src/modules/extra/m_ssl_gnutls.cpp

   1 #include <string>
   2 #include <vector>
   3
   4 #include <gnutls/gnutls.h>
   5
   6 #include "inspircd_config.h"
   7 #include "users.h"
   8 #include "channels.h"
   9 #include "modules.h"
  10 #include "helperfuncs.h"
  11 #include "socket.h"
  12 #include "hashcomp.h"
  13
  14 /* $ModDesc: Provides SSL support for clients */
  15 /* $CompileFlags: `libgnutls-config --cflags` */
  16 /* $LinkerFlags: `libgnutls-config --libs` */
  17
  18 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING_READ, ISSL_HANDSHAKING_WRITE, ISSL_HANDSHAKEN, ISSL_CLOSING, ISSL_CLOSED };
  19
  20 bool isin(int port, const std::vector<int> &portlist)
  21 {
  22         for(unsigned int i = 0; i < portlist.size(); i++)
  23                 if(portlist[i] == port)
  24                         return true;
  25
  26         return false;
  27 }
  28
  29 class issl_session
  30 {
  31 public:
  32         gnutls_session_t sess;
  33         issl_status status;
  34         std::string outbuf;
  35         int inbufoffset;
  36         char* inbuf;
  37         int fd;
  38 };
  39
  40 class ModuleSSLGnuTLS : public Module
  41 {
  42         Server* Srv;
  43         ServerConfig* SrvConf;
  44         ConfigReader* Conf;
  45
  46         CullList culllist;
  47
  48         std::vector<int> listenports;
  49
  50         int inbufsize;
  51         issl_session sessions[MAX_DESCRIPTORS];
  52
  53         gnutls_certificate_credentials x509_cred;
  54         gnutls_dh_params dh_params;
  55
  56         std::string keyfile;
  57         std::string certfile;
  58         std::string cafile;
  59         std::string crlfile;
  60         int dh_bits;
  61
  62  public:
  63
  64         ModuleSSLGnuTLS(Server* Me)
  65                 : Module::Module(Me)
  66         {
  67                 Srv = Me;
  68                 SrvConf = Srv->GetConfig();
  69
  70                 // Not rehashable...because I cba to reduce all the sizes of existing buffers.
  71                 inbufsize = SrvConf->NetBufferSize;
  72
  73                 gnutls_global_init(); // This must be called once in the program
  74
  75                 if(gnutls_certificate_allocate_credentials(&x509_cred) != 0)
  76                         log(DEFAULT, "m_ssl_gnutls.so: Failed to allocate certificate credentials");
  77
  78                 // Guessing return meaning
  79                 if(gnutls_dh_params_init(&dh_params) < 0)
  80                         log(DEFAULT, "m_ssl_gnutls.so: Failed to initialise DH parameters");
  81
  82                 // Needs the flag as it ignores a plain /rehash
  83                 OnRehash("ssl");
  84
  85                 // Void return, guess we assume success
  86                 gnutls_certificate_set_dh_params(x509_cred, dh_params);
  87         }
  88
  89         virtual void OnRehash(std::string param)
  90         {
  91                 if(param != "ssl")
  92                         return;
  93
  94                 Conf = new ConfigReader;
  95
  96                 for(unsigned int i = 0; i < listenports.size(); i++)
  97                 {
  98                         SrvConf->DelIOHook(listenports[i]);
  99                 }
 100
 101                 listenports.clear();
 102
 103                 for(int i = 0; i < Conf->Enumerate("bind"); i++)
 104                 {
 105                         // For each <bind> tag
 106                         if(((Conf->ReadValue("bind", "type", i) == "") || (Conf->ReadValue("bind", "type", i) == "clients")) && (Conf->ReadValue("bind", "ssl", i) == "gnutls"))
 107                         {
 108                                 // Get the port we're meant to be listening on with SSL
 109                                 unsigned int port = Conf->ReadInteger("bind", "port", i, true);
 110                                 if(SrvConf->AddIOHook(port, this))
 111                                 {
 112                                         // We keep a record of which ports we're listening on with SSL
 113                                         listenports.push_back(port);
 114
 115                                         log(DEFAULT, "m_ssl_gnutls.so: Enabling SSL for port %d", port);
 116                                 }
 117                                 else
 118                                 {
 119                                         log(DEFAULT, "m_ssl_gnutls.so: FAILED to enable SSL on port %d, maybe you have another ssl or similar module loaded?", port);
 120                                 }
 121                         }
 122                 }
 123
 124                 std::string confdir(CONFIG_FILE);
 125                 // +1 so we the path ends with a /
 126                 confdir = confdir.substr(0, confdir.find_last_of('/') + 1);
 127
 128                 cafile  = Conf->ReadValue("gnutls", "cafile", 0);
 129                 crlfile = Conf->ReadValue("gnutls", "crlfile", 0);
 130                 certfile        = Conf->ReadValue("gnutls", "certfile", 0);
 131                 keyfile = Conf->ReadValue("gnutls", "keyfile", 0);
 132                 dh_bits = Conf->ReadInteger("gnutls", "dhbits", 0, false);
 133
 134                 // Set all the default values needed.
 135                 if(cafile == "")
 136                         cafile = "ca.pem";
 137
 138                 if(crlfile == "")
 139                         crlfile = "crl.pem";
 140
 141                 if(certfile == "")
 142                         certfile = "cert.pem";
 143
 144                 if(keyfile == "")
 145                         keyfile = "key.pem";
 146
 147                 if((dh_bits != 768) && (dh_bits != 1024) && (dh_bits != 2048) && (dh_bits != 3072) && (dh_bits != 4096))
 148                         dh_bits = 1024;
 149
 150                 // Prepend relative paths with the path to the config directory.
 151                 if(cafile[0] != '/')
 152                         cafile = confdir + cafile;
 153
 154                 if(crlfile[0] != '/')
 155                         crlfile = confdir + crlfile;
 156
 157                 if(certfile[0] != '/')
 158                         certfile = confdir + certfile;
 159
 160                 if(keyfile[0] != '/')
 161                         keyfile = confdir + keyfile;
 162
 163                 if(gnutls_certificate_set_x509_trust_file(x509_cred, cafile.c_str(), GNUTLS_X509_FMT_PEM) < 0)
 164                         log(DEFAULT, "m_ssl_gnutls.so: Failed to set X.509 trust file: %s", cafile.c_str());
 165
 166                 if(gnutls_certificate_set_x509_crl_file (x509_cred, crlfile.c_str(), GNUTLS_X509_FMT_PEM) < 0)
 167                         log(DEFAULT, "m_ssl_gnutls.so: Failed to set X.509 CRL file: %s", crlfile.c_str());
 168
 169                 // Guessing on the return value of this, manual doesn't say :|
 170                 if(gnutls_certificate_set_x509_key_file (x509_cred, certfile.c_str(), keyfile.c_str(), GNUTLS_X509_FMT_PEM) < 0)
 171                         log(DEFAULT, "m_ssl_gnutls.so: Failed to set X.509 certificate and key files: %s and %s", certfile.c_str(), keyfile.c_str());
 172
 173                 // This may be on a large (once a day or week) timer eventually.
 174                 GenerateDHParams();
 175         }
 176
 177         void GenerateDHParams()
 178         {
 179                 // Generate Diffie Hellman parameters - for use with DHE
 180                 // kx algorithms. These should be discarded and regenerated
 181                 // once a day, once a week or once a month. Depending on the
 182                 // security requirements.
 183
 184                 if(gnutls_dh_params_generate2(dh_params, dh_bits) < 0)
 185                         log(DEFAULT, "m_ssl_gnutls.so: Failed to generate DH parameters (%d bits)", dh_bits);
 186         }
 187
 188         virtual ~ModuleSSLGnuTLS()
 189         {
 190                 delete Conf;
 191                 gnutls_dh_params_deinit(dh_params);
 192                 gnutls_certificate_free_credentials(x509_cred);
 193                 gnutls_global_deinit();
 194         }
 195
 196         virtual void OnCleanup(int target_type, void* item)
 197         {
 198                 if(target_type == TYPE_USER)
 199                 {
 200                         userrec* user = (userrec*)item;
 201
 202                         if(user->GetExt("ssl") && IS_LOCAL(user) && isin(user->port, listenports))
 203                         {
 204                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 205                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 206                                 log(DEBUG, "m_ssl_gnutls.so: Adding user %s to cull list", user->nick);
 207                                 culllist.AddItem(user, "SSL module unloading");
 208                         }
 209                 }
 210         }
 211
 212         virtual void OnUnloadModule(Module* mod, std::string name)
 213         {
 214                 if(mod == this)
 215                 {
 216                         // We're being unloaded, kill all the users added to the cull list in OnCleanup
 217                         int numusers = culllist.Apply();
 218                         log(DEBUG, "m_ssl_gnutls.so: Killed %d users for unload of GnuTLS SSL module", numusers);
 219
 220                         for(unsigned int i = 0; i < listenports.size(); i++)
 221                                 SrvConf->DelIOHook(listenports[i]);
 222                 }
 223         }
 224
 225         virtual Version GetVersion()
 226         {
 227                 return Version(1, 0, 0, 0, VF_VENDOR);
 228         }
 229
 230         void Implements(char* List)
 231         {
 232                 List[I_OnRawSocketAccept] = List[I_OnRawSocketClose] = List[I_OnRawSocketRead] = List[I_OnRawSocketWrite] = List[I_OnCleanup] = 1;
 233                 List[I_OnSyncUserMetaData] = List[I_OnDecodeMetaData] = List[I_OnUnloadModule] = List[I_OnRehash] = List[I_OnWhois] = 1;
 234         }
 235
 236         virtual void OnRawSocketAccept(int fd, std::string ip, int localport)
 237         {
 238                 issl_session* session = &sessions[fd];
 239
 240                 session->fd = fd;
 241                 session->inbuf = new char[inbufsize];
 242                 session->inbufoffset = 0;
 243
 244                 gnutls_init(&session->sess, GNUTLS_SERVER);
 245
 246                 gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
 247                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 248                 gnutls_certificate_server_set_request(session->sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
 249                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 250                 gnutls_transport_set_ptr(session->sess, (gnutls_transport_ptr_t) fd); // Give gnutls the fd for the socket.
 251
 252                 Handshake(session);
 253         }
 254
 255         virtual void OnRawSocketClose(int fd)
 256         {
 257                 log(DEBUG, "OnRawSocketClose: %d", fd);
 258                 CloseSession(&sessions[fd]);
 259         }
 260
 261         virtual int OnRawSocketRead(int fd, char* buffer, unsigned int count, int &readresult)
 262         {
 263                 issl_session* session = &sessions[fd];
 264
 265                 if(!session->sess)
 266                 {
 267                         log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead: No session to read from");
 268                         readresult = 0;
 269                         CloseSession(session);
 270                         return 1;
 271                 }
 272
 273                 log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead(%d, buffer, %u, %d)", fd, count, readresult);
 274
 275                 if(session->status == ISSL_HANDSHAKING_READ)
 276                 {
 277                         // The handshake isn't finished, try to finish it.
 278
 279                         if(Handshake(session))
 280                         {
 281                                 // Handshake successfully resumed.
 282                                 log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead: successfully resumed handshake");
 283                         }
 284                         else
 285                         {
 286                                 // Couldn't resume handshake.
 287                                 log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead: failed to resume handshake");
 288                                 return -1;
 289                         }
 290                 }
 291                 else if(session->status == ISSL_HANDSHAKING_WRITE)
 292                 {
 293                         log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead: handshake wants to write data but we are currently reading");
 294                         return -1;
 295                 }
 296
 297                 // If we resumed the handshake then session->status will be ISSL_HANDSHAKEN.
 298
 299                 if(session->status == ISSL_HANDSHAKEN)
 300                 {
 301                         // Is this right? Not sure if the unencrypted data is garaunteed to be the same length.
 302                         // Read into the inbuffer, offset from the beginning by the amount of data we have that insp hasn't taken yet.
 303                         log(DEBUG, "m_ssl_gnutls.so: gnutls_record_recv(sess, inbuf+%d, %d-%d)", session->inbufoffset, inbufsize, session->inbufoffset);
 304
 305                         int ret = gnutls_record_recv(session->sess, session->inbuf + session->inbufoffset, inbufsize - session->inbufoffset);
 306
 307                         if(ret == 0)
 308                         {
 309                                 // Client closed connection.
 310                                 log(DEBUG, "m_ssl_gnutls.so: Client closed the connection");
 311                                 readresult = 0;
 312                                 CloseSession(session);
 313                                 return 1;
 314                         }
 315                         else if(ret < 0)
 316                         {
 317                                 if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 318                                 {
 319                                         log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead: Not all SSL data read: %s", gnutls_strerror(ret));
 320                                         return -1;
 321                                 }
 322                                 else
 323                                 {
 324                                         log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead: Error reading SSL data: %s", gnutls_strerror(ret));
 325                                         readresult = 0;
 326                                         CloseSession(session);
 327                                 }
 328                         }
 329                         else
 330                         {
 331                                 // Read successfully 'ret' bytes into inbuf + inbufoffset
 332                                 // There are 'ret' + 'inbufoffset' bytes of data in 'inbuf'
 333                                 // 'buffer' is 'count' long
 334
 335                                 unsigned int length = ret + session->inbufoffset;
 336
 337                                 log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead: Read %d bytes, now have %d waiting to be passed up", ret, length);
 338
 339                                 if(count <= length)
 340                                 {
 341                                         memcpy(buffer, session->inbuf, count);
 342                                         // Move the stuff left in inbuf to the beginning of it
 343                                         memcpy(session->inbuf, session->inbuf + count, (length - count));
 344                                         // Now we need to set session->inbufoffset to the amount of data still waiting to be handed to insp.
 345                                         session->inbufoffset = length - count;
 346                                         // Insp uses readresult as the count of how much data there is in buffer, so:
 347                                         readresult = count;
 348                                 }
 349                                 else
 350                                 {
 351                                         // There's not as much in the inbuf as there is space in the buffer, so just copy the whole thing.
 352                                         memcpy(buffer, session->inbuf, length);
 353                                         // Zero the offset, as there's nothing there..
 354                                         session->inbufoffset = 0;
 355                                         // As above
 356                                         readresult = length;
 357                                 }
 358
 359                                 log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead: Passing %d bytes up to insp:");
 360                                 Srv->Log(DEBUG, std::string(buffer, readresult));
 361                         }
 362                 }
 363                 else if(session->status == ISSL_CLOSING)
 364                 {
 365                         log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead: session closing...");
 366                         readresult = 0;
 367                 }
 368
 369                 return 1;
 370         }
 371
 372         virtual int OnRawSocketWrite(int fd, char* buffer, int count)
 373         {
 374                 issl_session* session = &sessions[fd];
 375                 const char* sendbuffer = buffer;
 376
 377                 if(!session->sess)
 378                 {
 379                         log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: No session to write to");
 380                         CloseSession(session);
 381                         return 1;
 382                 }
 383
 384                 if(session->status == ISSL_HANDSHAKING_WRITE)
 385                 {
 386                         // The handshake isn't finished, try to finish it.
 387
 388                         if(Handshake(session))
 389                         {
 390                                 // Handshake successfully resumed.
 391                                 log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: successfully resumed handshake");
 392                         }
 393                         else
 394                         {
 395                                 // Couldn't resume handshake.
 396                                 log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: failed to resume handshake");
 397                         }
 398                 }
 399                 else if(session->status == ISSL_HANDSHAKING_READ)
 400                 {
 401                         log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: handshake wants to read data but we are currently writing");
 402                 }
 403
 404                 log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: Adding %d bytes to the outgoing buffer", count);
 405                 session->outbuf.append(sendbuffer, count);
 406                 sendbuffer = session->outbuf.c_str();
 407                 count = session->outbuf.size();
 408
 409                 if(session->status == ISSL_HANDSHAKEN)
 410                 {
 411                         log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: Trying to write %d bytes:", count);
 412                         Srv->Log(DEBUG, session->outbuf);
 413
 414                         int ret = gnutls_record_send(session->sess, sendbuffer, count);
 415
 416                         if(ret == 0)
 417                         {
 418                                 log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: Client closed the connection");
 419                                 CloseSession(session);
 420                         }
 421                         else if(ret < 0)
 422                         {
 423                                 if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 424                                 {
 425                                         log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: Not all SSL data written: %s", gnutls_strerror(ret));
 426                                 }
 427                                 else
 428                                 {
 429                                         log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: Error writing SSL data: %s", gnutls_strerror(ret));
 430                                         CloseSession(session);
 431                                 }
 432                         }
 433                         else
 434                         {
 435                                 log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: Successfully wrote %d bytes", ret);
 436                                 session->outbuf = session->outbuf.substr(ret);
 437                         }
 438                 }
 439                 else if(session->status == ISSL_CLOSING)
 440                 {
 441                         log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: session closing...");
 442                 }
 443
 444                 return 1;
 445         }
 446
 447         // :kenny.chatspike.net 320 Om Epy|AFK :is a Secure Connection
 448         virtual void OnWhois(userrec* source, userrec* dest)
 449         {
 450                 if(dest->GetExt("ssl"))
 451                 {
 452                         WriteServ(source->fd, "320 %s %s :is a Secure Connection", source->nick, dest->nick);
 453                 }
 454         }
 455
 456         virtual void OnSyncUserMetaData(userrec* user, Module* proto, void* opaque, std::string extname)
 457         {
 458                 // check if the linking module wants to know about OUR metadata
 459                 if(extname == "ssl")
 460                 {
 461                         // check if this user has an swhois field to send
 462                         if(user->GetExt(extname))
 463                         {
 464                                 // call this function in the linking module, let it format the data how it
 465                                 // sees fit, and send it on its way. We dont need or want to know how.
 466                                 proto->ProtoSendMetaData(opaque, TYPE_USER, user, extname, "ON");
 467                         }
 468                 }
 469         }
 470
 471         virtual void OnDecodeMetaData(int target_type, void* target, std::string extname, std::string extdata)
 472         {
 473                 // check if its our metadata key, and its associated with a user
 474                 if ((target_type == TYPE_USER) && (extname == "ssl"))
 475                 {
 476                         userrec* dest = (userrec*)target;
 477                         // if they dont already have an ssl flag, accept the remote server's
 478                         if (!dest->GetExt(extname))
 479                         {
 480                                 dest->Extend(extname, "ON");
 481                         }
 482                 }
 483         }
 484
 485         bool Handshake(issl_session* session)
 486         {
 487                 int ret = gnutls_handshake(session->sess);
 488
 489       if(ret < 0)
 490                 {
 491                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 492                         {
 493                                 // Handshake needs resuming later, read() or write() would have blocked.
 494
 495                                 if(gnutls_record_get_direction(session->sess) == 0)
 496                                 {
 497                                         // gnutls_handshake() wants to read() again.
 498                                         session->status = ISSL_HANDSHAKING_READ;
 499                                         log(DEBUG, "m_ssl_gnutls.so: Handshake needs resuming (reading) later, error string: %s", gnutls_strerror(ret));
 500                                 }
 501                                 else
 502                                 {
 503                                         // gnutls_handshake() wants to write() again.
 504                                         session->status = ISSL_HANDSHAKING_WRITE;
 505                                         log(DEBUG, "m_ssl_gnutls.so: Handshake needs resuming (writing) later, error string: %s", gnutls_strerror(ret));
 506                                         MakePollWrite(session);
 507                                 }
 508                         }
 509                         else
 510                         {
 511                                 // Handshake failed.
 512                                 CloseSession(session);
 513                            log(DEBUG, "m_ssl_gnutls.so: Handshake failed, error string: %s", gnutls_strerror(ret));
 514                            session->status = ISSL_CLOSING;
 515                         }
 516
 517                         return false;
 518                 }
 519                 else
 520                 {
 521                         // Handshake complete.
 522                         log(DEBUG, "m_ssl_gnutls.so: Handshake completed");
 523
 524                         // This will do for setting the ssl flag...it could be done earlier if it's needed. But this seems neater.
 525                         Srv->FindDescriptor(session->fd)->Extend("ssl", "ON");
 526
 527                         session->status = ISSL_HANDSHAKEN;
 528
 529                         MakePollWrite(session);
 530
 531                         return true;
 532                 }
 533         }
 534
 535         void MakePollWrite(issl_session* session)
 536         {
 537                 OnRawSocketWrite(session->fd, NULL, 0);
 538         }
 539
 540         void CloseSession(issl_session* session)
 541         {
 542                 if(session->sess)
 543                 {
 544                         gnutls_bye(session->sess, GNUTLS_SHUT_WR);
 545                         gnutls_deinit(session->sess);
 546                 }
 547
 548                 if(session->inbuf)
 549                 {
 550                         delete[] session->inbuf;
 551                 }
 552
 553                 session->outbuf.clear();
 554                 session->inbuf = NULL;
 555                 session->sess = NULL;
 556                 session->status = ISSL_NONE;
 557         }
 558 };
 559
 560 class ModuleSSLGnuTLSFactory : public ModuleFactory
 561 {
 562  public:
 563         ModuleSSLGnuTLSFactory()
 564         {
 565         }
 566
 567         ~ModuleSSLGnuTLSFactory()
 568         {
 569         }
 570
 571         virtual Module * CreateModule(Server* Me)
 572         {
 573                 return new ModuleSSLGnuTLS(Me);
 574         }
 575 };
 576
 577
 578 extern "C" void * init_module( void )
 579 {
 580         return new ModuleSSLGnuTLSFactory;
 581 }
 582