src/modules/extra/m_ssl_openssl.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2009 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
  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  public:
 100
 101         ModuleSSLOpenSSL()
 102         {
 103                 ServerInstance->Modules->PublishInterface("BufferedSocketHook", this);
 104
 105                 sessions = new issl_session[ServerInstance->SE->GetMaxFds()];
 106
 107                 // Not rehashable...because I cba to reduce all the sizes of existing buffers.
 108                 inbufsize = ServerInstance->Config->NetBufferSize;
 109
 110                 /* Global SSL library initialization*/
 111                 SSL_library_init();
 112                 SSL_load_error_strings();
 113
 114                 /* Build our SSL contexts:
 115                  * NOTE: OpenSSL makes us have two contexts, one for servers and one for clients. ICK.
 116                  */
 117                 ctx = SSL_CTX_new( SSLv23_server_method() );
 118                 clictx = SSL_CTX_new( SSLv23_client_method() );
 119
 120                 SSL_CTX_set_mode(ctx, SSL_MODE_ENABLE_PARTIAL_WRITE | SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
 121                 SSL_CTX_set_mode(clictx, SSL_MODE_ENABLE_PARTIAL_WRITE | SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
 122
 123                 SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, OnVerify);
 124                 SSL_CTX_set_verify(clictx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, OnVerify);
 125
 126                 // Needs the flag as it ignores a plain /rehash
 127                 OnModuleRehash(NULL,"ssl");
 128                 Implementation eventlist[] = {
 129                         I_On005Numeric, I_OnRehash, I_OnModuleRehash, I_OnPostConnect,
 130                         I_OnHookIO };
 131                 ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
 132         }
 133
 134         void OnHookIO(StreamSocket* user, ListenSocketBase* lsb)
 135         {
 136                 if (!user->GetIOHook() && lsb->hook == "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                         ListenSocketBase* port = ServerInstance->ports[i];
 152                         if (port->hook != "openssl")
 153                                 continue;
 154
 155                         std::string portid = port->GetBindDesc();
 156                         ServerInstance->Logs->Log("m_ssl_openssl", DEFAULT, "m_ssl_openssl.so: Enabling SSL for port %s", portid.c_str());
 157                         if (port->type == "clients" && port->GetIP() != "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                 ServerInstance->Modules->UnpublishInterface("BufferedSocketHook", this);
 246                 delete[] sessions;
 247         }
 248
 249         void OnCleanup(int target_type, void* item)
 250         {
 251                 if (target_type == TYPE_USER)
 252                 {
 253                         User* user = (User*)item;
 254
 255                         if (user->GetIOHook() == this)
 256                         {
 257                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 258                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 259                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 260                                 user->DelIOHook();
 261                         }
 262                 }
 263         }
 264
 265         Version GetVersion()
 266         {
 267                 return Version("Provides SSL support for clients", VF_VENDOR);
 268         }
 269
 270
 271         void OnRequest(Request& request)
 272         {
 273                 Module* sslinfo = ServerInstance->Modules->Find("m_sslinfo.so");
 274                 if (sslinfo)
 275                         sslinfo->OnRequest(request);
 276         }
 277
 278
 279         void OnStreamSocketAccept(StreamSocket* user, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server)
 280         {
 281                 int fd = user->GetFd();
 282
 283                 issl_session* session = &sessions[fd];
 284
 285                 session->fd = fd;
 286                 session->sess = SSL_new(ctx);
 287                 session->status = ISSL_NONE;
 288                 session->outbound = false;
 289
 290                 if (session->sess == NULL)
 291                         return;
 292
 293                 if (SSL_set_fd(session->sess, fd) == 0)
 294                 {
 295                         ServerInstance->Logs->Log("m_ssl_openssl",DEBUG,"BUG: Can't set fd with SSL_set_fd: %d", fd);
 296                         return;
 297                 }
 298
 299                 Handshake(user, session);
 300         }
 301
 302         void OnStreamSocketConnect(StreamSocket* user)
 303         {
 304                 int fd = user->GetFd();
 305                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 306                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() -1))
 307                         return;
 308
 309                 issl_session* session = &sessions[fd];
 310
 311                 session->fd = fd;
 312                 session->sess = SSL_new(clictx);
 313                 session->status = ISSL_NONE;
 314                 session->outbound = true;
 315
 316                 if (session->sess == NULL)
 317                         return;
 318
 319                 if (SSL_set_fd(session->sess, fd) == 0)
 320                 {
 321                         ServerInstance->Logs->Log("m_ssl_openssl",DEBUG,"BUG: Can't set fd with SSL_set_fd: %d", fd);
 322                         return;
 323                 }
 324
 325                 Handshake(user, session);
 326         }
 327
 328         void OnStreamSocketClose(StreamSocket* user)
 329         {
 330                 int fd = user->GetFd();
 331                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 332                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 333                         return;
 334
 335                 CloseSession(&sessions[fd]);
 336         }
 337
 338         int OnStreamSocketRead(StreamSocket* user, std::string& recvq)
 339         {
 340                 int fd = user->GetFd();
 341                 /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
 342                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 343                         return -1;
 344
 345                 issl_session* session = &sessions[fd];
 346
 347                 if (!session->sess)
 348                 {
 349                         CloseSession(session);
 350                         return -1;
 351                 }
 352
 353                 if (session->status == ISSL_HANDSHAKING)
 354                 {
 355                         // The handshake isn't finished and it wants to read, try to finish it.
 356                         if (!Handshake(user, session))
 357                         {
 358                                 // Couldn't resume handshake.
 359                                 if (session->status == ISSL_NONE)
 360                                         return -1;
 361                                 return 0;
 362                         }
 363                 }
 364
 365                 // If we resumed the handshake then session->status will be ISSL_OPEN
 366
 367                 if (session->status == ISSL_OPEN)
 368                 {
 369                         char* buffer = ServerInstance->GetReadBuffer();
 370                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 371                         int ret = SSL_read(session->sess, buffer, bufsiz);
 372
 373                         if (ret > 0)
 374                         {
 375                                 recvq.append(buffer, ret);
 376                                 return 1;
 377                         }
 378                         else if (ret == 0)
 379                         {
 380                                 // Client closed connection.
 381                                 CloseSession(session);
 382                                 return -1;
 383                         }
 384                         else if (ret < 0)
 385                         {
 386                                 int err = SSL_get_error(session->sess, ret);
 387
 388                                 if (err == SSL_ERROR_WANT_READ)
 389                                 {
 390                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ);
 391                                         return 0;
 392                                 }
 393                                 else if (err == SSL_ERROR_WANT_WRITE)
 394                                 {
 395                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 396                                         return 0;
 397                                 }
 398                                 else
 399                                 {
 400                                         CloseSession(session);
 401                                         return -1;
 402                                 }
 403                         }
 404                 }
 405
 406                 return 0;
 407         }
 408
 409         int OnStreamSocketWrite(StreamSocket* user, std::string& buffer)
 410         {
 411                 int fd = user->GetFd();
 412
 413                 issl_session* session = &sessions[fd];
 414
 415                 if (!session->sess)
 416                 {
 417                         CloseSession(session);
 418                         return -1;
 419                 }
 420
 421                 session->data_to_write = true;
 422
 423                 if (session->status == ISSL_HANDSHAKING)
 424                 {
 425                         if (!Handshake(user, session))
 426                         {
 427                                 // Couldn't resume handshake.
 428                                 if (session->status == ISSL_NONE)
 429                                         return -1;
 430                                 return 0;
 431                         }
 432                 }
 433
 434                 if (session->status == ISSL_OPEN)
 435                 {
 436                         int ret = SSL_write(session->sess, buffer.data(), buffer.size());
 437                         if (ret == (int)buffer.length())
 438                         {
 439                                 session->data_to_write = false;
 440                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 441                                 return 1;
 442                         }
 443                         else if (ret > 0)
 444                         {
 445                                 buffer = buffer.substr(ret);
 446                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 447                                 return 0;
 448                         }
 449                         else if (ret == 0)
 450                         {
 451                                 CloseSession(session);
 452                                 return -1;
 453                         }
 454                         else if (ret < 0)
 455                         {
 456                                 int err = SSL_get_error(session->sess, ret);
 457
 458                                 if (err == SSL_ERROR_WANT_WRITE)
 459                                 {
 460                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 461                                         return 0;
 462                                 }
 463                                 else if (err == SSL_ERROR_WANT_READ)
 464                                 {
 465                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 466                                         return 0;
 467                                 }
 468                                 else
 469                                 {
 470                                         CloseSession(session);
 471                                         return -1;
 472                                 }
 473                         }
 474                 }
 475                 return 0;
 476         }
 477
 478         bool Handshake(EventHandler* user, issl_session* session)
 479         {
 480                 int ret;
 481
 482                 if (session->outbound)
 483                         ret = SSL_connect(session->sess);
 484                 else
 485                         ret = SSL_accept(session->sess);
 486
 487                 if (ret < 0)
 488                 {
 489                         int err = SSL_get_error(session->sess, ret);
 490
 491                         if (err == SSL_ERROR_WANT_READ)
 492                         {
 493                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 494                                 session->status = ISSL_HANDSHAKING;
 495                                 return true;
 496                         }
 497                         else if (err == SSL_ERROR_WANT_WRITE)
 498                         {
 499                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 500                                 session->status = ISSL_HANDSHAKING;
 501                                 return true;
 502                         }
 503                         else
 504                         {
 505                                 CloseSession(session);
 506                         }
 507
 508                         return false;
 509                 }
 510                 else if (ret > 0)
 511                 {
 512                         // Handshake complete.
 513                         VerifyCertificate(session, user);
 514
 515                         session->status = ISSL_OPEN;
 516
 517                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 518
 519                         return true;
 520                 }
 521                 else if (ret == 0)
 522                 {
 523                         CloseSession(session);
 524                         return true;
 525                 }
 526
 527                 return true;
 528         }
 529
 530         void CloseSession(issl_session* session)
 531         {
 532                 if (session->sess)
 533                 {
 534                         SSL_shutdown(session->sess);
 535                         SSL_free(session->sess);
 536                 }
 537
 538                 session->sess = NULL;
 539                 session->status = ISSL_NONE;
 540                 errno = EIO;
 541         }
 542
 543         void VerifyCertificate(issl_session* session, Extensible* user)
 544         {
 545                 if (!session->sess || !user)
 546                         return;
 547
 548                 Module* sslinfo = ServerInstance->Modules->Find("m_sslinfo.so");
 549                 if (!sslinfo)
 550                         return;
 551
 552                 X509* cert;
 553                 ssl_cert* certinfo = new ssl_cert;
 554                 unsigned int n;
 555                 unsigned char md[EVP_MAX_MD_SIZE];
 556                 const EVP_MD *digest = EVP_md5();
 557
 558                 cert = SSL_get_peer_certificate((SSL*)session->sess);
 559
 560                 if (!cert)
 561                 {
 562                         certinfo->error = "Could not get peer certificate: "+std::string(get_error());
 563                         SSLCertSubmission(user, this, sslinfo, certinfo);
 564                         return;
 565                 }
 566
 567                 certinfo->invalid = (SSL_get_verify_result(session->sess) != X509_V_OK);
 568
 569                 if (SelfSigned)
 570                 {
 571                         certinfo->unknownsigner = false;
 572                         certinfo->trusted = true;
 573                 }
 574                 else
 575                 {
 576                         certinfo->unknownsigner = true;
 577                         certinfo->trusted = false;
 578                 }
 579
 580                 certinfo->dn = X509_NAME_oneline(X509_get_subject_name(cert),0,0);
 581                 certinfo->issuer = X509_NAME_oneline(X509_get_issuer_name(cert),0,0);
 582
 583                 if (!X509_digest(cert, digest, md, &n))
 584                 {
 585                         certinfo->error = "Out of memory generating fingerprint";
 586                 }
 587                 else
 588                 {
 589                         certinfo->fingerprint = irc::hex(md, n);
 590                 }
 591
 592                 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))
 593                 {
 594                         certinfo->error = "Not activated, or expired certificate";
 595                 }
 596
 597                 X509_free(cert);
 598                 SSLCertSubmission(user, this, sslinfo, certinfo);
 599         }
 600
 601         void Prioritize()
 602         {
 603                 Module* server = ServerInstance->Modules->Find("m_spanningtree.so");
 604                 ServerInstance->Modules->SetPriority(this, I_OnPostConnect, PRIORITY_AFTER, &server);
 605         }
 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)