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, 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 #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         bool Handshake(StreamSocket* user)
 632         {
 633                 int ret = gnutls_handshake(this->sess);
 634
 635                 if (ret < 0)
 636                 {
 637                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 638                         {
 639                                 // Handshake needs resuming later, read() or write() would have blocked.
 640                                 this->status = ISSL_HANDSHAKING;
 641
 642                                 if (gnutls_record_get_direction(this->sess) == 0)
 643                                 {
 644                                         // gnutls_handshake() wants to read() again.
 645                                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 646                                 }
 647                                 else
 648                                 {
 649                                         // gnutls_handshake() wants to write() again.
 650                                         SocketEngine::ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 651                                 }
 652                         }
 653                         else
 654                         {
 655                                 user->SetError("Handshake Failed - " + std::string(gnutls_strerror(ret)));
 656                                 CloseSession();
 657                                 this->status = ISSL_CLOSING;
 658                         }
 659
 660                         return false;
 661                 }
 662                 else
 663                 {
 664                         // Change the seesion state
 665                         this->status = ISSL_HANDSHAKEN;
 666
 667                         VerifyCertificate();
 668
 669                         // Finish writing, if any left
 670                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 671
 672                         return true;
 673                 }
 674         }
 675
 676         void VerifyCertificate()
 677         {
 678                 unsigned int certstatus;
 679                 const gnutls_datum_t* cert_list;
 680                 int ret;
 681                 unsigned int cert_list_size;
 682                 gnutls_x509_crt_t cert;
 683                 char str[512];
 684                 unsigned char digest[512];
 685                 size_t digest_size = sizeof(digest);
 686                 size_t name_size = sizeof(str);
 687                 ssl_cert* certinfo = new ssl_cert;
 688                 this->certificate = certinfo;
 689
 690                 /* This verification function uses the trusted CAs in the credentials
 691                  * structure. So you must have installed one or more CA certificates.
 692                  */
 693                 ret = gnutls_certificate_verify_peers2(this->sess, &certstatus);
 694
 695                 if (ret < 0)
 696                 {
 697                         certinfo->error = std::string(gnutls_strerror(ret));
 698                         return;
 699                 }
 700
 701                 certinfo->invalid = (certstatus & GNUTLS_CERT_INVALID);
 702                 certinfo->unknownsigner = (certstatus & GNUTLS_CERT_SIGNER_NOT_FOUND);
 703                 certinfo->revoked = (certstatus & GNUTLS_CERT_REVOKED);
 704                 certinfo->trusted = !(certstatus & GNUTLS_CERT_SIGNER_NOT_CA);
 705
 706                 /* Up to here the process is the same for X.509 certificates and
 707                  * OpenPGP keys. From now on X.509 certificates are assumed. This can
 708                  * be easily extended to work with openpgp keys as well.
 709                  */
 710                 if (gnutls_certificate_type_get(this->sess) != GNUTLS_CRT_X509)
 711                 {
 712                         certinfo->error = "No X509 keys sent";
 713                         return;
 714                 }
 715
 716                 ret = gnutls_x509_crt_init(&cert);
 717                 if (ret < 0)
 718                 {
 719                         certinfo->error = gnutls_strerror(ret);
 720                         return;
 721                 }
 722
 723                 cert_list_size = 0;
 724                 cert_list = gnutls_certificate_get_peers(this->sess, &cert_list_size);
 725                 if (cert_list == NULL)
 726                 {
 727                         certinfo->error = "No certificate was found";
 728                         goto info_done_dealloc;
 729                 }
 730
 731                 /* This is not a real world example, since we only check the first
 732                  * certificate in the given chain.
 733                  */
 734
 735                 ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
 736                 if (ret < 0)
 737                 {
 738                         certinfo->error = gnutls_strerror(ret);
 739                         goto info_done_dealloc;
 740                 }
 741
 742                 if (gnutls_x509_crt_get_dn(cert, str, &name_size) == 0)
 743                 {
 744                         std::string& dn = certinfo->dn;
 745                         dn = str;
 746                         // Make sure there are no chars in the string that we consider invalid
 747                         if (dn.find_first_of("\r\n") != std::string::npos)
 748                                 dn.clear();
 749                 }
 750
 751                 name_size = sizeof(str);
 752                 if (gnutls_x509_crt_get_issuer_dn(cert, str, &name_size) == 0)
 753                 {
 754                         std::string& issuer = certinfo->issuer;
 755                         issuer = str;
 756                         if (issuer.find_first_of("\r\n") != std::string::npos)
 757                                 issuer.clear();
 758                 }
 759
 760                 if ((ret = gnutls_x509_crt_get_fingerprint(cert, profile->GetHash(), digest, &digest_size)) < 0)
 761                 {
 762                         certinfo->error = gnutls_strerror(ret);
 763                 }
 764                 else
 765                 {
 766                         certinfo->fingerprint = BinToHex(digest, digest_size);
 767                 }
 768
 769                 /* Beware here we do not check for errors.
 770                  */
 771                 if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
 772                 {
 773                         certinfo->error = "Not activated, or expired certificate";
 774                 }
 775
 776 info_done_dealloc:
 777                 gnutls_x509_crt_deinit(cert);
 778         }
 779
 780         static const char* UnknownIfNULL(const char* str)
 781         {
 782                 return str ? str : "UNKNOWN";
 783         }
 784
 785         static ssize_t gnutls_pull_wrapper(gnutls_transport_ptr_t session_wrap, void* buffer, size_t size)
 786         {
 787                 StreamSocket* sock = reinterpret_cast<StreamSocket*>(session_wrap);
 788 #ifdef _WIN32
 789                 GnuTLSIOHook* session = static_cast<GnuTLSIOHook*>(sock->GetIOHook());
 790 #endif
 791
 792                 if (sock->GetEventMask() & FD_READ_WILL_BLOCK)
 793                 {
 794 #ifdef _WIN32
 795                         gnutls_transport_set_errno(session->sess, EAGAIN);
 796 #else
 797                         errno = EAGAIN;
 798 #endif
 799                         return -1;
 800                 }
 801
 802                 int rv = SocketEngine::Recv(sock, reinterpret_cast<char *>(buffer), size, 0);
 803
 804 #ifdef _WIN32
 805                 if (rv < 0)
 806                 {
 807                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 808                          * and then set errno appropriately.
 809                          * The gnutls library may also have a different errno variable than us, see
 810                          * gnutls_transport_set_errno(3).
 811                          */
 812                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 813                 }
 814 #endif
 815
 816                 if (rv < (int)size)
 817                         SocketEngine::ChangeEventMask(sock, FD_READ_WILL_BLOCK);
 818                 return rv;
 819         }
 820
 821         static ssize_t gnutls_push_wrapper(gnutls_transport_ptr_t session_wrap, const void* buffer, size_t size)
 822         {
 823                 StreamSocket* sock = reinterpret_cast<StreamSocket*>(session_wrap);
 824 #ifdef _WIN32
 825                 GnuTLSIOHook* session = static_cast<GnuTLSIOHook*>(sock->GetIOHook());
 826 #endif
 827
 828                 if (sock->GetEventMask() & FD_WRITE_WILL_BLOCK)
 829                 {
 830 #ifdef _WIN32
 831                         gnutls_transport_set_errno(session->sess, EAGAIN);
 832 #else
 833                         errno = EAGAIN;
 834 #endif
 835                         return -1;
 836                 }
 837
 838                 int rv = SocketEngine::Send(sock, reinterpret_cast<const char *>(buffer), size, 0);
 839
 840 #ifdef _WIN32
 841                 if (rv < 0)
 842                 {
 843                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 844                          * and then set errno appropriately.
 845                          * The gnutls library may also have a different errno variable than us, see
 846                          * gnutls_transport_set_errno(3).
 847                          */
 848                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 849                 }
 850 #endif
 851
 852                 if (rv < (int)size)
 853                         SocketEngine::ChangeEventMask(sock, FD_WRITE_WILL_BLOCK);
 854                 return rv;
 855         }
 856
 857  public:
 858         GnuTLSIOHook(IOHookProvider* hookprov, StreamSocket* sock, bool outbound, const reference<GnuTLS::Profile>& sslprofile)
 859                 : SSLIOHook(hookprov)
 860                 , sess(NULL)
 861                 , status(ISSL_NONE)
 862                 , profile(sslprofile)
 863         {
 864                 InitSession(sock, outbound);
 865                 sock->AddIOHook(this);
 866                 Handshake(sock);
 867         }
 868
 869         void OnStreamSocketClose(StreamSocket* user) CXX11_OVERRIDE
 870         {
 871                 CloseSession();
 872         }
 873
 874         int OnStreamSocketRead(StreamSocket* user, std::string& recvq) CXX11_OVERRIDE
 875         {
 876                 if (!this->sess)
 877                 {
 878                         CloseSession();
 879                         user->SetError("No SSL session");
 880                         return -1;
 881                 }
 882
 883                 if (this->status == ISSL_HANDSHAKING)
 884                 {
 885                         // The handshake isn't finished, try to finish it.
 886
 887                         if (!Handshake(user))
 888                         {
 889                                 if (this->status != ISSL_CLOSING)
 890                                         return 0;
 891                                 return -1;
 892                         }
 893                 }
 894
 895                 // If we resumed the handshake then this->status will be ISSL_HANDSHAKEN.
 896
 897                 if (this->status == ISSL_HANDSHAKEN)
 898                 {
 899                         GnuTLS::DataReader reader(sess);
 900                         int ret = reader.ret();
 901                         if (ret > 0)
 902                         {
 903                                 reader.appendto(recvq);
 904                                 return 1;
 905                         }
 906                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 907                         {
 908                                 return 0;
 909                         }
 910                         else if (ret == 0)
 911                         {
 912                                 user->SetError("Connection closed");
 913                                 CloseSession();
 914                                 return -1;
 915                         }
 916                         else
 917                         {
 918                                 user->SetError(gnutls_strerror(ret));
 919                                 CloseSession();
 920                                 return -1;
 921                         }
 922                 }
 923                 else if (this->status == ISSL_CLOSING)
 924                         return -1;
 925
 926                 return 0;
 927         }
 928
 929         int OnStreamSocketWrite(StreamSocket* user, std::string& sendq) CXX11_OVERRIDE
 930         {
 931                 if (!this->sess)
 932                 {
 933                         CloseSession();
 934                         user->SetError("No SSL session");
 935                         return -1;
 936                 }
 937
 938                 if (this->status == ISSL_HANDSHAKING)
 939                 {
 940                         // The handshake isn't finished, try to finish it.
 941                         Handshake(user);
 942                         if (this->status != ISSL_CLOSING)
 943                                 return 0;
 944                         return -1;
 945                 }
 946
 947                 int ret = 0;
 948
 949                 if (this->status == ISSL_HANDSHAKEN)
 950                 {
 951                         ret = gnutls_record_send(this->sess, sendq.data(), sendq.length());
 952
 953                         if (ret == (int)sendq.length())
 954                         {
 955                                 SocketEngine::ChangeEventMask(user, FD_WANT_NO_WRITE);
 956                                 return 1;
 957                         }
 958                         else if (ret > 0)
 959                         {
 960                                 sendq.erase(0, ret);
 961                                 SocketEngine::ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 962                                 return 0;
 963                         }
 964                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED || ret == 0)
 965                         {
 966                                 SocketEngine::ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 967                                 return 0;
 968                         }
 969                         else // (ret < 0)
 970                         {
 971                                 user->SetError(gnutls_strerror(ret));
 972                                 CloseSession();
 973                                 return -1;
 974                         }
 975                 }
 976
 977                 return 0;
 978         }
 979
 980         void TellCiphersAndFingerprint(LocalUser* user)
 981         {
 982                 if (sess)
 983                 {
 984                         std::string text = "*** You are connected using SSL cipher '";
 985                         GetCiphersuite(text);
 986                         text += '\'';
 987                         if (!certificate->fingerprint.empty())
 988                                 text += " and your SSL certificate fingerprint is " + certificate->fingerprint;
 989
 990                         user->WriteNotice(text);
 991                 }
 992         }
 993
 994         void GetCiphersuite(std::string& out) const
 995         {
 996                 out.append(UnknownIfNULL(gnutls_protocol_get_name(gnutls_protocol_get_version(sess)))).push_back('-');
 997                 out.append(UnknownIfNULL(gnutls_kx_get_name(gnutls_kx_get(sess)))).push_back('-');
 998                 out.append(UnknownIfNULL(gnutls_cipher_get_name(gnutls_cipher_get(sess)))).push_back('-');
 999                 out.append(UnknownIfNULL(gnutls_mac_get_name(gnutls_mac_get(sess))));
1000         }
1001
1002         GnuTLS::Profile* GetProfile() { return profile; }
1003 };
1004
1005 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)
1006 {
1007 #ifndef GNUTLS_NEW_CERT_CALLBACK_API
1008         st->type = GNUTLS_CRT_X509;
1009 #else
1010         st->cert_type = GNUTLS_CRT_X509;
1011         st->key_type = GNUTLS_PRIVKEY_X509;
1012 #endif
1013         StreamSocket* sock = reinterpret_cast<StreamSocket*>(gnutls_transport_get_ptr(sess));
1014         GnuTLS::X509Credentials& cred = static_cast<GnuTLSIOHook*>(sock->GetIOHook())->GetProfile()->GetX509Credentials();
1015
1016         st->ncerts = cred.certs.size();
1017         st->cert.x509 = cred.certs.raw();
1018         st->key.x509 = cred.key.get();
1019         st->deinit_all = 0;
1020
1021         return 0;
1022 }
1023
1024 class GnuTLSIOHookProvider : public refcountbase, public IOHookProvider
1025 {
1026         reference<GnuTLS::Profile> profile;
1027
1028  public:
1029         GnuTLSIOHookProvider(Module* mod, reference<GnuTLS::Profile>& prof)
1030                 : IOHookProvider(mod, "ssl/" + prof->GetName(), IOHookProvider::IOH_SSL)
1031                 , profile(prof)
1032         {
1033                 ServerInstance->Modules->AddService(*this);
1034         }
1035
1036         ~GnuTLSIOHookProvider()
1037         {
1038                 ServerInstance->Modules->DelService(*this);
1039         }
1040
1041         void OnAccept(StreamSocket* sock, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server) CXX11_OVERRIDE
1042         {
1043                 new GnuTLSIOHook(this, sock, true, profile);
1044         }
1045
1046         void OnConnect(StreamSocket* sock) CXX11_OVERRIDE
1047         {
1048                 new GnuTLSIOHook(this, sock, false, profile);
1049         }
1050 };
1051
1052 class ModuleSSLGnuTLS : public Module
1053 {
1054         typedef std::vector<reference<GnuTLSIOHookProvider> > ProfileList;
1055
1056         // First member of the class, gets constructed first and destructed last
1057         GnuTLS::Init libinit;
1058         RandGen randhandler;
1059         ProfileList profiles;
1060
1061         void ReadProfiles()
1062         {
1063                 // First, store all profiles in a new, temporary container. If no problems occur, swap the two
1064                 // containers; this way if something goes wrong we can go back and continue using the current profiles,
1065                 // avoiding unpleasant situations where no new SSL connections are possible.
1066                 ProfileList newprofiles;
1067
1068                 ConfigTagList tags = ServerInstance->Config->ConfTags("sslprofile");
1069                 if (tags.first == tags.second)
1070                 {
1071                         // No <sslprofile> tags found, create a profile named "gnutls" from settings in the <gnutls> block
1072                         const std::string defname = "gnutls";
1073                         ConfigTag* tag = ServerInstance->Config->ConfValue(defname);
1074                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "No <sslprofile> tags found; using settings from the <gnutls> tag");
1075
1076                         try
1077                         {
1078                                 reference<GnuTLS::Profile> profile(GnuTLS::Profile::Create(defname, tag));
1079                                 newprofiles.push_back(new GnuTLSIOHookProvider(this, profile));
1080                         }
1081                         catch (CoreException& ex)
1082                         {
1083                                 throw ModuleException("Error while initializing the default SSL profile - " + ex.GetReason());
1084                         }
1085                 }
1086
1087                 for (ConfigIter i = tags.first; i != tags.second; ++i)
1088                 {
1089                         ConfigTag* tag = i->second;
1090                         if (tag->getString("provider") != "gnutls")
1091                                 continue;
1092
1093                         std::string name = tag->getString("name");
1094                         if (name.empty())
1095                         {
1096                                 ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Ignoring <sslprofile> tag without name at " + tag->getTagLocation());
1097                                 continue;
1098                         }
1099
1100                         reference<GnuTLS::Profile> profile;
1101                         try
1102                         {
1103                                 profile = GnuTLS::Profile::Create(name, tag);
1104                         }
1105                         catch (CoreException& ex)
1106                         {
1107                                 throw ModuleException("Error while initializing SSL profile \"" + name + "\" at " + tag->getTagLocation() + " - " + ex.GetReason());
1108                         }
1109
1110                         newprofiles.push_back(new GnuTLSIOHookProvider(this, profile));
1111                 }
1112
1113                 // New profiles are ok, begin using them
1114                 // Old profiles are deleted when their refcount drops to zero
1115                 profiles.swap(newprofiles);
1116         }
1117
1118  public:
1119         ModuleSSLGnuTLS()
1120         {
1121 #ifndef GNUTLS_HAS_RND
1122                 gcry_control (GCRYCTL_INITIALIZATION_FINISHED, 0);
1123 #endif
1124         }
1125
1126         void init() CXX11_OVERRIDE
1127         {
1128                 ReadProfiles();
1129                 ServerInstance->GenRandom = &randhandler;
1130         }
1131
1132         void OnModuleRehash(User* user, const std::string &param) CXX11_OVERRIDE
1133         {
1134                 if(param != "ssl")
1135                         return;
1136
1137                 try
1138                 {
1139                         ReadProfiles();
1140                 }
1141                 catch (ModuleException& ex)
1142                 {
1143                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, ex.GetReason() + " Not applying settings.");
1144                 }
1145         }
1146
1147         ~ModuleSSLGnuTLS()
1148         {
1149                 ServerInstance->GenRandom = &ServerInstance->HandleGenRandom;
1150         }
1151
1152         void OnCleanup(int target_type, void* item) CXX11_OVERRIDE
1153         {
1154                 if(target_type == TYPE_USER)
1155                 {
1156                         LocalUser* user = IS_LOCAL(static_cast<User*>(item));
1157
1158                         if (user && user->eh.GetIOHook() && user->eh.GetIOHook()->prov->creator == this)
1159                         {
1160                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
1161                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
1162                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
1163                         }
1164                 }
1165         }
1166
1167         Version GetVersion() CXX11_OVERRIDE
1168         {
1169                 return Version("Provides SSL support for clients", VF_VENDOR);
1170         }
1171
1172         void OnUserConnect(LocalUser* user) CXX11_OVERRIDE
1173         {
1174                 IOHook* hook = user->eh.GetIOHook();
1175                 if (hook && hook->prov->creator == this)
1176                         static_cast<GnuTLSIOHook*>(hook)->TellCiphersAndFingerprint(user);
1177         }
1178 };
1179
1180 MODULE_INIT(ModuleSSLGnuTLS)