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
  34
  35 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING, ISSL_OPEN };
  36
  37 static bool SelfSigned = false;
  38
  39 char* get_error()
  40 {
  41         return ERR_error_string(ERR_get_error(), NULL);
  42 }
  43
  44 static int error_callback(const char *str, size_t len, void *u);
  45
  46 /** Represents an SSL user's extra data
  47  */
  48 class issl_session
  49 {
  50 public:
  51         SSL* sess;
  52         issl_status status;
  53         reference<ssl_cert> cert;
  54
  55         int fd;
  56         bool outbound;
  57         bool data_to_write;
  58
  59         issl_session()
  60         {
  61                 outbound = false;
  62                 data_to_write = false;
  63         }
  64 };
  65
  66 static int OnVerify(int preverify_ok, X509_STORE_CTX *ctx)
  67 {
  68         /* XXX: This will allow self signed certificates.
  69          * In the future if we want an option to not allow this,
  70          * we can just return preverify_ok here, and openssl
  71          * will boot off self-signed and invalid peer certs.
  72          */
  73         int ve = X509_STORE_CTX_get_error(ctx);
  74
  75         SelfSigned = (ve == X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT);
  76
  77         return 1;
  78 }
  79
  80 class ModuleSSLOpenSSL : public Module
  81 {
  82         int inbufsize;
  83         issl_session* sessions;
  84
  85         SSL_CTX* ctx;
  86         SSL_CTX* clictx;
  87
  88         char cipher[MAXBUF];
  89
  90         std::string sslports;
  91         bool use_sha;
  92
  93         ServiceProvider iohook;
  94  public:
  95
  96         ModuleSSLOpenSSL() : iohook(this, "ssl/openssl", SERVICE_IOHOOK)
  97         {
  98                 sessions = new issl_session[ServerInstance->SE->GetMaxFds()];
  99
 100                 // Not rehashable...because I cba to reduce all the sizes of existing buffers.
 101                 inbufsize = ServerInstance->Config->NetBufferSize;
 102
 103                 /* Global SSL library initialization*/
 104                 SSL_library_init();
 105                 SSL_load_error_strings();
 106
 107                 /* Build our SSL contexts:
 108                  * NOTE: OpenSSL makes us have two contexts, one for servers and one for clients. ICK.
 109                  */
 110                 ctx = SSL_CTX_new( SSLv23_server_method() );
 111                 clictx = SSL_CTX_new( SSLv23_client_method() );
 112
 113                 SSL_CTX_set_mode(ctx, SSL_MODE_ENABLE_PARTIAL_WRITE | SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
 114                 SSL_CTX_set_mode(clictx, SSL_MODE_ENABLE_PARTIAL_WRITE | SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
 115
 116                 SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, OnVerify);
 117                 SSL_CTX_set_verify(clictx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, OnVerify);
 118         }
 119
 120         void init()
 121         {
 122                 // Needs the flag as it ignores a plain /rehash
 123                 OnModuleRehash(NULL,"ssl");
 124                 Implementation eventlist[] = { I_On005Numeric, I_OnRehash, I_OnModuleRehash, I_OnHookIO, I_OnUserConnect };
 125                 ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
 126                 ServerInstance->Modules->AddService(iohook);
 127         }
 128
 129         void OnHookIO(StreamSocket* user, ListenSocket* lsb)
 130         {
 131                 if (!user->GetIOHook() && lsb->bind_tag->getString("ssl") == "openssl")
 132                 {
 133                         /* Hook the user with our module */
 134                         user->AddIOHook(this);
 135                 }
 136         }
 137
 138         void OnRehash(User* user)
 139         {
 140                 sslports.clear();
 141
 142                 ConfigTag* Conf = ServerInstance->Config->ConfValue("openssl");
 143
 144                 if (Conf->getBool("showports", true))
 145                 {
 146                         for (size_t i = 0; i < ServerInstance->ports.size(); i++)
 147                         {
 148                                 ListenSocket* port = ServerInstance->ports[i];
 149                                 if (port->bind_tag->getString("ssl") != "openssl")
 150                                         continue;
 151
 152                                 std::string portid = port->bind_desc;
 153                                 ServerInstance->Logs->Log("m_ssl_openssl", DEFAULT, "m_ssl_openssl.so: Enabling SSL for port %s", portid.c_str());
 154                                 if (port->bind_tag->getString("type", "clients") == "clients" && port->bind_addr != "127.0.0.1")
 155                                         sslports.append(portid).append(";");
 156                         }
 157
 158                         if (!sslports.empty())
 159                                 sslports.erase(sslports.end() - 1);
 160                 }
 161         }
 162
 163         void OnModuleRehash(User* user, const std::string &param)
 164         {
 165                 if (param != "ssl")
 166                         return;
 167
 168                 std::string keyfile;
 169                 std::string certfile;
 170                 std::string cafile;
 171                 std::string dhfile;
 172                 OnRehash(user);
 173
 174                 ConfigTag* conf = ServerInstance->Config->ConfValue("openssl");
 175
 176                 cafile   = conf->getString("cafile", "conf/ca.pem");
 177                 certfile = conf->getString("certfile", "conf/cert.pem");
 178                 keyfile  = conf->getString("keyfile", "conf/key.pem");
 179                 dhfile   = conf->getString("dhfile", "conf/dhparams.pem");
 180                 std::string hash = conf->getString("hash", "md5");
 181                 if (hash != "sha1" && hash != "md5")
 182                         throw ModuleException("Unknown hash type " + hash);
 183                 use_sha = (hash == "sha1");
 184
 185
 186                 /* Load our keys and certificates
 187                  * NOTE: OpenSSL's error logging API sucks, don't blame us for this clusterfuck.
 188                  */
 189                 if ((!SSL_CTX_use_certificate_chain_file(ctx, certfile.c_str())) || (!SSL_CTX_use_certificate_chain_file(clictx, certfile.c_str())))
 190                 {
 191                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Can't read certificate file %s. %s", certfile.c_str(), strerror(errno));
 192                         ERR_print_errors_cb(error_callback, this);
 193                 }
 194
 195                 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)))
 196                 {
 197                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Can't read key file %s. %s", keyfile.c_str(), strerror(errno));
 198                         ERR_print_errors_cb(error_callback, this);
 199                 }
 200
 201                 /* Load the CAs we trust*/
 202                 if (((!SSL_CTX_load_verify_locations(ctx, cafile.c_str(), 0))) || (!SSL_CTX_load_verify_locations(clictx, cafile.c_str(), 0)))
 203                 {
 204                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Can't read CA list from %s. %s", cafile.c_str(), strerror(errno));
 205                         ERR_print_errors_cb(error_callback, this);
 206                 }
 207
 208                 FILE* dhpfile = fopen(dhfile.c_str(), "r");
 209                 DH* ret;
 210
 211                 if (dhpfile == NULL)
 212                 {
 213                         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so Couldn't open DH file %s: %s", dhfile.c_str(), strerror(errno));
 214                         throw ModuleException("Couldn't open DH file " + dhfile + ": " + strerror(errno));
 215                 }
 216                 else
 217                 {
 218                         ret = PEM_read_DHparams(dhpfile, NULL, NULL, NULL);
 219                         if ((SSL_CTX_set_tmp_dh(ctx, ret) < 0) || (SSL_CTX_set_tmp_dh(clictx, ret) < 0))
 220                         {
 221                                 ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Couldn't set DH parameters %s. SSL errors follow:", dhfile.c_str());
 222                                 ERR_print_errors_cb(error_callback, this);
 223                         }
 224                 }
 225
 226                 fclose(dhpfile);
 227         }
 228
 229         void On005Numeric(std::string &output)
 230         {
 231                 if (!sslports.empty())
 232                         output.append(" SSL=" + sslports);
 233         }
 234
 235         ~ModuleSSLOpenSSL()
 236         {
 237                 SSL_CTX_free(ctx);
 238                 SSL_CTX_free(clictx);
 239                 delete[] sessions;
 240         }
 241
 242         void OnUserConnect(LocalUser* user)
 243         {
 244                 if (user->eh.GetIOHook() == this)
 245                 {
 246                         if (sessions[user->eh.GetFd()].sess)
 247                         {
 248                                 if (!sessions[user->eh.GetFd()].cert->fingerprint.empty())
 249                                         user->WriteServ("NOTICE %s :*** You are connected using SSL fingerprint %s",
 250                                                 user->nick.c_str(), sessions[user->eh.GetFd()].cert->fingerprint.c_str());
 251                         }
 252                 }
 253         }
 254
 255         void OnCleanup(int target_type, void* item)
 256         {
 257                 if (target_type == TYPE_USER)
 258                 {
 259                         LocalUser* user = IS_LOCAL((User*)item);
 260
 261                         if (user && user->eh.GetIOHook() == this)
 262                         {
 263                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 264                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 265                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 266                         }
 267                 }
 268         }
 269
 270         Version GetVersion()
 271         {
 272                 return Version("Provides SSL support for clients", VF_VENDOR);
 273         }
 274
 275         void OnRequest(Request& request)
 276         {
 277                 if (strcmp("GET_SSL_CERT", request.id) == 0)
 278                 {
 279                         SocketCertificateRequest& req = static_cast<SocketCertificateRequest&>(request);
 280                         int fd = req.sock->GetFd();
 281                         issl_session* session = &sessions[fd];
 282
 283                         req.cert = session->cert;
 284                 }
 285         }
 286
 287         void OnStreamSocketAccept(StreamSocket* user, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server)
 288         {
 289                 int fd = user->GetFd();
 290
 291                 issl_session* session = &sessions[fd];
 292
 293                 session->fd = fd;
 294                 session->sess = SSL_new(ctx);
 295                 session->status = ISSL_NONE;
 296                 session->outbound = false;
 297
 298                 if (session->sess == NULL)
 299                         return;
 300
 301                 if (SSL_set_fd(session->sess, fd) == 0)
 302                 {
 303                         ServerInstance->Logs->Log("m_ssl_openssl",DEBUG,"BUG: Can't set fd with SSL_set_fd: %d", fd);
 304                         return;
 305                 }
 306
 307                 Handshake(user, session);
 308         }
 309
 310         void OnStreamSocketConnect(StreamSocket* user)
 311         {
 312                 int fd = user->GetFd();
 313                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 314                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() -1))
 315                         return;
 316
 317                 issl_session* session = &sessions[fd];
 318
 319                 session->fd = fd;
 320                 session->sess = SSL_new(clictx);
 321                 session->status = ISSL_NONE;
 322                 session->outbound = true;
 323
 324                 if (session->sess == NULL)
 325                         return;
 326
 327                 if (SSL_set_fd(session->sess, fd) == 0)
 328                 {
 329                         ServerInstance->Logs->Log("m_ssl_openssl",DEBUG,"BUG: Can't set fd with SSL_set_fd: %d", fd);
 330                         return;
 331                 }
 332
 333                 Handshake(user, session);
 334         }
 335
 336         void OnStreamSocketClose(StreamSocket* user)
 337         {
 338                 int fd = user->GetFd();
 339                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 340                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 341                         return;
 342
 343                 CloseSession(&sessions[fd]);
 344         }
 345
 346         int OnStreamSocketRead(StreamSocket* user, std::string& recvq)
 347         {
 348                 int fd = user->GetFd();
 349                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 350                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 351                         return -1;
 352
 353                 issl_session* session = &sessions[fd];
 354
 355                 if (!session->sess)
 356                 {
 357                         CloseSession(session);
 358                         return -1;
 359                 }
 360
 361                 if (session->status == ISSL_HANDSHAKING)
 362                 {
 363                         // The handshake isn't finished and it wants to read, try to finish it.
 364                         if (!Handshake(user, session))
 365                         {
 366                                 // Couldn't resume handshake.
 367                                 if (session->status == ISSL_NONE)
 368                                         return -1;
 369                                 return 0;
 370                         }
 371                 }
 372
 373                 // If we resumed the handshake then session->status will be ISSL_OPEN
 374
 375                 if (session->status == ISSL_OPEN)
 376                 {
 377                         char* buffer = ServerInstance->GetReadBuffer();
 378                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 379                         int ret = SSL_read(session->sess, buffer, bufsiz);
 380
 381                         if (ret > 0)
 382                         {
 383                                 recvq.append(buffer, ret);
 384                                 if (session->data_to_write)
 385                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_SINGLE_WRITE);
 386                                 return 1;
 387                         }
 388                         else if (ret == 0)
 389                         {
 390                                 // Client closed connection.
 391                                 CloseSession(session);
 392                                 return -1;
 393                         }
 394                         else if (ret < 0)
 395                         {
 396                                 int err = SSL_get_error(session->sess, ret);
 397
 398                                 if (err == SSL_ERROR_WANT_READ)
 399                                 {
 400                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ);
 401                                         return 0;
 402                                 }
 403                                 else if (err == SSL_ERROR_WANT_WRITE)
 404                                 {
 405                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 406                                         return 0;
 407                                 }
 408                                 else
 409                                 {
 410                                         CloseSession(session);
 411                                         return -1;
 412                                 }
 413                         }
 414                 }
 415
 416                 return 0;
 417         }
 418
 419         int OnStreamSocketWrite(StreamSocket* user, std::string& buffer)
 420         {
 421                 int fd = user->GetFd();
 422
 423                 issl_session* session = &sessions[fd];
 424
 425                 if (!session->sess)
 426                 {
 427                         CloseSession(session);
 428                         return -1;
 429                 }
 430
 431                 session->data_to_write = true;
 432
 433                 if (session->status == ISSL_HANDSHAKING)
 434                 {
 435                         if (!Handshake(user, session))
 436                         {
 437                                 // Couldn't resume handshake.
 438                                 if (session->status == ISSL_NONE)
 439                                         return -1;
 440                                 return 0;
 441                         }
 442                 }
 443
 444                 if (session->status == ISSL_OPEN)
 445                 {
 446                         int ret = SSL_write(session->sess, buffer.data(), buffer.size());
 447                         if (ret == (int)buffer.length())
 448                         {
 449                                 session->data_to_write = false;
 450                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 451                                 return 1;
 452                         }
 453                         else if (ret > 0)
 454                         {
 455                                 buffer = buffer.substr(ret);
 456                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 457                                 return 0;
 458                         }
 459                         else if (ret == 0)
 460                         {
 461                                 CloseSession(session);
 462                                 return -1;
 463                         }
 464                         else if (ret < 0)
 465                         {
 466                                 int err = SSL_get_error(session->sess, ret);
 467
 468                                 if (err == SSL_ERROR_WANT_WRITE)
 469                                 {
 470                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 471                                         return 0;
 472                                 }
 473                                 else if (err == SSL_ERROR_WANT_READ)
 474                                 {
 475                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ);
 476                                         return 0;
 477                                 }
 478                                 else
 479                                 {
 480                                         CloseSession(session);
 481                                         return -1;
 482                                 }
 483                         }
 484                 }
 485                 return 0;
 486         }
 487
 488         bool Handshake(StreamSocket* user, issl_session* session)
 489         {
 490                 int ret;
 491
 492                 if (session->outbound)
 493                         ret = SSL_connect(session->sess);
 494                 else
 495                         ret = SSL_accept(session->sess);
 496
 497                 if (ret < 0)
 498                 {
 499                         int err = SSL_get_error(session->sess, ret);
 500
 501                         if (err == SSL_ERROR_WANT_READ)
 502                         {
 503                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 504                                 session->status = ISSL_HANDSHAKING;
 505                                 return true;
 506                         }
 507                         else if (err == SSL_ERROR_WANT_WRITE)
 508                         {
 509                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 510                                 session->status = ISSL_HANDSHAKING;
 511                                 return true;
 512                         }
 513                         else
 514                         {
 515                                 CloseSession(session);
 516                         }
 517
 518                         return false;
 519                 }
 520                 else if (ret > 0)
 521                 {
 522                         // Handshake complete.
 523                         VerifyCertificate(session, user);
 524
 525                         session->status = ISSL_OPEN;
 526
 527                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 528
 529                         return true;
 530                 }
 531                 else if (ret == 0)
 532                 {
 533                         CloseSession(session);
 534                         return true;
 535                 }
 536
 537                 return true;
 538         }
 539
 540         void CloseSession(issl_session* session)
 541         {
 542                 if (session->sess)
 543                 {
 544                         SSL_shutdown(session->sess);
 545                         SSL_free(session->sess);
 546                 }
 547
 548                 session->sess = NULL;
 549                 session->status = ISSL_NONE;
 550                 errno = EIO;
 551         }
 552
 553         void VerifyCertificate(issl_session* session, StreamSocket* user)
 554         {
 555                 if (!session->sess || !user || session->cert)
 556                         return;
 557
 558                 X509* cert;
 559                 ssl_cert* certinfo = new ssl_cert;
 560                 session->cert = certinfo;
 561                 unsigned int n;
 562                 unsigned char md[EVP_MAX_MD_SIZE];
 563                 const EVP_MD *digest = use_sha ? EVP_sha1() : EVP_md5();
 564
 565                 cert = SSL_get_peer_certificate((SSL*)session->sess);
 566
 567                 if (!cert)
 568                 {
 569                         certinfo->error = "Could not get peer certificate: "+std::string(get_error());
 570                         return;
 571                 }
 572
 573                 certinfo->invalid = (SSL_get_verify_result(session->sess) != X509_V_OK);
 574
 575                 if (SelfSigned)
 576                 {
 577                         certinfo->unknownsigner = false;
 578                         certinfo->trusted = true;
 579                 }
 580                 else
 581                 {
 582                         certinfo->unknownsigner = true;
 583                         certinfo->trusted = false;
 584                 }
 585
 586                 certinfo->dn = X509_NAME_oneline(X509_get_subject_name(cert),0,0);
 587                 certinfo->issuer = X509_NAME_oneline(X509_get_issuer_name(cert),0,0);
 588
 589                 if (!X509_digest(cert, digest, md, &n))
 590                 {
 591                         certinfo->error = "Out of memory generating fingerprint";
 592                 }
 593                 else
 594                 {
 595                         certinfo->fingerprint = irc::hex(md, n);
 596                 }
 597
 598                 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))
 599                 {
 600                         certinfo->error = "Not activated, or expired certificate";
 601                 }
 602
 603                 X509_free(cert);
 604         }
 605 };
 606
 607 static int error_callback(const char *str, size_t len, void *u)
 608 {
 609         ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "SSL error: " + std::string(str, len - 1));
 610
 611         //
 612         // XXX: Remove this line, it causes valgrind warnings...
 613         //
 614         // MD_update(&m, buf, j);
 615         //
 616         //
 617         // ... ONLY JOKING! :-)
 618         //
 619
 620         return 0;
 621 }
 622
 623 MODULE_INIT(ModuleSSLOpenSSL)