src/modules/extra/m_ssl_openssl.cpp

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