;
 569                         }
 570                         else if (err == SSL_ERROR_WANT_WRITE)
 571                         {
 572                                 SocketEngine::ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 573                                 this->status = ISSL_HANDSHAKING;
 574                                 return 0;
 575                         }
 576                         else
 577                         {
 578                                 CloseSession();
 579                                 return -1;
 580                         }
 581                 }
 582                 else if (ret > 0)
 583                 {
 584                         // Handshake complete.
 585                         VerifyCertificate();
 586
 587                         status = ISSL_OPEN;
 588
 589                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 590
 591                         return 1;
 592                 }
 593                 else if (ret == 0)
 594                 {
 595                         CloseSession();
 596                 }
 597                 return -1;
 598         }
 599
 600         void CloseSession()
 601         {
 602                 if (sess)
 603                 {
 604                         SSL_shutdown(sess);
 605                         SSL_free(sess);
 606                 }
 607                 sess = NULL;
 608                 certificate = NULL;
 609                 status = ISSL_NONE;
 610         }
 611
 612         void VerifyCertificate()
 613         {
 614                 X509* cert;
 615                 ssl_cert* certinfo = new ssl_cert;
 616                 this->certificate = certinfo;
 617                 unsigned int n;
 618                 unsigned char md[EVP_MAX_MD_SIZE];
 619
 620                 cert = SSL_get_peer_certificate(sess);
 621
 622                 if (!cert)
 623                 {
 624                         certinfo->error = "Could not get peer certificate: "+std::string(get_error());
 625                         return;
 626                 }
 627
 628                 certinfo->invalid = (SSL_get_verify_result(sess) != X509_V_OK);
 629
 630                 if (!SelfSigned)
 631                 {
 632                         certinfo->unknownsigner = false;
 633                         certinfo->trusted = true;
 634                 }
 635                 else
 636                 {
 637                         certinfo->unknownsigner = true;
 638                         certinfo->trusted = false;
 639                 }
 640
 641                 char buf[512];
 642                 X509_NAME_oneline(X509_get_subject_name(cert), buf, sizeof(buf));
 643                 certinfo->dn = buf;
 644                 // Make sure there are no chars in the string that we consider invalid
 645                 if (certinfo->dn.find_first_of("\r\n") != std::string::npos)
 646                         certinfo->dn.clear();
 647
 648                 X509_NAME_oneline(X509_get_issuer_name(cert), buf, sizeof(buf));
 649                 certinfo->issuer = buf;
 650                 if (certinfo->issuer.find_first_of("\r\n") != std::string::npos)
 651                         certinfo->issuer.clear();
 652
 653                 if (!X509_digest(cert, GetProfile().GetDigest(), md, &n))
 654                 {
 655                         certinfo->error = "Out of memory generating fingerprint";
 656                 }
 657                 else
 658                 {
 659                         certinfo->fingerprint = BinToHex(md, n);
 660                 }
 661
 662                 if ((ASN1_UTCTIME_cmp_time_t(X509_getm_notAfter(cert), ServerInstance->Time()) == -1) || (ASN1_UTCTIME_cmp_time_t(X509_getm_notBefore(cert), ServerInstance->Time()) == 0))
 663                 {
 664                         certinfo->error = "Not activated, or expired certificate";
 665                 }
 666
 667                 X509_free(cert);
 668         }
 669
 670         void SSLInfoCallback(int where, int rc)
 671         {
 672                 if ((where & SSL_CB_HANDSHAKE_START) && (status == ISSL_OPEN))
 673                 {
 674                         if (GetProfile().AllowRenegotiation())
 675                                 return;
 676
 677                         // The other side is trying to renegotiate, kill the connection and change status
 678                         // to ISSL_NONE so CheckRenego() closes the session
 679                         status = ISSL_NONE;
 680                         BIO* bio = SSL_get_rbio(sess);
 681                         EventHandler* eh = static_cast<StreamSocket*>(BIO_get_data(bio));
 682                         SocketEngine::Shutdown(eh, 2);
 683                 }
 684         }
 685
 686         bool CheckRenego(StreamSocket* sock)
 687         {
 688                 if (status != ISSL_NONE)
 689                         return true;
 690
 691                 ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Session %p killed, attempted to renegotiate", (void*)sess);
 692                 CloseSession();
 693                 sock->SetError("Renegotiation is not allowed");
 694                 return false;
 695         }
 696
 697         // Returns 1 if application I/O should proceed, 0 if it must wait for the underlying protocol to progress, -1 on fatal error
 698         int PrepareIO(StreamSocket* sock)
 699         {
 700                 if (status == ISSL_OPEN)
 701                         return 1;
 702                 else if (status == ISSL_HANDSHAKING)
 703                 {
 704                         // The handshake isn't finished, try to finish it
 705                         return Handshake(sock);
 706                 }
 707
 708                 CloseSession();
 709                 return -1;
 710         }
 711
 712         // Calls our private SSLInfoCallback()
 713         friend void StaticSSLInfoCallback(const SSL* ssl, int where, int rc);
 714
 715  public:
 716         OpenSSLIOHook(IOHookProvider* hookprov, StreamSocket* sock, SSL* session)
 717                 : SSLIOHook(hookprov)
 718                 , sess(session)
 719                 , status(ISSL_NONE)
 720                 , data_to_write(false)
 721         {
 722                 // Create BIO instance and store a pointer to the socket in it which will be used by the read and write functions
 723 #ifdef INSPIRCD_OPENSSL_OPAQUE_BIO
 724                 BIO* bio = BIO_new(biomethods);
 725 #else
 726                 BIO* bio = BIO_new(&biomethods);
 727 #endif
 728                 BIO_set_data(bio, sock);
 729                 SSL_set_bio(sess, bio, bio);
 730
 731                 SSL_set_ex_data(sess, exdataindex, this);
 732                 sock->AddIOHook(this);
 733                 Handshake(sock);
 734         }
 735
 736         void OnStreamSocketClose(StreamSocket* user) CXX11_OVERRIDE
 737         {
 738                 CloseSession();
 739         }
 740
 741         int OnStreamSocketRead(StreamSocket* user, std::string& recvq) CXX11_OVERRIDE
 742         {
 743                 // Finish handshake if needed
 744                 int prepret = PrepareIO(user);
 745                 if (prepret <= 0)
 746                         return prepret;
 747
 748                 // If we resumed the handshake then this->status will be ISSL_OPEN
 749                 {
 750                         ERR_clear_error();
 751                         char* buffer = ServerInstance->GetReadBuffer();
 752                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 753                         int ret = SSL_read(sess, buffer, bufsiz);
 754
 755                         if (!CheckRenego(user))
 756                                 return -1;
 757
 758                         if (ret > 0)
 759                         {
 760                                 recvq.append(buffer, ret);
 761                                 int mask = 0;
 762                                 // Schedule a read if there is still data in the OpenSSL buffer
 763                                 if (SSL_pending(sess) > 0)
 764                                         mask |= FD_ADD_TRIAL_READ;
 765                                 if (data_to_write)
 766                                         mask |= FD_WANT_POLL_READ | FD_WANT_SINGLE_WRITE;
 767                                 if (mask != 0)
 768                                         SocketEngine::ChangeEventMask(user, mask);
 769                                 return 1;
 770                         }
 771                         else if (ret == 0)
 772                         {
 773                                 // Client closed connection.
 774                                 CloseSession();
 775                                 user->SetError("Connection closed");
 776                                 return -1;
 777                         }
 778                         else // if (ret < 0)
 779                         {
 780                                 int err = SSL_get_error(sess, ret);
 781
 782                                 if (err == SSL_ERROR_WANT_READ)
 783                                 {
 784                                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ);
 785                                         return 0;
 786                                 }
 787                                 else if (err == SSL_ERROR_WANT_WRITE)
 788                                 {
 789                                         SocketEngine::ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 790                                         return 0;
 791                                 }
 792                                 else
 793                                 {
 794                                         CloseSession();
 795                                         return -1;
 796                                 }
 797                         }
 798                 }
 799         }
 800
 801         int OnStreamSocketWrite(StreamSocket* user, StreamSocket::SendQueue& sendq) CXX11_OVERRIDE
 802         {
 803                 // Finish handshake if needed
 804                 int prepret = PrepareIO(user);
 805                 if (prepret <= 0)
 806                         return prepret;
 807
 808                 data_to_write = true;
 809
 810                 // Session is ready for transferring application data
 811                 while (!sendq.empty())
 812                 {
 813                         ERR_clear_error();
 814                         FlattenSendQueue(sendq, GetProfile().GetOutgoingRecordSize());
 815                         const StreamSocket::SendQueue::Element& buffer = sendq.front();
 816                         int ret = SSL_write(sess, buffer.data(), buffer.size());
 817
 818                         if (!CheckRenego(user))
 819                                 return -1;
 820
 821                         if (ret == (int)buffer.length())
 822                         {
 823                                 // Wrote entire record, continue sending
 824                                 sendq.pop_front();
 825                         }
 826                         else if (ret > 0)
 827                         {
 828                                 sendq.erase_front(ret);
 829                                 SocketEngine::ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 830                                 return 0;
 831                         }
 832                         else if (ret == 0)
 833                         {
 834                                 CloseSession();
 835                                 return -1;
 836                         }
 837                         else // if (ret < 0)
 838                         {
 839                                 int err = SSL_get_error(sess, ret);
 840
 841                                 if (err == SSL_ERROR_WANT_WRITE)
 842                                 {
 843                                         SocketEngine::ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 844                                         return 0;
 845                                 }
 846                                 else if (err == SSL_ERROR_WANT_READ)
 847                                 {
 848                                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ);
 849                                         return 0;
 850                                 }
 851                                 else
 852                                 {
 853                                         CloseSession();
 854                                         return -1;
 855                                 }
 856                         }
 857                 }
 858
 859                 data_to_write = false;
 860                 SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 861                 return 1;
 862         }
 863
 864         void GetCiphersuite(std::string& out) const CXX11_OVERRIDE
 865         {
 866                 if (!IsHandshakeDone())
 867                         return;
 868                 out.append(SSL_get_version(sess)).push_back('-');
 869                 out.append(SSL_get_cipher(sess));
 870         }
 871
 872         bool GetServerName(std::string& out) const CXX11_OVERRIDE
 873         {
 874                 const char* name = SSL_get_servername(sess, TLSEXT_NAMETYPE_host_name);
 875                 if (!name)
 876                         return false;
 877
 878                 out.append(name);
 879                 return true;
 880         }
 881
 882         bool IsHandshakeDone() const { return (status == ISSL_OPEN); }
 883         OpenSSL::Profile& GetProfile();
 884 };
 885
 886 static void StaticSSLInfoCallback(const SSL* ssl, int where, int rc)
 887 {
 888         OpenSSLIOHook* hook = static_cast<OpenSSLIOHook*>(SSL_get_ex_data(ssl, exdataindex));
 889         hook->SSLInfoCallback(where, rc);
 890 }
 891
 892 static int OpenSSL::BIOMethod::write(BIO* bio, const char* buffer, int size)
 893 {
 894         BIO_clear_retry_flags(bio);
 895
 896         StreamSocket* sock = static_cast<StreamSocket*>(BIO_get_data(bio));
 897         if (sock->GetEventMask() & FD_WRITE_WILL_BLOCK)
 898         {
 899                 // Writes blocked earlier, don't retry syscall
 900                 BIO_set_retry_write(bio);
 901                 return -1;
 902         }
 903
 904         int ret = SocketEngine::Send(sock, buffer, size, 0);
 905         if ((ret < size) && ((ret > 0) || (SocketEngine::IgnoreError())))
 906         {
 907                 // Blocked, set retry flag for OpenSSL
 908                 SocketEngine::ChangeEventMask(sock, FD_WRITE_WILL_BLOCK);
 909                 BIO_set_retry_write(bio);
 910         }
 911
 912         return ret;
 913 }
 914
 915 static int OpenSSL::BIOMethod::read(BIO* bio, char* buffer, int size)
 916 {
 917         BIO_clear_retry_flags(bio);
 918
 919         StreamSocket* sock = static_cast<StreamSocket*>(BIO_get_data(bio));
 920         if (sock->GetEventMask() & FD_READ_WILL_BLOCK)
 921         {
 922                 // Reads blocked earlier, don't retry syscall
 923                 BIO_set_retry_read(bio);
 924                 return -1;
 925         }
 926
 927         int ret = SocketEngine::Recv(sock, buffer, size, 0);
 928         if ((ret < size) && ((ret > 0) || (SocketEngine::IgnoreError())))
 929         {
 930                 // Blocked, set retry flag for OpenSSL
 931                 SocketEngine::ChangeEventMask(sock, FD_READ_WILL_BLOCK);
 932                 BIO_set_retry_read(bio);
 933         }
 934
 935         return ret;
 936 }
 937
 938 class OpenSSLIOHookProvider : public IOHookProvider
 939 {
 940         OpenSSL::Profile profile;
 941
 942  public:
 943         OpenSSLIOHookProvider(Module* mod, const std::string& profilename, ConfigTag* tag)
 944                 : IOHookProvider(mod, "ssl/" + profilename, IOHookProvider::IOH_SSL)
 945                 , profile(profilename, tag)
 946         {
 947                 ServerInstance->Modules->AddService(*this);
 948         }
 949
 950         ~OpenSSLIOHookProvider()
 951         {
 952                 ServerInstance->Modules->DelService(*this);
 953         }
 954
 955         void OnAccept(StreamSocket* sock, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server) CXX11_OVERRIDE
 956         {
 957                 new OpenSSLIOHook(this, sock, profile.CreateServerSession());
 958         }
 959
 960         void OnConnect(StreamSocket* sock) CXX11_OVERRIDE
 961         {
 962                 new OpenSSLIOHook(this, sock, profile.CreateClientSession());
 963         }
 964
 965         OpenSSL::Profile& GetProfile() { return profile; }
 966 };
 967
 968 OpenSSL::Profile& OpenSSLIOHook::GetProfile()
 969 {
 970         IOHookProvider* hookprov = prov;
 971         return static_cast<OpenSSLIOHookProvider*>(hookprov)->GetProfile();
 972 }
 973
 974 class ModuleSSLOpenSSL : public Module
 975 {
 976         typedef std::vector<reference<OpenSSLIOHookProvider> > ProfileList;
 977
 978         ProfileList profiles;
 979
 980         void ReadProfiles()
 981         {
 982                 ProfileList newprofiles;
 983                 ConfigTagList tags = ServerInstance->Config->ConfTags("sslprofile");
 984                 if (tags.first == tags.second)
 985                 {
 986                         // Create a default profile named "openssl"
 987                         const std::string defname = "openssl";
 988                         ConfigTag* tag = ServerInstance->Config->ConfValue(defname);
 989                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "No <sslprofile> tags found, using settings from the deprecated <openssl> tag");
 990
 991                         try
 992                         {
 993                                 newprofiles.push_back(new OpenSSLIOHookProvider(this, defname, tag));
 994                         }
 995                         catch (OpenSSL::Exception& ex)
 996                         {
 997                                 throw ModuleException("Error while initializing the default TLS (SSL) profile - " + ex.GetReason());
 998                         }
 999                 }
1000                 else
1001                 {
1002                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "You have defined an <sslprofile> tag; you should use this in place of \"openssl\" when configuring TLS (SSL) connections in <bind:ssl> or <link:ssl>");
1003                         for (ConfigIter i = tags.first; i != tags.second; ++i)
1004                         {
1005                                 ConfigTag* tag = i->second;
1006                                 if (!stdalgo::string::equalsci(tag->getString("provider"), "openssl"))
1007                                 {
1008                                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Ignoring non-OpenSSL <sslprofile> tag at " + tag->getTagLocation());
1009                                         continue;
1010                                 }
1011
1012                                 std::string name = tag->getString("name");
1013                                 if (name.empty())
1014                                 {
1015                                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Ignoring <sslprofile> tag without name at " + tag->getTagLocation());
1016                                         continue;
1017                                 }
1018
1019                                 reference<OpenSSLIOHookProvider> prov;
1020                                 try
1021                                 {
1022                                         prov = new OpenSSLIOHookProvider(this, name, tag);
1023                                 }
1024                                 catch (CoreException& ex)
1025                                 {
1026                                         throw ModuleException("Error while initializing TLS (SSL) profile \"" + name + "\" at " + tag->getTagLocation() + " - " + ex.GetReason());
1027                                 }
1028
1029                                 newprofiles.push_back(prov);
1030                         }
1031                 }
1032
1033                 for (ProfileList::iterator i = profiles.begin(); i != profiles.end(); ++i)
1034                 {
1035                         OpenSSLIOHookProvider& prov = **i;
1036                         ServerInstance->Modules.DelService(prov);
1037                 }
1038
1039                 profiles.swap(newprofiles);
1040         }
1041
1042  public:
1043         ModuleSSLOpenSSL()
1044         {
1045                 // Initialize OpenSSL
1046                 OPENSSL_init_ssl(0, NULL);
1047 #ifdef INSPIRCD_OPENSSL_OPAQUE_BIO
1048                 biomethods = OpenSSL::BIOMethod::alloc();
1049         }
1050
1051         ~ModuleSSLOpenSSL()
1052         {
1053                 BIO_meth_free(biomethods);
1054 #endif
1055         }
1056
1057         void init() CXX11_OVERRIDE
1058         {
1059                 ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "OpenSSL lib version \"%s\" module was compiled for \"" OPENSSL_VERSION_TEXT "\"", OpenSSL_version(OPENSSL_VERSION));
1060
1061                 // Register application specific data
1062                 char exdatastr[] = "inspircd";
1063                 exdataindex = SSL_get_ex_new_index(0, exdatastr, NULL, NULL, NULL);
1064                 if (exdataindex < 0)
1065                         throw ModuleException("Failed to register application specific data");
1066
1067                 ReadProfiles();
1068         }
1069
1070         void OnModuleRehash(User* user, const std::string &param) CXX11_OVERRIDE
1071         {
1072                 if (!irc::equals(param, "tls") && !irc::equals(param, "ssl"))
1073                         return;
1074
1075                 try
1076                 {
1077                         ReadProfiles();
1078                         ServerInstance->SNO->WriteToSnoMask('a', "OpenSSL TLS (SSL) profiles have been reloaded.");
1079                 }
1080                 catch (ModuleException& ex)
1081                 {
1082                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, ex.GetReason() + " Not applying settings.");
1083                 }
1084         }
1085
1086         void OnCleanup(ExtensionItem::ExtensibleType type, Extensible* item) CXX11_OVERRIDE
1087         {
1088                 if (type == ExtensionItem::EXT_USER)
1089                 {
1090                         LocalUser* user = IS_LOCAL((User*)item);
1091
1092                         if ((user) && (user->eh.GetModHook(this)))
1093                         {
1094                                 // User is using TLS (SSL), they're a local user, and they're using one of *our* TLS (SSL) ports.
1095                                 // Potentially there could be multiple TLS (SSL) modules loaded at once on different ports.
1096                                 ServerInstance->Users->QuitUser(user, "OpenSSL module unloading");
1097                         }
1098                 }
1099         }
1100
1101         ModResult OnCheckReady(LocalUser* user) CXX11_OVERRIDE
1102         {
1103                 const OpenSSLIOHook* const iohook = static_cast<OpenSSLIOHook*>(user->eh.GetModHook(this));
1104                 if ((iohook) && (!iohook->IsHandshakeDone()))
1105                         return MOD_RES_DENY;
1106                 return MOD_RES_PASSTHRU;
1107         }
1108
1109         Version GetVersion() CXX11_OVERRIDE
1110         {
1111                 return Version("Allows TLS (SSL) encrypted connections using the OpenSSL library.", VF_VENDOR);
1112         }
1113 };
1114
1115 MODULE_INIT(ModuleSSLOpenSSL)