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 DataReader
 455         {
 456                 int retval;
 457                 char* const buffer;
 458
 459          public:
 460                 DataReader(gnutls_session_t sess)
 461                         : buffer(ServerInstance->GetReadBuffer())
 462                 {
 463                         // Read data from GnuTLS buffers into ReadBuffer
 464                         retval = gnutls_record_recv(sess, buffer, ServerInstance->Config->NetBufferSize);
 465                 }
 466
 467                 void appendto(std::string& recvq)
 468                 {
 469                         // Copy data from ReadBuffer to recvq
 470                         recvq.append(buffer, retval);
 471                 }
 472
 473                 int ret() const { return retval; }
 474         };
 475
 476         class Profile : public refcountbase
 477         {
 478                 /** Name of this profile
 479                  */
 480                 const std::string name;
 481
 482                 /** X509 certificate(s) and key
 483                  */
 484                 X509Credentials x509cred;
 485
 486                 /** The minimum length in bits for the DH prime to be accepted as a client
 487                  */
 488                 unsigned int min_dh_bits;
 489
 490                 /** Hashing algorithm to use when generating certificate fingerprints
 491                  */
 492                 Hash hash;
 493
 494                 /** Priorities for ciphers, compression methods, etc.
 495                  */
 496                 Priority priority;
 497
 498                 Profile(const std::string& profilename, const std::string& certstr, const std::string& keystr,
 499                                 std::auto_ptr<DHParams>& DH, unsigned int mindh, const std::string& hashstr,
 500                                 const std::string& priostr, std::auto_ptr<X509CertList>& CA, std::auto_ptr<X509CRL>& CRL)
 501                         : name(profilename)
 502                         , x509cred(certstr, keystr)
 503                         , min_dh_bits(mindh)
 504                         , hash(hashstr)
 505                         , priority(priostr)
 506                 {
 507                         x509cred.SetDH(DH);
 508                         x509cred.SetCA(CA, CRL);
 509                 }
 510
 511                 static std::string ReadFile(const std::string& filename)
 512                 {
 513                         FileReader reader(filename);
 514                         std::string ret = reader.GetString();
 515                         if (ret.empty())
 516                                 throw Exception("Cannot read file " + filename);
 517                         return ret;
 518                 }
 519
 520          public:
 521                 static reference<Profile> Create(const std::string& profilename, ConfigTag* tag)
 522                 {
 523                         std::string certstr = ReadFile(tag->getString("certfile", "cert.pem"));
 524                         std::string keystr = ReadFile(tag->getString("keyfile", "key.pem"));
 525
 526                         std::auto_ptr<DHParams> dh;
 527                         int gendh = tag->getInt("gendh");
 528                         if (gendh)
 529                         {
 530                                 gendh = (gendh < 1024 ? 1024 : gendh);
 531                                 dh = DHParams::Generate(gendh);
 532                         }
 533                         else
 534                                 dh = DHParams::Import(ReadFile(tag->getString("dhfile", "dhparams.pem")));
 535
 536                         // Use default priority string if this tag does not specify one
 537                         std::string priostr = tag->getString("priority", "NORMAL");
 538                         unsigned int mindh = tag->getInt("mindhbits", 1024);
 539                         std::string hashstr = tag->getString("hash", "md5");
 540
 541                         // Load trusted CA and revocation list, if set
 542                         std::auto_ptr<X509CertList> ca;
 543                         std::auto_ptr<X509CRL> crl;
 544                         std::string filename = tag->getString("cafile");
 545                         if (!filename.empty())
 546                         {
 547                                 ca.reset(new X509CertList(ReadFile(filename)));
 548
 549                                 filename = tag->getString("crlfile");
 550                                 if (!filename.empty())
 551                                         crl.reset(new X509CRL(ReadFile(filename)));
 552                         }
 553
 554                         return new Profile(profilename, certstr, keystr, dh, mindh, hashstr, priostr, ca, crl);
 555                 }
 556
 557                 /** Set up the given session with the settings in this profile
 558                  */
 559                 void SetupSession(gnutls_session_t sess)
 560                 {
 561                         priority.SetupSession(sess);
 562                         x509cred.SetupSession(sess);
 563                         gnutls_dh_set_prime_bits(sess, min_dh_bits);
 564                 }
 565
 566                 const std::string& GetName() const { return name; }
 567                 X509Credentials& GetX509Credentials() { return x509cred; }
 568                 gnutls_digest_algorithm_t GetHash() const { return hash.get(); }
 569         };
 570 }
 571
 572 class GnuTLSIOHook : public SSLIOHook
 573 {
 574  private:
 575         gnutls_session_t sess;
 576         issl_status status;
 577         reference<GnuTLS::Profile> profile;
 578
 579         void InitSession(StreamSocket* user, bool me_server)
 580         {
 581                 gnutls_init(&sess, me_server ? GNUTLS_SERVER : GNUTLS_CLIENT);
 582
 583                 profile->SetupSession(sess);
 584                 gnutls_transport_set_ptr(sess, reinterpret_cast<gnutls_transport_ptr_t>(user));
 585                 gnutls_transport_set_push_function(sess, gnutls_push_wrapper);
 586                 gnutls_transport_set_pull_function(sess, gnutls_pull_wrapper);
 587
 588                 if (me_server)
 589                         gnutls_certificate_server_set_request(sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
 590         }
 591
 592         void CloseSession()
 593         {
 594                 if (this->sess)
 595                 {
 596                         gnutls_bye(this->sess, GNUTLS_SHUT_WR);
 597                         gnutls_deinit(this->sess);
 598                 }
 599                 sess = NULL;
 600                 certificate = NULL;
 601                 status = ISSL_NONE;
 602         }
 603
 604         bool Handshake(StreamSocket* user)
 605         {
 606                 int ret = gnutls_handshake(this->sess);
 607
 608                 if (ret < 0)
 609                 {
 610                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 611                         {
 612                                 // Handshake needs resuming later, read() or write() would have blocked.
 613
 614                                 if (gnutls_record_get_direction(this->sess) == 0)
 615                                 {
 616                                         // gnutls_handshake() wants to read() again.
 617                                         this->status = ISSL_HANDSHAKING_READ;
 618                                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 619                                 }
 620                                 else
 621                                 {
 622                                         // gnutls_handshake() wants to write() again.
 623                                         this->status = ISSL_HANDSHAKING_WRITE;
 624                                         SocketEngine::ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 625                                 }
 626                         }
 627                         else
 628                         {
 629                                 user->SetError("Handshake Failed - " + std::string(gnutls_strerror(ret)));
 630                                 CloseSession();
 631                                 this->status = ISSL_CLOSING;
 632                         }
 633
 634                         return false;
 635                 }
 636                 else
 637                 {
 638                         // Change the seesion state
 639                         this->status = ISSL_HANDSHAKEN;
 640
 641                         VerifyCertificate();
 642
 643                         // Finish writing, if any left
 644                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 645
 646                         return true;
 647                 }
 648         }
 649
 650         void VerifyCertificate()
 651         {
 652                 unsigned int certstatus;
 653                 const gnutls_datum_t* cert_list;
 654                 int ret;
 655                 unsigned int cert_list_size;
 656                 gnutls_x509_crt_t cert;
 657                 char str[512];
 658                 unsigned char digest[512];
 659                 size_t digest_size = sizeof(digest);
 660                 size_t name_size = sizeof(str);
 661                 ssl_cert* certinfo = new ssl_cert;
 662                 this->certificate = certinfo;
 663
 664                 /* This verification function uses the trusted CAs in the credentials
 665                  * structure. So you must have installed one or more CA certificates.
 666                  */
 667                 ret = gnutls_certificate_verify_peers2(this->sess, &certstatus);
 668
 669                 if (ret < 0)
 670                 {
 671                         certinfo->error = std::string(gnutls_strerror(ret));
 672                         return;
 673                 }
 674
 675                 certinfo->invalid = (certstatus & GNUTLS_CERT_INVALID);
 676                 certinfo->unknownsigner = (certstatus & GNUTLS_CERT_SIGNER_NOT_FOUND);
 677                 certinfo->revoked = (certstatus & GNUTLS_CERT_REVOKED);
 678                 certinfo->trusted = !(certstatus & GNUTLS_CERT_SIGNER_NOT_CA);
 679
 680                 /* Up to here the process is the same for X.509 certificates and
 681                  * OpenPGP keys. From now on X.509 certificates are assumed. This can
 682                  * be easily extended to work with openpgp keys as well.
 683                  */
 684                 if (gnutls_certificate_type_get(this->sess) != GNUTLS_CRT_X509)
 685                 {
 686                         certinfo->error = "No X509 keys sent";
 687                         return;
 688                 }
 689
 690                 ret = gnutls_x509_crt_init(&cert);
 691                 if (ret < 0)
 692                 {
 693                         certinfo->error = gnutls_strerror(ret);
 694                         return;
 695                 }
 696
 697                 cert_list_size = 0;
 698                 cert_list = gnutls_certificate_get_peers(this->sess, &cert_list_size);
 699                 if (cert_list == NULL)
 700                 {
 701                         certinfo->error = "No certificate was found";
 702                         goto info_done_dealloc;
 703                 }
 704
 705                 /* This is not a real world example, since we only check the first
 706                  * certificate in the given chain.
 707                  */
 708
 709                 ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
 710                 if (ret < 0)
 711                 {
 712                         certinfo->error = gnutls_strerror(ret);
 713                         goto info_done_dealloc;
 714                 }
 715
 716                 if (gnutls_x509_crt_get_dn(cert, str, &name_size) == 0)
 717                 {
 718                         std::string& dn = certinfo->dn;
 719                         dn = str;
 720                         // Make sure there are no chars in the string that we consider invalid
 721                         if (dn.find_first_of("\r\n") != std::string::npos)
 722                                 dn.clear();
 723                 }
 724
 725                 name_size = sizeof(str);
 726                 if (gnutls_x509_crt_get_issuer_dn(cert, str, &name_size) == 0)
 727                 {
 728                         std::string& issuer = certinfo->issuer;
 729                         issuer = str;
 730                         if (issuer.find_first_of("\r\n") != std::string::npos)
 731                                 issuer.clear();
 732                 }
 733
 734                 if ((ret = gnutls_x509_crt_get_fingerprint(cert, profile->GetHash(), digest, &digest_size)) < 0)
 735                 {
 736                         certinfo->error = gnutls_strerror(ret);
 737                 }
 738                 else
 739                 {
 740                         certinfo->fingerprint = BinToHex(digest, digest_size);
 741                 }
 742
 743                 /* Beware here we do not check for errors.
 744                  */
 745                 if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
 746                 {
 747                         certinfo->error = "Not activated, or expired certificate";
 748                 }
 749
 750 info_done_dealloc:
 751                 gnutls_x509_crt_deinit(cert);
 752         }
 753
 754         static const char* UnknownIfNULL(const char* str)
 755         {
 756                 return str ? str : "UNKNOWN";
 757         }
 758
 759         static ssize_t gnutls_pull_wrapper(gnutls_transport_ptr_t session_wrap, void* buffer, size_t size)
 760         {
 761                 StreamSocket* sock = reinterpret_cast<StreamSocket*>(session_wrap);
 762 #ifdef _WIN32
 763                 GnuTLSIOHook* session = static_cast<GnuTLSIOHook*>(sock->GetIOHook());
 764 #endif
 765
 766                 if (sock->GetEventMask() & FD_READ_WILL_BLOCK)
 767                 {
 768 #ifdef _WIN32
 769                         gnutls_transport_set_errno(session->sess, EAGAIN);
 770 #else
 771                         errno = EAGAIN;
 772 #endif
 773                         return -1;
 774                 }
 775
 776                 int rv = SocketEngine::Recv(sock, reinterpret_cast<char *>(buffer), size, 0);
 777
 778 #ifdef _WIN32
 779                 if (rv < 0)
 780                 {
 781                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 782                          * and then set errno appropriately.
 783                          * The gnutls library may also have a different errno variable than us, see
 784                          * gnutls_transport_set_errno(3).
 785                          */
 786                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 787                 }
 788 #endif
 789
 790                 if (rv < (int)size)
 791                         SocketEngine::ChangeEventMask(sock, FD_READ_WILL_BLOCK);
 792                 return rv;
 793         }
 794
 795         static ssize_t gnutls_push_wrapper(gnutls_transport_ptr_t session_wrap, const void* buffer, size_t size)
 796         {
 797                 StreamSocket* sock = reinterpret_cast<StreamSocket*>(session_wrap);
 798 #ifdef _WIN32
 799                 GnuTLSIOHook* session = static_cast<GnuTLSIOHook*>(sock->GetIOHook());
 800 #endif
 801
 802                 if (sock->GetEventMask() & FD_WRITE_WILL_BLOCK)
 803                 {
 804 #ifdef _WIN32
 805                         gnutls_transport_set_errno(session->sess, EAGAIN);
 806 #else
 807                         errno = EAGAIN;
 808 #endif
 809                         return -1;
 810                 }
 811
 812                 int rv = SocketEngine::Send(sock, reinterpret_cast<const char *>(buffer), size, 0);
 813
 814 #ifdef _WIN32
 815                 if (rv < 0)
 816                 {
 817                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 818                          * and then set errno appropriately.
 819                          * The gnutls library may also have a different errno variable than us, see
 820                          * gnutls_transport_set_errno(3).
 821                          */
 822                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 823                 }
 824 #endif
 825
 826                 if (rv < (int)size)
 827                         SocketEngine::ChangeEventMask(sock, FD_WRITE_WILL_BLOCK);
 828                 return rv;
 829         }
 830
 831  public:
 832         GnuTLSIOHook(IOHookProvider* hookprov, StreamSocket* sock, bool outbound, const reference<GnuTLS::Profile>& sslprofile)
 833                 : SSLIOHook(hookprov)
 834                 , sess(NULL)
 835                 , status(ISSL_NONE)
 836                 , profile(sslprofile)
 837         {
 838                 InitSession(sock, outbound);
 839                 sock->AddIOHook(this);
 840                 Handshake(sock);
 841         }
 842
 843         void OnStreamSocketClose(StreamSocket* user) CXX11_OVERRIDE
 844         {
 845                 CloseSession();
 846         }
 847
 848         int OnStreamSocketRead(StreamSocket* user, std::string& recvq) CXX11_OVERRIDE
 849         {
 850                 if (!this->sess)
 851                 {
 852                         CloseSession();
 853                         user->SetError("No SSL session");
 854                         return -1;
 855                 }
 856
 857                 if (this->status == ISSL_HANDSHAKING_READ || this->status == ISSL_HANDSHAKING_WRITE)
 858                 {
 859                         // The handshake isn't finished, try to finish it.
 860
 861                         if (!Handshake(user))
 862                         {
 863                                 if (this->status != ISSL_CLOSING)
 864                                         return 0;
 865                                 return -1;
 866                         }
 867                 }
 868
 869                 // If we resumed the handshake then this->status will be ISSL_HANDSHAKEN.
 870
 871                 if (this->status == ISSL_HANDSHAKEN)
 872                 {
 873                         GnuTLS::DataReader reader(sess);
 874                         int ret = reader.ret();
 875                         if (ret > 0)
 876                         {
 877                                 reader.appendto(recvq);
 878                                 return 1;
 879                         }
 880                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 881                         {
 882                                 return 0;
 883                         }
 884                         else if (ret == 0)
 885                         {
 886                                 user->SetError("Connection closed");
 887                                 CloseSession();
 888                                 return -1;
 889                         }
 890                         else
 891                         {
 892                                 user->SetError(gnutls_strerror(ret));
 893                                 CloseSession();
 894                                 return -1;
 895                         }
 896                 }
 897                 else if (this->status == ISSL_CLOSING)
 898                         return -1;
 899
 900                 return 0;
 901         }
 902
 903         int OnStreamSocketWrite(StreamSocket* user, std::string& sendq) CXX11_OVERRIDE
 904         {
 905                 if (!this->sess)
 906                 {
 907                         CloseSession();
 908                         user->SetError("No SSL session");
 909                         return -1;
 910                 }
 911
 912                 if (this->status == ISSL_HANDSHAKING_WRITE || this->status == ISSL_HANDSHAKING_READ)
 913                 {
 914                         // The handshake isn't finished, try to finish it.
 915                         Handshake(user);
 916                         if (this->status != ISSL_CLOSING)
 917                                 return 0;
 918                         return -1;
 919                 }
 920
 921                 int ret = 0;
 922
 923                 if (this->status == ISSL_HANDSHAKEN)
 924                 {
 925                         ret = gnutls_record_send(this->sess, sendq.data(), sendq.length());
 926
 927                         if (ret == (int)sendq.length())
 928                         {
 929                                 SocketEngine::ChangeEventMask(user, FD_WANT_NO_WRITE);
 930                                 return 1;
 931                         }
 932                         else if (ret > 0)
 933                         {
 934                                 sendq.erase(0, ret);
 935                                 SocketEngine::ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 936                                 return 0;
 937                         }
 938                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED || ret == 0)
 939                         {
 940                                 SocketEngine::ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 941                                 return 0;
 942                         }
 943                         else // (ret < 0)
 944                         {
 945                                 user->SetError(gnutls_strerror(ret));
 946                                 CloseSession();
 947                                 return -1;
 948                         }
 949                 }
 950
 951                 return 0;
 952         }
 953
 954         void TellCiphersAndFingerprint(LocalUser* user)
 955         {
 956                 if (sess)
 957                 {
 958                         std::string text = "*** You are connected using SSL cipher '";
 959                         GetCiphersuite(text);
 960                         text += '\'';
 961                         if (!certificate->fingerprint.empty())
 962                                 text += " and your SSL certificate fingerprint is " + certificate->fingerprint;
 963
 964                         user->WriteNotice(text);
 965                 }
 966         }
 967
 968         void GetCiphersuite(std::string& out) const
 969         {
 970                 out.append(UnknownIfNULL(gnutls_protocol_get_name(gnutls_protocol_get_version(sess)))).push_back('-');
 971                 out.append(UnknownIfNULL(gnutls_kx_get_name(gnutls_kx_get(sess)))).push_back('-');
 972                 out.append(UnknownIfNULL(gnutls_cipher_get_name(gnutls_cipher_get(sess)))).push_back('-');
 973                 out.append(UnknownIfNULL(gnutls_mac_get_name(gnutls_mac_get(sess))));
 974         }
 975
 976         GnuTLS::Profile* GetProfile() { return profile; }
 977 };
 978
 979 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)
 980 {
 981 #ifndef GNUTLS_NEW_CERT_CALLBACK_API
 982         st->type = GNUTLS_CRT_X509;
 983 #else
 984         st->cert_type = GNUTLS_CRT_X509;
 985         st->key_type = GNUTLS_PRIVKEY_X509;
 986 #endif
 987         StreamSocket* sock = reinterpret_cast<StreamSocket*>(gnutls_transport_get_ptr(sess));
 988         GnuTLS::X509Credentials& cred = static_cast<GnuTLSIOHook*>(sock->GetIOHook())->GetProfile()->GetX509Credentials();
 989
 990         st->ncerts = cred.certs.size();
 991         st->cert.x509 = cred.certs.raw();
 992         st->key.x509 = cred.key.get();
 993         st->deinit_all = 0;
 994
 995         return 0;
 996 }
 997
 998 class GnuTLSIOHookProvider : public refcountbase, public IOHookProvider
 999 {
1000         reference<GnuTLS::Profile> profile;
1001
1002  public:
1003         GnuTLSIOHookProvider(Module* mod, reference<GnuTLS::Profile>& prof)
1004                 : IOHookProvider(mod, "ssl/" + prof->GetName(), IOHookProvider::IOH_SSL)
1005                 , profile(prof)
1006         {
1007                 ServerInstance->Modules->AddService(*this);
1008         }
1009
1010         ~GnuTLSIOHookProvider()
1011         {
1012                 ServerInstance->Modules->DelService(*this);
1013         }
1014
1015         void OnAccept(StreamSocket* sock, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server) CXX11_OVERRIDE
1016         {
1017                 new GnuTLSIOHook(this, sock, true, profile);
1018         }
1019
1020         void OnConnect(StreamSocket* sock) CXX11_OVERRIDE
1021         {
1022                 new GnuTLSIOHook(this, sock, false, profile);
1023         }
1024 };
1025
1026 class ModuleSSLGnuTLS : public Module
1027 {
1028         typedef std::vector<reference<GnuTLSIOHookProvider> > ProfileList;
1029
1030         // First member of the class, gets constructed first and destructed last
1031         GnuTLS::Init libinit;
1032         RandGen randhandler;
1033         ProfileList profiles;
1034
1035         void ReadProfiles()
1036         {
1037                 // First, store all profiles in a new, temporary container. If no problems occur, swap the two
1038                 // containers; this way if something goes wrong we can go back and continue using the current profiles,
1039                 // avoiding unpleasant situations where no new SSL connections are possible.
1040                 ProfileList newprofiles;
1041
1042                 ConfigTagList tags = ServerInstance->Config->ConfTags("sslprofile");
1043                 if (tags.first == tags.second)
1044                 {
1045                         // No <sslprofile> tags found, create a profile named "gnutls" from settings in the <gnutls> block
1046                         const std::string defname = "gnutls";
1047                         ConfigTag* tag = ServerInstance->Config->ConfValue(defname);
1048                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "No <sslprofile> tags found; using settings from the <gnutls> tag");
1049
1050                         try
1051                         {
1052                                 reference<GnuTLS::Profile> profile(GnuTLS::Profile::Create(defname, tag));
1053                                 newprofiles.push_back(new GnuTLSIOHookProvider(this, profile));
1054                         }
1055                         catch (CoreException& ex)
1056                         {
1057                                 throw ModuleException("Error while initializing the default SSL profile - " + ex.GetReason());
1058                         }
1059                 }
1060
1061                 for (ConfigIter i = tags.first; i != tags.second; ++i)
1062                 {
1063                         ConfigTag* tag = i->second;
1064                         if (tag->getString("provider") != "gnutls")
1065                                 continue;
1066
1067                         std::string name = tag->getString("name");
1068                         if (name.empty())
1069                         {
1070                                 ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Ignoring <sslprofile> tag without name at " + tag->getTagLocation());
1071                                 continue;
1072                         }
1073
1074                         reference<GnuTLS::Profile> profile;
1075                         try
1076                         {
1077                                 profile = GnuTLS::Profile::Create(name, tag);
1078                         }
1079                         catch (CoreException& ex)
1080                         {
1081                                 throw ModuleException("Error while initializing SSL profile \"" + name + "\" at " + tag->getTagLocation() + " - " + ex.GetReason());
1082                         }
1083
1084                         newprofiles.push_back(new GnuTLSIOHookProvider(this, profile));
1085                 }
1086
1087                 // New profiles are ok, begin using them
1088                 // Old profiles are deleted when their refcount drops to zero
1089                 profiles.swap(newprofiles);
1090         }
1091
1092  public:
1093         ModuleSSLGnuTLS()
1094         {
1095 #ifndef GNUTLS_HAS_RND
1096                 gcry_control (GCRYCTL_INITIALIZATION_FINISHED, 0);
1097 #endif
1098         }
1099
1100         void init() CXX11_OVERRIDE
1101         {
1102                 ReadProfiles();
1103                 ServerInstance->GenRandom = &randhandler;
1104         }
1105
1106         void OnModuleRehash(User* user, const std::string &param) CXX11_OVERRIDE
1107         {
1108                 if(param != "ssl")
1109                         return;
1110
1111                 try
1112                 {
1113                         ReadProfiles();
1114                 }
1115                 catch (ModuleException& ex)
1116                 {
1117                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, ex.GetReason() + " Not applying settings.");
1118                 }
1119         }
1120
1121         ~ModuleSSLGnuTLS()
1122         {
1123                 ServerInstance->GenRandom = &ServerInstance->HandleGenRandom;
1124         }
1125
1126         void OnCleanup(int target_type, void* item) CXX11_OVERRIDE
1127         {
1128                 if(target_type == TYPE_USER)
1129                 {
1130                         LocalUser* user = IS_LOCAL(static_cast<User*>(item));
1131
1132                         if (user && user->eh.GetIOHook() && user->eh.GetIOHook()->prov->creator == this)
1133                         {
1134                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
1135                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
1136                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
1137                         }
1138                 }
1139         }
1140
1141         Version GetVersion() CXX11_OVERRIDE
1142         {
1143                 return Version("Provides SSL support for clients", VF_VENDOR);
1144         }
1145
1146         void OnUserConnect(LocalUser* user) CXX11_OVERRIDE
1147         {
1148                 IOHook* hook = user->eh.GetIOHook();
1149                 if (hook && hook->prov->creator == this)
1150                         static_cast<GnuTLSIOHook*>(hook)->TellCiphersAndFingerprint(user);
1151         }
1152 };
1153
1154 MODULE_INIT(ModuleSSLGnuTLS)