src/modules/extra/m_ssl_openssl.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2010 InspIRCd Development Team
   6  * See: http://wiki.inspircd.org/Credits
   7  *
   8  * This program is free but copyrighted software; see
   9  *            the file COPYING for details.
  10  *
  11  * ---------------------------------------------------
  12  */
  13
  14 #include "inspircd.h"
  15 #include <openssl/ssl.h>
  16 #include <openssl/err.h>
  17 #include "ssl.h"
  18
  19 #ifdef WINDOWS
  20 #pragma comment(lib, "libeay32MTd")
  21 #pragma comment(lib, "ssleay32MTd")
  22 #undef MAX_DESCRIPTORS
  23 #define MAX_DESCRIPTORS 10000
  24 #endif
  25
  26 /* $ModDesc: Provides SSL support for clients */
  27
  28 /* $LinkerFlags: if("USE_FREEBSD_BASE_SSL") -lssl -lcrypto */
  29 /* $CompileFlags: if(!"USE_FREEBSD_BASE_SSL") pkgconfversion("openssl","0.9.7") pkgconfincludes("openssl","/openssl/ssl.h","") */
  30 /* $LinkerFlags: if(!"USE_FREEBSD_BASE_SSL") rpath("pkg-config --libs openssl") pkgconflibs("openssl","/libssl.so","-lssl -lcrypto -ldl") */
  31
  32 /* $ModDep: transport.h */
  33 /* $NoPedantic */
  34 /* $CopyInstall: conf/key.pem $(CONPATH) */
  35 /* $CopyInstall: conf/cert.pem $(CONPATH) */
  36
  37
  38 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING, ISSL_OPEN };
  39
  40 static bool SelfSigned = false;
  41
  42 char* get_error()
  43 {
  44         return ERR_error_string(ERR_get_error(), NULL);
  45 }
  46
  47 static int error_callback(const char *str, size_t len, void *u);
  48
  49 /** Represents an SSL user's extra data
  50  */
  51 class issl_session
  52 {
  53 public:
  54         SSL* sess;
  55         issl_status status;
  56         reference<ssl_cert> cert;
  57
  58         int fd;
  59         bool outbound;
  60         bool data_to_write;
  61
  62         issl_session()
  63         {
  64                 outbound = false;
  65                 data_to_write = false;
  66         }
  67 };
  68
  69 static int OnVerify(int preverify_ok, X509_STORE_CTX *ctx)
  70 {
  71         /* XXX: This will allow self signed certificates.
  72          * In the future if we want an option to not allow this,
  73          * we can just return preverify_ok here, and openssl
  74          * will boot off self-signed and invalid peer certs.
  75          */
  76         int ve = X509_STORE_CTX_get_error(ctx);
  77
  78         SelfSigned = (ve == X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT);
  79
  80         return 1;
  81 }
  82
  83 class ModuleSSLOpenSSL : public Module
  84 {
  85         int inbufsize;
  86         issl_session* sessions;
  87
  88         SSL_CTX* ctx;
  89         SSL_CTX* clictx;
  90
  91         char cipher[MAXBUF];
  92
  93         std::string keyfile;
  94         std::string certfile;
  95         std::string cafile;
  96         // std::string crlfile;
  97         std::string dhfile;
  98         std::string sslports;
  99
 100         ServiceProvider iohook;
 101  public:
 102
 103         ModuleSSLOpenSSL() : iohook(this, "ssl/openssl", SERVICE_IOHOOK)
 104         {
 105
 106                 sessions = new issl_session[ServerInstance->SE->GetMaxFds()];
 107
 108                 // Not rehashable...because I cba to reduce all the sizes of existing buffers.
 109                 inbufsize = ServerInstance->Config->NetBufferSize;
 110
 111                 /* Global SSL library initialization*/
 112                 SSL_library_init();
 113                 SSL_load_error_strings();
 114
 115                 /* Build our SSL contexts:
 116                  * NOTE: OpenSSL makes us have two contexts, one for servers and one for clients. ICK.
 117                  */
 118                 ctx = SSL_CTX_new( SSLv23_server_method() );
 119                 clictx = SSL_CTX_new( SSLv23_client_method() );
 120
 121                 SSL_CTX_set_mode(ctx, SSL_MODE_ENABLE_PARTIAL_WRITE | SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
 122                 SSL_CTX_set_mode(clictx, SSL_MODE_ENABLE_PARTIAL_WRITE | SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
 123
 124                 SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, OnVerify);
 125                 SSL_CTX_set_verify(clictx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, OnVerify);
 126
 127                 // Needs the flag as it ignores a plain /rehash
 128                 OnModuleRehash(NULL,"ssl");
 129                 Implementation eventlist[] = { I_On005Numeric, I_OnRehash, I_OnModuleRehash, I_OnHookIO, I_OnUserConnect };
 130                 ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
 131                 ServerInstance->Modules->AddService(iohook);
 132         }
 133
 134         void OnHookIO(StreamSocket* user, ListenSocket* lsb)
 135         {
 136                 if (!user->GetIOHook() && lsb->bind_tag->getString("ssl") == "openssl")
 137                 {
 138                         /* Hook the user with our module */
 139                         user->AddIOHook(this);
 140                 }
 141         }
 142
 143         void OnRehash(User* user)
 144         {
 145                 ConfigReader Conf;
 146
 147                 sslports.clear();
 148
 149                 for (size_t i = 0; i < ServerInstance->ports.size(); i++)
 150                 {
 151                         ListenSocket* port = ServerInstance->ports[i];
 152                         if (port->bind_tag->getString("ssl") != "openssl")
 153                                 continue;
 154
 155                         std::string portid = port->bind_desc;
 156                         ServerInstance->Logs->Log("m_ssl_openssl", DEFAULT, "m_ssl_openssl.so: Enabling SSL for port %s", portid.c_str());
 157                         if (port->bind_tag->getString("type", "clients") == "clients" && port->bind_addr != "127.0.0.1")
 158                                 sslports.append(portid).append(";");
 159                 }
 160
 161                 if (!sslports.empty())
 162                         sslports.erase(sslports.end() - 1);
 163         }
 164
 165         void OnModuleRehash(User* user, const std::string &param)
 166         {
 167                 if (param != "ssl")
 168                         return;
 169
 170                 OnRehash(user);
 171
 172                 ConfigReader Conf;
 173
 174                 cafile   = Conf.ReadValue("openssl", "cafile", 0);
 175                 certfile = Conf.ReadValue("openssl", "certfile", 0);
 176                 keyfile  = Conf.ReadValue("openssl", "keyfile", 0);
 177                 dhfile   = Conf.ReadValue("openssl", "dhfile", 0);
 178
 179                 // Set all the default values needed.
 180                 if (cafile.empty())
 181                         cafile = "conf/ca.pem";
 182
 183                 if (certfile.empty())
 184                         certfile = "conf/cert.pem";
 185
 186                 if (keyfile.empty())
 187                         keyfile = "conf/key.pem";
 188
 189                 if (dhfile.empty())
 190                         dhfile = "conf/dhparams.pem";
 191
 192                 /* Load our keys and certificates
 193                  * NOTE: OpenSSL's error logging API sucks, don't blame us for this clusterfuck.
 194                  */
 195                 if ((!SSL_CTX_use_certificate_chain_file(ctx, certfile.c_str())) || (!SSL_CTX_use_certificate_chain_file(clictx, certfile.c_str())))
 196                 {
 197                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Can't read certificate file %s. %s", certfile.c_str(), strerror(errno));
 198                         ERR_print_errors_cb(error_callback, this);
 199                 }
 200
 201                 if (((!SSL_CTX_use_PrivateKey_file(ctx, keyfile.c_str(), SSL_FILETYPE_PEM))) || (!SSL_CTX_use_PrivateKey_file(clictx, keyfile.c_str(), SSL_FILETYPE_PEM)))
 202                 {
 203                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Can't read key file %s. %s", keyfile.c_str(), strerror(errno));
 204                         ERR_print_errors_cb(error_callback, this);
 205                 }
 206
 207                 /* Load the CAs we trust*/
 208                 if (((!SSL_CTX_load_verify_locations(ctx, cafile.c_str(), 0))) || (!SSL_CTX_load_verify_locations(clictx, cafile.c_str(), 0)))
 209                 {
 210                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Can't read CA list from %s. %s", cafile.c_str(), strerror(errno));
 211                         ERR_print_errors_cb(error_callback, this);
 212                 }
 213
 214                 FILE* dhpfile = fopen(dhfile.c_str(), "r");
 215                 DH* ret;
 216
 217                 if (dhpfile == NULL)
 218                 {
 219                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so Couldn't open DH file %s: %s", dhfile.c_str(), strerror(errno));
 220                         throw ModuleException("Couldn't open DH file " + dhfile + ": " + strerror(errno));
 221                 }
 222                 else
 223                 {
 224                         ret = PEM_read_DHparams(dhpfile, NULL, NULL, NULL);
 225                         if ((SSL_CTX_set_tmp_dh(ctx, ret) < 0) || (SSL_CTX_set_tmp_dh(clictx, ret) < 0))
 226                         {
 227                                 ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Couldn't set DH parameters %s. SSL errors follow:", dhfile.c_str());
 228                                 ERR_print_errors_cb(error_callback, this);
 229                         }
 230                 }
 231
 232                 fclose(dhpfile);
 233         }
 234
 235         void On005Numeric(std::string &output)
 236         {
 237                 if (!sslports.empty())
 238                         output.append(" SSL=" + sslports);
 239         }
 240
 241         ~ModuleSSLOpenSSL()
 242         {
 243                 SSL_CTX_free(ctx);
 244                 SSL_CTX_free(clictx);
 245                 delete[] sessions;
 246         }
 247
 248         void OnUserConnect(LocalUser* user)
 249         {
 250                 if (user->eh.GetIOHook() == this)
 251                 {
 252                         if (sessions[user->GetFd()].sess)
 253                         {
 254                                 SSLCertSubmission(user, this, ServerInstance->Modules->Find("m_sslinfo.so"), sessions[user->GetFd()].cert);
 255                         }
 256                 }
 257         }
 258
 259         void OnCleanup(int target_type, void* item)
 260         {
 261                 if (target_type == TYPE_USER)
 262                 {
 263                         LocalUser* user = IS_LOCAL((User*)item);
 264
 265                         if (user && user->eh.GetIOHook() == this)
 266                         {
 267                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 268                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 269                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 270                         }
 271                 }
 272         }
 273
 274         Version GetVersion()
 275         {
 276                 return Version("Provides SSL support for clients", VF_VENDOR);
 277         }
 278
 279         void OnRequest(Request& request)
 280         {
 281                 if (strcmp("GET_SSL_CERT", request.id) == 0)
 282                 {
 283                         SocketCertificateRequest& req = static_cast<SocketCertificateRequest&>(request);
 284                         int fd = req.sock->GetFd();
 285                         issl_session* session = &sessions[fd];
 286
 287                         req.cert = session->cert;
 288                 }
 289         }
 290
 291         void OnStreamSocketAccept(StreamSocket* user, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server)
 292         {
 293                 int fd = user->GetFd();
 294
 295                 issl_session* session = &sessions[fd];
 296
 297                 session->fd = fd;
 298                 session->sess = SSL_new(ctx);
 299                 session->status = ISSL_NONE;
 300                 session->outbound = false;
 301
 302                 if (session->sess == NULL)
 303                         return;
 304
 305                 if (SSL_set_fd(session->sess, fd) == 0)
 306                 {
 307                         ServerInstance->Logs->Log("m_ssl_openssl",DEBUG,"BUG: Can't set fd with SSL_set_fd: %d", fd);
 308                         return;
 309                 }
 310
 311                 Handshake(user, session);
 312         }
 313
 314         void OnStreamSocketConnect(StreamSocket* user)
 315         {
 316                 int fd = user->GetFd();
 317                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 318                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() -1))
 319                         return;
 320
 321                 issl_session* session = &sessions[fd];
 322
 323                 session->fd = fd;
 324                 session->sess = SSL_new(clictx);
 325                 session->status = ISSL_NONE;
 326                 session->outbound = true;
 327
 328                 if (session->sess == NULL)
 329                         return;
 330
 331                 if (SSL_set_fd(session->sess, fd) == 0)
 332                 {
 333                         ServerInstance->Logs->Log("m_ssl_openssl",DEBUG,"BUG: Can't set fd with SSL_set_fd: %d", fd);
 334                         return;
 335                 }
 336
 337                 Handshake(user, session);
 338         }
 339
 340         void OnStreamSocketClose(StreamSocket* user)
 341         {
 342                 int fd = user->GetFd();
 343                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 344                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 345                         return;
 346
 347                 CloseSession(&sessions[fd]);
 348         }
 349
 350         int OnStreamSocketRead(StreamSocket* user, std::string& recvq)
 351         {
 352                 int fd = user->GetFd();
 353                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 354                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 355                         return -1;
 356
 357                 issl_session* session = &sessions[fd];
 358
 359                 if (!session->sess)
 360                 {
 361                         CloseSession(session);
 362                         return -1;
 363                 }
 364
 365                 if (session->status == ISSL_HANDSHAKING)
 366                 {
 367                         // The handshake isn't finished and it wants to read, try to finish it.
 368                         if (!Handshake(user, session))
 369                         {
 370                                 // Couldn't resume handshake.
 371                                 if (session->status == ISSL_NONE)
 372                                         return -1;
 373                                 return 0;
 374                         }
 375                 }
 376
 377                 // If we resumed the handshake then session->status will be ISSL_OPEN
 378
 379                 if (session->status == ISSL_OPEN)
 380                 {
 381                         char* buffer = ServerInstance->GetReadBuffer();
 382                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 383                         int ret = SSL_read(session->sess, buffer, bufsiz);
 384
 385                         if (ret > 0)
 386                         {
 387                                 recvq.append(buffer, ret);
 388                                 return 1;
 389                         }
 390                         else if (ret == 0)
 391                         {
 392                                 // Client closed connection.
 393                                 CloseSession(session);
 394                                 return -1;
 395                         }
 396                         else if (ret < 0)
 397                         {
 398                                 int err = SSL_get_error(session->sess, ret);
 399
 400                                 if (err == SSL_ERROR_WANT_READ)
 401                                 {
 402                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ);
 403                                         return 0;
 404                                 }
 405                                 else if (err == SSL_ERROR_WANT_WRITE)
 406                                 {
 407                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 408                                         return 0;
 409                                 }
 410                                 else
 411                                 {
 412                                         CloseSession(session);
 413                                         return -1;
 414                                 }
 415                         }
 416                 }
 417
 418                 return 0;
 419         }
 420
 421         int OnStreamSocketWrite(StreamSocket* user, std::string& buffer)
 422         {
 423                 int fd = user->GetFd();
 424
 425                 issl_session* session = &sessions[fd];
 426
 427                 if (!session->sess)
 428                 {
 429                         CloseSession(session);
 430                         return -1;
 431                 }
 432
 433                 session->data_to_write = true;
 434
 435                 if (session->status == ISSL_HANDSHAKING)
 436                 {
 437                         if (!Handshake(user, session))
 438                         {
 439                                 // Couldn't resume handshake.
 440                                 if (session->status == ISSL_NONE)
 441                                         return -1;
 442                                 return 0;
 443                         }
 444                 }
 445
 446                 if (session->status == ISSL_OPEN)
 447                 {
 448                         int ret = SSL_write(session->sess, buffer.data(), buffer.size());
 449                         if (ret == (int)buffer.length())
 450                         {
 451                                 session->data_to_write = false;
 452                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 453                                 return 1;
 454                         }
 455                         else if (ret > 0)
 456                         {
 457                                 buffer = buffer.substr(ret);
 458                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 459                                 return 0;
 460                         }
 461                         else if (ret == 0)
 462                         {
 463                                 CloseSession(session);
 464                                 return -1;
 465                         }
 466                         else if (ret < 0)
 467                         {
 468                                 int err = SSL_get_error(session->sess, ret);
 469
 470                                 if (err == SSL_ERROR_WANT_WRITE)
 471                                 {
 472                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 473                                         return 0;
 474                                 }
 475                                 else if (err == SSL_ERROR_WANT_READ)
 476                                 {
 477                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 478                                         return 0;
 479                                 }
 480                                 else
 481                                 {
 482                                         CloseSession(session);
 483                                         return -1;
 484                                 }
 485                         }
 486                 }
 487                 return 0;
 488         }
 489
 490         bool Handshake(StreamSocket* user, issl_session* session)
 491         {
 492                 int ret;
 493
 494                 if (session->outbound)
 495                         ret = SSL_connect(session->sess);
 496                 else
 497                         ret = SSL_accept(session->sess);
 498
 499                 if (ret < 0)
 500                 {
 501                         int err = SSL_get_error(session->sess, ret);
 502
 503                         if (err == SSL_ERROR_WANT_READ)
 504                         {
 505                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 506                                 session->status = ISSL_HANDSHAKING;
 507                                 return true;
 508                         }
 509                         else if (err == SSL_ERROR_WANT_WRITE)
 510                         {
 511                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 512                                 session->status = ISSL_HANDSHAKING;
 513                                 return true;
 514                         }
 515                         else
 516                         {
 517                                 CloseSession(session);
 518                         }
 519
 520                         return false;
 521                 }
 522                 else if (ret > 0)
 523                 {
 524                         // Handshake complete.
 525                         VerifyCertificate(session, user);
 526
 527                         session->status = ISSL_OPEN;
 528
 529                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 530
 531                         return true;
 532                 }
 533                 else if (ret == 0)
 534                 {
 535                         CloseSession(session);
 536                         return true;
 537                 }
 538
 539                 return true;
 540         }
 541
 542         void CloseSession(issl_session* session)
 543         {
 544                 if (session->sess)
 545                 {
 546                         SSL_shutdown(session->sess);
 547                         SSL_free(session->sess);
 548                 }
 549
 550                 session->sess = NULL;
 551                 session->status = ISSL_NONE;
 552                 errno = EIO;
 553         }
 554
 555         void VerifyCertificate(issl_session* session, StreamSocket* user)
 556         {
 557                 if (!session->sess || !user || session->cert)
 558                         return;
 559
 560                 X509* cert;
 561                 ssl_cert* certinfo = new ssl_cert;
 562                 session->cert = certinfo;
 563                 unsigned int n;
 564                 unsigned char md[EVP_MAX_MD_SIZE];
 565                 const EVP_MD *digest = EVP_md5();
 566
 567                 cert = SSL_get_peer_certificate((SSL*)session->sess);
 568
 569                 if (!cert)
 570                 {
 571                         certinfo->error = "Could not get peer certificate: "+std::string(get_error());
 572                         return;
 573                 }
 574
 575                 certinfo->invalid = (SSL_get_verify_result(session->sess) != X509_V_OK);
 576
 577                 if (SelfSigned)
 578                 {
 579                         certinfo->unknownsigner = false;
 580                         certinfo->trusted = true;
 581                 }
 582                 else
 583                 {
 584                         certinfo->unknownsigner = true;
 585                         certinfo->trusted = false;
 586                 }
 587
 588                 certinfo->dn = X509_NAME_oneline(X509_get_subject_name(cert),0,0);
 589                 certinfo->issuer = X509_NAME_oneline(X509_get_issuer_name(cert),0,0);
 590
 591                 if (!X509_digest(cert, digest, md, &n))
 592                 {
 593                         certinfo->error = "Out of memory generating fingerprint";
 594                 }
 595                 else
 596                 {
 597                         certinfo->fingerprint = irc::hex(md, n);
 598                 }
 599
 600                 if ((ASN1_UTCTIME_cmp_time_t(X509_get_notAfter(cert), ServerInstance->Time()) == -1) || (ASN1_UTCTIME_cmp_time_t(X509_get_notBefore(cert), ServerInstance->Time()) == 0))
 601                 {
 602                         certinfo->error = "Not activated, or expired certificate";
 603                 }
 604
 605                 X509_free(cert);
 606         }
 607 };
 608
 609 static int error_callback(const char *str, size_t len, void *u)
 610 {
 611         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "SSL error: " + std::string(str, len - 1));
 612
 613         //
 614         // XXX: Remove this line, it causes valgrind warnings...
 615         //
 616         // MD_update(&m, buf, j);
 617         //
 618         //
 619         // ... ONLY JOKING! :-)
 620         //
 621
 622         return 0;
 623 }
 624
 625 MODULE_INIT(ModuleSSLOpenSSL)