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, ISSL_HANDSHAKEN };
  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 #if INSPIRCD_GNUTLS_HAS_VERSION(3, 3, 5)
  83 #define INSPIRCD_GNUTLS_HAS_RECV_PACKET
  84 #endif
  85
  86 class RandGen : public HandlerBase2<void, char*, size_t>
  87 {
  88  public:
  89         void Call(char* buffer, size_t len)
  90         {
  91 #ifdef GNUTLS_HAS_RND
  92                 gnutls_rnd(GNUTLS_RND_RANDOM, buffer, len);
  93 #else
  94                 gcry_randomize(buffer, len, GCRY_STRONG_RANDOM);
  95 #endif
  96         }
  97 };
  98
  99 namespace GnuTLS
 100 {
 101         class Init
 102         {
 103          public:
 104                 Init() { gnutls_global_init(); }
 105                 ~Init() { gnutls_global_deinit(); }
 106         };
 107
 108         class Exception : public ModuleException
 109         {
 110          public:
 111                 Exception(const std::string& reason)
 112                         : ModuleException(reason) { }
 113         };
 114
 115         void ThrowOnError(int errcode, const char* msg)
 116         {
 117                 if (errcode < 0)
 118                 {
 119                         std::string reason = msg;
 120                         reason.append(" :").append(gnutls_strerror(errcode));
 121                         throw Exception(reason);
 122                 }
 123         }
 124
 125         /** Used to create a gnutls_datum_t* from a std::string
 126          */
 127         class Datum
 128         {
 129                 gnutls_datum_t datum;
 130
 131          public:
 132                 Datum(const std::string& dat)
 133                 {
 134                         datum.data = (unsigned char*)dat.data();
 135                         datum.size = static_cast<unsigned int>(dat.length());
 136                 }
 137
 138                 const gnutls_datum_t* get() const { return &datum; }
 139         };
 140
 141         class Hash
 142         {
 143                 gnutls_digest_algorithm_t hash;
 144
 145          public:
 146                 // Nothing to deallocate, constructor may throw freely
 147                 Hash(const std::string& hashname)
 148                 {
 149                         // As older versions of gnutls can't do this, let's disable it where needed.
 150 #ifdef GNUTLS_HAS_MAC_GET_ID
 151                         // As gnutls_digest_algorithm_t and gnutls_mac_algorithm_t are mapped 1:1, we can do this
 152                         // There is no gnutls_dig_get_id() at the moment, but it may come later
 153                         hash = (gnutls_digest_algorithm_t)gnutls_mac_get_id(hashname.c_str());
 154                         if (hash == GNUTLS_DIG_UNKNOWN)
 155                                 throw Exception("Unknown hash type " + hashname);
 156
 157                         // Check if the user is giving us something that is a valid MAC but not digest
 158                         gnutls_hash_hd_t is_digest;
 159                         if (gnutls_hash_init(&is_digest, hash) < 0)
 160                                 throw Exception("Unknown hash type " + hashname);
 161                         gnutls_hash_deinit(is_digest, NULL);
 162 #else
 163                         if (hashname == "md5")
 164                                 hash = GNUTLS_DIG_MD5;
 165                         else if (hashname == "sha1")
 166                                 hash = GNUTLS_DIG_SHA1;
 167 #ifdef INSPIRCD_GNUTLS_ENABLE_SHA256_FINGERPRINT
 168                         else if (hashname == "sha256")
 169                                 hash = GNUTLS_DIG_SHA256;
 170 #endif
 171                         else
 172                                 throw Exception("Unknown hash type " + hashname);
 173 #endif
 174                 }
 175
 176                 gnutls_digest_algorithm_t get() const { return hash; }
 177         };
 178
 179         class DHParams
 180         {
 181                 gnutls_dh_params_t dh_params;
 182
 183                 DHParams()
 184                 {
 185                         ThrowOnError(gnutls_dh_params_init(&dh_params), "gnutls_dh_params_init() failed");
 186                 }
 187
 188          public:
 189                 /** Import */
 190                 static std::auto_ptr<DHParams> Import(const std::string& dhstr)
 191                 {
 192                         std::auto_ptr<DHParams> dh(new DHParams);
 193                         int ret = gnutls_dh_params_import_pkcs3(dh->dh_params, Datum(dhstr).get(), GNUTLS_X509_FMT_PEM);
 194                         ThrowOnError(ret, "Unable to import DH params");
 195                         return dh;
 196                 }
 197
 198                 /** Generate */
 199                 static std::auto_ptr<DHParams> Generate(unsigned int bits)
 200                 {
 201                         std::auto_ptr<DHParams> dh(new DHParams);
 202                         ThrowOnError(gnutls_dh_params_generate2(dh->dh_params, bits), "Unable to generate DH params");
 203                         return dh;
 204                 }
 205
 206                 ~DHParams()
 207                 {
 208                         gnutls_dh_params_deinit(dh_params);
 209                 }
 210
 211                 const gnutls_dh_params_t& get() const { return dh_params; }
 212         };
 213
 214         class X509Key
 215         {
 216                 /** Ensure that the key is deinited in case the constructor of X509Key throws
 217                  */
 218                 class RAIIKey
 219                 {
 220                  public:
 221                         gnutls_x509_privkey_t key;
 222
 223                         RAIIKey()
 224                         {
 225                                 ThrowOnError(gnutls_x509_privkey_init(&key), "gnutls_x509_privkey_init() failed");
 226                         }
 227
 228                         ~RAIIKey()
 229                         {
 230                                 gnutls_x509_privkey_deinit(key);
 231                         }
 232                 } key;
 233
 234          public:
 235                 /** Import */
 236                 X509Key(const std::string& keystr)
 237                 {
 238                         int ret = gnutls_x509_privkey_import(key.key, Datum(keystr).get(), GNUTLS_X509_FMT_PEM);
 239                         ThrowOnError(ret, "Unable to import private key");
 240                 }
 241
 242                 gnutls_x509_privkey_t& get() { return key.key; }
 243         };
 244
 245         class X509CertList
 246         {
 247                 std::vector<gnutls_x509_crt_t> certs;
 248
 249          public:
 250                 /** Import */
 251                 X509CertList(const std::string& certstr)
 252                 {
 253                         unsigned int certcount = 3;
 254                         certs.resize(certcount);
 255                         Datum datum(certstr);
 256
 257                         int ret = gnutls_x509_crt_list_import(raw(), &certcount, datum.get(), GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 258                         if (ret == GNUTLS_E_SHORT_MEMORY_BUFFER)
 259                         {
 260                                 // the buffer wasn't big enough to hold all certs but gnutls changed certcount to the number of available certs,
 261                                 // try again with a bigger buffer
 262                                 certs.resize(certcount);
 263                                 ret = gnutls_x509_crt_list_import(raw(), &certcount, datum.get(), GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 264                         }
 265
 266                         ThrowOnError(ret, "Unable to load certificates");
 267
 268                         // Resize the vector to the actual number of certs because we rely on its size being correct
 269                         // when deallocating the certs
 270                         certs.resize(certcount);
 271                 }
 272
 273                 ~X509CertList()
 274                 {
 275                         for (std::vector<gnutls_x509_crt_t>::iterator i = certs.begin(); i != certs.end(); ++i)
 276                                 gnutls_x509_crt_deinit(*i);
 277                 }
 278
 279                 gnutls_x509_crt_t* raw() { return &certs[0]; }
 280                 unsigned int size() const { return certs.size(); }
 281         };
 282
 283         class X509CRL : public refcountbase
 284         {
 285                 class RAIICRL
 286                 {
 287                  public:
 288                         gnutls_x509_crl_t crl;
 289
 290                         RAIICRL()
 291                         {
 292                                 ThrowOnError(gnutls_x509_crl_init(&crl), "gnutls_x509_crl_init() failed");
 293                         }
 294
 295                         ~RAIICRL()
 296                         {
 297                                 gnutls_x509_crl_deinit(crl);
 298                         }
 299                 } crl;
 300
 301          public:
 302                 /** Import */
 303                 X509CRL(const std::string& crlstr)
 304                 {
 305                         int ret = gnutls_x509_crl_import(get(), Datum(crlstr).get(), GNUTLS_X509_FMT_PEM);
 306                         ThrowOnError(ret, "Unable to load certificate revocation list");
 307                 }
 308
 309                 gnutls_x509_crl_t& get() { return crl.crl; }
 310         };
 311
 312 #ifdef GNUTLS_NEW_PRIO_API
 313         class Priority
 314         {
 315                 gnutls_priority_t priority;
 316
 317          public:
 318                 Priority(const std::string& priorities)
 319                 {
 320                         // Try to set the priorities for ciphers, kex methods etc. to the user supplied string
 321                         // If the user did not supply anything then the string is already set to "NORMAL"
 322                         const char* priocstr = priorities.c_str();
 323                         const char* prioerror;
 324
 325                         int ret = gnutls_priority_init(&priority, priocstr, &prioerror);
 326                         if (ret < 0)
 327                         {
 328                                 // gnutls did not understand the user supplied string
 329                                 throw Exception("Unable to initialize priorities to \"" + priorities + "\": " + gnutls_strerror(ret) + " Syntax error at position " + ConvToStr((unsigned int) (prioerror - priocstr)));
 330                         }
 331                 }
 332
 333                 ~Priority()
 334                 {
 335                         gnutls_priority_deinit(priority);
 336                 }
 337
 338                 void SetupSession(gnutls_session_t sess)
 339                 {
 340                         gnutls_priority_set(sess, priority);
 341                 }
 342         };
 343 #else
 344         /** Dummy class, used when gnutls_priority_set() is not available
 345          */
 346         class Priority
 347         {
 348          public:
 349                 Priority(const std::string& priorities)
 350                 {
 351                         if (priorities != "NORMAL")
 352                                 throw Exception("You've set a non-default priority string, but GnuTLS lacks support for it");
 353                 }
 354
 355                 static void SetupSession(gnutls_session_t sess)
 356                 {
 357                         // Always set the default priorities
 358                         gnutls_set_default_priority(sess);
 359                 }
 360         };
 361 #endif
 362
 363         class CertCredentials
 364         {
 365                 /** DH parameters associated with these credentials
 366                  */
 367                 std::auto_ptr<DHParams> dh;
 368
 369          protected:
 370                 gnutls_certificate_credentials_t cred;
 371
 372          public:
 373                 CertCredentials()
 374                 {
 375                         ThrowOnError(gnutls_certificate_allocate_credentials(&cred), "Cannot allocate certificate credentials");
 376                 }
 377
 378                 ~CertCredentials()
 379                 {
 380                         gnutls_certificate_free_credentials(cred);
 381                 }
 382
 383                 /** Associates these credentials with the session
 384                  */
 385                 void SetupSession(gnutls_session_t sess)
 386                 {
 387                         gnutls_credentials_set(sess, GNUTLS_CRD_CERTIFICATE, cred);
 388                 }
 389
 390                 /** Set the given DH parameters to be used with these credentials
 391                  */
 392                 void SetDH(std::auto_ptr<DHParams>& DH)
 393                 {
 394                         dh = DH;
 395                         gnutls_certificate_set_dh_params(cred, dh->get());
 396                 }
 397         };
 398
 399         class X509Credentials : public CertCredentials
 400         {
 401                 /** Private key
 402                  */
 403                 X509Key key;
 404
 405                 /** Certificate list, presented to the peer
 406                  */
 407                 X509CertList certs;
 408
 409                 /** Trusted CA, may be NULL
 410                  */
 411                 std::auto_ptr<X509CertList> trustedca;
 412
 413                 /** Certificate revocation list, may be NULL
 414                  */
 415                 std::auto_ptr<X509CRL> crl;
 416
 417                 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);
 418
 419          public:
 420                 X509Credentials(const std::string& certstr, const std::string& keystr)
 421                         : key(keystr)
 422                         , certs(certstr)
 423                 {
 424                         // Throwing is ok here, the destructor of Credentials is called in that case
 425                         int ret = gnutls_certificate_set_x509_key(cred, certs.raw(), certs.size(), key.get());
 426                         ThrowOnError(ret, "Unable to set cert/key pair");
 427
 428 #ifdef GNUTLS_NEW_CERT_CALLBACK_API
 429                         gnutls_certificate_set_retrieve_function(cred, cert_callback);
 430 #else
 431                         gnutls_certificate_client_set_retrieve_function(cred, cert_callback);
 432 #endif
 433                 }
 434
 435                 /** Sets the trusted CA and the certificate revocation list
 436                  * to use when verifying certificates
 437                  */
 438                 void SetCA(std::auto_ptr<X509CertList>& certlist, std::auto_ptr<X509CRL>& CRL)
 439                 {
 440                         // Do nothing if certlist is NULL
 441                         if (certlist.get())
 442                         {
 443                                 int ret = gnutls_certificate_set_x509_trust(cred, certlist->raw(), certlist->size());
 444                                 ThrowOnError(ret, "gnutls_certificate_set_x509_trust() failed");
 445
 446                                 if (CRL.get())
 447                                 {
 448                                         ret = gnutls_certificate_set_x509_crl(cred, &CRL->get(), 1);
 449                                         ThrowOnError(ret, "gnutls_certificate_set_x509_crl() failed");
 450                                 }
 451
 452                                 trustedca = certlist;
 453                                 crl = CRL;
 454                         }
 455                 }
 456         };
 457
 458         class DataReader
 459         {
 460                 int retval;
 461 #ifdef INSPIRCD_GNUTLS_HAS_RECV_PACKET
 462                 gnutls_packet_t packet;
 463
 464          public:
 465                 DataReader(gnutls_session_t sess)
 466                 {
 467                         // Using the packet API avoids the final copy of the data which GnuTLS does if we supply
 468                         // our own buffer. Instead, we get the buffer containing the data from GnuTLS and copy it
 469                         // to the recvq directly from there in appendto().
 470                         retval = gnutls_record_recv_packet(sess, &packet);
 471                 }
 472
 473                 void appendto(std::string& recvq)
 474                 {
 475                         // Copy data from GnuTLS buffers to recvq
 476                         gnutls_datum_t datum;
 477                         gnutls_packet_get(packet, &datum, NULL);
 478                         recvq.append(reinterpret_cast<const char*>(datum.data), datum.size);
 479
 480                         gnutls_packet_deinit(packet);
 481                 }
 482 #else
 483                 char* const buffer;
 484
 485          public:
 486                 DataReader(gnutls_session_t sess)
 487                         : buffer(ServerInstance->GetReadBuffer())
 488                 {
 489                         // Read data from GnuTLS buffers into ReadBuffer
 490                         retval = gnutls_record_recv(sess, buffer, ServerInstance->Config->NetBufferSize);
 491                 }
 492
 493                 void appendto(std::string& recvq)
 494                 {
 495                         // Copy data from ReadBuffer to recvq
 496                         recvq.append(buffer, retval);
 497                 }
 498 #endif
 499
 500                 int ret() const { return retval; }
 501         };
 502
 503         class Profile : public refcountbase
 504         {
 505                 /** Name of this profile
 506                  */
 507                 const std::string name;
 508
 509                 /** X509 certificate(s) and key
 510                  */
 511                 X509Credentials x509cred;
 512
 513                 /** The minimum length in bits for the DH prime to be accepted as a client
 514                  */
 515                 unsigned int min_dh_bits;
 516
 517                 /** Hashing algorithm to use when generating certificate fingerprints
 518                  */
 519                 Hash hash;
 520
 521                 /** Priorities for ciphers, compression methods, etc.
 522                  */
 523                 Priority priority;
 524
 525                 Profile(const std::string& profilename, const std::string& certstr, const std::string& keystr,
 526                                 std::auto_ptr<DHParams>& DH, unsigned int mindh, const std::string& hashstr,
 527                                 const std::string& priostr, std::auto_ptr<X509CertList>& CA, std::auto_ptr<X509CRL>& CRL)
 528                         : name(profilename)
 529                         , x509cred(certstr, keystr)
 530                         , min_dh_bits(mindh)
 531                         , hash(hashstr)
 532                         , priority(priostr)
 533                 {
 534                         x509cred.SetDH(DH);
 535                         x509cred.SetCA(CA, CRL);
 536                 }
 537
 538                 static std::string ReadFile(const std::string& filename)
 539                 {
 540                         FileReader reader(filename);
 541                         std::string ret = reader.GetString();
 542                         if (ret.empty())
 543                                 throw Exception("Cannot read file " + filename);
 544                         return ret;
 545                 }
 546
 547          public:
 548                 static reference<Profile> Create(const std::string& profilename, ConfigTag* tag)
 549                 {
 550                         std::string certstr = ReadFile(tag->getString("certfile", "cert.pem"));
 551                         std::string keystr = ReadFile(tag->getString("keyfile", "key.pem"));
 552
 553                         std::auto_ptr<DHParams> dh;
 554                         int gendh = tag->getInt("gendh");
 555                         if (gendh)
 556                         {
 557                                 gendh = (gendh < 1024 ? 1024 : gendh);
 558                                 dh = DHParams::Generate(gendh);
 559                         }
 560                         else
 561                                 dh = DHParams::Import(ReadFile(tag->getString("dhfile", "dhparams.pem")));
 562
 563                         // Use default priority string if this tag does not specify one
 564                         std::string priostr = tag->getString("priority", "NORMAL");
 565                         unsigned int mindh = tag->getInt("mindhbits", 1024);
 566                         std::string hashstr = tag->getString("hash", "md5");
 567
 568                         // Load trusted CA and revocation list, if set
 569                         std::auto_ptr<X509CertList> ca;
 570                         std::auto_ptr<X509CRL> crl;
 571                         std::string filename = tag->getString("cafile");
 572                         if (!filename.empty())
 573                         {
 574                                 ca.reset(new X509CertList(ReadFile(filename)));
 575
 576                                 filename = tag->getString("crlfile");
 577                                 if (!filename.empty())
 578                                         crl.reset(new X509CRL(ReadFile(filename)));
 579                         }
 580
 581                         return new Profile(profilename, certstr, keystr, dh, mindh, hashstr, priostr, ca, crl);
 582                 }
 583
 584                 /** Set up the given session with the settings in this profile
 585                  */
 586                 void SetupSession(gnutls_session_t sess)
 587                 {
 588                         priority.SetupSession(sess);
 589                         x509cred.SetupSession(sess);
 590                         gnutls_dh_set_prime_bits(sess, min_dh_bits);
 591                 }
 592
 593                 const std::string& GetName() const { return name; }
 594                 X509Credentials& GetX509Credentials() { return x509cred; }
 595                 gnutls_digest_algorithm_t GetHash() const { return hash.get(); }
 596         };
 597 }
 598
 599 class GnuTLSIOHook : public SSLIOHook
 600 {
 601  private:
 602         gnutls_session_t sess;
 603         issl_status status;
 604         reference<GnuTLS::Profile> profile;
 605
 606         void InitSession(StreamSocket* user, bool me_server)
 607         {
 608                 gnutls_init(&sess, me_server ? GNUTLS_SERVER : GNUTLS_CLIENT);
 609
 610                 profile->SetupSession(sess);
 611                 gnutls_transport_set_ptr(sess, reinterpret_cast<gnutls_transport_ptr_t>(user));
 612                 gnutls_transport_set_push_function(sess, gnutls_push_wrapper);
 613                 gnutls_transport_set_pull_function(sess, gnutls_pull_wrapper);
 614
 615                 if (me_server)
 616                         gnutls_certificate_server_set_request(sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
 617         }
 618
 619         void CloseSession()
 620         {
 621                 if (this->sess)
 622                 {
 623                         gnutls_bye(this->sess, GNUTLS_SHUT_WR);
 624                         gnutls_deinit(this->sess);
 625                 }
 626                 sess = NULL;
 627                 certificate = NULL;
 628                 status = ISSL_NONE;
 629         }
 630
 631         // Returns 1 if handshake succeeded, 0 if it is still in progress, -1 if it failed
 632         int Handshake(StreamSocket* user)
 633         {
 634                 int ret = gnutls_handshake(this->sess);
 635
 636                 if (ret < 0)
 637                 {
 638                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 639                         {
 640                                 // Handshake needs resuming later, read() or write() would have blocked.
 641                                 this->status = ISSL_HANDSHAKING;
 642
 643                                 if (gnutls_record_get_direction(this->sess) == 0)
 644                                 {
 645                                         // gnutls_handshake() wants to read() again.
 646                                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 647                                 }
 648                                 else
 649                                 {
 650                                         // gnutls_handshake() wants to write() again.
 651                                         SocketEngine::ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 652                                 }
 653
 654                                 return 0;
 655                         }
 656                         else
 657                         {
 658                                 user->SetError("Handshake Failed - " + std::string(gnutls_strerror(ret)));
 659                                 CloseSession();
 660                                 return -1;
 661                         }
 662                 }
 663                 else
 664                 {
 665                         // Change the seesion state
 666                         this->status = ISSL_HANDSHAKEN;
 667
 668                         VerifyCertificate();
 669
 670                         // Finish writing, if any left
 671                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 672
 673                         return 1;
 674                 }
 675         }
 676
 677         void VerifyCertificate()
 678         {
 679                 unsigned int certstatus;
 680                 const gnutls_datum_t* cert_list;
 681                 int ret;
 682                 unsigned int cert_list_size;
 683                 gnutls_x509_crt_t cert;
 684                 char str[512];
 685                 unsigned char digest[512];
 686                 size_t digest_size = sizeof(digest);
 687                 size_t name_size = sizeof(str);
 688                 ssl_cert* certinfo = new ssl_cert;
 689                 this->certificate = certinfo;
 690
 691                 /* This verification function uses the trusted CAs in the credentials
 692                  * structure. So you must have installed one or more CA certificates.
 693                  */
 694                 ret = gnutls_certificate_verify_peers2(this->sess, &certstatus);
 695
 696                 if (ret < 0)
 697                 {
 698                         certinfo->error = std::string(gnutls_strerror(ret));
 699                         return;
 700                 }
 701
 702                 certinfo->invalid = (certstatus & GNUTLS_CERT_INVALID);
 703                 certinfo->unknownsigner = (certstatus & GNUTLS_CERT_SIGNER_NOT_FOUND);
 704                 certinfo->revoked = (certstatus & GNUTLS_CERT_REVOKED);
 705                 certinfo->trusted = !(certstatus & GNUTLS_CERT_SIGNER_NOT_CA);
 706
 707                 /* Up to here the process is the same for X.509 certificates and
 708                  * OpenPGP keys. From now on X.509 certificates are assumed. This can
 709                  * be easily extended to work with openpgp keys as well.
 710                  */
 711                 if (gnutls_certificate_type_get(this->sess) != GNUTLS_CRT_X509)
 712                 {
 713                         certinfo->error = "No X509 keys sent";
 714                         return;
 715                 }
 716
 717                 ret = gnutls_x509_crt_init(&cert);
 718                 if (ret < 0)
 719                 {
 720                         certinfo->error = gnutls_strerror(ret);
 721                         return;
 722                 }
 723
 724                 cert_list_size = 0;
 725                 cert_list = gnutls_certificate_get_peers(this->sess, &cert_list_size);
 726                 if (cert_list == NULL)
 727                 {
 728                         certinfo->error = "No certificate was found";
 729                         goto info_done_dealloc;
 730                 }
 731
 732                 /* This is not a real world example, since we only check the first
 733                  * certificate in the given chain.
 734                  */
 735
 736                 ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
 737                 if (ret < 0)
 738                 {
 739                         certinfo->error = gnutls_strerror(ret);
 740                         goto info_done_dealloc;
 741                 }
 742
 743                 if (gnutls_x509_crt_get_dn(cert, str, &name_size) == 0)
 744                 {
 745                         std::string& dn = certinfo->dn;
 746                         dn = str;
 747                         // Make sure there are no chars in the string that we consider invalid
 748                         if (dn.find_first_of("\r\n") != std::string::npos)
 749                                 dn.clear();
 750                 }
 751
 752                 name_size = sizeof(str);
 753                 if (gnutls_x509_crt_get_issuer_dn(cert, str, &name_size) == 0)
 754                 {
 755                         std::string& issuer = certinfo->issuer;
 756                         issuer = str;
 757                         if (issuer.find_first_of("\r\n") != std::string::npos)
 758                                 issuer.clear();
 759                 }
 760
 761                 if ((ret = gnutls_x509_crt_get_fingerprint(cert, profile->GetHash(), digest, &digest_size)) < 0)
 762                 {
 763                         certinfo->error = gnutls_strerror(ret);
 764                 }
 765                 else
 766                 {
 767                         certinfo->fingerprint = BinToHex(digest, digest_size);
 768                 }
 769
 770                 /* Beware here we do not check for errors.
 771                  */
 772                 if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
 773                 {
 774                         certinfo->error = "Not activated, or expired certificate";
 775                 }
 776
 777 info_done_dealloc:
 778                 gnutls_x509_crt_deinit(cert);
 779         }
 780
 781         static const char* UnknownIfNULL(const char* str)
 782         {
 783                 return str ? str : "UNKNOWN";
 784         }
 785
 786         static ssize_t gnutls_pull_wrapper(gnutls_transport_ptr_t session_wrap, void* buffer, size_t size)
 787         {
 788                 StreamSocket* sock = reinterpret_cast<StreamSocket*>(session_wrap);
 789 #ifdef _WIN32
 790                 GnuTLSIOHook* session = static_cast<GnuTLSIOHook*>(sock->GetIOHook());
 791 #endif
 792
 793                 if (sock->GetEventMask() & FD_READ_WILL_BLOCK)
 794                 {
 795 #ifdef _WIN32
 796                         gnutls_transport_set_errno(session->sess, EAGAIN);
 797 #else
 798                         errno = EAGAIN;
 799 #endif
 800                         return -1;
 801                 }
 802
 803                 int rv = SocketEngine::Recv(sock, reinterpret_cast<char *>(buffer), size, 0);
 804
 805 #ifdef _WIN32
 806                 if (rv < 0)
 807                 {
 808                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 809                          * and then set errno appropriately.
 810                          * The gnutls library may also have a different errno variable than us, see
 811                          * gnutls_transport_set_errno(3).
 812                          */
 813                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 814                 }
 815 #endif
 816
 817                 if (rv < (int)size)
 818                         SocketEngine::ChangeEventMask(sock, FD_READ_WILL_BLOCK);
 819                 return rv;
 820         }
 821
 822         static ssize_t gnutls_push_wrapper(gnutls_transport_ptr_t session_wrap, const void* buffer, size_t size)
 823         {
 824                 StreamSocket* sock = reinterpret_cast<StreamSocket*>(session_wrap);
 825 #ifdef _WIN32
 826                 GnuTLSIOHook* session = static_cast<GnuTLSIOHook*>(sock->GetIOHook());
 827 #endif
 828
 829                 if (sock->GetEventMask() & FD_WRITE_WILL_BLOCK)
 830                 {
 831 #ifdef _WIN32
 832                         gnutls_transport_set_errno(session->sess, EAGAIN);
 833 #else
 834                         errno = EAGAIN;
 835 #endif
 836                         return -1;
 837                 }
 838
 839                 int rv = SocketEngine::Send(sock, reinterpret_cast<const char *>(buffer), size, 0);
 840
 841 #ifdef _WIN32
 842                 if (rv < 0)
 843                 {
 844                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 845                          * and then set errno appropriately.
 846                          * The gnutls library may also have a different errno variable than us, see
 847                          * gnutls_transport_set_errno(3).
 848                          */
 849                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 850                 }
 851 #endif
 852
 853                 if (rv < (int)size)
 854                         SocketEngine::ChangeEventMask(sock, FD_WRITE_WILL_BLOCK);
 855                 return rv;
 856         }
 857
 858  public:
 859         GnuTLSIOHook(IOHookProvider* hookprov, StreamSocket* sock, bool outbound, const reference<GnuTLS::Profile>& sslprofile)
 860                 : SSLIOHook(hookprov)
 861                 , sess(NULL)
 862                 , status(ISSL_NONE)
 863                 , profile(sslprofile)
 864         {
 865                 InitSession(sock, outbound);
 866                 sock->AddIOHook(this);
 867                 Handshake(sock);
 868         }
 869
 870         void OnStreamSocketClose(StreamSocket* user) CXX11_OVERRIDE
 871         {
 872                 CloseSession();
 873         }
 874
 875         int OnStreamSocketRead(StreamSocket* user, std::string& recvq) CXX11_OVERRIDE
 876         {
 877                 if (!this->sess)
 878                 {
 879                         CloseSession();
 880                         user->SetError("No SSL session");
 881                         return -1;
 882                 }
 883
 884                 if (this->status == ISSL_HANDSHAKING)
 885                 {
 886                         // The handshake isn't finished, try to finish it.
 887                         int ret = Handshake(user);
 888                         if (ret <= 0)
 889                                 return ret;
 890                 }
 891
 892                 // If we resumed the handshake then this->status will be ISSL_HANDSHAKEN.
 893                 {
 894                         GnuTLS::DataReader reader(sess);
 895                         int ret = reader.ret();
 896                         if (ret > 0)
 897                         {
 898                                 reader.appendto(recvq);
 899                                 return 1;
 900                         }
 901                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 902                         {
 903                                 return 0;
 904                         }
 905                         else if (ret == 0)
 906                         {
 907                                 user->SetError("Connection closed");
 908                                 CloseSession();
 909                                 return -1;
 910                         }
 911                         else
 912                         {
 913                                 user->SetError(gnutls_strerror(ret));
 914                                 CloseSession();
 915                                 return -1;
 916                         }
 917                 }
 918         }
 919
 920         int OnStreamSocketWrite(StreamSocket* user, std::string& sendq) CXX11_OVERRIDE
 921         {
 922                 if (!this->sess)
 923                 {
 924                         CloseSession();
 925                         user->SetError("No SSL session");
 926                         return -1;
 927                 }
 928
 929                 if (this->status == ISSL_HANDSHAKING)
 930                 {
 931                         // The handshake isn't finished, try to finish it.
 932                         int ret = Handshake(user);
 933                         if (ret <= 0)
 934                                 return ret;
 935                 }
 936
 937                 // Session is ready for transferring application data
 938                 int ret = 0;
 939
 940                 {
 941                         ret = gnutls_record_send(this->sess, sendq.data(), sendq.length());
 942
 943                         if (ret == (int)sendq.length())
 944                         {
 945                                 SocketEngine::ChangeEventMask(user, FD_WANT_NO_WRITE);
 946                                 return 1;
 947                         }
 948                         else if (ret > 0)
 949                         {
 950                                 sendq.erase(0, ret);
 951                                 SocketEngine::ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 952                                 return 0;
 953                         }
 954                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED || ret == 0)
 955                         {
 956                                 SocketEngine::ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 957                                 return 0;
 958                         }
 959                         else // (ret < 0)
 960                         {
 961                                 user->SetError(gnutls_strerror(ret));
 962                                 CloseSession();
 963                                 return -1;
 964                         }
 965                 }
 966         }
 967
 968         void TellCiphersAndFingerprint(LocalUser* user)
 969         {
 970                 if (sess)
 971                 {
 972                         std::string text = "*** You are connected using SSL cipher '";
 973                         GetCiphersuite(text);
 974                         text += '\'';
 975                         if (!certificate->fingerprint.empty())
 976                                 text += " and your SSL certificate fingerprint is " + certificate->fingerprint;
 977
 978                         user->WriteNotice(text);
 979                 }
 980         }
 981
 982         void GetCiphersuite(std::string& out) const
 983         {
 984                 out.append(UnknownIfNULL(gnutls_protocol_get_name(gnutls_protocol_get_version(sess)))).push_back('-');
 985                 out.append(UnknownIfNULL(gnutls_kx_get_name(gnutls_kx_get(sess)))).push_back('-');
 986                 out.append(UnknownIfNULL(gnutls_cipher_get_name(gnutls_cipher_get(sess)))).push_back('-');
 987                 out.append(UnknownIfNULL(gnutls_mac_get_name(gnutls_mac_get(sess))));
 988         }
 989
 990         GnuTLS::Profile* GetProfile() { return profile; }
 991 };
 992
 993 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)
 994 {
 995 #ifndef GNUTLS_NEW_CERT_CALLBACK_API
 996         st->type = GNUTLS_CRT_X509;
 997 #else
 998         st->cert_type = GNUTLS_CRT_X509;
 999         st->key_type = GNUTLS_PRIVKEY_X509;
1000 #endif
1001         StreamSocket* sock = reinterpret_cast<StreamSocket*>(gnutls_transport_get_ptr(sess));
1002         GnuTLS::X509Credentials& cred = static_cast<GnuTLSIOHook*>(sock->GetIOHook())->GetProfile()->GetX509Credentials();
1003
1004         st->ncerts = cred.certs.size();
1005         st->cert.x509 = cred.certs.raw();
1006         st->key.x509 = cred.key.get();
1007         st->deinit_all = 0;
1008
1009         return 0;
1010 }
1011
1012 class GnuTLSIOHookProvider : public refcountbase, public IOHookProvider
1013 {
1014         reference<GnuTLS::Profile> profile;
1015
1016  public:
1017         GnuTLSIOHookProvider(Module* mod, reference<GnuTLS::Profile>& prof)
1018                 : IOHookProvider(mod, "ssl/" + prof->GetName(), IOHookProvider::IOH_SSL)
1019                 , profile(prof)
1020         {
1021                 ServerInstance->Modules->AddService(*this);
1022         }
1023
1024         ~GnuTLSIOHookProvider()
1025         {
1026                 ServerInstance->Modules->DelService(*this);
1027         }
1028
1029         void OnAccept(StreamSocket* sock, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server) CXX11_OVERRIDE
1030         {
1031                 new GnuTLSIOHook(this, sock, true, profile);
1032         }
1033
1034         void OnConnect(StreamSocket* sock) CXX11_OVERRIDE
1035         {
1036                 new GnuTLSIOHook(this, sock, false, profile);
1037         }
1038 };
1039
1040 class ModuleSSLGnuTLS : public Module
1041 {
1042         typedef std::vector<reference<GnuTLSIOHookProvider> > ProfileList;
1043
1044         // First member of the class, gets constructed first and destructed last
1045         GnuTLS::Init libinit;
1046         RandGen randhandler;
1047         ProfileList profiles;
1048
1049         void ReadProfiles()
1050         {
1051                 // First, store all profiles in a new, temporary container. If no problems occur, swap the two
1052                 // containers; this way if something goes wrong we can go back and continue using the current profiles,
1053                 // avoiding unpleasant situations where no new SSL connections are possible.
1054                 ProfileList newprofiles;
1055
1056                 ConfigTagList tags = ServerInstance->Config->ConfTags("sslprofile");
1057                 if (tags.first == tags.second)
1058                 {
1059                         // No <sslprofile> tags found, create a profile named "gnutls" from settings in the <gnutls> block
1060                         const std::string defname = "gnutls";
1061                         ConfigTag* tag = ServerInstance->Config->ConfValue(defname);
1062                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "No <sslprofile> tags found; using settings from the <gnutls> tag");
1063
1064                         try
1065                         {
1066                                 reference<GnuTLS::Profile> profile(GnuTLS::Profile::Create(defname, tag));
1067                                 newprofiles.push_back(new GnuTLSIOHookProvider(this, profile));
1068                         }
1069                         catch (CoreException& ex)
1070                         {
1071                                 throw ModuleException("Error while initializing the default SSL profile - " + ex.GetReason());
1072                         }
1073                 }
1074
1075                 for (ConfigIter i = tags.first; i != tags.second; ++i)
1076                 {
1077                         ConfigTag* tag = i->second;
1078                         if (tag->getString("provider") != "gnutls")
1079                                 continue;
1080
1081                         std::string name = tag->getString("name");
1082                         if (name.empty())
1083                         {
1084                                 ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Ignoring <sslprofile> tag without name at " + tag->getTagLocation());
1085                                 continue;
1086                         }
1087
1088                         reference<GnuTLS::Profile> profile;
1089                         try
1090                         {
1091                                 profile = GnuTLS::Profile::Create(name, tag);
1092                         }
1093                         catch (CoreException& ex)
1094                         {
1095                                 throw ModuleException("Error while initializing SSL profile \"" + name + "\" at " + tag->getTagLocation() + " - " + ex.GetReason());
1096                         }
1097
1098                         newprofiles.push_back(new GnuTLSIOHookProvider(this, profile));
1099                 }
1100
1101                 // New profiles are ok, begin using them
1102                 // Old profiles are deleted when their refcount drops to zero
1103                 profiles.swap(newprofiles);
1104         }
1105
1106  public:
1107         ModuleSSLGnuTLS()
1108         {
1109 #ifndef GNUTLS_HAS_RND
1110                 gcry_control (GCRYCTL_INITIALIZATION_FINISHED, 0);
1111 #endif
1112         }
1113
1114         void init() CXX11_OVERRIDE
1115         {
1116                 ReadProfiles();
1117                 ServerInstance->GenRandom = &randhandler;
1118         }
1119
1120         void OnModuleRehash(User* user, const std::string &param) CXX11_OVERRIDE
1121         {
1122                 if(param != "ssl")
1123                         return;
1124
1125                 try
1126                 {
1127                         ReadProfiles();
1128                 }
1129                 catch (ModuleException& ex)
1130                 {
1131                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, ex.GetReason() + " Not applying settings.");
1132                 }
1133         }
1134
1135         ~ModuleSSLGnuTLS()
1136         {
1137                 ServerInstance->GenRandom = &ServerInstance->HandleGenRandom;
1138         }
1139
1140         void OnCleanup(int target_type, void* item) CXX11_OVERRIDE
1141         {
1142                 if(target_type == TYPE_USER)
1143                 {
1144                         LocalUser* user = IS_LOCAL(static_cast<User*>(item));
1145
1146                         if (user && user->eh.GetIOHook() && user->eh.GetIOHook()->prov->creator == this)
1147                         {
1148                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
1149                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
1150                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
1151                         }
1152                 }
1153         }
1154
1155         Version GetVersion() CXX11_OVERRIDE
1156         {
1157                 return Version("Provides SSL support for clients", VF_VENDOR);
1158         }
1159
1160         void OnUserConnect(LocalUser* user) CXX11_OVERRIDE
1161         {
1162                 IOHook* hook = user->eh.GetIOHook();
1163                 if (hook && hook->prov->creator == this)
1164                         static_cast<GnuTLSIOHook*>(hook)->TellCiphersAndFingerprint(user);
1165         }
1166 };
1167
1168 MODULE_INIT(ModuleSSLGnuTLS)