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, "libcrypto.lib")
  21 # pragma comment(lib, "libssl.lib")
  22 # pragma comment(lib, "user32.lib")
  23 # pragma comment(lib, "advapi32.lib")
  24 # pragma comment(lib, "libgcc.lib")
  25 # pragma comment(lib, "libmingwex.lib")
  26 # pragma comment(lib, "gdi32.lib")
  27 # undef MAX_DESCRIPTORS
  28 # define MAX_DESCRIPTORS 10000
  29 #endif
  30
  31 /* $ModDesc: Provides SSL support for clients */
  32
  33 /* $LinkerFlags: if("USE_FREEBSD_BASE_SSL") -lssl -lcrypto */
  34 /* $CompileFlags: if(!"USE_FREEBSD_BASE_SSL") pkgconfversion("openssl","0.9.7") pkgconfincludes("openssl","/openssl/ssl.h","") */
  35 /* $LinkerFlags: if(!"USE_FREEBSD_BASE_SSL") rpath("pkg-config --libs openssl") pkgconflibs("openssl","/libssl.so","-lssl -lcrypto -ldl") */
  36
  37 /* $NoPedantic */
  38
  39
  40 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING, ISSL_OPEN };
  41
  42 static bool SelfSigned = false;
  43
  44 char* get_error()
  45 {
  46         return ERR_error_string(ERR_get_error(), NULL);
  47 }
  48
  49 static int error_callback(const char *str, size_t len, void *u);
  50
  51 /** Represents an SSL user's extra data
  52  */
  53 class issl_session
  54 {
  55 public:
  56         SSL* sess;
  57         issl_status status;
  58         reference<ssl_cert> cert;
  59
  60         int fd;
  61         bool outbound;
  62         bool data_to_write;
  63
  64         issl_session()
  65         {
  66                 outbound = false;
  67                 data_to_write = false;
  68         }
  69 };
  70
  71 static int OnVerify(int preverify_ok, X509_STORE_CTX *ctx)
  72 {
  73         /* XXX: This will allow self signed certificates.
  74          * In the future if we want an option to not allow this,
  75          * we can just return preverify_ok here, and openssl
  76          * will boot off self-signed and invalid peer certs.
  77          */
  78         int ve = X509_STORE_CTX_get_error(ctx);
  79
  80         SelfSigned = (ve == X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT);
  81
  82         return 1;
  83 }
  84
  85 class ModuleSSLOpenSSL : public Module
  86 {
  87         int inbufsize;
  88         issl_session* sessions;
  89
  90         SSL_CTX* ctx;
  91         SSL_CTX* clictx;
  92
  93         char cipher[MAXBUF];
  94
  95         std::string sslports;
  96         bool use_sha;
  97
  98         ServiceProvider iohook;
  99  public:
 100
 101         ModuleSSLOpenSSL() : iohook(this, "ssl/openssl", SERVICE_IOHOOK)
 102         {
 103                 sessions = new issl_session[ServerInstance->SE->GetMaxFds()];
 104
 105                 // Not rehashable...because I cba to reduce all the sizes of existing buffers.
 106                 inbufsize = ServerInstance->Config->NetBufferSize;
 107
 108                 /* Global SSL library initialization*/
 109                 SSL_library_init();
 110                 SSL_load_error_strings();
 111
 112                 /* Build our SSL contexts:
 113                  * NOTE: OpenSSL makes us have two contexts, one for servers and one for clients. ICK.
 114                  */
 115                 ctx = SSL_CTX_new( SSLv23_server_method() );
 116                 clictx = SSL_CTX_new( SSLv23_client_method() );
 117
 118                 SSL_CTX_set_mode(ctx, SSL_MODE_ENABLE_PARTIAL_WRITE | SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
 119                 SSL_CTX_set_mode(clictx, SSL_MODE_ENABLE_PARTIAL_WRITE | SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
 120
 121                 SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, OnVerify);
 122                 SSL_CTX_set_verify(clictx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, OnVerify);
 123         }
 124
 125         void init()
 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                 sslports.clear();
 146
 147                 ConfigTag* Conf = ServerInstance->Config->ConfValue("openssl");
 148
 149                 if (Conf->getBool("showports", true))
 150                 {
 151                         for (size_t i = 0; i < ServerInstance->ports.size(); i++)
 152                         {
 153                                 ListenSocket* port = ServerInstance->ports[i];
 154                                 if (port->bind_tag->getString("ssl") != "openssl")
 155                                         continue;
 156
 157                                 std::string portid = port->bind_desc;
 158                                 ServerInstance->Logs->Log("m_ssl_openssl", DEFAULT, "m_ssl_openssl.so: Enabling SSL for port %s", portid.c_str());
 159                                 if (port->bind_tag->getString("type", "clients") == "clients" && port->bind_addr != "127.0.0.1")
 160                                         sslports.append(portid).append(";");
 161                         }
 162
 163                         if (!sslports.empty())
 164                                 sslports.erase(sslports.end() - 1);
 165                 }
 166         }
 167
 168         void OnModuleRehash(User* user, const std::string &param)
 169         {
 170                 if (param != "ssl")
 171                         return;
 172
 173                 std::string keyfile;
 174                 std::string certfile;
 175                 std::string cafile;
 176                 std::string dhfile;
 177                 OnRehash(user);
 178
 179                 ConfigTag* conf = ServerInstance->Config->ConfValue("openssl");
 180
 181                 cafile   = conf->getString("cafile", "conf/ca.pem");
 182                 certfile = conf->getString("certfile", "conf/cert.pem");
 183                 keyfile  = conf->getString("keyfile", "conf/key.pem");
 184                 dhfile   = conf->getString("dhfile", "conf/dhparams.pem");
 185                 std::string hash = conf->getString("hash", "md5");
 186                 if (hash != "sha1" && hash != "md5")
 187                         throw ModuleException("Unknown hash type " + hash);
 188                 use_sha = (hash == "sha1");
 189
 190
 191                 /* Load our keys and certificates
 192                  * NOTE: OpenSSL's error logging API sucks, don't blame us for this clusterfuck.
 193                  */
 194                 if ((!SSL_CTX_use_certificate_chain_file(ctx, certfile.c_str())) || (!SSL_CTX_use_certificate_chain_file(clictx, certfile.c_str())))
 195                 {
 196                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Can't read certificate file %s. %s", certfile.c_str(), strerror(errno));
 197                         ERR_print_errors_cb(error_callback, this);
 198                 }
 199
 200                 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)))
 201                 {
 202                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Can't read key file %s. %s", keyfile.c_str(), strerror(errno));
 203                         ERR_print_errors_cb(error_callback, this);
 204                 }
 205
 206                 /* Load the CAs we trust*/
 207                 if (((!SSL_CTX_load_verify_locations(ctx, cafile.c_str(), 0))) || (!SSL_CTX_load_verify_locations(clictx, cafile.c_str(), 0)))
 208                 {
 209                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Can't read CA list from %s. %s", cafile.c_str(), strerror(errno));
 210                         ERR_print_errors_cb(error_callback, this);
 211                 }
 212
 213                 FILE* dhpfile = fopen(dhfile.c_str(), "r");
 214                 DH* ret;
 215
 216                 if (dhpfile == NULL)
 217                 {
 218                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so Couldn't open DH file %s: %s", dhfile.c_str(), strerror(errno));
 219                         throw ModuleException("Couldn't open DH file " + dhfile + ": " + strerror(errno));
 220                 }
 221                 else
 222                 {
 223                         ret = PEM_read_DHparams(dhpfile, NULL, NULL, NULL);
 224                         if ((SSL_CTX_set_tmp_dh(ctx, ret) < 0) || (SSL_CTX_set_tmp_dh(clictx, ret) < 0))
 225                         {
 226                                 ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Couldn't set DH parameters %s. SSL errors follow:", dhfile.c_str());
 227                                 ERR_print_errors_cb(error_callback, this);
 228                         }
 229                 }
 230
 231                 fclose(dhpfile);
 232         }
 233
 234         void On005Numeric(std::string &output)
 235         {
 236                 if (!sslports.empty())
 237                         output.append(" SSL=" + sslports);
 238         }
 239
 240         ~ModuleSSLOpenSSL()
 241         {
 242                 SSL_CTX_free(ctx);
 243                 SSL_CTX_free(clictx);
 244                 delete[] sessions;
 245         }
 246
 247         void OnUserConnect(LocalUser* user)
 248         {
 249                 if (user->eh.GetIOHook() == this)
 250                 {
 251                         if (sessions[user->eh.GetFd()].sess)
 252                         {
 253                                 if (!sessions[user->eh.GetFd()].cert->fingerprint.empty())
 254                                         user->WriteServ("NOTICE %s :*** You are connected using SSL fingerprint %s",
 255                                                 user->nick.c_str(), sessions[user->eh.GetFd()].cert->fingerprint.c_str());
 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                 session->cert = NULL;
 303
 304                 if (session->sess == NULL)
 305                         return;
 306
 307                 if (SSL_set_fd(session->sess, fd) == 0)
 308                 {
 309                         ServerInstance->Logs->Log("m_ssl_openssl",DEBUG,"BUG: Can't set fd with SSL_set_fd: %d", fd);
 310                         return;
 311                 }
 312
 313                 Handshake(user, session);
 314         }
 315
 316         void OnStreamSocketConnect(StreamSocket* user)
 317         {
 318                 int fd = user->GetFd();
 319                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 320                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() -1))
 321                         return;
 322
 323                 issl_session* session = &sessions[fd];
 324
 325                 session->fd = fd;
 326                 session->sess = SSL_new(clictx);
 327                 session->status = ISSL_NONE;
 328                 session->outbound = true;
 329
 330                 if (session->sess == NULL)
 331                         return;
 332
 333                 if (SSL_set_fd(session->sess, fd) == 0)
 334                 {
 335                         ServerInstance->Logs->Log("m_ssl_openssl",DEBUG,"BUG: Can't set fd with SSL_set_fd: %d", fd);
 336                         return;
 337                 }
 338
 339                 Handshake(user, session);
 340         }
 341
 342         void OnStreamSocketClose(StreamSocket* user)
 343         {
 344                 int fd = user->GetFd();
 345                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 346                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 347                         return;
 348
 349                 CloseSession(&sessions[fd]);
 350         }
 351
 352         int OnStreamSocketRead(StreamSocket* user, std::string& recvq)
 353         {
 354                 int fd = user->GetFd();
 355                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 356                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 357                         return -1;
 358
 359                 issl_session* session = &sessions[fd];
 360
 361                 if (!session->sess)
 362                 {
 363                         CloseSession(session);
 364                         return -1;
 365                 }
 366
 367                 if (session->status == ISSL_HANDSHAKING)
 368                 {
 369                         // The handshake isn't finished and it wants to read, try to finish it.
 370                         if (!Handshake(user, session))
 371                         {
 372                                 // Couldn't resume handshake.
 373                                 if (session->status == ISSL_NONE)
 374                                         return -1;
 375                                 return 0;
 376                         }
 377                 }
 378
 379                 // If we resumed the handshake then session->status will be ISSL_OPEN
 380
 381                 if (session->status == ISSL_OPEN)
 382                 {
 383                         char* buffer = ServerInstance->GetReadBuffer();
 384                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 385                         int ret = SSL_read(session->sess, buffer, bufsiz);
 386
 387                         if (ret > 0)
 388                         {
 389                                 recvq.append(buffer, ret);
 390                                 if (session->data_to_write)
 391                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_SINGLE_WRITE);
 392                                 return 1;
 393                         }
 394                         else if (ret == 0)
 395                         {
 396                                 // Client closed connection.
 397                                 CloseSession(session);
 398                                 return -1;
 399                         }
 400                         else if (ret < 0)
 401                         {
 402                                 int err = SSL_get_error(session->sess, ret);
 403
 404                                 if (err == SSL_ERROR_WANT_READ)
 405                                 {
 406                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ);
 407                                         return 0;
 408                                 }
 409                                 else if (err == SSL_ERROR_WANT_WRITE)
 410                                 {
 411                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 412                                         return 0;
 413                                 }
 414                                 else
 415                                 {
 416                                         CloseSession(session);
 417                                         return -1;
 418                                 }
 419                         }
 420                 }
 421
 422                 return 0;
 423         }
 424
 425         int OnStreamSocketWrite(StreamSocket* user, std::string& buffer)
 426         {
 427                 int fd = user->GetFd();
 428
 429                 issl_session* session = &sessions[fd];
 430
 431                 if (!session->sess)
 432                 {
 433                         CloseSession(session);
 434                         return -1;
 435                 }
 436
 437                 session->data_to_write = true;
 438
 439                 if (session->status == ISSL_HANDSHAKING)
 440                 {
 441                         if (!Handshake(user, session))
 442                         {
 443                                 // Couldn't resume handshake.
 444                                 if (session->status == ISSL_NONE)
 445                                         return -1;
 446                                 return 0;
 447                         }
 448                 }
 449
 450                 if (session->status == ISSL_OPEN)
 451                 {
 452                         int ret = SSL_write(session->sess, buffer.data(), buffer.size());
 453                         if (ret == (int)buffer.length())
 454                         {
 455                                 session->data_to_write = false;
 456                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 457                                 return 1;
 458                         }
 459                         else if (ret > 0)
 460                         {
 461                                 buffer = buffer.substr(ret);
 462                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 463                                 return 0;
 464                         }
 465                         else if (ret == 0)
 466                         {
 467                                 CloseSession(session);
 468                                 return -1;
 469                         }
 470                         else if (ret < 0)
 471                         {
 472                                 int err = SSL_get_error(session->sess, ret);
 473
 474                                 if (err == SSL_ERROR_WANT_WRITE)
 475                                 {
 476                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 477                                         return 0;
 478                                 }
 479                                 else if (err == SSL_ERROR_WANT_READ)
 480                                 {
 481                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ);
 482                                         return 0;
 483                                 }
 484                                 else
 485                                 {
 486                                         CloseSession(session);
 487                                         return -1;
 488                                 }
 489                         }
 490                 }
 491                 return 0;
 492         }
 493
 494         bool Handshake(StreamSocket* user, issl_session* session)
 495         {
 496                 int ret;
 497
 498                 if (session->outbound)
 499                         ret = SSL_connect(session->sess);
 500                 else
 501                         ret = SSL_accept(session->sess);
 502
 503                 if (ret < 0)
 504                 {
 505                         int err = SSL_get_error(session->sess, ret);
 506
 507                         if (err == SSL_ERROR_WANT_READ)
 508                         {
 509                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 510                                 session->status = ISSL_HANDSHAKING;
 511                                 return true;
 512                         }
 513                         else if (err == SSL_ERROR_WANT_WRITE)
 514                         {
 515                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 516                                 session->status = ISSL_HANDSHAKING;
 517                                 return true;
 518                         }
 519                         else
 520                         {
 521                                 CloseSession(session);
 522                         }
 523
 524                         return false;
 525                 }
 526                 else if (ret > 0)
 527                 {
 528                         // Handshake complete.
 529                         VerifyCertificate(session, user);
 530
 531                         session->status = ISSL_OPEN;
 532
 533                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 534
 535                         return true;
 536                 }
 537                 else if (ret == 0)
 538                 {
 539                         CloseSession(session);
 540                         return true;
 541                 }
 542
 543                 return true;
 544         }
 545
 546         void CloseSession(issl_session* session)
 547         {
 548                 if (session->sess)
 549                 {
 550                         SSL_shutdown(session->sess);
 551                         SSL_free(session->sess);
 552                 }
 553
 554                 session->sess = NULL;
 555                 session->status = ISSL_NONE;
 556                 errno = EIO;
 557         }
 558
 559         void VerifyCertificate(issl_session* session, StreamSocket* user)
 560         {
 561                 if (!session->sess || !user)
 562                         return;
 563
 564                 X509* cert;
 565                 ssl_cert* certinfo = new ssl_cert;
 566                 session->cert = certinfo;
 567                 unsigned int n;
 568                 unsigned char md[EVP_MAX_MD_SIZE];
 569                 const EVP_MD *digest = use_sha ? EVP_sha1() : EVP_md5();
 570
 571                 cert = SSL_get_peer_certificate((SSL*)session->sess);
 572
 573                 if (!cert)
 574                 {
 575                         certinfo->error = "Could not get peer certificate: "+std::string(get_error());
 576                         return;
 577                 }
 578
 579                 certinfo->invalid = (SSL_get_verify_result(session->sess) != X509_V_OK);
 580
 581                 if (SelfSigned)
 582                 {
 583                         certinfo->unknownsigner = false;
 584                         certinfo->trusted = true;
 585                 }
 586                 else
 587                 {
 588                         certinfo->unknownsigner = true;
 589                         certinfo->trusted = false;
 590                 }
 591
 592                 certinfo->dn = X509_NAME_oneline(X509_get_subject_name(cert),0,0);
 593                 certinfo->issuer = X509_NAME_oneline(X509_get_issuer_name(cert),0,0);
 594
 595                 if (!X509_digest(cert, digest, md, &n))
 596                 {
 597                         certinfo->error = "Out of memory generating fingerprint";
 598                 }
 599                 else
 600                 {
 601                         certinfo->fingerprint = irc::hex(md, n);
 602                 }
 603
 604                 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))
 605                 {
 606                         certinfo->error = "Not activated, or expired certificate";
 607                 }
 608
 609                 X509_free(cert);
 610         }
 611 };
 612
 613 static int error_callback(const char *str, size_t len, void *u)
 614 {
 615         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "SSL error: " + std::string(str, len - 1));
 616
 617         //
 618         // XXX: Remove this line, it causes valgrind warnings...
 619         //
 620         // MD_update(&m, buf, j);
 621         //
 622         //
 623         // ... ONLY JOKING! :-)
 624         //
 625
 626         return 0;
 627 }
 628
 629 MODULE_INIT(ModuleSSLOpenSSL)