src/modules/extra/m_ssl_gnutls.cpp

   1 /*
   2  * InspIRCd -- Internet Relay Chat Daemon
   3  *
   4  *   Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
   5  *   Copyright (C) 2008 John Brooks <john.brooks@dereferenced.net>
   6  *   Copyright (C) 2006-2008 Craig Edwards <craigedwards@brainbox.cc>
   7  *   Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
   8  *   Copyright (C) 2006 Oliver Lupton <oliverlupton@gmail.com>
   9  *
  10  * This file is part of InspIRCd.  InspIRCd is free software: you can
  11  * redistribute it and/or modify it under the terms of the GNU General Public
  12  * License as published by the Free Software Foundation, version 2.
  13  *
  14  * This program is distributed in the hope that it will be useful, but WITHOUT
  15  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  16  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  17  * details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21  */
  22
  23
  24 #include "inspircd.h"
  25 #include "modules/ssl.h"
  26 #include <memory>
  27
  28 // Fix warnings about the use of commas at end of enumerator lists on C++03.
  29 #if defined __clang__
  30 # pragma clang diagnostic ignored "-Wc++11-extensions"
  31 #elif defined __GNUC__
  32 # pragma GCC diagnostic ignored "-pedantic"
  33 #endif
  34
  35 #include <gnutls/gnutls.h>
  36 #include <gnutls/x509.h>
  37
  38 #ifndef GNUTLS_VERSION_NUMBER
  39 #define GNUTLS_VERSION_NUMBER LIBGNUTLS_VERSION_NUMBER
  40 #endif
  41
  42 // Check if the GnuTLS library is at least version major.minor.patch
  43 #define INSPIRCD_GNUTLS_HAS_VERSION(major, minor, patch) (GNUTLS_VERSION_NUMBER >= ((major << 16) | (minor << 8) | patch))
  44
  45 #if INSPIRCD_GNUTLS_HAS_VERSION(2, 9, 8)
  46 #define GNUTLS_HAS_MAC_GET_ID
  47 #include <gnutls/crypto.h>
  48 #endif
  49
  50 #if INSPIRCD_GNUTLS_HAS_VERSION(2, 12, 0)
  51 # define GNUTLS_HAS_RND
  52 #else
  53 # include <gcrypt.h>
  54 #endif
  55
  56 #ifdef _WIN32
  57 # pragma comment(lib, "libgnutls-28.lib")
  58 #endif
  59
  60 /* $CompileFlags: pkgconfincludes("gnutls","/gnutls/gnutls.h","") eval("print `libgcrypt-config --cflags | tr -d \r` if `pkg-config --modversion gnutls 2>/dev/null | tr -d \r` lt '2.12'") */
  61 /* $LinkerFlags: rpath("pkg-config --libs gnutls") pkgconflibs("gnutls","/libgnutls.so","-lgnutls") eval("print `libgcrypt-config --libs | tr -d \r` if `pkg-config --modversion gnutls 2>/dev/null | tr -d \r` lt '2.12'") */
  62
  63 // These don't exist in older GnuTLS versions
  64 #if INSPIRCD_GNUTLS_HAS_VERSION(2, 1, 7)
  65 #define GNUTLS_NEW_PRIO_API
  66 #endif
  67
  68 #if (!INSPIRCD_GNUTLS_HAS_VERSION(2, 0, 0))
  69 typedef gnutls_certificate_credentials_t gnutls_certificate_credentials;
  70 typedef gnutls_dh_params_t gnutls_dh_params;
  71 #endif
  72
  73 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING_READ, ISSL_HANDSHAKING_WRITE, ISSL_HANDSHAKEN, ISSL_CLOSING, ISSL_CLOSED };
  74
  75 #if INSPIRCD_GNUTLS_HAS_VERSION(2, 12, 0)
  76 #define GNUTLS_NEW_CERT_CALLBACK_API
  77 typedef gnutls_retr2_st cert_cb_last_param_type;
  78 #else
  79 typedef gnutls_retr_st cert_cb_last_param_type;
  80 #endif
  81
  82 class RandGen : public HandlerBase2<void, char*, size_t>
  83 {
  84  public:
  85         void Call(char* buffer, size_t len)
  86         {
  87 #ifdef GNUTLS_HAS_RND
  88                 gnutls_rnd(GNUTLS_RND_RANDOM, buffer, len);
  89 #else
  90                 gcry_randomize(buffer, len, GCRY_STRONG_RANDOM);
  91 #endif
  92         }
  93 };
  94
  95 namespace GnuTLS
  96 {
  97         class Init
  98         {
  99          public:
 100                 Init() { gnutls_global_init(); }
 101                 ~Init() { gnutls_global_deinit(); }
 102         };
 103
 104         class Exception : public ModuleException
 105         {
 106          public:
 107                 Exception(const std::string& reason)
 108                         : ModuleException(reason) { }
 109         };
 110
 111         void ThrowOnError(int errcode, const char* msg)
 112         {
 113                 if (errcode < 0)
 114                 {
 115                         std::string reason = msg;
 116                         reason.append(" :").append(gnutls_strerror(errcode));
 117                         throw Exception(reason);
 118                 }
 119         }
 120
 121         /** Used to create a gnutls_datum_t* from a std::string
 122          */
 123         class Datum
 124         {
 125                 gnutls_datum_t datum;
 126
 127          public:
 128                 Datum(const std::string& dat)
 129                 {
 130                         datum.data = (unsigned char*)dat.data();
 131                         datum.size = static_cast<unsigned int>(dat.length());
 132                 }
 133
 134                 const gnutls_datum_t* get() const { return &datum; }
 135         };
 136
 137         class Hash
 138         {
 139                 gnutls_digest_algorithm_t hash;
 140
 141          public:
 142                 // Nothing to deallocate, constructor may throw freely
 143                 Hash(const std::string& hashname)
 144                 {
 145                         // As older versions of gnutls can't do this, let's disable it where needed.
 146 #ifdef GNUTLS_HAS_MAC_GET_ID
 147                         // As gnutls_digest_algorithm_t and gnutls_mac_algorithm_t are mapped 1:1, we can do this
 148                         // There is no gnutls_dig_get_id() at the moment, but it may come later
 149                         hash = (gnutls_digest_algorithm_t)gnutls_mac_get_id(hashname.c_str());
 150                         if (hash == GNUTLS_DIG_UNKNOWN)
 151                                 throw Exception("Unknown hash type " + hashname);
 152
 153                         // Check if the user is giving us something that is a valid MAC but not digest
 154                         gnutls_hash_hd_t is_digest;
 155                         if (gnutls_hash_init(&is_digest, hash) < 0)
 156                                 throw Exception("Unknown hash type " + hashname);
 157                         gnutls_hash_deinit(is_digest, NULL);
 158 #else
 159                         if (hashname == "md5")
 160                                 hash = GNUTLS_DIG_MD5;
 161                         else if (hashname == "sha1")
 162                                 hash = GNUTLS_DIG_SHA1;
 163 #ifdef INSPIRCD_GNUTLS_ENABLE_SHA256_FINGERPRINT
 164                         else if (hashname == "sha256")
 165                                 hash = GNUTLS_DIG_SHA256;
 166 #endif
 167                         else
 168                                 throw Exception("Unknown hash type " + hashname);
 169 #endif
 170                 }
 171
 172                 gnutls_digest_algorithm_t get() const { return hash; }
 173         };
 174
 175         class DHParams
 176         {
 177                 gnutls_dh_params_t dh_params;
 178
 179                 DHParams()
 180                 {
 181                         ThrowOnError(gnutls_dh_params_init(&dh_params), "gnutls_dh_params_init() failed");
 182                 }
 183
 184          public:
 185                 /** Import */
 186                 static std::auto_ptr<DHParams> Import(const std::string& dhstr)
 187                 {
 188                         std::auto_ptr<DHParams> dh(new DHParams);
 189                         int ret = gnutls_dh_params_import_pkcs3(dh->dh_params, Datum(dhstr).get(), GNUTLS_X509_FMT_PEM);
 190                         ThrowOnError(ret, "Unable to import DH params");
 191                         return dh;
 192                 }
 193
 194                 /** Generate */
 195                 static std::auto_ptr<DHParams> Generate(unsigned int bits)
 196                 {
 197                         std::auto_ptr<DHParams> dh(new DHParams);
 198                         ThrowOnError(gnutls_dh_params_generate2(dh->dh_params, bits), "Unable to generate DH params");
 199                         return dh;
 200                 }
 201
 202                 ~DHParams()
 203                 {
 204                         gnutls_dh_params_deinit(dh_params);
 205                 }
 206
 207                 const gnutls_dh_params_t& get() const { return dh_params; }
 208         };
 209
 210         class X509Key
 211         {
 212                 /** Ensure that the key is deinited in case the constructor of X509Key throws
 213                  */
 214                 class RAIIKey
 215                 {
 216                  public:
 217                         gnutls_x509_privkey_t key;
 218
 219                         RAIIKey()
 220                         {
 221                                 ThrowOnError(gnutls_x509_privkey_init(&key), "gnutls_x509_privkey_init() failed");
 222                         }
 223
 224                         ~RAIIKey()
 225                         {
 226                                 gnutls_x509_privkey_deinit(key);
 227                         }
 228                 } key;
 229
 230          public:
 231                 /** Import */
 232                 X509Key(const std::string& keystr)
 233                 {
 234                         int ret = gnutls_x509_privkey_import(key.key, Datum(keystr).get(), GNUTLS_X509_FMT_PEM);
 235                         ThrowOnError(ret, "Unable to import private key");
 236                 }
 237
 238                 gnutls_x509_privkey_t& get() { return key.key; }
 239         };
 240
 241         class X509CertList
 242         {
 243                 std::vector<gnutls_x509_crt_t> certs;
 244
 245          public:
 246                 /** Import */
 247                 X509CertList(const std::string& certstr)
 248                 {
 249                         unsigned int certcount = 3;
 250                         certs.resize(certcount);
 251                         Datum datum(certstr);
 252
 253                         int ret = gnutls_x509_crt_list_import(raw(), &certcount, datum.get(), GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 254                         if (ret == GNUTLS_E_SHORT_MEMORY_BUFFER)
 255                         {
 256                                 // the buffer wasn't big enough to hold all certs but gnutls changed certcount to the number of available certs,
 257                                 // try again with a bigger buffer
 258                                 certs.resize(certcount);
 259                                 ret = gnutls_x509_crt_list_import(raw(), &certcount, datum.get(), GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 260                         }
 261
 262                         ThrowOnError(ret, "Unable to load certificates");
 263
 264                         // Resize the vector to the actual number of certs because we rely on its size being correct
 265                         // when deallocating the certs
 266                         certs.resize(certcount);
 267                 }
 268
 269                 ~X509CertList()
 270                 {
 271                         for (std::vector<gnutls_x509_crt_t>::iterator i = certs.begin(); i != certs.end(); ++i)
 272                                 gnutls_x509_crt_deinit(*i);
 273                 }
 274
 275                 gnutls_x509_crt_t* raw() { return &certs[0]; }
 276                 unsigned int size() const { return certs.size(); }
 277         };
 278
 279         class X509CRL : public refcountbase
 280         {
 281                 class RAIICRL
 282                 {
 283                  public:
 284                         gnutls_x509_crl_t crl;
 285
 286                         RAIICRL()
 287                         {
 288                                 ThrowOnError(gnutls_x509_crl_init(&crl), "gnutls_x509_crl_init() failed");
 289                         }
 290
 291                         ~RAIICRL()
 292                         {
 293                                 gnutls_x509_crl_deinit(crl);
 294                         }
 295                 } crl;
 296
 297          public:
 298                 /** Import */
 299                 X509CRL(const std::string& crlstr)
 300                 {
 301                         int ret = gnutls_x509_crl_import(get(), Datum(crlstr).get(), GNUTLS_X509_FMT_PEM);
 302                         ThrowOnError(ret, "Unable to load certificate revocation list");
 303                 }
 304
 305                 gnutls_x509_crl_t& get() { return crl.crl; }
 306         };
 307
 308 #ifdef GNUTLS_NEW_PRIO_API
 309         class Priority
 310         {
 311                 gnutls_priority_t priority;
 312
 313          public:
 314                 Priority(const std::string& priorities)
 315                 {
 316                         // Try to set the priorities for ciphers, kex methods etc. to the user supplied string
 317                         // If the user did not supply anything then the string is already set to "NORMAL"
 318                         const char* priocstr = priorities.c_str();
 319                         const char* prioerror;
 320
 321                         int ret = gnutls_priority_init(&priority, priocstr, &prioerror);
 322                         if (ret < 0)
 323                         {
 324                                 // gnutls did not understand the user supplied string
 325                                 throw Exception("Unable to initialize priorities to \"" + priorities + "\": " + gnutls_strerror(ret) + " Syntax error at position " + ConvToStr((unsigned int) (prioerror - priocstr)));
 326                         }
 327                 }
 328
 329                 ~Priority()
 330                 {
 331                         gnutls_priority_deinit(priority);
 332                 }
 333
 334                 void SetupSession(gnutls_session_t sess)
 335                 {
 336                         gnutls_priority_set(sess, priority);
 337                 }
 338         };
 339 #else
 340         /** Dummy class, used when gnutls_priority_set() is not available
 341          */
 342         class Priority
 343         {
 344          public:
 345                 Priority(const std::string& priorities)
 346                 {
 347                         if (priorities != "NORMAL")
 348                                 throw Exception("You've set a non-default priority string, but GnuTLS lacks support for it");
 349                 }
 350
 351                 static void SetupSession(gnutls_session_t sess)
 352                 {
 353                         // Always set the default priorities
 354                         gnutls_set_default_priority(sess);
 355                 }
 356         };
 357 #endif
 358
 359         class CertCredentials
 360         {
 361                 /** DH parameters associated with these credentials
 362                  */
 363                 std::auto_ptr<DHParams> dh;
 364
 365          protected:
 366                 gnutls_certificate_credentials_t cred;
 367
 368          public:
 369                 CertCredentials()
 370                 {
 371                         ThrowOnError(gnutls_certificate_allocate_credentials(&cred), "Cannot allocate certificate credentials");
 372                 }
 373
 374                 ~CertCredentials()
 375                 {
 376                         gnutls_certificate_free_credentials(cred);
 377                 }
 378
 379                 /** Associates these credentials with the session
 380                  */
 381                 void SetupSession(gnutls_session_t sess)
 382                 {
 383                         gnutls_credentials_set(sess, GNUTLS_CRD_CERTIFICATE, cred);
 384                 }
 385
 386                 /** Set the given DH parameters to be used with these credentials
 387                  */
 388                 void SetDH(std::auto_ptr<DHParams>& DH)
 389                 {
 390                         dh = DH;
 391                         gnutls_certificate_set_dh_params(cred, dh->get());
 392                 }
 393         };
 394
 395         class X509Credentials : public CertCredentials
 396         {
 397                 /** Private key
 398                  */
 399                 X509Key key;
 400
 401                 /** Certificate list, presented to the peer
 402                  */
 403                 X509CertList certs;
 404
 405                 /** Trusted CA, may be NULL
 406                  */
 407                 std::auto_ptr<X509CertList> trustedca;
 408
 409                 /** Certificate revocation list, may be NULL
 410                  */
 411                 std::auto_ptr<X509CRL> crl;
 412
 413                 static int cert_callback(gnutls_session_t session, const gnutls_datum_t* req_ca_rdn, int nreqs, const gnutls_pk_algorithm_t* sign_algos, int sign_algos_length, cert_cb_last_param_type* st);
 414
 415          public:
 416                 X509Credentials(const std::string& certstr, const std::string& keystr)
 417                         : key(keystr)
 418                         , certs(certstr)
 419                 {
 420                         // Throwing is ok here, the destructor of Credentials is called in that case
 421                         int ret = gnutls_certificate_set_x509_key(cred, certs.raw(), certs.size(), key.get());
 422                         ThrowOnError(ret, "Unable to set cert/key pair");
 423
 424 #ifdef GNUTLS_NEW_CERT_CALLBACK_API
 425                         gnutls_certificate_set_retrieve_function(cred, cert_callback);
 426 #else
 427                         gnutls_certificate_client_set_retrieve_function(cred, cert_callback);
 428 #endif
 429                 }
 430
 431                 /** Sets the trusted CA and the certificate revocation list
 432                  * to use when verifying certificates
 433                  */
 434                 void SetCA(std::auto_ptr<X509CertList>& certlist, std::auto_ptr<X509CRL>& CRL)
 435                 {
 436                         // Do nothing if certlist is NULL
 437                         if (certlist.get())
 438                         {
 439                                 int ret = gnutls_certificate_set_x509_trust(cred, certlist->raw(), certlist->size());
 440                                 ThrowOnError(ret, "gnutls_certificate_set_x509_trust() failed");
 441
 442                                 if (CRL.get())
 443                                 {
 444                                         ret = gnutls_certificate_set_x509_crl(cred, &CRL->get(), 1);
 445                                         ThrowOnError(ret, "gnutls_certificate_set_x509_crl() failed");
 446                                 }
 447
 448                                 trustedca = certlist;
 449                                 crl = CRL;
 450                         }
 451                 }
 452         };
 453
 454         class Profile : public refcountbase
 455         {
 456                 /** Name of this profile
 457                  */
 458                 const std::string name;
 459
 460                 /** X509 certificate(s) and key
 461                  */
 462                 X509Credentials x509cred;
 463
 464                 /** The minimum length in bits for the DH prime to be accepted as a client
 465                  */
 466                 unsigned int min_dh_bits;
 467
 468                 /** Hashing algorithm to use when generating certificate fingerprints
 469                  */
 470                 Hash hash;
 471
 472                 /** Priorities for ciphers, compression methods, etc.
 473                  */
 474                 Priority priority;
 475
 476                 Profile(const std::string& profilename, const std::string& certstr, const std::string& keystr,
 477                                 std::auto_ptr<DHParams>& DH, unsigned int mindh, const std::string& hashstr,
 478                                 const std::string& priostr, std::auto_ptr<X509CertList>& CA, std::auto_ptr<X509CRL>& CRL)
 479                         : name(profilename)
 480                         , x509cred(certstr, keystr)
 481                         , min_dh_bits(mindh)
 482                         , hash(hashstr)
 483                         , priority(priostr)
 484                 {
 485                         x509cred.SetDH(DH);
 486                         x509cred.SetCA(CA, CRL);
 487                 }
 488
 489                 static std::string ReadFile(const std::string& filename)
 490                 {
 491                         FileReader reader(filename);
 492                         std::string ret = reader.GetString();
 493                         if (ret.empty())
 494                                 throw Exception("Cannot read file " + filename);
 495                         return ret;
 496                 }
 497
 498          public:
 499                 static reference<Profile> Create(const std::string& profilename, ConfigTag* tag)
 500                 {
 501                         std::string certstr = ReadFile(tag->getString("certfile", "cert.pem"));
 502                         std::string keystr = ReadFile(tag->getString("keyfile", "key.pem"));
 503
 504                         std::auto_ptr<DHParams> dh;
 505                         int gendh = tag->getInt("gendh");
 506                         if (gendh)
 507                         {
 508                                 gendh = (gendh < 1024 ? 1024 : gendh);
 509                                 dh = DHParams::Generate(gendh);
 510                         }
 511                         else
 512                                 dh = DHParams::Import(ReadFile(tag->getString("dhfile", "dhparams.pem")));
 513
 514                         // Use default priority string if this tag does not specify one
 515                         std::string priostr = tag->getString("priority", "NORMAL");
 516                         unsigned int mindh = tag->getInt("mindhbits", 1024);
 517                         std::string hashstr = tag->getString("hash", "md5");
 518
 519                         // Load trusted CA and revocation list, if set
 520                         std::auto_ptr<X509CertList> ca;
 521                         std::auto_ptr<X509CRL> crl;
 522                         std::string filename = tag->getString("cafile");
 523                         if (!filename.empty())
 524                         {
 525                                 ca.reset(new X509CertList(ReadFile(filename)));
 526
 527                                 filename = tag->getString("crlfile");
 528                                 if (!filename.empty())
 529                                         crl.reset(new X509CRL(ReadFile(filename)));
 530                         }
 531
 532                         return new Profile(profilename, certstr, keystr, dh, mindh, hashstr, priostr, ca, crl);
 533                 }
 534
 535                 /** Set up the given session with the settings in this profile
 536                  */
 537                 void SetupSession(gnutls_session_t sess)
 538                 {
 539                         priority.SetupSession(sess);
 540                         x509cred.SetupSession(sess);
 541                         gnutls_dh_set_prime_bits(sess, min_dh_bits);
 542                 }
 543
 544                 const std::string& GetName() const { return name; }
 545                 X509Credentials& GetX509Credentials() { return x509cred; }
 546                 gnutls_digest_algorithm_t GetHash() const { return hash.get(); }
 547         };
 548 }
 549
 550 class GnuTLSIOHook : public SSLIOHook
 551 {
 552  private:
 553         gnutls_session_t sess;
 554         issl_status status;
 555         reference<GnuTLS::Profile> profile;
 556
 557         void InitSession(StreamSocket* user, bool me_server)
 558         {
 559                 gnutls_init(&sess, me_server ? GNUTLS_SERVER : GNUTLS_CLIENT);
 560
 561                 profile->SetupSession(sess);
 562                 gnutls_transport_set_ptr(sess, reinterpret_cast<gnutls_transport_ptr_t>(user));
 563                 gnutls_transport_set_push_function(sess, gnutls_push_wrapper);
 564                 gnutls_transport_set_pull_function(sess, gnutls_pull_wrapper);
 565
 566                 if (me_server)
 567                         gnutls_certificate_server_set_request(sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
 568         }
 569
 570         void CloseSession()
 571         {
 572                 if (this->sess)
 573                 {
 574                         gnutls_bye(this->sess, GNUTLS_SHUT_WR);
 575                         gnutls_deinit(this->sess);
 576                 }
 577                 sess = NULL;
 578                 certificate = NULL;
 579                 status = ISSL_NONE;
 580         }
 581
 582         bool Handshake(StreamSocket* user)
 583         {
 584                 int ret = gnutls_handshake(this->sess);
 585
 586                 if (ret < 0)
 587                 {
 588                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 589                         {
 590                                 // Handshake needs resuming later, read() or write() would have blocked.
 591
 592                                 if (gnutls_record_get_direction(this->sess) == 0)
 593                                 {
 594                                         // gnutls_handshake() wants to read() again.
 595                                         this->status = ISSL_HANDSHAKING_READ;
 596                                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 597                                 }
 598                                 else
 599                                 {
 600                                         // gnutls_handshake() wants to write() again.
 601                                         this->status = ISSL_HANDSHAKING_WRITE;
 602                                         SocketEngine::ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 603                                 }
 604                         }
 605                         else
 606                         {
 607                                 user->SetError("Handshake Failed - " + std::string(gnutls_strerror(ret)));
 608                                 CloseSession();
 609                                 this->status = ISSL_CLOSING;
 610                         }
 611
 612                         return false;
 613                 }
 614                 else
 615                 {
 616                         // Change the seesion state
 617                         this->status = ISSL_HANDSHAKEN;
 618
 619                         VerifyCertificate();
 620
 621                         // Finish writing, if any left
 622                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 623
 624                         return true;
 625                 }
 626         }
 627
 628         void VerifyCertificate()
 629         {
 630                 unsigned int certstatus;
 631                 const gnutls_datum_t* cert_list;
 632                 int ret;
 633                 unsigned int cert_list_size;
 634                 gnutls_x509_crt_t cert;
 635                 char str[512];
 636                 unsigned char digest[512];
 637                 size_t digest_size = sizeof(digest);
 638                 size_t name_size = sizeof(str);
 639                 ssl_cert* certinfo = new ssl_cert;
 640                 this->certificate = certinfo;
 641
 642                 /* This verification function uses the trusted CAs in the credentials
 643                  * structure. So you must have installed one or more CA certificates.
 644                  */
 645                 ret = gnutls_certificate_verify_peers2(this->sess, &certstatus);
 646
 647                 if (ret < 0)
 648                 {
 649                         certinfo->error = std::string(gnutls_strerror(ret));
 650                         return;
 651                 }
 652
 653                 certinfo->invalid = (certstatus & GNUTLS_CERT_INVALID);
 654                 certinfo->unknownsigner = (certstatus & GNUTLS_CERT_SIGNER_NOT_FOUND);
 655                 certinfo->revoked = (certstatus & GNUTLS_CERT_REVOKED);
 656                 certinfo->trusted = !(certstatus & GNUTLS_CERT_SIGNER_NOT_CA);
 657
 658                 /* Up to here the process is the same for X.509 certificates and
 659                  * OpenPGP keys. From now on X.509 certificates are assumed. This can
 660                  * be easily extended to work with openpgp keys as well.
 661                  */
 662                 if (gnutls_certificate_type_get(this->sess) != GNUTLS_CRT_X509)
 663                 {
 664                         certinfo->error = "No X509 keys sent";
 665                         return;
 666                 }
 667
 668                 ret = gnutls_x509_crt_init(&cert);
 669                 if (ret < 0)
 670                 {
 671                         certinfo->error = gnutls_strerror(ret);
 672                         return;
 673                 }
 674
 675                 cert_list_size = 0;
 676                 cert_list = gnutls_certificate_get_peers(this->sess, &cert_list_size);
 677                 if (cert_list == NULL)
 678                 {
 679                         certinfo->error = "No certificate was found";
 680                         goto info_done_dealloc;
 681                 }
 682
 683                 /* This is not a real world example, since we only check the first
 684                  * certificate in the given chain.
 685                  */
 686
 687                 ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
 688                 if (ret < 0)
 689                 {
 690                         certinfo->error = gnutls_strerror(ret);
 691                         goto info_done_dealloc;
 692                 }
 693
 694                 if (gnutls_x509_crt_get_dn(cert, str, &name_size) == 0)
 695                 {
 696                         std::string& dn = certinfo->dn;
 697                         dn = str;
 698                         // Make sure there are no chars in the string that we consider invalid
 699                         if (dn.find_first_of("\r\n") != std::string::npos)
 700                                 dn.clear();
 701                 }
 702
 703                 name_size = sizeof(str);
 704                 if (gnutls_x509_crt_get_issuer_dn(cert, str, &name_size) == 0)
 705                 {
 706                         std::string& issuer = certinfo->issuer;
 707                         issuer = str;
 708                         if (issuer.find_first_of("\r\n") != std::string::npos)
 709                                 issuer.clear();
 710                 }
 711
 712                 if ((ret = gnutls_x509_crt_get_fingerprint(cert, profile->GetHash(), digest, &digest_size)) < 0)
 713                 {
 714                         certinfo->error = gnutls_strerror(ret);
 715                 }
 716                 else
 717                 {
 718                         certinfo->fingerprint = BinToHex(digest, digest_size);
 719                 }
 720
 721                 /* Beware here we do not check for errors.
 722                  */
 723                 if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
 724                 {
 725                         certinfo->error = "Not activated, or expired certificate";
 726                 }
 727
 728 info_done_dealloc:
 729                 gnutls_x509_crt_deinit(cert);
 730         }
 731
 732         static const char* UnknownIfNULL(const char* str)
 733         {
 734                 return str ? str : "UNKNOWN";
 735         }
 736
 737         static ssize_t gnutls_pull_wrapper(gnutls_transport_ptr_t session_wrap, void* buffer, size_t size)
 738         {
 739                 StreamSocket* sock = reinterpret_cast<StreamSocket*>(session_wrap);
 740 #ifdef _WIN32
 741                 GnuTLSIOHook* session = static_cast<GnuTLSIOHook*>(sock->GetIOHook());
 742 #endif
 743
 744                 if (sock->GetEventMask() & FD_READ_WILL_BLOCK)
 745                 {
 746 #ifdef _WIN32
 747                         gnutls_transport_set_errno(session->sess, EAGAIN);
 748 #else
 749                         errno = EAGAIN;
 750 #endif
 751                         return -1;
 752                 }
 753
 754                 int rv = SocketEngine::Recv(sock, reinterpret_cast<char *>(buffer), size, 0);
 755
 756 #ifdef _WIN32
 757                 if (rv < 0)
 758                 {
 759                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 760                          * and then set errno appropriately.
 761                          * The gnutls library may also have a different errno variable than us, see
 762                          * gnutls_transport_set_errno(3).
 763                          */
 764                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 765                 }
 766 #endif
 767
 768                 if (rv < (int)size)
 769                         SocketEngine::ChangeEventMask(sock, FD_READ_WILL_BLOCK);
 770                 return rv;
 771         }
 772
 773         static ssize_t gnutls_push_wrapper(gnutls_transport_ptr_t session_wrap, const void* buffer, size_t size)
 774         {
 775                 StreamSocket* sock = reinterpret_cast<StreamSocket*>(session_wrap);
 776 #ifdef _WIN32
 777                 GnuTLSIOHook* session = static_cast<GnuTLSIOHook*>(sock->GetIOHook());
 778 #endif
 779
 780                 if (sock->GetEventMask() & FD_WRITE_WILL_BLOCK)
 781                 {
 782 #ifdef _WIN32
 783                         gnutls_transport_set_errno(session->sess, EAGAIN);
 784 #else
 785                         errno = EAGAIN;
 786 #endif
 787                         return -1;
 788                 }
 789
 790                 int rv = SocketEngine::Send(sock, reinterpret_cast<const char *>(buffer), size, 0);
 791
 792 #ifdef _WIN32
 793                 if (rv < 0)
 794                 {
 795                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 796                          * and then set errno appropriately.
 797                          * The gnutls library may also have a different errno variable than us, see
 798                          * gnutls_transport_set_errno(3).
 799                          */
 800                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 801                 }
 802 #endif
 803
 804                 if (rv < (int)size)
 805                         SocketEngine::ChangeEventMask(sock, FD_WRITE_WILL_BLOCK);
 806                 return rv;
 807         }
 808
 809  public:
 810         GnuTLSIOHook(IOHookProvider* hookprov, StreamSocket* sock, bool outbound, const reference<GnuTLS::Profile>& sslprofile)
 811                 : SSLIOHook(hookprov)
 812                 , sess(NULL)
 813                 , status(ISSL_NONE)
 814                 , profile(sslprofile)
 815         {
 816                 InitSession(sock, outbound);
 817                 sock->AddIOHook(this);
 818                 Handshake(sock);
 819         }
 820
 821         void OnStreamSocketClose(StreamSocket* user) CXX11_OVERRIDE
 822         {
 823                 CloseSession();
 824         }
 825
 826         int OnStreamSocketRead(StreamSocket* user, std::string& recvq) CXX11_OVERRIDE
 827         {
 828                 if (!this->sess)
 829                 {
 830                         CloseSession();
 831                         user->SetError("No SSL session");
 832                         return -1;
 833                 }
 834
 835                 if (this->status == ISSL_HANDSHAKING_READ || this->status == ISSL_HANDSHAKING_WRITE)
 836                 {
 837                         // The handshake isn't finished, try to finish it.
 838
 839                         if (!Handshake(user))
 840                         {
 841                                 if (this->status != ISSL_CLOSING)
 842                                         return 0;
 843                                 return -1;
 844                         }
 845                 }
 846
 847                 // If we resumed the handshake then this->status will be ISSL_HANDSHAKEN.
 848
 849                 if (this->status == ISSL_HANDSHAKEN)
 850                 {
 851                         char* buffer = ServerInstance->GetReadBuffer();
 852                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 853                         int ret = gnutls_record_recv(this->sess, buffer, bufsiz);
 854                         if (ret > 0)
 855                         {
 856                                 recvq.append(buffer, ret);
 857                                 return 1;
 858                         }
 859                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 860                         {
 861                                 return 0;
 862                         }
 863                         else if (ret == 0)
 864                         {
 865                                 user->SetError("Connection closed");
 866                                 CloseSession();
 867                                 return -1;
 868                         }
 869                         else
 870                         {
 871                                 user->SetError(gnutls_strerror(ret));
 872                                 CloseSession();
 873                                 return -1;
 874                         }
 875                 }
 876                 else if (this->status == ISSL_CLOSING)
 877                         return -1;
 878
 879                 return 0;
 880         }
 881
 882         int OnStreamSocketWrite(StreamSocket* user, std::string& sendq) CXX11_OVERRIDE
 883         {
 884                 if (!this->sess)
 885                 {
 886                         CloseSession();
 887                         user->SetError("No SSL session");
 888                         return -1;
 889                 }
 890
 891                 if (this->status == ISSL_HANDSHAKING_WRITE || this->status == ISSL_HANDSHAKING_READ)
 892                 {
 893                         // The handshake isn't finished, try to finish it.
 894                         Handshake(user);
 895                         if (this->status != ISSL_CLOSING)
 896                                 return 0;
 897                         return -1;
 898                 }
 899
 900                 int ret = 0;
 901
 902                 if (this->status == ISSL_HANDSHAKEN)
 903                 {
 904                         ret = gnutls_record_send(this->sess, sendq.data(), sendq.length());
 905
 906                         if (ret == (int)sendq.length())
 907                         {
 908                                 SocketEngine::ChangeEventMask(user, FD_WANT_NO_WRITE);
 909                                 return 1;
 910                         }
 911                         else if (ret > 0)
 912                         {
 913                                 sendq.erase(0, ret);
 914                                 SocketEngine::ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 915                                 return 0;
 916                         }
 917                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED || ret == 0)
 918                         {
 919                                 SocketEngine::ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 920                                 return 0;
 921                         }
 922                         else // (ret < 0)
 923                         {
 924                                 user->SetError(gnutls_strerror(ret));
 925                                 CloseSession();
 926                                 return -1;
 927                         }
 928                 }
 929
 930                 return 0;
 931         }
 932
 933         void TellCiphersAndFingerprint(LocalUser* user)
 934         {
 935                 if (sess)
 936                 {
 937                         std::string text = "*** You are connected using SSL cipher '";
 938                         GetCiphersuite(text);
 939                         text += '\'';
 940                         if (!certificate->fingerprint.empty())
 941                                 text += " and your SSL certificate fingerprint is " + certificate->fingerprint;
 942
 943                         user->WriteNotice(text);
 944                 }
 945         }
 946
 947         void GetCiphersuite(std::string& out) const
 948         {
 949                 out.append(UnknownIfNULL(gnutls_protocol_get_name(gnutls_protocol_get_version(sess)))).push_back('-');
 950                 out.append(UnknownIfNULL(gnutls_kx_get_name(gnutls_kx_get(sess)))).push_back('-');
 951                 out.append(UnknownIfNULL(gnutls_cipher_get_name(gnutls_cipher_get(sess)))).push_back('-');
 952                 out.append(UnknownIfNULL(gnutls_mac_get_name(gnutls_mac_get(sess))));
 953         }
 954
 955         GnuTLS::Profile* GetProfile() { return profile; }
 956 };
 957
 958 int GnuTLS::X509Credentials::cert_callback(gnutls_session_t sess, const gnutls_datum_t* req_ca_rdn, int nreqs, const gnutls_pk_algorithm_t* sign_algos, int sign_algos_length, cert_cb_last_param_type* st)
 959 {
 960 #ifndef GNUTLS_NEW_CERT_CALLBACK_API
 961         st->type = GNUTLS_CRT_X509;
 962 #else
 963         st->cert_type = GNUTLS_CRT_X509;
 964         st->key_type = GNUTLS_PRIVKEY_X509;
 965 #endif
 966         StreamSocket* sock = reinterpret_cast<StreamSocket*>(gnutls_transport_get_ptr(sess));
 967         GnuTLS::X509Credentials& cred = static_cast<GnuTLSIOHook*>(sock->GetIOHook())->GetProfile()->GetX509Credentials();
 968
 969         st->ncerts = cred.certs.size();
 970         st->cert.x509 = cred.certs.raw();
 971         st->key.x509 = cred.key.get();
 972         st->deinit_all = 0;
 973
 974         return 0;
 975 }
 976
 977 class GnuTLSIOHookProvider : public refcountbase, public IOHookProvider
 978 {
 979         reference<GnuTLS::Profile> profile;
 980
 981  public:
 982         GnuTLSIOHookProvider(Module* mod, reference<GnuTLS::Profile>& prof)
 983                 : IOHookProvider(mod, "ssl/" + prof->GetName(), IOHookProvider::IOH_SSL)
 984                 , profile(prof)
 985         {
 986                 ServerInstance->Modules->AddService(*this);
 987         }
 988
 989         ~GnuTLSIOHookProvider()
 990         {
 991                 ServerInstance->Modules->DelService(*this);
 992         }
 993
 994         void OnAccept(StreamSocket* sock, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server) CXX11_OVERRIDE
 995         {
 996                 new GnuTLSIOHook(this, sock, true, profile);
 997         }
 998
 999         void OnConnect(StreamSocket* sock) CXX11_OVERRIDE
1000         {
1001                 new GnuTLSIOHook(this, sock, false, profile);
1002         }
1003 };
1004
1005 class ModuleSSLGnuTLS : public Module
1006 {
1007         typedef std::vector<reference<GnuTLSIOHookProvider> > ProfileList;
1008
1009         // First member of the class, gets constructed first and destructed last
1010         GnuTLS::Init libinit;
1011         RandGen randhandler;
1012         ProfileList profiles;
1013
1014         void ReadProfiles()
1015         {
1016                 // First, store all profiles in a new, temporary container. If no problems occur, swap the two
1017                 // containers; this way if something goes wrong we can go back and continue using the current profiles,
1018                 // avoiding unpleasant situations where no new SSL connections are possible.
1019                 ProfileList newprofiles;
1020
1021                 ConfigTagList tags = ServerInstance->Config->ConfTags("sslprofile");
1022                 if (tags.first == tags.second)
1023                 {
1024                         // No <sslprofile> tags found, create a profile named "gnutls" from settings in the <gnutls> block
1025                         const std::string defname = "gnutls";
1026                         ConfigTag* tag = ServerInstance->Config->ConfValue(defname);
1027                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "No <sslprofile> tags found; using settings from the <gnutls> tag");
1028
1029                         try
1030                         {
1031                                 reference<GnuTLS::Profile> profile(GnuTLS::Profile::Create(defname, tag));
1032                                 newprofiles.push_back(new GnuTLSIOHookProvider(this, profile));
1033                         }
1034                         catch (CoreException& ex)
1035                         {
1036                                 throw ModuleException("Error while initializing the default SSL profile - " + ex.GetReason());
1037                         }
1038                 }
1039
1040                 for (ConfigIter i = tags.first; i != tags.second; ++i)
1041                 {
1042                         ConfigTag* tag = i->second;
1043                         if (tag->getString("provider") != "gnutls")
1044                                 continue;
1045
1046                         std::string name = tag->getString("name");
1047                         if (name.empty())
1048                         {
1049                                 ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Ignoring <sslprofile> tag without name at " + tag->getTagLocation());
1050                                 continue;
1051                         }
1052
1053                         reference<GnuTLS::Profile> profile;
1054                         try
1055                         {
1056                                 profile = GnuTLS::Profile::Create(name, tag);
1057                         }
1058                         catch (CoreException& ex)
1059                         {
1060                                 throw ModuleException("Error while initializing SSL profile \"" + name + "\" at " + tag->getTagLocation() + " - " + ex.GetReason());
1061                         }
1062
1063                         newprofiles.push_back(new GnuTLSIOHookProvider(this, profile));
1064                 }
1065
1066                 // New profiles are ok, begin using them
1067                 // Old profiles are deleted when their refcount drops to zero
1068                 profiles.swap(newprofiles);
1069         }
1070
1071  public:
1072         ModuleSSLGnuTLS()
1073         {
1074 #ifndef GNUTLS_HAS_RND
1075                 gcry_control (GCRYCTL_INITIALIZATION_FINISHED, 0);
1076 #endif
1077         }
1078
1079         void init() CXX11_OVERRIDE
1080         {
1081                 ReadProfiles();
1082                 ServerInstance->GenRandom = &randhandler;
1083         }
1084
1085         void OnModuleRehash(User* user, const std::string &param) CXX11_OVERRIDE
1086         {
1087                 if(param != "ssl")
1088                         return;
1089
1090                 try
1091                 {
1092                         ReadProfiles();
1093                 }
1094                 catch (ModuleException& ex)
1095                 {
1096                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, ex.GetReason() + " Not applying settings.");
1097                 }
1098         }
1099
1100         ~ModuleSSLGnuTLS()
1101         {
1102                 ServerInstance->GenRandom = &ServerInstance->HandleGenRandom;
1103         }
1104
1105         void OnCleanup(int target_type, void* item) CXX11_OVERRIDE
1106         {
1107                 if(target_type == TYPE_USER)
1108                 {
1109                         LocalUser* user = IS_LOCAL(static_cast<User*>(item));
1110
1111                         if (user && user->eh.GetIOHook() && user->eh.GetIOHook()->prov->creator == this)
1112                         {
1113                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
1114                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
1115                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
1116                         }
1117                 }
1118         }
1119
1120         Version GetVersion() CXX11_OVERRIDE
1121         {
1122                 return Version("Provides SSL support for clients", VF_VENDOR);
1123         }
1124
1125         void OnUserConnect(LocalUser* user) CXX11_OVERRIDE
1126         {
1127                 IOHook* hook = user->eh.GetIOHook();
1128                 if (hook && hook->prov->creator == this)
1129                         static_cast<GnuTLSIOHook*>(hook)->TellCiphersAndFingerprint(user);
1130         }
1131 };
1132
1133 MODULE_INIT(ModuleSSLGnuTLS)