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, 2016-2021 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 Dennis Friis <peavey@inspircd.org>
  16  *   Copyright (C) 2006-2008, 2010 Craig Edwards <brain@inspircd.org>
  17  *   Copyright (C) 2006 Oliver Lupton <om@inspircd.org>
  18  *
  19  * This file is part of InspIRCd.  InspIRCd is free software: you can
  20  * redistribute it and/or modify it under the terms of the GNU General Public
  21  * License as published by the Free Software Foundation, version 2.
  22  *
  23  * This program is distributed in the hope that it will be useful, but WITHOUT
  24  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  25  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  26  * details.
  27  *
  28  * You should have received a copy of the GNU General Public License
  29  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  30  */
  31
  32 /// $CompilerFlags: find_compiler_flags("openssl" "")
  33 /// $LinkerFlags: find_linker_flags("openssl" "-lssl -lcrypto")
  34
  35 /// $PackageInfo: require_system("arch") openssl pkgconf
  36 /// $PackageInfo: require_system("centos") openssl-devel pkgconfig
  37 /// $PackageInfo: require_system("darwin") openssl pkg-config
  38 /// $PackageInfo: require_system("debian") libssl-dev openssl pkg-config
  39 /// $PackageInfo: require_system("ubuntu") libssl-dev openssl pkg-config
  40
  41
  42 #include "inspircd.h"
  43 #include "iohook.h"
  44 #include "modules/ssl.h"
  45
  46 #ifdef __GNUC__
  47 # pragma GCC diagnostic push
  48 #endif
  49
  50 // Ignore OpenSSL deprecation warnings on OS X Lion and newer.
  51 #if defined __APPLE__
  52 # pragma GCC diagnostic ignored "-Wdeprecated-declarations"
  53 #endif
  54
  55 // LibreSSL lies about the version of OpenSSL it is compatible with and is a general pain
  56 // to support. Support for it was removed in the master branch at the same time that
  57 // support for OpenSSL pre-1.1 was.
  58 #if defined __GNUC__ && defined LIBRESSL_VERSION_NUMBER
  59 # warning LibreSSL support will be discontinued in the future. Consider using the ssl_gnutls or ssl_mbedtls modules instead.
  60 #endif
  61
  62 // Fix warnings about the use of `long long` on C++03.
  63 #if defined __clang__
  64 # pragma clang diagnostic ignored "-Wc++11-long-long"
  65 #elif defined __GNUC__
  66 # pragma GCC diagnostic ignored "-Wlong-long"
  67 #endif
  68
  69 #include <openssl/ssl.h>
  70 #include <openssl/err.h>
  71 #include <openssl/dh.h>
  72
  73 #ifdef __GNUC__
  74 # pragma GCC diagnostic pop
  75 #endif
  76
  77 #ifdef _WIN32
  78 # pragma comment(lib, "ssleay32.lib")
  79 # pragma comment(lib, "libeay32.lib")
  80 #endif
  81
  82 // Compatibility layer to allow OpenSSL 1.0 to use the 1.1 API.
  83 #if ((defined LIBRESSL_VERSION_NUMBER) || (OPENSSL_VERSION_NUMBER < 0x10100000L))
  84
  85 // BIO is opaque in OpenSSL 1.1 but the access API does not exist in 1.0.
  86 # define BIO_get_data(BIO) BIO->ptr
  87 # define BIO_set_data(BIO, VALUE) BIO->ptr = VALUE;
  88 # define BIO_set_init(BIO, VALUE) BIO->init = VALUE;
  89
  90 // These functions have been renamed in OpenSSL 1.1.
  91 # define OpenSSL_version SSLeay_version
  92 # define X509_getm_notAfter X509_get_notAfter
  93 # define X509_getm_notBefore X509_get_notBefore
  94 # define OPENSSL_init_ssl(OPTIONS, SETTINGS) \
  95         SSL_library_init(); \
  96         SSL_load_error_strings();
  97
  98 // These macros have been renamed in OpenSSL 1.1.
  99 # define OPENSSL_VERSION SSLEAY_VERSION
 100
 101 #else
 102 # define INSPIRCD_OPENSSL_OPAQUE_BIO
 103 #endif
 104
 105 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING, ISSL_OPEN };
 106
 107 static bool SelfSigned = false;
 108 static int exdataindex;
 109
 110 char* get_error()
 111 {
 112         return ERR_error_string(ERR_get_error(), NULL);
 113 }
 114
 115 static int OnVerify(int preverify_ok, X509_STORE_CTX* ctx);
 116 static void StaticSSLInfoCallback(const SSL* ssl, int where, int rc);
 117
 118 namespace OpenSSL
 119 {
 120         class Exception : public ModuleException
 121         {
 122          public:
 123                 Exception(const std::string& reason)
 124                         : ModuleException(reason) { }
 125         };
 126
 127         class DHParams
 128         {
 129                 DH* dh;
 130
 131          public:
 132                 DHParams(const std::string& filename)
 133                 {
 134                         BIO* dhpfile = BIO_new_file(filename.c_str(), "r");
 135                         if (dhpfile == NULL)
 136                                 throw Exception("Couldn't open DH file " + filename);
 137
 138                         dh = PEM_read_bio_DHparams(dhpfile, NULL, NULL, NULL);
 139                         BIO_free(dhpfile);
 140
 141                         if (!dh)
 142                                 throw Exception("Couldn't read DH params from file " + filename);
 143                 }
 144
 145                 ~DHParams()
 146                 {
 147                         DH_free(dh);
 148                 }
 149
 150                 DH* get()
 151                 {
 152                         return dh;
 153                 }
 154         };
 155
 156         class Context
 157         {
 158                 SSL_CTX* const ctx;
 159                 long ctx_options;
 160
 161          public:
 162                 Context(SSL_CTX* context)
 163                         : ctx(context)
 164                 {
 165                         // Sane default options for OpenSSL see https://www.openssl.org/docs/ssl/SSL_CTX_set_options.html
 166                         // and when choosing a cipher, use the server's preferences instead of the client preferences.
 167                         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;
 168                         // Only turn options on if they exist
 169 #ifdef SSL_OP_SINGLE_ECDH_USE
 170                         opts |= SSL_OP_SINGLE_ECDH_USE;
 171 #endif
 172 #ifdef SSL_OP_NO_TICKET
 173                         opts |= SSL_OP_NO_TICKET;
 174 #endif
 175
 176                         ctx_options = SSL_CTX_set_options(ctx, opts);
 177
 178                         long mode = SSL_MODE_ENABLE_PARTIAL_WRITE | SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER;
 179 #ifdef SSL_MODE_RELEASE_BUFFERS
 180                         mode |= SSL_MODE_RELEASE_BUFFERS;
 181 #endif
 182                         SSL_CTX_set_mode(ctx, mode);
 183                         SSL_CTX_set_verify(ctx, SSL_VERIFY_NONE, NULL);
 184                         SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_OFF);
 185                         SSL_CTX_set_info_callback(ctx, StaticSSLInfoCallback);
 186                 }
 187
 188                 ~Context()
 189                 {
 190                         SSL_CTX_free(ctx);
 191                 }
 192
 193                 bool SetDH(DHParams& dh)
 194                 {
 195                         ERR_clear_error();
 196                         return (SSL_CTX_set_tmp_dh(ctx, dh.get()) >= 0);
 197                 }
 198
 199 #ifndef OPENSSL_NO_ECDH
 200                 void SetECDH(const std::string& curvename)
 201                 {
 202                         int nid = OBJ_sn2nid(curvename.c_str());
 203                         if (nid == 0)
 204                                 throw Exception("Unknown curve: " + curvename);
 205
 206                         EC_KEY* eckey = EC_KEY_new_by_curve_name(nid);
 207                         if (!eckey)
 208                                 throw Exception("Unable to create EC key object");
 209
 210                         ERR_clear_error();
 211                         bool ret = (SSL_CTX_set_tmp_ecdh(ctx, eckey) >= 0);
 212                         EC_KEY_free(eckey);
 213                         if (!ret)
 214                                 throw Exception("Couldn't set ECDH parameters");
 215                 }
 216 #endif
 217
 218                 bool SetCiphers(const std::string& ciphers)
 219                 {
 220                         ERR_clear_error();
 221                         return SSL_CTX_set_cipher_list(ctx, ciphers.c_str());
 222                 }
 223
 224                 bool SetCerts(const std::string& filename)
 225                 {
 226                         ERR_clear_error();
 227                         return SSL_CTX_use_certificate_chain_file(ctx, filename.c_str());
 228                 }
 229
 230                 bool SetPrivateKey(const std::string& filename)
 231                 {
 232                         ERR_clear_error();
 233                         return SSL_CTX_use_PrivateKey_file(ctx, filename.c_str(), SSL_FILETYPE_PEM);
 234                 }
 235
 236                 bool SetCA(const std::string& filename)
 237                 {
 238                         ERR_clear_error();
 239                         return SSL_CTX_load_verify_locations(ctx, filename.c_str(), 0);
 240                 }
 241
 242                 void SetCRL(const std::string& crlfile, const std::string& crlpath, const std::string& crlmode)
 243                 {
 244                         if (crlfile.empty() && crlpath.empty())
 245                                 return;
 246
 247                         /* Set CRL mode */
 248                         unsigned long crlflags = X509_V_FLAG_CRL_CHECK;
 249                         if (stdalgo::string::equalsci(crlmode, "chain"))
 250                         {
 251                                 crlflags |= X509_V_FLAG_CRL_CHECK_ALL;
 252                         }
 253                         else if (!stdalgo::string::equalsci(crlmode, "leaf"))
 254                         {
 255                                 throw ModuleException("Unknown mode '" + crlmode + "'; expected either 'chain' (default) or 'leaf'");
 256                         }
 257
 258                         /* Load CRL files */
 259                         X509_STORE* store = SSL_CTX_get_cert_store(ctx);
 260                         if (!store)
 261                         {
 262                                 throw ModuleException("Unable to get X509_STORE from TLS (SSL) context; this should never happen");
 263                         }
 264                         ERR_clear_error();
 265                         if (!X509_STORE_load_locations(store,
 266                                 crlfile.empty() ? NULL : crlfile.c_str(),
 267                                 crlpath.empty() ? NULL : crlpath.c_str()))
 268                         {
 269                                 int err = ERR_get_error();
 270                                 throw ModuleException("Unable to load CRL file '" + crlfile + "' or CRL path '" + crlpath + "': '" + (err ? ERR_error_string(err, NULL) : "unknown") + "'");
 271                         }
 272
 273                         /* Set CRL mode */
 274                         if (X509_STORE_set_flags(store, crlflags) != 1)
 275                         {
 276                                 throw ModuleException("Unable to set X509 CRL flags");
 277                         }
 278                 }
 279
 280
 281                 long GetDefaultContextOptions() const
 282                 {
 283                         return ctx_options;
 284                 }
 285
 286                 long SetRawContextOptions(long setoptions, long clearoptions)
 287                 {
 288                         // Clear everything
 289                         SSL_CTX_clear_options(ctx, SSL_CTX_get_options(ctx));
 290
 291                         // Set the default options and what is in the conf
 292                         SSL_CTX_set_options(ctx, ctx_options | setoptions);
 293                         return SSL_CTX_clear_options(ctx, clearoptions);
 294                 }
 295
 296                 void SetVerifyCert()
 297                 {
 298                         SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, OnVerify);
 299                 }
 300
 301                 SSL* CreateServerSession()
 302                 {
 303                         SSL* sess = SSL_new(ctx);
 304                         SSL_set_accept_state(sess); // Act as server
 305                         return sess;
 306                 }
 307
 308                 SSL* CreateClientSession()
 309                 {
 310                         SSL* sess = SSL_new(ctx);
 311                         SSL_set_connect_state(sess); // Act as client
 312                         return sess;
 313                 }
 314         };
 315
 316         class Profile
 317         {
 318                 /** Name of this profile
 319                  */
 320                 const std::string name;
 321
 322                 /** DH parameters in use
 323                  */
 324                 DHParams dh;
 325
 326                 /** OpenSSL makes us have two contexts, one for servers and one for clients
 327                  */
 328                 Context ctx;
 329                 Context clictx;
 330
 331                 /** Digest to use when generating fingerprints
 332                  */
 333                 const EVP_MD* digest;
 334
 335                 /** Last error, set by error_callback()
 336                  */
 337                 std::string lasterr;
 338
 339                 /** True if renegotiations are allowed, false if not
 340                  */
 341                 const bool allowrenego;
 342
 343                 /** Rough max size of records to send
 344                  */
 345                 const unsigned int outrecsize;
 346
 347                 static int error_callback(const char* str, size_t len, void* u)
 348                 {
 349                         Profile* profile = reinterpret_cast<Profile*>(u);
 350                         profile->lasterr = std::string(str, len - 1);
 351                         return 0;
 352                 }
 353
 354                 /** Set raw OpenSSL context (SSL_CTX) options from a config tag
 355                  * @param ctxname Name of the context, client or server
 356                  * @param tag Config tag defining this profile
 357                  * @param context Context object to manipulate
 358                  */
 359                 void SetContextOptions(const std::string& ctxname, ConfigTag* tag, Context& context)
 360                 {
 361                         long setoptions = tag->getInt(ctxname + "setoptions", 0);
 362                         long clearoptions = tag->getInt(ctxname + "clearoptions", 0);
 363
 364 #ifdef SSL_OP_NO_COMPRESSION
 365                         // Disable compression by default
 366                         if (!tag->getBool("compression", false))
 367                                 setoptions |= SSL_OP_NO_COMPRESSION;
 368 #endif
 369
 370                         // Disable TLSv1.0 by default.
 371                         if (!tag->getBool("tlsv1", false))
 372                                 setoptions |= SSL_OP_NO_TLSv1;
 373
 374 #ifdef SSL_OP_NO_TLSv1_1
 375                         // Enable TLSv1.1 by default.
 376                         if (!tag->getBool("tlsv11", true))
 377                                 setoptions |= SSL_OP_NO_TLSv1_1;
 378 #endif
 379
 380 #ifdef SSL_OP_NO_TLSv1_2
 381                         // Enable TLSv1.2 by default.
 382                         if (!tag->getBool("tlsv12", true))
 383                                 setoptions |= SSL_OP_NO_TLSv1_2;
 384 #endif
 385
 386                         if (!setoptions && !clearoptions)
 387                                 return; // Nothing to do
 388
 389                         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);
 390                         long final = context.SetRawContextOptions(setoptions, clearoptions);
 391                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "%s %s context options: %ld", name.c_str(), ctxname.c_str(), final);
 392                 }
 393
 394          public:
 395                 Profile(const std::string& profilename, ConfigTag* tag)
 396                         : name(profilename)
 397                         , dh(ServerInstance->Config->Paths.PrependConfig(tag->getString("dhfile", "dhparams.pem", 1)))
 398                         , ctx(SSL_CTX_new(SSLv23_server_method()))
 399                         , clictx(SSL_CTX_new(SSLv23_client_method()))
 400                         , allowrenego(tag->getBool("renegotiation")) // Disallow by default
 401                         , outrecsize(tag->getUInt("outrecsize", 2048, 512, 16384))
 402                 {
 403                         if ((!ctx.SetDH(dh)) || (!clictx.SetDH(dh)))
 404                                 throw Exception("Couldn't set DH parameters");
 405
 406                         const std::string hash = tag->getString("hash", "md5", 1);
 407                         digest = EVP_get_digestbyname(hash.c_str());
 408                         if (digest == NULL)
 409                                 throw Exception("Unknown hash type " + hash);
 410
 411                         std::string ciphers = tag->getString("ciphers");
 412                         if (!ciphers.empty())
 413                         {
 414                                 if ((!ctx.SetCiphers(ciphers)) || (!clictx.SetCiphers(ciphers)))
 415                                 {
 416                                         ERR_print_errors_cb(error_callback, this);
 417                                         throw Exception("Can't set cipher list to \"" + ciphers + "\" " + lasterr);
 418                                 }
 419                         }
 420
 421 #ifndef OPENSSL_NO_ECDH
 422                         const std::string curvename = tag->getString("ecdhcurve", "prime256v1", 1);
 423                         if (!curvename.empty())
 424                                 ctx.SetECDH(curvename);
 425 #endif
 426
 427                         SetContextOptions("server", tag, ctx);
 428                         SetContextOptions("client", tag, clictx);
 429
 430                         /* Load our keys and certificates
 431                          * NOTE: OpenSSL's error logging API sucks, don't blame us for this clusterfuck.
 432                          */
 433                         std::string filename = ServerInstance->Config->Paths.PrependConfig(tag->getString("certfile", "cert.pem", 1));
 434                         if ((!ctx.SetCerts(filename)) || (!clictx.SetCerts(filename)))
 435                         {
 436                                 ERR_print_errors_cb(error_callback, this);
 437                                 throw Exception("Can't read certificate file: " + lasterr);
 438                         }
 439
 440                         filename = ServerInstance->Config->Paths.PrependConfig(tag->getString("keyfile", "key.pem", 1));
 441                         if ((!ctx.SetPrivateKey(filename)) || (!clictx.SetPrivateKey(filename)))
 442                         {
 443                                 ERR_print_errors_cb(error_callback, this);
 444                                 throw Exception("Can't read key file: " + lasterr);
 445                         }
 446
 447                         // Load the CAs we trust
 448                         filename = ServerInstance->Config->Paths.PrependConfig(tag->getString("cafile", "ca.pem", 1));
 449                         if ((!ctx.SetCA(filename)) || (!clictx.SetCA(filename)))
 450                         {
 451                                 ERR_print_errors_cb(error_callback, this);
 452                                 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());
 453                         }
 454
 455                         // Load the CRLs.
 456                         const std::string crlfile = tag->getString("crlfile");
 457                         const std::string crlpath = tag->getString("crlpath");
 458                         const std::string crlmode = tag->getString("crlmode", "chain", 1);
 459                         ctx.SetCRL(crlfile, crlpath, crlmode);
 460
 461                         clictx.SetVerifyCert();
 462                         if (tag->getBool("requestclientcert", true))
 463                                 ctx.SetVerifyCert();
 464                 }
 465
 466                 const std::string& GetName() const { return name; }
 467                 SSL* CreateServerSession() { return ctx.CreateServerSession(); }
 468                 SSL* CreateClientSession() { return clictx.CreateClientSession(); }
 469                 const EVP_MD* GetDigest() { return digest; }
 470                 bool AllowRenegotiation() const { return allowrenego; }
 471                 unsigned int GetOutgoingRecordSize() const { return outrecsize; }
 472         };
 473
 474         namespace BIOMethod
 475         {
 476                 static int create(BIO* bio)
 477                 {
 478                         BIO_set_init(bio, 1);
 479                         return 1;
 480                 }
 481
 482                 static int destroy(BIO* bio)
 483                 {
 484                         // XXX: Dummy function to avoid a memory leak in OpenSSL.
 485                         // The memory leak happens in BIO_free() (bio_lib.c) when the destroy func of the BIO is NULL.
 486                         // This is fixed in OpenSSL but some distros still ship the unpatched version hence we provide this workaround.
 487                         return 1;
 488                 }
 489
 490                 static long ctrl(BIO* bio, int cmd, long num, void* ptr)
 491                 {
 492                         if (cmd == BIO_CTRL_FLUSH)
 493                                 return 1;
 494                         return 0;
 495                 }
 496
 497                 static int read(BIO* bio, char* buf, int len);
 498                 static int write(BIO* bio, const char* buf, int len);
 499
 500 #ifdef INSPIRCD_OPENSSL_OPAQUE_BIO
 501                 static BIO_METHOD* alloc()
 502                 {
 503                         BIO_METHOD* meth = BIO_meth_new(100 | BIO_TYPE_SOURCE_SINK, "inspircd");
 504                         BIO_meth_set_write(meth, OpenSSL::BIOMethod::write);
 505                         BIO_meth_set_read(meth, OpenSSL::BIOMethod::read);
 506                         BIO_meth_set_ctrl(meth, OpenSSL::BIOMethod::ctrl);
 507                         BIO_meth_set_create(meth, OpenSSL::BIOMethod::create);
 508                         BIO_meth_set_destroy(meth, OpenSSL::BIOMethod::destroy);
 509                         return meth;
 510                 }
 511 #endif
 512         }
 513 }
 514
 515 // BIO_METHOD is opaque in OpenSSL 1.1 so we can't do this.
 516 // See OpenSSL::BIOMethod::alloc for the new method.
 517 #ifndef INSPIRCD_OPENSSL_OPAQUE_BIO
 518 static BIO_METHOD biomethods =
 519 {
 520         (100 | BIO_TYPE_SOURCE_SINK),
 521         "inspircd",
 522         OpenSSL::BIOMethod::write,
 523         OpenSSL::BIOMethod::read,
 524         NULL, // puts
 525         NULL, // gets
 526         OpenSSL::BIOMethod::ctrl,
 527         OpenSSL::BIOMethod::create,
 528         OpenSSL::BIOMethod::destroy, // destroy, does nothing, see function body for more info
 529         NULL // callback_ctrl
 530 };
 531 #else
 532 static BIO_METHOD* biomethods;
 533 #endif
 534
 535 static int OnVerify(int preverify_ok, X509_STORE_CTX *ctx)
 536 {
 537         /* XXX: This will allow self signed certificates.
 538          * In the future if we want an option to not allow this,
 539          * we can just return preverify_ok here, and openssl
 540          * will boot off self-signed and invalid peer certs.
 541          */
 542         int ve = X509_STORE_CTX_get_error(ctx);
 543
 544         SelfSigned = (ve == X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT);
 545
 546         return 1;
 547 }
 548
 549 class OpenSSLIOHook : public SSLIOHook
 550 {
 551  private:
 552         SSL* sess;
 553         issl_status status;
 554         bool data_to_write;
 555
 556         // Returns 1 if handshake succeeded, 0 if it is still in progress, -1 if it failed
 557         int Handshake(StreamSocket* user)
 558         {
 559                 ERR_clear_error();
 560                 int ret = SSL_do_handshake(sess);
 561                 if (ret < 0)
 562                 {
 563                         int err = SSL_get_error(sess, ret);
 564
 565                         if (err == SSL_ERROR_WANT_READ)
 566                         {
 567                                 SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 568                                 this->status = ISSL_HANDSHAKING;
 569                                 return 0;
 570                         }
 571                         else if (err == SSL_ERROR_WANT_WRITE)
 572                         {
 573                                 SocketEngine::ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 574                                 this->status = ISSL_HANDSHAKING;
 575                                 return 0;
 576                         }
 577                         else
 578                         {
 579                                 CloseSession();
 580                                 return -1;
 581                         }
 582                 }
 583                 else if (ret > 0)
 584                 {
 585                         // Handshake complete.
 586                         VerifyCertificate();
 587
 588                         status = ISSL_OPEN;
 589
 590                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 591
 592                         return 1;
 593                 }
 594                 else if (ret == 0)
 595                 {
 596                         CloseSession();
 597                 }
 598                 return -1;
 599         }
 600
 601         void CloseSession()
 602         {
 603                 if (sess)
 604                 {
 605                         SSL_shutdown(sess);
 606                         SSL_free(sess);
 607                 }
 608                 sess = NULL;
 609                 certificate = NULL;
 610                 status = ISSL_NONE;
 611         }
 612
 613         void VerifyCertificate()
 614         {
 615                 X509* cert;
 616                 ssl_cert* certinfo = new ssl_cert;
 617                 this->certificate = certinfo;
 618                 unsigned int n;
 619                 unsigned char md[EVP_MAX_MD_SIZE];
 620
 621                 cert = SSL_get_peer_certificate(sess);
 622
 623                 if (!cert)
 624                 {
 625                         certinfo->error = "Could not get peer certificate: "+std::string(get_error());
 626                         return;
 627                 }
 628
 629                 certinfo->invalid = (SSL_get_verify_result(sess) != X509_V_OK);
 630
 631                 if (!SelfSigned)
 632                 {
 633                         certinfo->unknownsigner = false;
 634                         certinfo->trusted = true;
 635                 }
 636                 else
 637                 {
 638                         certinfo->unknownsigner = true;
 639                         certinfo->trusted = false;
 640                 }
 641
 642                 char buf[512];
 643                 X509_NAME_oneline(X509_get_subject_name(cert), buf, sizeof(buf));
 644                 certinfo->dn = buf;
 645                 // Make sure there are no chars in the string that we consider invalid
 646                 if (certinfo->dn.find_first_of("\r\n") != std::string::npos)
 647                         certinfo->dn.clear();
 648
 649                 X509_NAME_oneline(X509_get_issuer_name(cert), buf, sizeof(buf));
 650                 certinfo->issuer = buf;
 651                 if (certinfo->issuer.find_first_of("\r\n") != std::string::npos)
 652                         certinfo->issuer.clear();
 653
 654                 if (!X509_digest(cert, GetProfile().GetDigest(), md, &n))
 655                 {
 656                         certinfo->error = "Out of memory generating fingerprint";
 657                 }
 658                 else
 659                 {
 660                         certinfo->fingerprint = BinToHex(md, n);
 661                 }
 662
 663                 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))
 664                 {
 665                         certinfo->error = "Not activated, or expired certificate";
 666                 }
 667
 668                 X509_free(cert);
 669         }
 670
 671         void SSLInfoCallback(int where, int rc)
 672         {
 673                 if ((where & SSL_CB_HANDSHAKE_START) && (status == ISSL_OPEN))
 674                 {
 675                         if (GetProfile().AllowRenegotiation())
 676                                 return;
 677
 678                         // The other side is trying to renegotiate, kill the connection and change status
 679                         // to ISSL_NONE so CheckRenego() closes the session
 680                         status = ISSL_NONE;
 681                         BIO* bio = SSL_get_rbio(sess);
 682                         EventHandler* eh = static_cast<StreamSocket*>(BIO_get_data(bio));
 683                         SocketEngine::Shutdown(eh, 2);
 684                 }
 685         }
 686
 687         bool CheckRenego(StreamSocket* sock)
 688         {
 689                 if (status != ISSL_NONE)
 690                         return true;
 691
 692                 ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Session %p killed, attempted to renegotiate", (void*)sess);
 693                 CloseSession();
 694                 sock->SetError("Renegotiation is not allowed");
 695                 return false;
 696         }
 697
 698         // Returns 1 if application I/O should proceed, 0 if it must wait for the underlying protocol to progress, -1 on fatal error
 699         int PrepareIO(StreamSocket* sock)
 700         {
 701                 if (status == ISSL_OPEN)
 702                         return 1;
 703                 else if (status == ISSL_HANDSHAKING)
 704                 {
 705                         // The handshake isn't finished, try to finish it
 706                         return Handshake(sock);
 707                 }
 708
 709                 CloseSession();
 710                 return -1;
 711         }
 712
 713         // Calls our private SSLInfoCallback()
 714         friend void StaticSSLInfoCallback(const SSL* ssl, int where, int rc);
 715
 716  public:
 717         OpenSSLIOHook(IOHookProvider* hookprov, StreamSocket* sock, SSL* session)
 718                 : SSLIOHook(hookprov)
 719                 , sess(session)
 720                 , status(ISSL_NONE)
 721                 , data_to_write(false)
 722         {
 723                 // Create BIO instance and store a pointer to the socket in it which will be used by the read and write functions
 724 #ifdef INSPIRCD_OPENSSL_OPAQUE_BIO
 725                 BIO* bio = BIO_new(biomethods);
 726 #else
 727                 BIO* bio = BIO_new(&biomethods);
 728 #endif
 729                 BIO_set_data(bio, sock);
 730                 SSL_set_bio(sess, bio, bio);
 731
 732                 SSL_set_ex_data(sess, exdataindex, this);
 733                 sock->AddIOHook(this);
 734                 Handshake(sock);
 735         }
 736
 737         void OnStreamSocketClose(StreamSocket* user) CXX11_OVERRIDE
 738         {
 739                 CloseSession();
 740         }
 741
 742         int OnStreamSocketRead(StreamSocket* user, std::string& recvq) CXX11_OVERRIDE
 743         {
 744                 // Finish handshake if needed
 745                 int prepret = PrepareIO(user);
 746                 if (prepret <= 0)
 747                         return prepret;
 748
 749                 // If we resumed the handshake then this->status will be ISSL_OPEN
 750                 {
 751                         ERR_clear_error();
 752                         char* buffer = ServerInstance->GetReadBuffer();
 753                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 754                         int ret = SSL_read(sess, buffer, bufsiz);
 755
 756                         if (!CheckRenego(user))
 757                                 return -1;
 758
 759                         if (ret > 0)
 760                         {
 761                                 recvq.append(buffer, ret);
 762                                 int mask = 0;
 763                                 // Schedule a read if there is still data in the OpenSSL buffer
 764                                 if (SSL_pending(sess) > 0)
 765                                         mask |= FD_ADD_TRIAL_READ;
 766                                 if (data_to_write)
 767                                         mask |= FD_WANT_POLL_READ | FD_WANT_SINGLE_WRITE;
 768                                 if (mask != 0)
 769                                         SocketEngine::ChangeEventMask(user, mask);
 770                                 return 1;
 771                         }
 772                         else if (ret == 0)
 773                         {
 774                                 // Client closed connection.
 775                                 CloseSession();
 776                                 user->SetError("Connection closed");
 777                                 return -1;
 778                         }
 779                         else // if (ret < 0)
 780                         {
 781                                 int err = SSL_get_error(sess, ret);
 782
 783                                 if (err == SSL_ERROR_WANT_READ)
 784                                 {
 785                                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ);
 786                                         return 0;
 787                                 }
 788                                 else if (err == SSL_ERROR_WANT_WRITE)
 789                                 {
 790                                         SocketEngine::ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 791                                         return 0;
 792                                 }
 793                                 else
 794                                 {
 795                                         CloseSession();
 796                                         return -1;
 797                                 }
 798                         }
 799                 }
 800         }
 801
 802         int OnStreamSocketWrite(StreamSocket* user, StreamSocket::SendQueue& sendq) CXX11_OVERRIDE
 803         {
 804                 // Finish handshake if needed
 805                 int prepret = PrepareIO(user);
 806                 if (prepret <= 0)
 807                         return prepret;
 808
 809                 data_to_write = true;
 810
 811                 // Session is ready for transferring application data
 812                 while (!sendq.empty())
 813                 {
 814                         ERR_clear_error();
 815                         FlattenSendQueue(sendq, GetProfile().GetOutgoingRecordSize());
 816                         const StreamSocket::SendQueue::Element& buffer = sendq.front();
 817                         int ret = SSL_write(sess, buffer.data(), buffer.size());
 818
 819                         if (!CheckRenego(user))
 820                                 return -1;
 821
 822                         if (ret == (int)buffer.length())
 823                         {
 824                                 // Wrote entire record, continue sending
 825                                 sendq.pop_front();
 826                         }
 827                         else if (ret > 0)
 828                         {
 829                                 sendq.erase_front(ret);
 830                                 SocketEngine::ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 831                                 return 0;
 832                         }
 833                         else if (ret == 0)
 834                         {
 835                                 CloseSession();
 836                                 return -1;
 837                         }
 838                         else // if (ret < 0)
 839                         {
 840                                 int err = SSL_get_error(sess, ret);
 841
 842                                 if (err == SSL_ERROR_WANT_WRITE)
 843                                 {
 844                                         SocketEngine::ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 845                                         return 0;
 846                                 }
 847                                 else if (err == SSL_ERROR_WANT_READ)
 848                                 {
 849                                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ);
 850                                         return 0;
 851                                 }
 852                                 else
 853                                 {
 854                                         CloseSession();
 855                                         return -1;
 856                                 }
 857                         }
 858                 }
 859
 860                 data_to_write = false;
 861                 SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 862                 return 1;
 863         }
 864
 865         void GetCiphersuite(std::string& out) const CXX11_OVERRIDE
 866         {
 867                 if (!IsHandshakeDone())
 868                         return;
 869                 out.append(SSL_get_version(sess)).push_back('-');
 870                 out.append(SSL_get_cipher(sess));
 871         }
 872
 873         bool GetServerName(std::string& out) const CXX11_OVERRIDE
 874         {
 875                 const char* name = SSL_get_servername(sess, TLSEXT_NAMETYPE_host_name);
 876                 if (!name)
 877                         return false;
 878
 879                 out.append(name);
 880                 return true;
 881         }
 882
 883         bool IsHandshakeDone() const { return (status == ISSL_OPEN); }
 884         OpenSSL::Profile& GetProfile();
 885 };
 886
 887 static void StaticSSLInfoCallback(const SSL* ssl, int where, int rc)
 888 {
 889         OpenSSLIOHook* hook = static_cast<OpenSSLIOHook*>(SSL_get_ex_data(ssl, exdataindex));
 890         hook->SSLInfoCallback(where, rc);
 891 }
 892
 893 static int OpenSSL::BIOMethod::write(BIO* bio, const char* buffer, int size)
 894 {
 895         BIO_clear_retry_flags(bio);
 896
 897         StreamSocket* sock = static_cast<StreamSocket*>(BIO_get_data(bio));
 898         if (sock->GetEventMask() & FD_WRITE_WILL_BLOCK)
 899         {
 900                 // Writes blocked earlier, don't retry syscall
 901                 BIO_set_retry_write(bio);
 902                 return -1;
 903         }
 904
 905         int ret = SocketEngine::Send(sock, buffer, size, 0);
 906         if ((ret < size) && ((ret > 0) || (SocketEngine::IgnoreError())))
 907         {
 908                 // Blocked, set retry flag for OpenSSL
 909                 SocketEngine::ChangeEventMask(sock, FD_WRITE_WILL_BLOCK);
 910                 BIO_set_retry_write(bio);
 911         }
 912
 913         return ret;
 914 }
 915
 916 static int OpenSSL::BIOMethod::read(BIO* bio, char* buffer, int size)
 917 {
 918         BIO_clear_retry_flags(bio);
 919
 920         StreamSocket* sock = static_cast<StreamSocket*>(BIO_get_data(bio));
 921         if (sock->GetEventMask() & FD_READ_WILL_BLOCK)
 922         {
 923                 // Reads blocked earlier, don't retry syscall
 924                 BIO_set_retry_read(bio);
 925                 return -1;
 926         }
 927
 928         int ret = SocketEngine::Recv(sock, buffer, size, 0);
 929         if ((ret < size) && ((ret > 0) || (SocketEngine::IgnoreError())))
 930         {
 931                 // Blocked, set retry flag for OpenSSL
 932                 SocketEngine::ChangeEventMask(sock, FD_READ_WILL_BLOCK);
 933                 BIO_set_retry_read(bio);
 934         }
 935
 936         return ret;
 937 }
 938
 939 class OpenSSLIOHookProvider : public IOHookProvider
 940 {
 941         OpenSSL::Profile profile;
 942
 943  public:
 944         OpenSSLIOHookProvider(Module* mod, const std::string& profilename, ConfigTag* tag)
 945                 : IOHookProvider(mod, "ssl/" + profilename, IOHookProvider::IOH_SSL)
 946                 , profile(profilename, tag)
 947         {
 948                 ServerInstance->Modules->AddService(*this);
 949         }
 950
 951         ~OpenSSLIOHookProvider()
 952         {
 953                 ServerInstance->Modules->DelService(*this);
 954         }
 955
 956         void OnAccept(StreamSocket* sock, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server) CXX11_OVERRIDE
 957         {
 958                 new OpenSSLIOHook(this, sock, profile.CreateServerSession());
 959         }
 960
 961         void OnConnect(StreamSocket* sock) CXX11_OVERRIDE
 962         {
 963                 new OpenSSLIOHook(this, sock, profile.CreateClientSession());
 964         }
 965
 966         OpenSSL::Profile& GetProfile() { return profile; }
 967 };
 968
 969 OpenSSL::Profile& OpenSSLIOHook::GetProfile()
 970 {
 971         IOHookProvider* hookprov = prov;
 972         return static_cast<OpenSSLIOHookProvider*>(hookprov)->GetProfile();
 973 }
 974
 975 class ModuleSSLOpenSSL : public Module
 976 {
 977         typedef std::vector<reference<OpenSSLIOHookProvider> > ProfileList;
 978
 979         ProfileList profiles;
 980
 981         void ReadProfiles()
 982         {
 983                 ProfileList newprofiles;
 984                 ConfigTagList tags = ServerInstance->Config->ConfTags("sslprofile");
 985                 if (tags.first == tags.second)
 986                 {
 987                         // Create a default profile named "openssl"
 988                         const std::string defname = "openssl";
 989                         ConfigTag* tag = ServerInstance->Config->ConfValue(defname);
 990                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "No <sslprofile> tags found, using settings from the deprecated <openssl> tag");
 991
 992                         try
 993                         {
 994                                 newprofiles.push_back(new OpenSSLIOHookProvider(this, defname, tag));
 995                         }
 996                         catch (OpenSSL::Exception& ex)
 997                         {
 998                                 throw ModuleException("Error while initializing the default TLS (SSL) profile - " + ex.GetReason());
 999                         }
1000                 }
1001                 else
1002                 {
1003                         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>");
1004                         for (ConfigIter i = tags.first; i != tags.second; ++i)
1005                         {
1006                                 ConfigTag* tag = i->second;
1007                                 if (!stdalgo::string::equalsci(tag->getString("provider"), "openssl"))
1008                                 {
1009                                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Ignoring non-OpenSSL <sslprofile> tag at " + tag->getTagLocation());
1010                                         continue;
1011                                 }
1012
1013                                 std::string name = tag->getString("name");
1014                                 if (name.empty())
1015                                 {
1016                                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Ignoring <sslprofile> tag without name at " + tag->getTagLocation());
1017                                         continue;
1018                                 }
1019
1020                                 reference<OpenSSLIOHookProvider> prov;
1021                                 try
1022                                 {
1023                                         prov = new OpenSSLIOHookProvider(this, name, tag);
1024                                 }
1025                                 catch (CoreException& ex)
1026                                 {
1027                                         throw ModuleException("Error while initializing TLS (SSL) profile \"" + name + "\" at " + tag->getTagLocation() + " - " + ex.GetReason());
1028                                 }
1029
1030                                 newprofiles.push_back(prov);
1031                         }
1032                 }
1033
1034                 for (ProfileList::iterator i = profiles.begin(); i != profiles.end(); ++i)
1035                 {
1036                         OpenSSLIOHookProvider& prov = **i;
1037                         ServerInstance->Modules.DelService(prov);
1038                 }
1039
1040                 profiles.swap(newprofiles);
1041         }
1042
1043  public:
1044         ModuleSSLOpenSSL()
1045         {
1046                 // Initialize OpenSSL
1047                 OPENSSL_init_ssl(0, NULL);
1048 #ifdef INSPIRCD_OPENSSL_OPAQUE_BIO
1049                 biomethods = OpenSSL::BIOMethod::alloc();
1050         }
1051
1052         ~ModuleSSLOpenSSL()
1053         {
1054                 BIO_meth_free(biomethods);
1055 #endif
1056         }
1057
1058         void init() CXX11_OVERRIDE
1059         {
1060                 ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "OpenSSL lib version \"%s\" module was compiled for \"" OPENSSL_VERSION_TEXT "\"", OpenSSL_version(OPENSSL_VERSION));
1061
1062                 // Register application specific data
1063                 char exdatastr[] = "inspircd";
1064                 exdataindex = SSL_get_ex_new_index(0, exdatastr, NULL, NULL, NULL);
1065                 if (exdataindex < 0)
1066                         throw ModuleException("Failed to register application specific data");
1067
1068                 ReadProfiles();
1069         }
1070
1071         void OnModuleRehash(User* user, const std::string &param) CXX11_OVERRIDE
1072         {
1073                 if (!irc::equals(param, "tls") && !irc::equals(param, "ssl"))
1074                         return;
1075
1076                 try
1077                 {
1078                         ReadProfiles();
1079                         ServerInstance->SNO->WriteToSnoMask('a', "OpenSSL TLS (SSL) profiles have been reloaded.");
1080                 }
1081                 catch (ModuleException& ex)
1082                 {
1083                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, ex.GetReason() + " Not applying settings.");
1084                 }
1085         }
1086
1087         void OnCleanup(ExtensionItem::ExtensibleType type, Extensible* item) CXX11_OVERRIDE
1088         {
1089                 if (type == ExtensionItem::EXT_USER)
1090                 {
1091                         LocalUser* user = IS_LOCAL((User*)item);
1092
1093                         if ((user) && (user->eh.GetModHook(this)))
1094                         {
1095                                 // User is using TLS (SSL), they're a local user, and they're using one of *our* TLS (SSL) ports.
1096                                 // Potentially there could be multiple TLS (SSL) modules loaded at once on different ports.
1097                                 ServerInstance->Users->QuitUser(user, "OpenSSL module unloading");
1098                         }
1099                 }
1100         }
1101
1102         ModResult OnCheckReady(LocalUser* user) CXX11_OVERRIDE
1103         {
1104                 const OpenSSLIOHook* const iohook = static_cast<OpenSSLIOHook*>(user->eh.GetModHook(this));
1105                 if ((iohook) && (!iohook->IsHandshakeDone()))
1106                         return MOD_RES_DENY;
1107                 return MOD_RES_PASSTHRU;
1108         }
1109
1110         Version GetVersion() CXX11_OVERRIDE
1111         {
1112                 return Version("Allows TLS (SSL) encrypted connections using the OpenSSL library.", VF_VENDOR);
1113         }
1114 };
1115
1116 MODULE_INIT(ModuleSSLOpenSSL)