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 /* $NoPedantic */
  33 /* $CopyInstall: conf/key.pem $(CONPATH) -m 0400 -o $(INSTUID) */
  34 /* $CopyInstall: conf/cert.pem $(CONPATH) -m 0444 */
  35
  36
  37 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING, ISSL_OPEN };
  38
  39 static bool SelfSigned = false;
  40
  41 char* get_error()
  42 {
  43         return ERR_error_string(ERR_get_error(), NULL);
  44 }
  45
  46 static int error_callback(const char *str, size_t len, void *u);
  47
  48 /** Represents an SSL user's extra data
  49  */
  50 class issl_session
  51 {
  52 public:
  53         SSL* sess;
  54         issl_status status;
  55         reference<ssl_cert> cert;
  56
  57         int fd;
  58         bool outbound;
  59         bool data_to_write;
  60
  61         issl_session()
  62         {
  63                 outbound = false;
  64                 data_to_write = false;
  65         }
  66 };
  67
  68 static int OnVerify(int preverify_ok, X509_STORE_CTX *ctx)
  69 {
  70         /* XXX: This will allow self signed certificates.
  71          * In the future if we want an option to not allow this,
  72          * we can just return preverify_ok here, and openssl
  73          * will boot off self-signed and invalid peer certs.
  74          */
  75         int ve = X509_STORE_CTX_get_error(ctx);
  76
  77         SelfSigned = (ve == X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT);
  78
  79         return 1;
  80 }
  81
  82 class ModuleSSLOpenSSL : public Module
  83 {
  84         int inbufsize;
  85         issl_session* sessions;
  86
  87         SSL_CTX* ctx;
  88         SSL_CTX* clictx;
  89
  90         char cipher[MAXBUF];
  91
  92         std::string keyfile;
  93         std::string certfile;
  94         std::string cafile;
  95         // std::string crlfile;
  96         std::string dhfile;
  97         std::string sslports;
  98
  99         ServiceProvider iohook;
 100  public:
 101
 102         ModuleSSLOpenSSL() : iohook(this, "ssl/openssl", SERVICE_IOHOOK)
 103         {
 104                 sessions = new issl_session[ServerInstance->SE->GetMaxFds()];
 105
 106                 // Not rehashable...because I cba to reduce all the sizes of existing buffers.
 107                 inbufsize = ServerInstance->Config->NetBufferSize;
 108
 109                 /* Global SSL library initialization*/
 110                 SSL_library_init();
 111                 SSL_load_error_strings();
 112
 113                 /* Build our SSL contexts:
 114                  * NOTE: OpenSSL makes us have two contexts, one for servers and one for clients. ICK.
 115                  */
 116                 ctx = SSL_CTX_new( SSLv23_server_method() );
 117                 clictx = SSL_CTX_new( SSLv23_client_method() );
 118
 119                 SSL_CTX_set_mode(ctx, SSL_MODE_ENABLE_PARTIAL_WRITE | SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
 120                 SSL_CTX_set_mode(clictx, SSL_MODE_ENABLE_PARTIAL_WRITE | SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
 121
 122                 SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, OnVerify);
 123                 SSL_CTX_set_verify(clictx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, OnVerify);
 124         }
 125
 126         void init()
 127         {
 128                 // Needs the flag as it ignores a plain /rehash
 129                 OnModuleRehash(NULL,"ssl");
 130                 Implementation eventlist[] = { I_On005Numeric, I_OnRehash, I_OnModuleRehash, I_OnHookIO, I_OnUserConnect };
 131                 ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
 132                 ServerInstance->Modules->AddService(iohook);
 133         }
 134
 135         void OnHookIO(StreamSocket* user, ListenSocket* lsb)
 136         {
 137                 if (!user->GetIOHook() && lsb->bind_tag->getString("ssl") == "openssl")
 138                 {
 139                         /* Hook the user with our module */
 140                         user->AddIOHook(this);
 141                 }
 142         }
 143
 144         void OnRehash(User* user)
 145         {
 146                 ConfigReader Conf;
 147
 148                 sslports.clear();
 149
 150                 for (size_t i = 0; i < ServerInstance->ports.size(); i++)
 151                 {
 152                         ListenSocket* port = ServerInstance->ports[i];
 153                         if (port->bind_tag->getString("ssl") != "openssl")
 154                                 continue;
 155
 156                         std::string portid = port->bind_desc;
 157                         ServerInstance->Logs->Log("m_ssl_openssl", DEFAULT, "m_ssl_openssl.so: Enabling SSL for port %s", portid.c_str());
 158                         if (port->bind_tag->getString("type", "clients") == "clients" && port->bind_addr != "127.0.0.1")
 159                                 sslports.append(portid).append(";");
 160                 }
 161
 162                 if (!sslports.empty())
 163                         sslports.erase(sslports.end() - 1);
 164         }
 165
 166         void OnModuleRehash(User* user, const std::string &param)
 167         {
 168                 if (param != "ssl")
 169                         return;
 170
 171                 OnRehash(user);
 172
 173                 ConfigReader Conf;
 174
 175                 cafile   = Conf.ReadValue("openssl", "cafile", 0);
 176                 certfile = Conf.ReadValue("openssl", "certfile", 0);
 177                 keyfile  = Conf.ReadValue("openssl", "keyfile", 0);
 178                 dhfile   = Conf.ReadValue("openssl", "dhfile", 0);
 179
 180                 // Set all the default values needed.
 181                 if (cafile.empty())
 182                         cafile = "conf/ca.pem";
 183
 184                 if (certfile.empty())
 185                         certfile = "conf/cert.pem";
 186
 187                 if (keyfile.empty())
 188                         keyfile = "conf/key.pem";
 189
 190                 if (dhfile.empty())
 191                         dhfile = "conf/dhparams.pem";
 192
 193                 /* Load our keys and certificates
 194                  * NOTE: OpenSSL's error logging API sucks, don't blame us for this clusterfuck.
 195                  */
 196                 if ((!SSL_CTX_use_certificate_chain_file(ctx, certfile.c_str())) || (!SSL_CTX_use_certificate_chain_file(clictx, certfile.c_str())))
 197                 {
 198                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Can't read certificate file %s. %s", certfile.c_str(), strerror(errno));
 199                         ERR_print_errors_cb(error_callback, this);
 200                 }
 201
 202                 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)))
 203                 {
 204                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Can't read key file %s. %s", keyfile.c_str(), strerror(errno));
 205                         ERR_print_errors_cb(error_callback, this);
 206                 }
 207
 208                 /* Load the CAs we trust*/
 209                 if (((!SSL_CTX_load_verify_locations(ctx, cafile.c_str(), 0))) || (!SSL_CTX_load_verify_locations(clictx, cafile.c_str(), 0)))
 210                 {
 211                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Can't read CA list from %s. %s", cafile.c_str(), strerror(errno));
 212                         ERR_print_errors_cb(error_callback, this);
 213                 }
 214
 215                 FILE* dhpfile = fopen(dhfile.c_str(), "r");
 216                 DH* ret;
 217
 218                 if (dhpfile == NULL)
 219                 {
 220                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so Couldn't open DH file %s: %s", dhfile.c_str(), strerror(errno));
 221                         throw ModuleException("Couldn't open DH file " + dhfile + ": " + strerror(errno));
 222                 }
 223                 else
 224                 {
 225                         ret = PEM_read_DHparams(dhpfile, NULL, NULL, NULL);
 226                         if ((SSL_CTX_set_tmp_dh(ctx, ret) < 0) || (SSL_CTX_set_tmp_dh(clictx, ret) < 0))
 227                         {
 228                                 ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Couldn't set DH parameters %s. SSL errors follow:", dhfile.c_str());
 229                                 ERR_print_errors_cb(error_callback, this);
 230                         }
 231                 }
 232
 233                 fclose(dhpfile);
 234         }
 235
 236         void On005Numeric(std::string &output)
 237         {
 238                 if (!sslports.empty())
 239                         output.append(" SSL=" + sslports);
 240         }
 241
 242         ~ModuleSSLOpenSSL()
 243         {
 244                 SSL_CTX_free(ctx);
 245                 SSL_CTX_free(clictx);
 246                 delete[] sessions;
 247         }
 248
 249         void OnUserConnect(LocalUser* user)
 250         {
 251                 if (user->eh.GetIOHook() == this)
 252                 {
 253                         if (sessions[user->GetFd()].sess)
 254                         {
 255                                 SSLCertSubmission(user, this, ServerInstance->Modules->Find("m_sslinfo.so"), sessions[user->GetFd()].cert);
 256                         }
 257                 }
 258         }
 259
 260         void OnCleanup(int target_type, void* item)
 261         {
 262                 if (target_type == TYPE_USER)
 263                 {
 264                         LocalUser* user = IS_LOCAL((User*)item);
 265
 266                         if (user && user->eh.GetIOHook() == this)
 267                         {
 268                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 269                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 270                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 271                         }
 272                 }
 273         }
 274
 275         Version GetVersion()
 276         {
 277                 return Version("Provides SSL support for clients", VF_VENDOR);
 278         }
 279
 280         void OnRequest(Request& request)
 281         {
 282                 if (strcmp("GET_SSL_CERT", request.id) == 0)
 283                 {
 284                         SocketCertificateRequest& req = static_cast<SocketCertificateRequest&>(request);
 285                         int fd = req.sock->GetFd();
 286                         issl_session* session = &sessions[fd];
 287
 288                         req.cert = session->cert;
 289                 }
 290         }
 291
 292         void OnStreamSocketAccept(StreamSocket* user, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server)
 293         {
 294                 int fd = user->GetFd();
 295
 296                 issl_session* session = &sessions[fd];
 297
 298                 session->fd = fd;
 299                 session->sess = SSL_new(ctx);
 300                 session->status = ISSL_NONE;
 301                 session->outbound = false;
 302
 303                 if (session->sess == NULL)
 304                         return;
 305
 306                 if (SSL_set_fd(session->sess, fd) == 0)
 307                 {
 308                         ServerInstance->Logs->Log("m_ssl_openssl",DEBUG,"BUG: Can't set fd with SSL_set_fd: %d", fd);
 309                         return;
 310                 }
 311
 312                 Handshake(user, session);
 313         }
 314
 315         void OnStreamSocketConnect(StreamSocket* user)
 316         {
 317                 int fd = user->GetFd();
 318                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 319                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() -1))
 320                         return;
 321
 322                 issl_session* session = &sessions[fd];
 323
 324                 session->fd = fd;
 325                 session->sess = SSL_new(clictx);
 326                 session->status = ISSL_NONE;
 327                 session->outbound = true;
 328
 329                 if (session->sess == NULL)
 330                         return;
 331
 332                 if (SSL_set_fd(session->sess, fd) == 0)
 333                 {
 334                         ServerInstance->Logs->Log("m_ssl_openssl",DEBUG,"BUG: Can't set fd with SSL_set_fd: %d", fd);
 335                         return;
 336                 }
 337
 338                 Handshake(user, session);
 339         }
 340
 341         void OnStreamSocketClose(StreamSocket* user)
 342         {
 343                 int fd = user->GetFd();
 344                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 345                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 346                         return;
 347
 348                 CloseSession(&sessions[fd]);
 349         }
 350
 351         int OnStreamSocketRead(StreamSocket* user, std::string& recvq)
 352         {
 353                 int fd = user->GetFd();
 354                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 355                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 356                         return -1;
 357
 358                 issl_session* session = &sessions[fd];
 359
 360                 if (!session->sess)
 361                 {
 362                         CloseSession(session);
 363                         return -1;
 364                 }
 365
 366                 if (session->status == ISSL_HANDSHAKING)
 367                 {
 368                         // The handshake isn't finished and it wants to read, try to finish it.
 369                         if (!Handshake(user, session))
 370                         {
 371                                 // Couldn't resume handshake.
 372                                 if (session->status == ISSL_NONE)
 373                                         return -1;
 374                                 return 0;
 375                         }
 376                 }
 377
 378                 // If we resumed the handshake then session->status will be ISSL_OPEN
 379
 380                 if (session->status == ISSL_OPEN)
 381                 {
 382                         char* buffer = ServerInstance->GetReadBuffer();
 383                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 384                         int ret = SSL_read(session->sess, buffer, bufsiz);
 385
 386                         if (ret > 0)
 387                         {
 388                                 recvq.append(buffer, ret);
 389                                 return 1;
 390                         }
 391                         else if (ret == 0)
 392                         {
 393                                 // Client closed connection.
 394                                 CloseSession(session);
 395                                 return -1;
 396                         }
 397                         else if (ret < 0)
 398                         {
 399                                 int err = SSL_get_error(session->sess, ret);
 400
 401                                 if (err == SSL_ERROR_WANT_READ)
 402                                 {
 403                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ);
 404                                         return 0;
 405                                 }
 406                                 else if (err == SSL_ERROR_WANT_WRITE)
 407                                 {
 408                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 409                                         return 0;
 410                                 }
 411                                 else
 412                                 {
 413                                         CloseSession(session);
 414                                         return -1;
 415                                 }
 416                         }
 417                 }
 418
 419                 return 0;
 420         }
 421
 422         int OnStreamSocketWrite(StreamSocket* user, std::string& buffer)
 423         {
 424                 int fd = user->GetFd();
 425
 426                 issl_session* session = &sessions[fd];
 427
 428                 if (!session->sess)
 429                 {
 430                         CloseSession(session);
 431                         return -1;
 432                 }
 433
 434                 session->data_to_write = true;
 435
 436                 if (session->status == ISSL_HANDSHAKING)
 437                 {
 438                         if (!Handshake(user, session))
 439                         {
 440                                 // Couldn't resume handshake.
 441                                 if (session->status == ISSL_NONE)
 442                                         return -1;
 443                                 return 0;
 444                         }
 445                 }
 446
 447                 if (session->status == ISSL_OPEN)
 448                 {
 449                         int ret = SSL_write(session->sess, buffer.data(), buffer.size());
 450                         if (ret == (int)buffer.length())
 451                         {
 452                                 session->data_to_write = false;
 453                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 454                                 return 1;
 455                         }
 456                         else if (ret > 0)
 457                         {
 458                                 buffer = buffer.substr(ret);
 459                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 460                                 return 0;
 461                         }
 462                         else if (ret == 0)
 463                         {
 464                                 CloseSession(session);
 465                                 return -1;
 466                         }
 467                         else if (ret < 0)
 468                         {
 469                                 int err = SSL_get_error(session->sess, ret);
 470
 471                                 if (err == SSL_ERROR_WANT_WRITE)
 472                                 {
 473                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 474                                         return 0;
 475                                 }
 476                                 else if (err == SSL_ERROR_WANT_READ)
 477                                 {
 478                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 479                                         return 0;
 480                                 }
 481                                 else
 482                                 {
 483                                         CloseSession(session);
 484                                         return -1;
 485                                 }
 486                         }
 487                 }
 488                 return 0;
 489         }
 490
 491         bool Handshake(StreamSocket* user, issl_session* session)
 492         {
 493                 int ret;
 494
 495                 if (session->outbound)
 496                         ret = SSL_connect(session->sess);
 497                 else
 498                         ret = SSL_accept(session->sess);
 499
 500                 if (ret < 0)
 501                 {
 502                         int err = SSL_get_error(session->sess, ret);
 503
 504                         if (err == SSL_ERROR_WANT_READ)
 505                         {
 506                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 507                                 session->status = ISSL_HANDSHAKING;
 508                                 return true;
 509                         }
 510                         else if (err == SSL_ERROR_WANT_WRITE)
 511                         {
 512                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 513                                 session->status = ISSL_HANDSHAKING;
 514                                 return true;
 515                         }
 516                         else
 517                         {
 518                                 CloseSession(session);
 519                         }
 520
 521                         return false;
 522                 }
 523                 else if (ret > 0)
 524                 {
 525                         // Handshake complete.
 526                         VerifyCertificate(session, user);
 527
 528                         session->status = ISSL_OPEN;
 529
 530                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 531
 532                         return true;
 533                 }
 534                 else if (ret == 0)
 535                 {
 536                         CloseSession(session);
 537                         return true;
 538                 }
 539
 540                 return true;
 541         }
 542
 543         void CloseSession(issl_session* session)
 544         {
 545                 if (session->sess)
 546                 {
 547                         SSL_shutdown(session->sess);
 548                         SSL_free(session->sess);
 549                 }
 550
 551                 session->sess = NULL;
 552                 session->status = ISSL_NONE;
 553                 errno = EIO;
 554         }
 555
 556         void VerifyCertificate(issl_session* session, StreamSocket* user)
 557         {
 558                 if (!session->sess || !user || session->cert)
 559                         return;
 560
 561                 X509* cert;
 562                 ssl_cert* certinfo = new ssl_cert;
 563                 session->cert = certinfo;
 564                 unsigned int n;
 565                 unsigned char md[EVP_MAX_MD_SIZE];
 566                 const EVP_MD *digest = EVP_md5();
 567
 568                 cert = SSL_get_peer_certificate((SSL*)session->sess);
 569
 570                 if (!cert)
 571                 {
 572                         certinfo->error = "Could not get peer certificate: "+std::string(get_error());
 573                         return;
 574                 }
 575
 576                 certinfo->invalid = (SSL_get_verify_result(session->sess) != X509_V_OK);
 577
 578                 if (SelfSigned)
 579                 {
 580                         certinfo->unknownsigner = false;
 581                         certinfo->trusted = true;
 582                 }
 583                 else
 584                 {
 585                         certinfo->unknownsigner = true;
 586                         certinfo->trusted = false;
 587                 }
 588
 589                 certinfo->dn = X509_NAME_oneline(X509_get_subject_name(cert),0,0);
 590                 certinfo->issuer = X509_NAME_oneline(X509_get_issuer_name(cert),0,0);
 591
 592                 if (!X509_digest(cert, digest, md, &n))
 593                 {
 594                         certinfo->error = "Out of memory generating fingerprint";
 595                 }
 596                 else
 597                 {
 598                         certinfo->fingerprint = irc::hex(md, n);
 599                 }
 600
 601                 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))
 602                 {
 603                         certinfo->error = "Not activated, or expired certificate";
 604                 }
 605
 606                 X509_free(cert);
 607         }
 608 };
 609
 610 static int error_callback(const char *str, size_t len, void *u)
 611 {
 612         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "SSL error: " + std::string(str, len - 1));
 613
 614         //
 615         // XXX: Remove this line, it causes valgrind warnings...
 616         //
 617         // MD_update(&m, buf, j);
 618         //
 619         //
 620         // ... ONLY JOKING! :-)
 621         //
 622
 623         return 0;
 624 }
 625
 626 MODULE_INIT(ModuleSSLOpenSSL)