src/ngircd/conn-ssl.c

   1 /*
   2  * ngIRCd -- The Next Generation IRC Daemon
   3  * Copyright (c) 2005-2008 Florian Westphal <fw@strlen.de>
   4  */
   5
   6 #include "portab.h"
   7
   8 /**
   9  * @file
  10  * SSL wrapper functions
  11  */
  12
  13 #include "imp.h"
  14 #include "conf-ssl.h"
  15
  16 #ifdef SSL_SUPPORT
  17
  18 #include "io.h"
  19 #include <assert.h>
  20 #include <stdio.h>
  21 #include <string.h>
  22 #include <stdlib.h>
  23 #include <errno.h>
  24
  25 #define CONN_MODULE
  26 #include "conn.h"
  27 #include "conf.h"
  28 #include "conn-func.h"
  29 #include "conn-ssl.h"
  30 #include "log.h"
  31
  32 #include "exp.h"
  33 #include "defines.h"
  34
  35 extern struct SSLOptions Conf_SSLOptions;
  36
  37 #ifdef HAVE_LIBSSL
  38 #include <openssl/err.h>
  39 #include <openssl/rand.h>
  40
  41 static SSL_CTX * ssl_ctx;
  42 static DH *dh_params;
  43
  44 static bool ConnSSL_LoadServerKey_openssl PARAMS(( SSL_CTX *c ));
  45 #endif
  46
  47 #ifdef HAVE_LIBGNUTLS
  48 #include <sys/types.h>
  49 #include <sys/stat.h>
  50 #include <fcntl.h>
  51 #include <unistd.h>
  52 #include <gnutls/x509.h>
  53
  54 #define DH_BITS 2048
  55 #define DH_BITS_MIN 1024
  56
  57 #define MAX_HASH_SIZE   64      /* from gnutls-int.h */
  58
  59 static gnutls_certificate_credentials_t x509_cred;
  60 static gnutls_dh_params_t dh_params;
  61 static gnutls_priority_t priorities_cache;
  62 static bool ConnSSL_LoadServerKey_gnutls PARAMS(( void ));
  63 #endif
  64
  65 #define SHA1_STRING_LEN (20 * 2 + 1)
  66
  67 static bool ConnSSL_Init_SSL PARAMS(( CONNECTION *c ));
  68 static int ConnectAccept PARAMS(( CONNECTION *c, bool connect ));
  69 static int ConnSSL_HandleError PARAMS(( CONNECTION *c, const int code, const char *fname ));
  70
  71 #ifdef HAVE_LIBGNUTLS
  72 static char * openreadclose(const char *name, size_t *len)
  73 {
  74         char *buf = NULL;
  75         struct stat s;
  76         ssize_t br;
  77         int fd = open(name, O_RDONLY);
  78         if (fd < 0) {
  79                 Log(LOG_ERR, "Could not open %s: %s", name, strerror(errno));
  80                 return NULL;
  81         }
  82         if (fstat(fd, &s)) {
  83                 Log(LOG_ERR, "Could not fstat %s: %s", name, strerror(errno));
  84                 goto out;
  85         }
  86         if (!S_ISREG(s.st_mode)) {
  87                 Log(LOG_ERR, "%s: Not a regular file", name);
  88                 goto out;
  89         }
  90         if (s.st_size <= 0) {
  91                 Log(LOG_ERR, "%s: invalid file length (size %ld <= 0)", name, (long) s.st_size);
  92                 goto out;
  93         }
  94         buf = malloc(s.st_size);
  95         if (!buf) {
  96                 Log(LOG_ERR, "Could not malloc %lu bytes for file %s: %s", s.st_size, name, strerror(errno));
  97                 goto out;
  98         }
  99         br = read(fd, buf, s.st_size);
 100         if (br != (ssize_t)s.st_size) {
 101                 Log(LOG_ERR, "Could not read file %s: read returned %ld, expected %ld: %s",
 102                         name, (long) br, (long) s.st_size, br == -1 ? strerror(errno):"short read?!");
 103                 memset(buf, 0, s.st_size);
 104                 free(buf);
 105                 buf = NULL;
 106         } else {
 107                 *len = br;
 108         }
 109 out:
 110         close(fd);
 111         return buf;
 112 }
 113 #endif
 114
 115
 116 #ifdef HAVE_LIBSSL
 117 /**
 118  * Log OpenSSL error message.
 119  *
 120  * @param msg The error message.
 121  * @param info Additional information text or NULL.
 122  */
 123 static void
 124 LogOpenSSLError(const char *error, const char *info)
 125 {
 126         unsigned long err = ERR_get_error();
 127         char * errmsg = err
 128                 ? ERR_error_string(err, NULL)
 129                 : "Unable to determine error";
 130
 131         assert(error != NULL);
 132
 133         if (info)
 134                 Log(LOG_ERR, "%s: %s (%s)", error, info, errmsg);
 135         else
 136                 Log(LOG_ERR, "%s: %s", error, errmsg);
 137 }
 138
 139
 140 static int
 141 pem_passwd_cb(char *buf, int size, int rwflag, void *password)
 142 {
 143         array *pass = password;
 144         int passlen;
 145
 146         (void)rwflag;           /* rwflag is unused if DEBUG is not set. */
 147         assert(rwflag == 0);    /* 0 -> callback used for decryption.
 148                                  * See SSL_CTX_set_default_passwd_cb(3) */
 149
 150         passlen = (int) array_bytes(pass);
 151
 152         LogDebug("pem_passwd_cb buf size %d, array size %d", size, passlen);
 153         assert(passlen >= 0);
 154         if (passlen <= 0) {
 155                 Log(LOG_ERR, "PEM password required but not set [in pem_passwd_cb()]!");
 156                 return 0;
 157         }
 158         size = passlen > size ? size : passlen;
 159         memcpy(buf, (char *)(array_start(pass)), size);
 160         return size;
 161 }
 162
 163
 164 static int
 165 Verify_openssl(UNUSED int preverify_ok, UNUSED X509_STORE_CTX *x509_ctx)
 166 {
 167         return 1;
 168 }
 169 #endif
 170
 171
 172 static bool
 173 Load_DH_params(void)
 174 {
 175 #ifdef HAVE_LIBSSL
 176         FILE *fp;
 177         bool ret = true;
 178
 179         if (!Conf_SSLOptions.DHFile) {
 180                 Log(LOG_NOTICE, "Configuration option \"DHFile\" not set!");
 181                 return false;
 182         }
 183         fp = fopen(Conf_SSLOptions.DHFile, "r");
 184         if (!fp) {
 185                 Log(LOG_ERR, "%s: %s", Conf_SSLOptions.DHFile, strerror(errno));
 186                 return false;
 187         }
 188         dh_params = PEM_read_DHparams(fp, NULL, NULL, NULL);
 189         if (!dh_params) {
 190                 Log(LOG_ERR, "%s: Failed to read SSL DH parameters!",
 191                     Conf_SSLOptions.DHFile);
 192                 ret = false;
 193         }
 194         fclose(fp);
 195         return ret;
 196 #endif
 197 #ifdef HAVE_LIBGNUTLS
 198         bool need_dhgenerate = true;
 199         int err;
 200         gnutls_dh_params_t tmp_dh_params;
 201
 202         err = gnutls_dh_params_init(&tmp_dh_params);
 203         if (err < 0) {
 204                 Log(LOG_ERR, "Failed to initialize SSL DH parameters: %s",
 205                     gnutls_strerror(err));
 206                 return false;
 207         }
 208         if (Conf_SSLOptions.DHFile) {
 209                 gnutls_datum_t dhparms;
 210                 size_t size;
 211                 dhparms.data = (unsigned char *) openreadclose(Conf_SSLOptions.DHFile, &size);
 212                 if (dhparms.data) {
 213                         dhparms.size = size;
 214                         err = gnutls_dh_params_import_pkcs3(tmp_dh_params, &dhparms, GNUTLS_X509_FMT_PEM);
 215                         if (err == 0)
 216                                 need_dhgenerate = false;
 217                         else
 218                                 Log(LOG_ERR,
 219                                     "Failed to initialize SSL DH parameters: %s",
 220                                     gnutls_strerror(err));
 221
 222                         memset(dhparms.data, 0, size);
 223                         free(dhparms.data);
 224                 }
 225         }
 226         if (need_dhgenerate) {
 227                 Log(LOG_WARNING,
 228                     "DHFile not set, generating %u bit DH parameters. This may take a while ...",
 229                     DH_BITS);
 230                 err = gnutls_dh_params_generate2(tmp_dh_params, DH_BITS);
 231                 if (err < 0) {
 232                         Log(LOG_ERR, "Failed to generate SSL DH parameters: %s",
 233                             gnutls_strerror(err));
 234                         return false;
 235                 }
 236         }
 237         dh_params = tmp_dh_params;
 238         return true;
 239 #endif
 240 }
 241
 242
 243 void ConnSSL_Free(CONNECTION *c)
 244 {
 245 #ifdef HAVE_LIBSSL
 246         SSL *ssl = c->ssl_state.ssl;
 247         if (ssl) {
 248                 SSL_shutdown(ssl);
 249                 SSL_free(ssl);
 250                 c->ssl_state.ssl = NULL;
 251                 if (c->ssl_state.fingerprint) {
 252                         free(c->ssl_state.fingerprint);
 253                         c->ssl_state.fingerprint = NULL;
 254                 }
 255         }
 256 #endif
 257 #ifdef HAVE_LIBGNUTLS
 258         gnutls_session_t sess = c->ssl_state.gnutls_session;
 259         if (Conn_OPTION_ISSET(c, CONN_SSL)) {
 260                 gnutls_bye(sess, GNUTLS_SHUT_RDWR);
 261                 gnutls_deinit(sess);
 262         }
 263 #endif
 264         assert(Conn_OPTION_ISSET(c, CONN_SSL));
 265         /* can't just set bitmask to 0 -- there are other, non-ssl related flags, e.g. CONN_ZIP. */
 266         Conn_OPTION_DEL(c, CONN_SSL_FLAGS_ALL);
 267 }
 268
 269
 270 bool
 271 ConnSSL_InitLibrary( void )
 272 {
 273         if (!Conf_SSLInUse()) {
 274                 LogDebug("SSL not in use, skipping initialization.");
 275                 return true;
 276         }
 277
 278 #ifdef HAVE_LIBSSL
 279         SSL_CTX *newctx;
 280
 281         if (!ssl_ctx) {
 282                 SSL_library_init();
 283                 SSL_load_error_strings();
 284         }
 285
 286         if (!RAND_status()) {
 287                 Log(LOG_ERR, "OpenSSL PRNG not seeded: /dev/urandom missing?");
 288                 /*
 289                  * it is probably best to fail and let the user install EGD or
 290                  * a similar program if no kernel random device is available.
 291                  * According to OpenSSL RAND_egd(3): "The automatic query of
 292                  * /var/run/egd-pool et al was added in OpenSSL 0.9.7";
 293                  * so it makes little sense to deal with PRNGD seeding ourselves.
 294                  */
 295                 array_free(&Conf_SSLOptions.ListenPorts);
 296                 return false;
 297         }
 298
 299         newctx = SSL_CTX_new(SSLv23_method());
 300         if (!newctx) {
 301                 LogOpenSSLError("Failed to create SSL context", NULL);
 302                 array_free(&Conf_SSLOptions.ListenPorts);
 303                 return false;
 304         }
 305
 306         if (!ConnSSL_LoadServerKey_openssl(newctx))
 307                 goto out;
 308
 309         if(Conf_SSLOptions.CipherList && *Conf_SSLOptions.CipherList) {
 310                 if(SSL_CTX_set_cipher_list(newctx, Conf_SSLOptions.CipherList) == 0 ) {
 311                         Log(LOG_ERR,
 312                             "Failed to apply OpenSSL cipher list \"%s\"!",
 313                             Conf_SSLOptions.CipherList);
 314                         goto out;
 315                 } else {
 316                         Log(LOG_INFO,
 317                             "Successfully applied OpenSSL cipher list \"%s\".",
 318                             Conf_SSLOptions.CipherList);
 319                 }
 320         }
 321
 322         SSL_CTX_set_options(newctx, SSL_OP_SINGLE_DH_USE|SSL_OP_NO_SSLv2);
 323         SSL_CTX_set_mode(newctx, SSL_MODE_ENABLE_PARTIAL_WRITE);
 324         SSL_CTX_set_verify(newctx, SSL_VERIFY_PEER|SSL_VERIFY_CLIENT_ONCE,
 325                            Verify_openssl);
 326         SSL_CTX_free(ssl_ctx);
 327         ssl_ctx = newctx;
 328         Log(LOG_INFO, "%s initialized.", SSLeay_version(SSLEAY_VERSION));
 329         return true;
 330 out:
 331         SSL_CTX_free(newctx);
 332         array_free(&Conf_SSLOptions.ListenPorts);
 333         return false;
 334 #endif
 335 #ifdef HAVE_LIBGNUTLS
 336         int err;
 337         static bool initialized;
 338
 339         if (initialized) {
 340                 /* TODO: cannot reload gnutls keys: can't simply free x509
 341                  * context -- it may still be in use */
 342                 return false;
 343         }
 344
 345         err = gnutls_global_init();
 346         if (err) {
 347                 Log(LOG_ERR, "Failed to initialize GnuTLS: %s",
 348                     gnutls_strerror(err));
 349                 goto out;
 350         }
 351
 352         if (!ConnSSL_LoadServerKey_gnutls())
 353                 goto out;
 354
 355         if(Conf_SSLOptions.CipherList && *Conf_SSLOptions.CipherList) {
 356                 err = gnutls_priority_init(&priorities_cache,
 357                                            Conf_SSLOptions.CipherList, NULL);
 358                 if (err != GNUTLS_E_SUCCESS) {
 359                         Log(LOG_ERR,
 360                             "Failed to apply GnuTLS cipher list \"%s\"!",
 361                             Conf_SSLOptions.CipherList);
 362                         goto out;
 363                 }
 364                 Log(LOG_INFO,
 365                     "Successfully applied GnuTLS cipher list \"%s\".",
 366                     Conf_SSLOptions.CipherList);
 367         } else {
 368                 err = gnutls_priority_init(&priorities_cache, "NORMAL", NULL);
 369                 if (err != GNUTLS_E_SUCCESS) {
 370                         Log(LOG_ERR,
 371                             "Failed to apply GnuTLS cipher list \"NORMAL\"!");
 372                         goto out;
 373                 }
 374         }
 375
 376         Log(LOG_INFO, "GnuTLS %s initialized.", gnutls_check_version(NULL));
 377         initialized = true;
 378         return true;
 379 out:
 380         array_free(&Conf_SSLOptions.ListenPorts);
 381         return false;
 382 #endif
 383 }
 384
 385
 386 #ifdef HAVE_LIBGNUTLS
 387 static bool
 388 ConnSSL_LoadServerKey_gnutls(void)
 389 {
 390         int err;
 391         const char *cert_file;
 392
 393         err = gnutls_certificate_allocate_credentials(&x509_cred);
 394         if (err < 0) {
 395                 Log(LOG_ERR, "Failed to allocate certificate credentials: %s",
 396                     gnutls_strerror(err));
 397                 return false;
 398         }
 399
 400         cert_file = Conf_SSLOptions.CertFile ? Conf_SSLOptions.CertFile:Conf_SSLOptions.KeyFile;
 401         if (!cert_file) {
 402                 Log(LOG_ERR, "No SSL server key configured!");
 403                 return false;
 404         }
 405
 406         if (array_bytes(&Conf_SSLOptions.KeyFilePassword))
 407                 Log(LOG_WARNING,
 408                     "Ignoring SSL \"KeyFilePassword\": Not supported by GnuTLS.");
 409
 410         if (!Load_DH_params())
 411                 return false;
 412
 413         gnutls_certificate_set_dh_params(x509_cred, dh_params);
 414         err = gnutls_certificate_set_x509_key_file(x509_cred, cert_file, Conf_SSLOptions.KeyFile, GNUTLS_X509_FMT_PEM);
 415         if (err < 0) {
 416                 Log(LOG_ERR,
 417                     "Failed to set certificate key file (cert %s, key %s): %s",
 418                     cert_file,
 419                     Conf_SSLOptions.KeyFile ? Conf_SSLOptions.KeyFile : "(NULL)",
 420                     gnutls_strerror(err));
 421                 return false;
 422         }
 423         return true;
 424 }
 425 #endif
 426
 427
 428 #ifdef HAVE_LIBSSL
 429 static bool
 430 ConnSSL_LoadServerKey_openssl(SSL_CTX *ctx)
 431 {
 432         char *cert_key;
 433
 434         assert(ctx);
 435         if (!Conf_SSLOptions.KeyFile) {
 436                 Log(LOG_ERR, "No SSL server key configured!");
 437                 return false;
 438         }
 439
 440         SSL_CTX_set_default_passwd_cb(ctx, pem_passwd_cb);
 441         SSL_CTX_set_default_passwd_cb_userdata(ctx, &Conf_SSLOptions.KeyFilePassword);
 442
 443         if (SSL_CTX_use_PrivateKey_file(ctx, Conf_SSLOptions.KeyFile, SSL_FILETYPE_PEM) != 1) {
 444                 array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 445                 LogOpenSSLError("Failed to add private key", Conf_SSLOptions.KeyFile);
 446                 return false;
 447         }
 448
 449         cert_key = Conf_SSLOptions.CertFile ? Conf_SSLOptions.CertFile:Conf_SSLOptions.KeyFile;
 450         if (SSL_CTX_use_certificate_chain_file(ctx, cert_key) != 1) {
 451                 array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 452                 LogOpenSSLError("Failed to load certificate chain", cert_key);
 453                 return false;
 454         }
 455
 456         array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 457
 458         if (!SSL_CTX_check_private_key(ctx)) {
 459                 LogOpenSSLError("Server private key does not match certificate", NULL);
 460                 return false;
 461         }
 462         if (Load_DH_params()) {
 463                 if (SSL_CTX_set_tmp_dh(ctx, dh_params) != 1)
 464                         LogOpenSSLError("Error setting DH parameters", Conf_SSLOptions.DHFile);
 465                 /* don't return false here: the non-DH modes will still work */
 466                 DH_free(dh_params);
 467                 dh_params = NULL;
 468         }
 469         return true;
 470 }
 471
 472
 473 #endif
 474 static bool
 475 ConnSSL_Init_SSL(CONNECTION *c)
 476 {
 477         int ret;
 478
 479         LogDebug("Initializing SSL ...");
 480         assert(c != NULL);
 481
 482 #ifdef HAVE_LIBSSL
 483         if (!ssl_ctx) {
 484                 Log(LOG_ERR,
 485                     "Can't initialize SSL context, OpenSSL initialization failed at startup!");
 486                 return false;
 487         }
 488         assert(c->ssl_state.ssl == NULL);
 489         assert(c->ssl_state.fingerprint == NULL);
 490
 491         c->ssl_state.ssl = SSL_new(ssl_ctx);
 492         if (!c->ssl_state.ssl) {
 493                 LogOpenSSLError("Failed to create SSL structure", NULL);
 494                 return false;
 495         }
 496         Conn_OPTION_ADD(c, CONN_SSL);
 497
 498         ret = SSL_set_fd(c->ssl_state.ssl, c->sock);
 499         if (ret != 1) {
 500                 LogOpenSSLError("Failed to set SSL file descriptor", NULL);
 501                 ConnSSL_Free(c);
 502                 return false;
 503         }
 504 #endif
 505 #ifdef HAVE_LIBGNUTLS
 506         Conn_OPTION_ADD(c, CONN_SSL);
 507         ret = gnutls_priority_set(c->ssl_state.gnutls_session, priorities_cache);
 508         if (ret != 0) {
 509                 Log(LOG_ERR, "Failed to set GnuTLS session priorities: %s",
 510                     gnutls_strerror(ret));
 511                 ConnSSL_Free(c);
 512                 return false;
 513         }
 514         /*
 515          * The intermediate (long) cast is here to avoid a warning like:
 516          * "cast to pointer from integer of different size" on 64-bit platforms.
 517          * There doesn't seem to be an alternate GNUTLS API we could use instead, see e.g.
 518          * http://www.mail-archive.com/help-gnutls@gnu.org/msg00286.html
 519          */
 520         gnutls_transport_set_ptr(c->ssl_state.gnutls_session,
 521                                  (gnutls_transport_ptr_t) (long) c->sock);
 522         gnutls_certificate_server_set_request(c->ssl_state.gnutls_session,
 523                                               GNUTLS_CERT_REQUEST);
 524         ret = gnutls_credentials_set(c->ssl_state.gnutls_session,
 525                                      GNUTLS_CRD_CERTIFICATE, x509_cred);
 526         if (ret != 0) {
 527                 Log(LOG_ERR, "Failed to set SSL credentials: %s",
 528                     gnutls_strerror(ret));
 529                 ConnSSL_Free(c);
 530                 return false;
 531         }
 532         gnutls_dh_set_prime_bits(c->ssl_state.gnutls_session, DH_BITS_MIN);
 533 #endif
 534         return true;
 535 }
 536
 537
 538 bool
 539 ConnSSL_PrepareConnect(CONNECTION *c, UNUSED CONF_SERVER *s)
 540 {
 541         bool ret;
 542 #ifdef HAVE_LIBGNUTLS
 543         int err;
 544
 545         err = gnutls_init(&c->ssl_state.gnutls_session, GNUTLS_CLIENT);
 546         if (err) {
 547                 Log(LOG_ERR, "Failed to initialize new SSL session: %s",
 548                     gnutls_strerror(err));
 549                 return false;
 550         }
 551 #endif
 552         ret = ConnSSL_Init_SSL(c);
 553         if (!ret)
 554                 return false;
 555         Conn_OPTION_ADD(c, CONN_SSL_CONNECT);
 556 #ifdef HAVE_LIBSSL
 557         assert(c->ssl_state.ssl);
 558         SSL_set_verify(c->ssl_state.ssl, SSL_VERIFY_NONE, NULL);
 559 #endif
 560         return true;
 561 }
 562
 563
 564 /**
 565  * Check and handle error return codes after failed calls to SSL functions.
 566  *
 567  * OpenSSL:
 568  * SSL_connect(), SSL_accept(), SSL_do_handshake(), SSL_read(), SSL_peek(), or
 569  * SSL_write() on ssl.
 570  *
 571  * GnuTLS:
 572  * gnutlsssl_read(), gnutls_write() or gnutls_handshake().
 573  *
 574  * @param c The connection handle.
 575  * @prarm code The return code.
 576  * @param fname The name of the function in which the error occurred.
 577  * @return -1 on fatal errors, 0 if we can try again later.
 578  */
 579 static int
 580 ConnSSL_HandleError(CONNECTION * c, const int code, const char *fname)
 581 {
 582 #ifdef HAVE_LIBSSL
 583         int ret = SSL_ERROR_SYSCALL;
 584         unsigned long sslerr;
 585         int real_errno = errno;
 586
 587         ret = SSL_get_error(c->ssl_state.ssl, code);
 588
 589         switch (ret) {
 590         case SSL_ERROR_WANT_READ:
 591                 io_event_del(c->sock, IO_WANTWRITE);
 592                 Conn_OPTION_ADD(c, CONN_SSL_WANT_READ);
 593                 return 0;       /* try again later */
 594         case SSL_ERROR_WANT_WRITE:
 595                 io_event_del(c->sock, IO_WANTREAD);
 596                 Conn_OPTION_ADD(c, CONN_SSL_WANT_WRITE); /* fall through */
 597         case SSL_ERROR_NONE:
 598                 return 0;       /* try again later */
 599         case SSL_ERROR_ZERO_RETURN:
 600                 LogDebug("SSL connection shut down normally.");
 601                 break;
 602         case SSL_ERROR_SYSCALL:
 603                 /* SSL_ERROR_WANT_CONNECT, SSL_ERROR_WANT_ACCEPT,
 604                  * and SSL_ERROR_WANT_X509_LOOKUP */
 605                 sslerr = ERR_get_error();
 606                 if (sslerr) {
 607                         Log(LOG_ERR, "SSL error: %s [in %s()]!",
 608                             ERR_error_string(sslerr, NULL), fname);
 609                 } else {
 610                         switch (code) { /* EOF that violated protocol */
 611                         case 0:
 612                                 Log(LOG_ERR,
 613                                     "SSL error, client disconnected [in %s()]!",
 614                                     fname);
 615                                 break;
 616                         case -1:        /* low level socket I/O error, check errno */
 617                                 Log(LOG_ERR, "SSL error: %s [in %s()]!",
 618                                     strerror(real_errno), fname);
 619                         }
 620                 }
 621                 break;
 622         case SSL_ERROR_SSL:
 623                 LogOpenSSLError("SSL protocol error", fname);
 624                 break;
 625         default:
 626                 Log(LOG_ERR, "Unknown SSL error %d [in %s()]!", ret, fname);
 627         }
 628         ConnSSL_Free(c);
 629         return -1;
 630 #endif
 631 #ifdef HAVE_LIBGNUTLS
 632         switch (code) {
 633         case GNUTLS_E_AGAIN:
 634         case GNUTLS_E_INTERRUPTED:
 635                 if (gnutls_record_get_direction(c->ssl_state.gnutls_session)) {
 636                         Conn_OPTION_ADD(c, CONN_SSL_WANT_WRITE);
 637                         io_event_del(c->sock, IO_WANTREAD);
 638                 } else {
 639                         Conn_OPTION_ADD(c, CONN_SSL_WANT_READ);
 640                         io_event_del(c->sock, IO_WANTWRITE);
 641                 }
 642                 break;
 643         default:
 644                 assert(code < 0);
 645                 if (gnutls_error_is_fatal(code)) {
 646                         Log(LOG_ERR, "SSL error: %s [%s].",
 647                             gnutls_strerror(code), fname);
 648                         ConnSSL_Free(c);
 649                         return -1;
 650                 }
 651         }
 652         return 0;
 653 #endif
 654 }
 655
 656
 657 static void
 658 ConnSSL_LogCertInfo( CONNECTION *c )
 659 {
 660 #ifdef HAVE_LIBSSL
 661         SSL *ssl = c->ssl_state.ssl;
 662
 663         assert(ssl);
 664
 665         Log(LOG_INFO, "Connection %d: initialized %s using cipher %s.",
 666                 c->sock, SSL_get_version(ssl), SSL_get_cipher(ssl));
 667 #endif
 668 #ifdef HAVE_LIBGNUTLS
 669         gnutls_session_t sess = c->ssl_state.gnutls_session;
 670         gnutls_cipher_algorithm_t cipher = gnutls_cipher_get(sess);
 671
 672         Log(LOG_INFO, "Connection %d: initialized %s using cipher %s-%s.",
 673             c->sock,
 674             gnutls_protocol_get_name(gnutls_protocol_get_version(sess)),
 675             gnutls_cipher_get_name(cipher),
 676             gnutls_mac_get_name(gnutls_mac_get(sess)));
 677 #endif
 678 }
 679
 680
 681 /*
 682  Accept incoming SSL connection.
 683  Return Values:
 684          1: SSL Connection established
 685          0: try again
 686         -1: SSL Connection not established due to fatal error.
 687 */
 688 int
 689 ConnSSL_Accept( CONNECTION *c )
 690 {
 691         assert(c != NULL);
 692         if (!Conn_OPTION_ISSET(c, CONN_SSL)) {
 693 #ifdef HAVE_LIBGNUTLS
 694                 int err = gnutls_init(&c->ssl_state.gnutls_session, GNUTLS_SERVER);
 695                 if (err) {
 696                         Log(LOG_ERR, "Failed to initialize new SSL session: %s",
 697                             gnutls_strerror(err));
 698                         return false;
 699                 }
 700 #endif
 701                 if (!ConnSSL_Init_SSL(c))
 702                         return -1;
 703         }
 704         return ConnectAccept(c, false );
 705 }
 706
 707
 708 int
 709 ConnSSL_Connect( CONNECTION *c )
 710 {
 711         assert(c != NULL);
 712 #ifdef HAVE_LIBSSL
 713         assert(c->ssl_state.ssl);
 714 #endif
 715         assert(Conn_OPTION_ISSET(c, CONN_SSL));
 716         return ConnectAccept(c, true);
 717 }
 718
 719 static int
 720 ConnSSL_InitCertFp( CONNECTION *c )
 721 {
 722         const char hex[] = "0123456789abcdef";
 723         int i;
 724
 725 #ifdef HAVE_LIBSSL
 726         unsigned char digest[EVP_MAX_MD_SIZE];
 727         unsigned int digest_size;
 728         X509 *cert;
 729
 730         cert = SSL_get_peer_certificate(c->ssl_state.ssl);
 731         if (!cert)
 732                 return 0;
 733
 734         if (!X509_digest(cert, EVP_sha1(), digest, &digest_size)) {
 735                 X509_free(cert);
 736                 return 0;
 737         }
 738
 739         X509_free(cert);
 740 #endif /* HAVE_LIBSSL */
 741 #ifdef HAVE_LIBGNUTLS
 742         gnutls_x509_crt_t cert;
 743         unsigned int cert_list_size;
 744         const gnutls_datum_t *cert_list;
 745         unsigned char digest[MAX_HASH_SIZE];
 746         size_t digest_size;
 747
 748         if (gnutls_certificate_type_get(c->ssl_state.gnutls_session) != GNUTLS_CRT_X509)
 749                 return 0;
 750
 751         if (gnutls_x509_crt_init(&cert) != GNUTLS_E_SUCCESS)
 752                 return 0;
 753
 754         cert_list_size = 0;
 755         cert_list = gnutls_certificate_get_peers(c->ssl_state.gnutls_session,
 756                                                  &cert_list_size);
 757         if (!cert_list) {
 758                 gnutls_x509_crt_deinit(cert);
 759                 return 0;
 760         }
 761
 762         if (gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER) != GNUTLS_E_SUCCESS) {
 763                 gnutls_x509_crt_deinit(cert);
 764                 return 0;
 765         }
 766
 767         digest_size = sizeof(digest);
 768         if (gnutls_x509_crt_get_fingerprint(cert, GNUTLS_DIG_SHA1, digest, &digest_size)) {
 769                 gnutls_x509_crt_deinit(cert);
 770                 return 0;
 771         }
 772
 773         gnutls_x509_crt_deinit(cert);
 774 #endif /* HAVE_LIBGNUTLS */
 775
 776         assert(c->ssl_state.fingerprint == NULL);
 777
 778         c->ssl_state.fingerprint = malloc(SHA1_STRING_LEN);
 779         if (!c->ssl_state.fingerprint)
 780                 return 0;
 781
 782         for (i = 0; i < (int)digest_size; i++) {
 783                 c->ssl_state.fingerprint[i * 2] = hex[digest[i] / 16];
 784                 c->ssl_state.fingerprint[i * 2 + 1] = hex[digest[i] % 16];
 785         }
 786         c->ssl_state.fingerprint[i * 2] = '\0';
 787
 788         return 1;
 789 }
 790
 791 /* accept/connect wrapper. if connect is true, connect to peer, otherwise wait for incoming connection */
 792 static int
 793 ConnectAccept( CONNECTION *c, bool connect)
 794 {
 795         int ret;
 796 #ifdef HAVE_LIBSSL
 797         SSL *ssl = c->ssl_state.ssl;
 798         assert(ssl != NULL);
 799
 800         ret = connect ? SSL_connect(ssl) : SSL_accept(ssl);
 801         if (1 != ret)
 802                 return ConnSSL_HandleError(c, ret, connect ? "SSL_connect": "SSL_accept");
 803 #endif
 804 #ifdef HAVE_LIBGNUTLS
 805         (void) connect;
 806         ret = gnutls_handshake(c->ssl_state.gnutls_session);
 807         if (ret)
 808                 return ConnSSL_HandleError(c, ret, "gnutls_handshake");
 809 #endif /* _GNUTLS */
 810         (void)ConnSSL_InitCertFp(c);
 811
 812         Conn_OPTION_DEL(c, (CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ|CONN_SSL_CONNECT));
 813         ConnSSL_LogCertInfo(c);
 814
 815         Conn_StartLogin(CONNECTION2ID(c));
 816         return 1;
 817 }
 818
 819
 820 ssize_t
 821 ConnSSL_Write(CONNECTION *c, const void *buf, size_t count)
 822 {
 823         ssize_t bw;
 824
 825         Conn_OPTION_DEL(c, CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ);
 826
 827         assert(count > 0);
 828 #ifdef HAVE_LIBSSL
 829         bw = (ssize_t) SSL_write(c->ssl_state.ssl, buf, count);
 830 #endif
 831 #ifdef HAVE_LIBGNUTLS
 832         bw = gnutls_write(c->ssl_state.gnutls_session, buf, count);
 833 #endif
 834         if (bw > 0)
 835                 return bw;
 836         if (ConnSSL_HandleError( c, bw, "ConnSSL_Write") == 0)
 837                 errno = EAGAIN; /* try again */
 838         return -1;
 839 }
 840
 841
 842 ssize_t
 843 ConnSSL_Read(CONNECTION *c, void * buf, size_t count)
 844 {
 845         ssize_t br;
 846
 847         Conn_OPTION_DEL(c, CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ);
 848 #ifdef HAVE_LIBSSL
 849         br = (ssize_t) SSL_read(c->ssl_state.ssl, buf, count);
 850         if (br > 0)     /* on EOF we have to call ConnSSL_HandleError(), see SSL_read(3) */
 851                 return br;
 852 #endif
 853 #ifdef HAVE_LIBGNUTLS
 854         br = gnutls_read(c->ssl_state.gnutls_session, buf, count);
 855         if (br >= 0)    /* on EOF we must _not_ call ConnSSL_HandleError, see gnutls_record_recv(3) */
 856                 return br;
 857 #endif
 858         /* error on read: switch ConnSSL_HandleError() return values -> 0 is "try again", so return -1 and set EAGAIN */
 859         if (ConnSSL_HandleError(c, br, "ConnSSL_Read") == 0) {
 860                 errno = EAGAIN;
 861                 return -1;
 862         }
 863         return 0;
 864 }
 865
 866
 867 bool
 868 ConnSSL_GetCipherInfo(CONNECTION *c, char *buf, size_t len)
 869 {
 870 #ifdef HAVE_LIBSSL
 871         char *nl;
 872         SSL *ssl = c->ssl_state.ssl;
 873
 874         if (!ssl)
 875                 return false;
 876         *buf = 0;
 877         SSL_CIPHER_description(SSL_get_current_cipher(ssl), buf, len);
 878         nl = strchr(buf, '\n');
 879         if (nl)
 880                 *nl = 0;
 881         return true;
 882 #endif
 883 #ifdef HAVE_LIBGNUTLS
 884         if (Conn_OPTION_ISSET(c, CONN_SSL)) {
 885                 const char *name_cipher, *name_mac, *name_proto, *name_keyexchange;
 886                 unsigned keysize;
 887
 888                 gnutls_session_t sess = c->ssl_state.gnutls_session;
 889                 gnutls_cipher_algorithm_t cipher = gnutls_cipher_get(sess);
 890                 name_cipher = gnutls_cipher_get_name(cipher);
 891                 name_mac = gnutls_mac_get_name(gnutls_mac_get(sess));
 892                 keysize = gnutls_cipher_get_key_size(cipher) * 8;
 893                 name_proto = gnutls_protocol_get_name(gnutls_protocol_get_version(sess));
 894                 name_keyexchange = gnutls_kx_get_name(gnutls_kx_get(sess));
 895
 896                 return snprintf(buf, len, "%s-%s%15s Kx=%s      Enc=%s(%u) Mac=%s",
 897                         name_cipher, name_mac, name_proto, name_keyexchange, name_cipher, keysize, name_mac) > 0;
 898         }
 899         return false;
 900 #endif
 901 }
 902
 903 char *
 904 ConnSSL_GetCertFp(CONNECTION *c)
 905 {
 906         return c->ssl_state.fingerprint;
 907 }
 908
 909 bool
 910 ConnSSL_SetCertFp(CONNECTION *c, const char *fingerprint)
 911 {
 912         assert (c != NULL);
 913         c->ssl_state.fingerprint = strndup(fingerprint, SHA1_STRING_LEN - 1);
 914         return c->ssl_state.fingerprint != NULL;
 915 }
 916 #else
 917
 918 bool
 919 ConnSSL_InitLibrary(void)
 920 {
 921         return true;
 922 }
 923
 924 #endif /* SSL_SUPPORT */
 925 /* -eof- */
 926
 927