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 INSPIRCD_GNUTLS_HAS_VECTOR_PUSH
  77 #define GNUTLS_NEW_CERT_CALLBACK_API
  78 typedef gnutls_retr2_st cert_cb_last_param_type;
  79 #else
  80 typedef gnutls_retr_st cert_cb_last_param_type;
  81 #endif
  82
  83 #if INSPIRCD_GNUTLS_HAS_VERSION(3, 3, 5)
  84 #define INSPIRCD_GNUTLS_HAS_RECV_PACKET
  85 #endif
  86
  87 #if INSPIRCD_GNUTLS_HAS_VERSION(2, 99, 0)
  88 // The second parameter of gnutls_init() has changed in 2.99.0 from gnutls_connection_end_t to unsigned int
  89 // (it became a general flags parameter) and the enum has been deprecated and generates a warning on use.
  90 typedef unsigned int inspircd_gnutls_session_init_flags_t;
  91 #else
  92 typedef gnutls_connection_end_t inspircd_gnutls_session_init_flags_t;
  93 #endif
  94
  95 class RandGen : public HandlerBase2<void, char*, size_t>
  96 {
  97  public:
  98         void Call(char* buffer, size_t len)
  99         {
 100 #ifdef GNUTLS_HAS_RND
 101                 gnutls_rnd(GNUTLS_RND_RANDOM, buffer, len);
 102 #else
 103                 gcry_randomize(buffer, len, GCRY_STRONG_RANDOM);
 104 #endif
 105         }
 106 };
 107
 108 namespace GnuTLS
 109 {
 110         class Init
 111         {
 112          public:
 113                 Init() { gnutls_global_init(); }
 114                 ~Init() { gnutls_global_deinit(); }
 115         };
 116
 117         class Exception : public ModuleException
 118         {
 119          public:
 120                 Exception(const std::string& reason)
 121                         : ModuleException(reason) { }
 122         };
 123
 124         void ThrowOnError(int errcode, const char* msg)
 125         {
 126                 if (errcode < 0)
 127                 {
 128                         std::string reason = msg;
 129                         reason.append(" :").append(gnutls_strerror(errcode));
 130                         throw Exception(reason);
 131                 }
 132         }
 133
 134         /** Used to create a gnutls_datum_t* from a std::string
 135          */
 136         class Datum
 137         {
 138                 gnutls_datum_t datum;
 139
 140          public:
 141                 Datum(const std::string& dat)
 142                 {
 143                         datum.data = (unsigned char*)dat.data();
 144                         datum.size = static_cast<unsigned int>(dat.length());
 145                 }
 146
 147                 const gnutls_datum_t* get() const { return &datum; }
 148         };
 149
 150         class Hash
 151         {
 152                 gnutls_digest_algorithm_t hash;
 153
 154          public:
 155                 // Nothing to deallocate, constructor may throw freely
 156                 Hash(const std::string& hashname)
 157                 {
 158                         // As older versions of gnutls can't do this, let's disable it where needed.
 159 #ifdef GNUTLS_HAS_MAC_GET_ID
 160                         // As gnutls_digest_algorithm_t and gnutls_mac_algorithm_t are mapped 1:1, we can do this
 161                         // There is no gnutls_dig_get_id() at the moment, but it may come later
 162                         hash = (gnutls_digest_algorithm_t)gnutls_mac_get_id(hashname.c_str());
 163                         if (hash == GNUTLS_DIG_UNKNOWN)
 164                                 throw Exception("Unknown hash type " + hashname);
 165
 166                         // Check if the user is giving us something that is a valid MAC but not digest
 167                         gnutls_hash_hd_t is_digest;
 168                         if (gnutls_hash_init(&is_digest, hash) < 0)
 169                                 throw Exception("Unknown hash type " + hashname);
 170                         gnutls_hash_deinit(is_digest, NULL);
 171 #else
 172                         if (hashname == "md5")
 173                                 hash = GNUTLS_DIG_MD5;
 174                         else if (hashname == "sha1")
 175                                 hash = GNUTLS_DIG_SHA1;
 176 #ifdef INSPIRCD_GNUTLS_ENABLE_SHA256_FINGERPRINT
 177                         else if (hashname == "sha256")
 178                                 hash = GNUTLS_DIG_SHA256;
 179 #endif
 180                         else
 181                                 throw Exception("Unknown hash type " + hashname);
 182 #endif
 183                 }
 184
 185                 gnutls_digest_algorithm_t get() const { return hash; }
 186         };
 187
 188         class DHParams
 189         {
 190                 gnutls_dh_params_t dh_params;
 191
 192                 DHParams()
 193                 {
 194                         ThrowOnError(gnutls_dh_params_init(&dh_params), "gnutls_dh_params_init() failed");
 195                 }
 196
 197          public:
 198                 /** Import */
 199                 static std::auto_ptr<DHParams> Import(const std::string& dhstr)
 200                 {
 201                         std::auto_ptr<DHParams> dh(new DHParams);
 202                         int ret = gnutls_dh_params_import_pkcs3(dh->dh_params, Datum(dhstr).get(), GNUTLS_X509_FMT_PEM);
 203                         ThrowOnError(ret, "Unable to import DH params");
 204                         return dh;
 205                 }
 206
 207                 /** Generate */
 208                 static std::auto_ptr<DHParams> Generate(unsigned int bits)
 209                 {
 210                         std::auto_ptr<DHParams> dh(new DHParams);
 211                         ThrowOnError(gnutls_dh_params_generate2(dh->dh_params, bits), "Unable to generate DH params");
 212                         return dh;
 213                 }
 214
 215                 ~DHParams()
 216                 {
 217                         gnutls_dh_params_deinit(dh_params);
 218                 }
 219
 220                 const gnutls_dh_params_t& get() const { return dh_params; }
 221         };
 222
 223         class X509Key
 224         {
 225                 /** Ensure that the key is deinited in case the constructor of X509Key throws
 226                  */
 227                 class RAIIKey
 228                 {
 229                  public:
 230                         gnutls_x509_privkey_t key;
 231
 232                         RAIIKey()
 233                         {
 234                                 ThrowOnError(gnutls_x509_privkey_init(&key), "gnutls_x509_privkey_init() failed");
 235                         }
 236
 237                         ~RAIIKey()
 238                         {
 239                                 gnutls_x509_privkey_deinit(key);
 240                         }
 241                 } key;
 242
 243          public:
 244                 /** Import */
 245                 X509Key(const std::string& keystr)
 246                 {
 247                         int ret = gnutls_x509_privkey_import(key.key, Datum(keystr).get(), GNUTLS_X509_FMT_PEM);
 248                         ThrowOnError(ret, "Unable to import private key");
 249                 }
 250
 251                 gnutls_x509_privkey_t& get() { return key.key; }
 252         };
 253
 254         class X509CertList
 255         {
 256                 std::vector<gnutls_x509_crt_t> certs;
 257
 258          public:
 259                 /** Import */
 260                 X509CertList(const std::string& certstr)
 261                 {
 262                         unsigned int certcount = 3;
 263                         certs.resize(certcount);
 264                         Datum datum(certstr);
 265
 266                         int ret = gnutls_x509_crt_list_import(raw(), &certcount, datum.get(), GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 267                         if (ret == GNUTLS_E_SHORT_MEMORY_BUFFER)
 268                         {
 269                                 // the buffer wasn't big enough to hold all certs but gnutls changed certcount to the number of available certs,
 270                                 // try again with a bigger buffer
 271                                 certs.resize(certcount);
 272                                 ret = gnutls_x509_crt_list_import(raw(), &certcount, datum.get(), GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 273                         }
 274
 275                         ThrowOnError(ret, "Unable to load certificates");
 276
 277                         // Resize the vector to the actual number of certs because we rely on its size being correct
 278                         // when deallocating the certs
 279                         certs.resize(certcount);
 280                 }
 281
 282                 ~X509CertList()
 283                 {
 284                         for (std::vector<gnutls_x509_crt_t>::iterator i = certs.begin(); i != certs.end(); ++i)
 285                                 gnutls_x509_crt_deinit(*i);
 286                 }
 287
 288                 gnutls_x509_crt_t* raw() { return &certs[0]; }
 289                 unsigned int size() const { return certs.size(); }
 290         };
 291
 292         class X509CRL : public refcountbase
 293         {
 294                 class RAIICRL
 295                 {
 296                  public:
 297                         gnutls_x509_crl_t crl;
 298
 299                         RAIICRL()
 300                         {
 301                                 ThrowOnError(gnutls_x509_crl_init(&crl), "gnutls_x509_crl_init() failed");
 302                         }
 303
 304                         ~RAIICRL()
 305                         {
 306                                 gnutls_x509_crl_deinit(crl);
 307                         }
 308                 } crl;
 309
 310          public:
 311                 /** Import */
 312                 X509CRL(const std::string& crlstr)
 313                 {
 314                         int ret = gnutls_x509_crl_import(get(), Datum(crlstr).get(), GNUTLS_X509_FMT_PEM);
 315                         ThrowOnError(ret, "Unable to load certificate revocation list");
 316                 }
 317
 318                 gnutls_x509_crl_t& get() { return crl.crl; }
 319         };
 320
 321 #ifdef GNUTLS_NEW_PRIO_API
 322         class Priority
 323         {
 324                 gnutls_priority_t priority;
 325
 326          public:
 327                 Priority(const std::string& priorities)
 328                 {
 329                         // Try to set the priorities for ciphers, kex methods etc. to the user supplied string
 330                         // If the user did not supply anything then the string is already set to "NORMAL"
 331                         const char* priocstr = priorities.c_str();
 332                         const char* prioerror;
 333
 334                         int ret = gnutls_priority_init(&priority, priocstr, &prioerror);
 335                         if (ret < 0)
 336                         {
 337                                 // gnutls did not understand the user supplied string
 338                                 throw Exception("Unable to initialize priorities to \"" + priorities + "\": " + gnutls_strerror(ret) + " Syntax error at position " + ConvToStr((unsigned int) (prioerror - priocstr)));
 339                         }
 340                 }
 341
 342                 ~Priority()
 343                 {
 344                         gnutls_priority_deinit(priority);
 345                 }
 346
 347                 void SetupSession(gnutls_session_t sess)
 348                 {
 349                         gnutls_priority_set(sess, priority);
 350                 }
 351         };
 352 #else
 353         /** Dummy class, used when gnutls_priority_set() is not available
 354          */
 355         class Priority
 356         {
 357          public:
 358                 Priority(const std::string& priorities)
 359                 {
 360                         if (priorities != "NORMAL")
 361                                 throw Exception("You've set a non-default priority string, but GnuTLS lacks support for it");
 362                 }
 363
 364                 static void SetupSession(gnutls_session_t sess)
 365                 {
 366                         // Always set the default priorities
 367                         gnutls_set_default_priority(sess);
 368                 }
 369         };
 370 #endif
 371
 372         class CertCredentials
 373         {
 374                 /** DH parameters associated with these credentials
 375                  */
 376                 std::auto_ptr<DHParams> dh;
 377
 378          protected:
 379                 gnutls_certificate_credentials_t cred;
 380
 381          public:
 382                 CertCredentials()
 383                 {
 384                         ThrowOnError(gnutls_certificate_allocate_credentials(&cred), "Cannot allocate certificate credentials");
 385                 }
 386
 387                 ~CertCredentials()
 388                 {
 389                         gnutls_certificate_free_credentials(cred);
 390                 }
 391
 392                 /** Associates these credentials with the session
 393                  */
 394                 void SetupSession(gnutls_session_t sess)
 395                 {
 396                         gnutls_credentials_set(sess, GNUTLS_CRD_CERTIFICATE, cred);
 397                 }
 398
 399                 /** Set the given DH parameters to be used with these credentials
 400                  */
 401                 void SetDH(std::auto_ptr<DHParams>& DH)
 402                 {
 403                         dh = DH;
 404                         gnutls_certificate_set_dh_params(cred, dh->get());
 405                 }
 406         };
 407
 408         class X509Credentials : public CertCredentials
 409         {
 410                 /** Private key
 411                  */
 412                 X509Key key;
 413
 414                 /** Certificate list, presented to the peer
 415                  */
 416                 X509CertList certs;
 417
 418                 /** Trusted CA, may be NULL
 419                  */
 420                 std::auto_ptr<X509CertList> trustedca;
 421
 422                 /** Certificate revocation list, may be NULL
 423                  */
 424                 std::auto_ptr<X509CRL> crl;
 425
 426                 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);
 427
 428          public:
 429                 X509Credentials(const std::string& certstr, const std::string& keystr)
 430                         : key(keystr)
 431                         , certs(certstr)
 432                 {
 433                         // Throwing is ok here, the destructor of Credentials is called in that case
 434                         int ret = gnutls_certificate_set_x509_key(cred, certs.raw(), certs.size(), key.get());
 435                         ThrowOnError(ret, "Unable to set cert/key pair");
 436
 437 #ifdef GNUTLS_NEW_CERT_CALLBACK_API
 438                         gnutls_certificate_set_retrieve_function(cred, cert_callback);
 439 #else
 440                         gnutls_certificate_client_set_retrieve_function(cred, cert_callback);
 441 #endif
 442                 }
 443
 444                 /** Sets the trusted CA and the certificate revocation list
 445                  * to use when verifying certificates
 446                  */
 447                 void SetCA(std::auto_ptr<X509CertList>& certlist, std::auto_ptr<X509CRL>& CRL)
 448                 {
 449                         // Do nothing if certlist is NULL
 450                         if (certlist.get())
 451                         {
 452                                 int ret = gnutls_certificate_set_x509_trust(cred, certlist->raw(), certlist->size());
 453                                 ThrowOnError(ret, "gnutls_certificate_set_x509_trust() failed");
 454
 455                                 if (CRL.get())
 456                                 {
 457                                         ret = gnutls_certificate_set_x509_crl(cred, &CRL->get(), 1);
 458                                         ThrowOnError(ret, "gnutls_certificate_set_x509_crl() failed");
 459                                 }
 460
 461                                 trustedca = certlist;
 462                                 crl = CRL;
 463                         }
 464                 }
 465         };
 466
 467         class DataReader
 468         {
 469                 int retval;
 470 #ifdef INSPIRCD_GNUTLS_HAS_RECV_PACKET
 471                 gnutls_packet_t packet;
 472
 473          public:
 474                 DataReader(gnutls_session_t sess)
 475                 {
 476                         // Using the packet API avoids the final copy of the data which GnuTLS does if we supply
 477                         // our own buffer. Instead, we get the buffer containing the data from GnuTLS and copy it
 478                         // to the recvq directly from there in appendto().
 479                         retval = gnutls_record_recv_packet(sess, &packet);
 480                 }
 481
 482                 void appendto(std::string& recvq)
 483                 {
 484                         // Copy data from GnuTLS buffers to recvq
 485                         gnutls_datum_t datum;
 486                         gnutls_packet_get(packet, &datum, NULL);
 487                         recvq.append(reinterpret_cast<const char*>(datum.data), datum.size);
 488
 489                         gnutls_packet_deinit(packet);
 490                 }
 491 #else
 492                 char* const buffer;
 493
 494          public:
 495                 DataReader(gnutls_session_t sess)
 496                         : buffer(ServerInstance->GetReadBuffer())
 497                 {
 498                         // Read data from GnuTLS buffers into ReadBuffer
 499                         retval = gnutls_record_recv(sess, buffer, ServerInstance->Config->NetBufferSize);
 500                 }
 501
 502                 void appendto(std::string& recvq)
 503                 {
 504                         // Copy data from ReadBuffer to recvq
 505                         recvq.append(buffer, retval);
 506                 }
 507 #endif
 508
 509                 int ret() const { return retval; }
 510         };
 511
 512         class Profile : public refcountbase
 513         {
 514                 /** Name of this profile
 515                  */
 516                 const std::string name;
 517
 518                 /** X509 certificate(s) and key
 519                  */
 520                 X509Credentials x509cred;
 521
 522                 /** The minimum length in bits for the DH prime to be accepted as a client
 523                  */
 524                 unsigned int min_dh_bits;
 525
 526                 /** Hashing algorithm to use when generating certificate fingerprints
 527                  */
 528                 Hash hash;
 529
 530                 /** Priorities for ciphers, compression methods, etc.
 531                  */
 532                 Priority priority;
 533
 534                 /** Rough max size of records to send
 535                  */
 536                 const unsigned int outrecsize;
 537
 538                 Profile(const std::string& profilename, const std::string& certstr, const std::string& keystr,
 539                                 std::auto_ptr<DHParams>& DH, unsigned int mindh, const std::string& hashstr,
 540                                 const std::string& priostr, std::auto_ptr<X509CertList>& CA, std::auto_ptr<X509CRL>& CRL,
 541                                 unsigned int recsize)
 542                         : name(profilename)
 543                         , x509cred(certstr, keystr)
 544                         , min_dh_bits(mindh)
 545                         , hash(hashstr)
 546                         , priority(priostr)
 547                         , outrecsize(recsize)
 548                 {
 549                         x509cred.SetDH(DH);
 550                         x509cred.SetCA(CA, CRL);
 551                 }
 552
 553                 static std::string ReadFile(const std::string& filename)
 554                 {
 555                         FileReader reader(filename);
 556                         std::string ret = reader.GetString();
 557                         if (ret.empty())
 558                                 throw Exception("Cannot read file " + filename);
 559                         return ret;
 560                 }
 561
 562          public:
 563                 static reference<Profile> Create(const std::string& profilename, ConfigTag* tag)
 564                 {
 565                         std::string certstr = ReadFile(tag->getString("certfile", "cert.pem"));
 566                         std::string keystr = ReadFile(tag->getString("keyfile", "key.pem"));
 567
 568                         std::auto_ptr<DHParams> dh;
 569                         int gendh = tag->getInt("gendh");
 570                         if (gendh)
 571                         {
 572                                 gendh = (gendh < 1024 ? 1024 : gendh);
 573                                 dh = DHParams::Generate(gendh);
 574                         }
 575                         else
 576                                 dh = DHParams::Import(ReadFile(tag->getString("dhfile", "dhparams.pem")));
 577
 578                         // Use default priority string if this tag does not specify one
 579                         std::string priostr = tag->getString("priority", "NORMAL");
 580                         unsigned int mindh = tag->getInt("mindhbits", 1024);
 581                         std::string hashstr = tag->getString("hash", "md5");
 582
 583                         // Load trusted CA and revocation list, if set
 584                         std::auto_ptr<X509CertList> ca;
 585                         std::auto_ptr<X509CRL> crl;
 586                         std::string filename = tag->getString("cafile");
 587                         if (!filename.empty())
 588                         {
 589                                 ca.reset(new X509CertList(ReadFile(filename)));
 590
 591                                 filename = tag->getString("crlfile");
 592                                 if (!filename.empty())
 593                                         crl.reset(new X509CRL(ReadFile(filename)));
 594                         }
 595
 596                         unsigned int outrecsize = tag->getInt("outrecsize", 2048, 512, 16384);
 597                         return new Profile(profilename, certstr, keystr, dh, mindh, hashstr, priostr, ca, crl, outrecsize);
 598                 }
 599
 600                 /** Set up the given session with the settings in this profile
 601                  */
 602                 void SetupSession(gnutls_session_t sess)
 603                 {
 604                         priority.SetupSession(sess);
 605                         x509cred.SetupSession(sess);
 606                         gnutls_dh_set_prime_bits(sess, min_dh_bits);
 607
 608                         // Request client certificate if we are a server, no-op if we're a client
 609                         gnutls_certificate_server_set_request(sess, GNUTLS_CERT_REQUEST);
 610                 }
 611
 612                 const std::string& GetName() const { return name; }
 613                 X509Credentials& GetX509Credentials() { return x509cred; }
 614                 gnutls_digest_algorithm_t GetHash() const { return hash.get(); }
 615                 unsigned int GetOutgoingRecordSize() const { return outrecsize; }
 616         };
 617 }
 618
 619 class GnuTLSIOHook : public SSLIOHook
 620 {
 621  private:
 622         gnutls_session_t sess;
 623         issl_status status;
 624         reference<GnuTLS::Profile> profile;
 625
 626         void CloseSession()
 627         {
 628                 if (this->sess)
 629                 {
 630                         gnutls_bye(this->sess, GNUTLS_SHUT_WR);
 631                         gnutls_deinit(this->sess);
 632                 }
 633                 sess = NULL;
 634                 certificate = NULL;
 635                 status = ISSL_NONE;
 636         }
 637
 638         // Returns 1 if handshake succeeded, 0 if it is still in progress, -1 if it failed
 639         int Handshake(StreamSocket* user)
 640         {
 641                 int ret = gnutls_handshake(this->sess);
 642
 643                 if (ret < 0)
 644                 {
 645                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 646                         {
 647                                 // Handshake needs resuming later, read() or write() would have blocked.
 648                                 this->status = ISSL_HANDSHAKING;
 649
 650                                 if (gnutls_record_get_direction(this->sess) == 0)
 651                                 {
 652                                         // gnutls_handshake() wants to read() again.
 653                                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 654                                 }
 655                                 else
 656                                 {
 657                                         // gnutls_handshake() wants to write() again.
 658                                         SocketEngine::ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 659                                 }
 660
 661                                 return 0;
 662                         }
 663                         else
 664                         {
 665                                 user->SetError("Handshake Failed - " + std::string(gnutls_strerror(ret)));
 666                                 CloseSession();
 667                                 return -1;
 668                         }
 669                 }
 670                 else
 671                 {
 672                         // Change the seesion state
 673                         this->status = ISSL_HANDSHAKEN;
 674
 675                         VerifyCertificate();
 676
 677                         // Finish writing, if any left
 678                         SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 679
 680                         return 1;
 681                 }
 682         }
 683
 684         void VerifyCertificate()
 685         {
 686                 unsigned int certstatus;
 687                 const gnutls_datum_t* cert_list;
 688                 int ret;
 689                 unsigned int cert_list_size;
 690                 gnutls_x509_crt_t cert;
 691                 char str[512];
 692                 unsigned char digest[512];
 693                 size_t digest_size = sizeof(digest);
 694                 size_t name_size = sizeof(str);
 695                 ssl_cert* certinfo = new ssl_cert;
 696                 this->certificate = certinfo;
 697
 698                 /* This verification function uses the trusted CAs in the credentials
 699                  * structure. So you must have installed one or more CA certificates.
 700                  */
 701                 ret = gnutls_certificate_verify_peers2(this->sess, &certstatus);
 702
 703                 if (ret < 0)
 704                 {
 705                         certinfo->error = std::string(gnutls_strerror(ret));
 706                         return;
 707                 }
 708
 709                 certinfo->invalid = (certstatus & GNUTLS_CERT_INVALID);
 710                 certinfo->unknownsigner = (certstatus & GNUTLS_CERT_SIGNER_NOT_FOUND);
 711                 certinfo->revoked = (certstatus & GNUTLS_CERT_REVOKED);
 712                 certinfo->trusted = !(certstatus & GNUTLS_CERT_SIGNER_NOT_CA);
 713
 714                 /* Up to here the process is the same for X.509 certificates and
 715                  * OpenPGP keys. From now on X.509 certificates are assumed. This can
 716                  * be easily extended to work with openpgp keys as well.
 717                  */
 718                 if (gnutls_certificate_type_get(this->sess) != GNUTLS_CRT_X509)
 719                 {
 720                         certinfo->error = "No X509 keys sent";
 721                         return;
 722                 }
 723
 724                 ret = gnutls_x509_crt_init(&cert);
 725                 if (ret < 0)
 726                 {
 727                         certinfo->error = gnutls_strerror(ret);
 728                         return;
 729                 }
 730
 731                 cert_list_size = 0;
 732                 cert_list = gnutls_certificate_get_peers(this->sess, &cert_list_size);
 733                 if (cert_list == NULL)
 734                 {
 735                         certinfo->error = "No certificate was found";
 736                         goto info_done_dealloc;
 737                 }
 738
 739                 /* This is not a real world example, since we only check the first
 740                  * certificate in the given chain.
 741                  */
 742
 743                 ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
 744                 if (ret < 0)
 745                 {
 746                         certinfo->error = gnutls_strerror(ret);
 747                         goto info_done_dealloc;
 748                 }
 749
 750                 if (gnutls_x509_crt_get_dn(cert, str, &name_size) == 0)
 751                 {
 752                         std::string& dn = certinfo->dn;
 753                         dn = str;
 754                         // Make sure there are no chars in the string that we consider invalid
 755                         if (dn.find_first_of("\r\n") != std::string::npos)
 756                                 dn.clear();
 757                 }
 758
 759                 name_size = sizeof(str);
 760                 if (gnutls_x509_crt_get_issuer_dn(cert, str, &name_size) == 0)
 761                 {
 762                         std::string& issuer = certinfo->issuer;
 763                         issuer = str;
 764                         if (issuer.find_first_of("\r\n") != std::string::npos)
 765                                 issuer.clear();
 766                 }
 767
 768                 if ((ret = gnutls_x509_crt_get_fingerprint(cert, profile->GetHash(), digest, &digest_size)) < 0)
 769                 {
 770                         certinfo->error = gnutls_strerror(ret);
 771                 }
 772                 else
 773                 {
 774                         certinfo->fingerprint = BinToHex(digest, digest_size);
 775                 }
 776
 777                 /* Beware here we do not check for errors.
 778                  */
 779                 if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
 780                 {
 781                         certinfo->error = "Not activated, or expired certificate";
 782                 }
 783
 784 info_done_dealloc:
 785                 gnutls_x509_crt_deinit(cert);
 786         }
 787
 788         // Returns 1 if application I/O should proceed, 0 if it must wait for the underlying protocol to progress, -1 on fatal error
 789         int PrepareIO(StreamSocket* sock)
 790         {
 791                 if (status == ISSL_HANDSHAKEN)
 792                         return 1;
 793                 else if (status == ISSL_HANDSHAKING)
 794                 {
 795                         // The handshake isn't finished, try to finish it
 796                         return Handshake(sock);
 797                 }
 798
 799                 CloseSession();
 800                 sock->SetError("No SSL session");
 801                 return -1;
 802         }
 803
 804         static const char* UnknownIfNULL(const char* str)
 805         {
 806                 return str ? str : "UNKNOWN";
 807         }
 808
 809         static ssize_t gnutls_pull_wrapper(gnutls_transport_ptr_t session_wrap, void* buffer, size_t size)
 810         {
 811                 StreamSocket* sock = reinterpret_cast<StreamSocket*>(session_wrap);
 812 #ifdef _WIN32
 813                 GnuTLSIOHook* session = static_cast<GnuTLSIOHook*>(sock->GetIOHook());
 814 #endif
 815
 816                 if (sock->GetEventMask() & FD_READ_WILL_BLOCK)
 817                 {
 818 #ifdef _WIN32
 819                         gnutls_transport_set_errno(session->sess, EAGAIN);
 820 #else
 821                         errno = EAGAIN;
 822 #endif
 823                         return -1;
 824                 }
 825
 826                 int rv = SocketEngine::Recv(sock, reinterpret_cast<char *>(buffer), size, 0);
 827
 828 #ifdef _WIN32
 829                 if (rv < 0)
 830                 {
 831                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 832                          * and then set errno appropriately.
 833                          * The gnutls library may also have a different errno variable than us, see
 834                          * gnutls_transport_set_errno(3).
 835                          */
 836                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 837                 }
 838 #endif
 839
 840                 if (rv < (int)size)
 841                         SocketEngine::ChangeEventMask(sock, FD_READ_WILL_BLOCK);
 842                 return rv;
 843         }
 844
 845 #ifdef INSPIRCD_GNUTLS_HAS_VECTOR_PUSH
 846         static ssize_t VectorPush(gnutls_transport_ptr_t transportptr, const giovec_t* iov, int iovcnt)
 847         {
 848                 StreamSocket* sock = reinterpret_cast<StreamSocket*>(transportptr);
 849 #ifdef _WIN32
 850                 GnuTLSIOHook* session = static_cast<GnuTLSIOHook*>(sock->GetIOHook());
 851 #endif
 852
 853                 if (sock->GetEventMask() & FD_WRITE_WILL_BLOCK)
 854                 {
 855 #ifdef _WIN32
 856                         gnutls_transport_set_errno(session->sess, EAGAIN);
 857 #else
 858                         errno = EAGAIN;
 859 #endif
 860                         return -1;
 861                 }
 862
 863                 // Cast the giovec_t to iovec not to IOVector so the correct function is called on Windows
 864                 int ret = SocketEngine::WriteV(sock, reinterpret_cast<const iovec*>(iov), iovcnt);
 865 #ifdef _WIN32
 866                 // See the function above for more info about the usage of gnutls_transport_set_errno() on Windows
 867                 if (ret < 0)
 868                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 869 #endif
 870
 871                 int size = 0;
 872                 for (int i = 0; i < iovcnt; i++)
 873                         size += iov[i].iov_len;
 874
 875                 if (ret < size)
 876                         SocketEngine::ChangeEventMask(sock, FD_WRITE_WILL_BLOCK);
 877                 return ret;
 878         }
 879
 880 #else // INSPIRCD_GNUTLS_HAS_VECTOR_PUSH
 881         static ssize_t gnutls_push_wrapper(gnutls_transport_ptr_t session_wrap, const void* buffer, size_t size)
 882         {
 883                 StreamSocket* sock = reinterpret_cast<StreamSocket*>(session_wrap);
 884 #ifdef _WIN32
 885                 GnuTLSIOHook* session = static_cast<GnuTLSIOHook*>(sock->GetIOHook());
 886 #endif
 887
 888                 if (sock->GetEventMask() & FD_WRITE_WILL_BLOCK)
 889                 {
 890 #ifdef _WIN32
 891                         gnutls_transport_set_errno(session->sess, EAGAIN);
 892 #else
 893                         errno = EAGAIN;
 894 #endif
 895                         return -1;
 896                 }
 897
 898                 int rv = SocketEngine::Send(sock, reinterpret_cast<const char *>(buffer), size, 0);
 899
 900 #ifdef _WIN32
 901                 if (rv < 0)
 902                 {
 903                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 904                          * and then set errno appropriately.
 905                          * The gnutls library may also have a different errno variable than us, see
 906                          * gnutls_transport_set_errno(3).
 907                          */
 908                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 909                 }
 910 #endif
 911
 912                 if (rv < (int)size)
 913                         SocketEngine::ChangeEventMask(sock, FD_WRITE_WILL_BLOCK);
 914                 return rv;
 915         }
 916 #endif // INSPIRCD_GNUTLS_HAS_VECTOR_PUSH
 917
 918  public:
 919         GnuTLSIOHook(IOHookProvider* hookprov, StreamSocket* sock, inspircd_gnutls_session_init_flags_t flags, const reference<GnuTLS::Profile>& sslprofile)
 920                 : SSLIOHook(hookprov)
 921                 , sess(NULL)
 922                 , status(ISSL_NONE)
 923                 , profile(sslprofile)
 924         {
 925                 gnutls_init(&sess, flags);
 926                 gnutls_transport_set_ptr(sess, reinterpret_cast<gnutls_transport_ptr_t>(sock));
 927 #ifdef INSPIRCD_GNUTLS_HAS_VECTOR_PUSH
 928                 gnutls_transport_set_vec_push_function(sess, VectorPush);
 929 #else
 930                 gnutls_transport_set_push_function(sess, gnutls_push_wrapper);
 931 #endif
 932                 gnutls_transport_set_pull_function(sess, gnutls_pull_wrapper);
 933                 profile->SetupSession(sess);
 934
 935                 sock->AddIOHook(this);
 936                 Handshake(sock);
 937         }
 938
 939         void OnStreamSocketClose(StreamSocket* user) CXX11_OVERRIDE
 940         {
 941                 CloseSession();
 942         }
 943
 944         int OnStreamSocketRead(StreamSocket* user, std::string& recvq) CXX11_OVERRIDE
 945         {
 946                 // Finish handshake if needed
 947                 int prepret = PrepareIO(user);
 948                 if (prepret <= 0)
 949                         return prepret;
 950
 951                 // If we resumed the handshake then this->status will be ISSL_HANDSHAKEN.
 952                 {
 953                         GnuTLS::DataReader reader(sess);
 954                         int ret = reader.ret();
 955                         if (ret > 0)
 956                         {
 957                                 reader.appendto(recvq);
 958                                 return 1;
 959                         }
 960                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 961                         {
 962                                 return 0;
 963                         }
 964                         else if (ret == 0)
 965                         {
 966                                 user->SetError("Connection closed");
 967                                 CloseSession();
 968                                 return -1;
 969                         }
 970                         else
 971                         {
 972                                 user->SetError(gnutls_strerror(ret));
 973                                 CloseSession();
 974                                 return -1;
 975                         }
 976                 }
 977         }
 978
 979         int OnStreamSocketWrite(StreamSocket* user) CXX11_OVERRIDE
 980         {
 981                 // Finish handshake if needed
 982                 int prepret = PrepareIO(user);
 983                 if (prepret <= 0)
 984                         return prepret;
 985
 986                 // Session is ready for transferring application data
 987                 StreamSocket::SendQueue& sendq = user->GetSendQ();
 988                 int ret = 0;
 989
 990                 {
 991                         const StreamSocket::SendQueue::Element& buffer = sendq.front();
 992                         ret = gnutls_record_send(this->sess, buffer.data(), buffer.length());
 993
 994                         if (ret == (int)buffer.length())
 995                         {
 996                                 SocketEngine::ChangeEventMask(user, FD_WANT_NO_WRITE);
 997                                 return 1;
 998                         }
 999                         else if (ret > 0)
1000                         {
1001                                 sendq.erase_front(ret);
1002                                 SocketEngine::ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
1003                                 return 0;
1004                         }
1005                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED || ret == 0)
1006                         {
1007                                 SocketEngine::ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
1008                                 return 0;
1009                         }
1010                         else // (ret < 0)
1011                         {
1012                                 user->SetError(gnutls_strerror(ret));
1013                                 CloseSession();
1014                                 return -1;
1015                         }
1016                 }
1017         }
1018
1019         void TellCiphersAndFingerprint(LocalUser* user)
1020         {
1021                 if (sess)
1022                 {
1023                         std::string text = "*** You are connected using SSL cipher '";
1024                         GetCiphersuite(text);
1025                         text += '\'';
1026                         if (!certificate->fingerprint.empty())
1027                                 text += " and your SSL certificate fingerprint is " + certificate->fingerprint;
1028
1029                         user->WriteNotice(text);
1030                 }
1031         }
1032
1033         void GetCiphersuite(std::string& out) const
1034         {
1035                 out.append(UnknownIfNULL(gnutls_protocol_get_name(gnutls_protocol_get_version(sess)))).push_back('-');
1036                 out.append(UnknownIfNULL(gnutls_kx_get_name(gnutls_kx_get(sess)))).push_back('-');
1037                 out.append(UnknownIfNULL(gnutls_cipher_get_name(gnutls_cipher_get(sess)))).push_back('-');
1038                 out.append(UnknownIfNULL(gnutls_mac_get_name(gnutls_mac_get(sess))));
1039         }
1040
1041         GnuTLS::Profile* GetProfile() { return profile; }
1042         bool IsHandshakeDone() const { return (status == ISSL_HANDSHAKEN); }
1043 };
1044
1045 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)
1046 {
1047 #ifndef GNUTLS_NEW_CERT_CALLBACK_API
1048         st->type = GNUTLS_CRT_X509;
1049 #else
1050         st->cert_type = GNUTLS_CRT_X509;
1051         st->key_type = GNUTLS_PRIVKEY_X509;
1052 #endif
1053         StreamSocket* sock = reinterpret_cast<StreamSocket*>(gnutls_transport_get_ptr(sess));
1054         GnuTLS::X509Credentials& cred = static_cast<GnuTLSIOHook*>(sock->GetIOHook())->GetProfile()->GetX509Credentials();
1055
1056         st->ncerts = cred.certs.size();
1057         st->cert.x509 = cred.certs.raw();
1058         st->key.x509 = cred.key.get();
1059         st->deinit_all = 0;
1060
1061         return 0;
1062 }
1063
1064 class GnuTLSIOHookProvider : public refcountbase, public IOHookProvider
1065 {
1066         reference<GnuTLS::Profile> profile;
1067
1068  public:
1069         GnuTLSIOHookProvider(Module* mod, reference<GnuTLS::Profile>& prof)
1070                 : IOHookProvider(mod, "ssl/" + prof->GetName(), IOHookProvider::IOH_SSL)
1071                 , profile(prof)
1072         {
1073                 ServerInstance->Modules->AddService(*this);
1074         }
1075
1076         ~GnuTLSIOHookProvider()
1077         {
1078                 ServerInstance->Modules->DelService(*this);
1079         }
1080
1081         void OnAccept(StreamSocket* sock, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server) CXX11_OVERRIDE
1082         {
1083                 new GnuTLSIOHook(this, sock, GNUTLS_SERVER, profile);
1084         }
1085
1086         void OnConnect(StreamSocket* sock) CXX11_OVERRIDE
1087         {
1088                 new GnuTLSIOHook(this, sock, GNUTLS_CLIENT, profile);
1089         }
1090 };
1091
1092 class ModuleSSLGnuTLS : public Module
1093 {
1094         typedef std::vector<reference<GnuTLSIOHookProvider> > ProfileList;
1095
1096         // First member of the class, gets constructed first and destructed last
1097         GnuTLS::Init libinit;
1098         RandGen randhandler;
1099         ProfileList profiles;
1100
1101         void ReadProfiles()
1102         {
1103                 // First, store all profiles in a new, temporary container. If no problems occur, swap the two
1104                 // containers; this way if something goes wrong we can go back and continue using the current profiles,
1105                 // avoiding unpleasant situations where no new SSL connections are possible.
1106                 ProfileList newprofiles;
1107
1108                 ConfigTagList tags = ServerInstance->Config->ConfTags("sslprofile");
1109                 if (tags.first == tags.second)
1110                 {
1111                         // No <sslprofile> tags found, create a profile named "gnutls" from settings in the <gnutls> block
1112                         const std::string defname = "gnutls";
1113                         ConfigTag* tag = ServerInstance->Config->ConfValue(defname);
1114                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "No <sslprofile> tags found; using settings from the <gnutls> tag");
1115
1116                         try
1117                         {
1118                                 reference<GnuTLS::Profile> profile(GnuTLS::Profile::Create(defname, tag));
1119                                 newprofiles.push_back(new GnuTLSIOHookProvider(this, profile));
1120                         }
1121                         catch (CoreException& ex)
1122                         {
1123                                 throw ModuleException("Error while initializing the default SSL profile - " + ex.GetReason());
1124                         }
1125                 }
1126
1127                 for (ConfigIter i = tags.first; i != tags.second; ++i)
1128                 {
1129                         ConfigTag* tag = i->second;
1130                         if (tag->getString("provider") != "gnutls")
1131                                 continue;
1132
1133                         std::string name = tag->getString("name");
1134                         if (name.empty())
1135                         {
1136                                 ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Ignoring <sslprofile> tag without name at " + tag->getTagLocation());
1137                                 continue;
1138                         }
1139
1140                         reference<GnuTLS::Profile> profile;
1141                         try
1142                         {
1143                                 profile = GnuTLS::Profile::Create(name, tag);
1144                         }
1145                         catch (CoreException& ex)
1146                         {
1147                                 throw ModuleException("Error while initializing SSL profile \"" + name + "\" at " + tag->getTagLocation() + " - " + ex.GetReason());
1148                         }
1149
1150                         newprofiles.push_back(new GnuTLSIOHookProvider(this, profile));
1151                 }
1152
1153                 // New profiles are ok, begin using them
1154                 // Old profiles are deleted when their refcount drops to zero
1155                 profiles.swap(newprofiles);
1156         }
1157
1158  public:
1159         ModuleSSLGnuTLS()
1160         {
1161 #ifndef GNUTLS_HAS_RND
1162                 gcry_control (GCRYCTL_INITIALIZATION_FINISHED, 0);
1163 #endif
1164         }
1165
1166         void init() CXX11_OVERRIDE
1167         {
1168                 ReadProfiles();
1169                 ServerInstance->GenRandom = &randhandler;
1170         }
1171
1172         void OnModuleRehash(User* user, const std::string &param) CXX11_OVERRIDE
1173         {
1174                 if(param != "ssl")
1175                         return;
1176
1177                 try
1178                 {
1179                         ReadProfiles();
1180                 }
1181                 catch (ModuleException& ex)
1182                 {
1183                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, ex.GetReason() + " Not applying settings.");
1184                 }
1185         }
1186
1187         ~ModuleSSLGnuTLS()
1188         {
1189                 ServerInstance->GenRandom = &ServerInstance->HandleGenRandom;
1190         }
1191
1192         void OnCleanup(int target_type, void* item) CXX11_OVERRIDE
1193         {
1194                 if(target_type == TYPE_USER)
1195                 {
1196                         LocalUser* user = IS_LOCAL(static_cast<User*>(item));
1197
1198                         if (user && user->eh.GetIOHook() && user->eh.GetIOHook()->prov->creator == this)
1199                         {
1200                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
1201                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
1202                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
1203                         }
1204                 }
1205         }
1206
1207         Version GetVersion() CXX11_OVERRIDE
1208         {
1209                 return Version("Provides SSL support for clients", VF_VENDOR);
1210         }
1211
1212         void OnUserConnect(LocalUser* user) CXX11_OVERRIDE
1213         {
1214                 IOHook* hook = user->eh.GetIOHook();
1215                 if (hook && hook->prov->creator == this)
1216                         static_cast<GnuTLSIOHook*>(hook)->TellCiphersAndFingerprint(user);
1217         }
1218
1219         ModResult OnCheckReady(LocalUser* user) CXX11_OVERRIDE
1220         {
1221                 if ((user->eh.GetIOHook()) && (user->eh.GetIOHook()->prov->creator == this))
1222                 {
1223                         GnuTLSIOHook* iohook = static_cast<GnuTLSIOHook*>(user->eh.GetIOHook());
1224                         if (!iohook->IsHandshakeDone())
1225                                 return MOD_RES_DENY;
1226                 }
1227
1228                 return MOD_RES_PASSTHRU;
1229         }
1230 };
1231
1232 MODULE_INIT(ModuleSSLGnuTLS)