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