src/ngircd/conn-ssl.c

   1 /*
   2  * ngIRCd -- The Next Generation IRC Daemon
   3  * Copyright (c)2005-2008 Florian Westphal (fw@strlen.de).
   4  * Copyright (c)2008-2014 Alexander Barton (alex@barton.de) and Contributors.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  * Please read the file COPYING, README and AUTHORS for more information.
  11  */
  12
  13 #include "portab.h"
  14
  15 /**
  16  * @file
  17  * SSL wrapper functions
  18  */
  19
  20 #include "conf-ssl.h"
  21
  22 #ifdef SSL_SUPPORT
  23
  24 #include "io.h"
  25 #include <assert.h>
  26 #include <stdio.h>
  27 #include <string.h>
  28 #include <stdlib.h>
  29 #include <errno.h>
  30
  31 #define CONN_MODULE
  32 #include "conn.h"
  33 #include "conf.h"
  34 #include "conn-func.h"
  35 #include "conn-ssl.h"
  36 #include "log.h"
  37
  38 #include "defines.h"
  39
  40 extern struct SSLOptions Conf_SSLOptions;
  41
  42 #ifdef HAVE_LIBSSL
  43 #include <openssl/err.h>
  44 #include <openssl/rand.h>
  45 #include <openssl/dh.h>
  46
  47 static SSL_CTX * ssl_ctx;
  48 static DH *dh_params;
  49
  50 static bool ConnSSL_LoadServerKey_openssl PARAMS(( SSL_CTX *c ));
  51 #endif
  52
  53 #ifdef HAVE_LIBGNUTLS
  54 #include <sys/types.h>
  55 #include <sys/stat.h>
  56 #include <fcntl.h>
  57 #include <unistd.h>
  58 #include <gnutls/x509.h>
  59
  60 #define DH_BITS 2048
  61 #define DH_BITS_MIN 1024
  62
  63 #define MAX_HASH_SIZE   64      /* from gnutls-int.h */
  64
  65 static gnutls_certificate_credentials_t x509_cred;
  66 static gnutls_dh_params_t dh_params;
  67 static gnutls_priority_t priorities_cache;
  68 static bool ConnSSL_LoadServerKey_gnutls PARAMS(( void ));
  69 #endif
  70
  71 #define SHA256_STRING_LEN       (32 * 2 + 1)
  72
  73 static bool ConnSSL_Init_SSL PARAMS(( CONNECTION *c ));
  74 static int ConnectAccept PARAMS(( CONNECTION *c, bool connect ));
  75 static int ConnSSL_HandleError PARAMS(( CONNECTION *c, const int code, const char *fname ));
  76
  77 #ifdef HAVE_LIBGNUTLS
  78 static char * openreadclose(const char *name, size_t *len)
  79 {
  80         char *buf = NULL;
  81         struct stat s;
  82         ssize_t br;
  83         int fd = open(name, O_RDONLY);
  84         if (fd < 0) {
  85                 Log(LOG_ERR, "Could not open %s: %s", name, strerror(errno));
  86                 return NULL;
  87         }
  88         if (fstat(fd, &s)) {
  89                 Log(LOG_ERR, "Could not fstat %s: %s", name, strerror(errno));
  90                 goto out;
  91         }
  92         if (!S_ISREG(s.st_mode)) {
  93                 Log(LOG_ERR, "%s: Not a regular file", name);
  94                 goto out;
  95         }
  96         if (s.st_size <= 0) {
  97                 Log(LOG_ERR, "%s: invalid file length (size %ld <= 0)", name, (long) s.st_size);
  98                 goto out;
  99         }
 100         buf = malloc(s.st_size);
 101         if (!buf) {
 102                 Log(LOG_ERR, "Could not malloc %lu bytes for file %s: %s", s.st_size, name, strerror(errno));
 103                 goto out;
 104         }
 105         br = read(fd, buf, s.st_size);
 106         if (br != (ssize_t)s.st_size) {
 107                 Log(LOG_ERR, "Could not read file %s: read returned %ld, expected %ld: %s",
 108                         name, (long) br, (long) s.st_size, br == -1 ? strerror(errno):"short read?!");
 109                 memset(buf, 0, s.st_size);
 110                 free(buf);
 111                 buf = NULL;
 112         } else {
 113                 *len = br;
 114         }
 115 out:
 116         close(fd);
 117         return buf;
 118 }
 119 #endif
 120
 121
 122 #ifdef HAVE_LIBSSL
 123 /**
 124  * Log OpenSSL error message.
 125  *
 126  * @param msg The error message.
 127  * @param info Additional information text or NULL.
 128  */
 129 static void
 130 LogOpenSSLError(const char *error, const char *info)
 131 {
 132         unsigned long err = ERR_get_error();
 133         char * errmsg = err
 134                 ? ERR_error_string(err, NULL)
 135                 : "Unable to determine error";
 136
 137         assert(error != NULL);
 138
 139         if (info)
 140                 Log(LOG_ERR, "%s: %s (%s)", error, info, errmsg);
 141         else
 142                 Log(LOG_ERR, "%s: %s", error, errmsg);
 143 }
 144
 145
 146 static int
 147 pem_passwd_cb(char *buf, int size, int rwflag, void *password)
 148 {
 149         array *pass = password;
 150         int passlen;
 151
 152         (void)rwflag;           /* rwflag is unused if DEBUG is not set. */
 153         assert(rwflag == 0);    /* 0 -> callback used for decryption.
 154                                  * See SSL_CTX_set_default_passwd_cb(3) */
 155
 156         passlen = (int) array_bytes(pass);
 157
 158         LogDebug("pem_passwd_cb buf size %d, array size %d", size, passlen);
 159         assert(passlen >= 0);
 160         if (passlen <= 0) {
 161                 Log(LOG_ERR, "PEM password required but not set [in pem_passwd_cb()]!");
 162                 return 0;
 163         }
 164         size = passlen > size ? size : passlen;
 165         memcpy(buf, (char *)(array_start(pass)), size);
 166         return size;
 167 }
 168
 169
 170 static int
 171 Verify_openssl(UNUSED int preverify_ok, UNUSED X509_STORE_CTX *x509_ctx)
 172 {
 173         return 1;
 174 }
 175 #endif
 176
 177
 178 static bool
 179 Load_DH_params(void)
 180 {
 181 #ifdef HAVE_LIBSSL
 182         FILE *fp;
 183         bool ret = true;
 184
 185         if (!Conf_SSLOptions.DHFile) {
 186                 Log(LOG_NOTICE, "Configuration option \"DHFile\" not set!");
 187                 return false;
 188         }
 189         fp = fopen(Conf_SSLOptions.DHFile, "r");
 190         if (!fp) {
 191                 Log(LOG_ERR, "%s: %s", Conf_SSLOptions.DHFile, strerror(errno));
 192                 return false;
 193         }
 194         dh_params = PEM_read_DHparams(fp, NULL, NULL, NULL);
 195         if (!dh_params) {
 196                 Log(LOG_ERR, "%s: Failed to read SSL DH parameters!",
 197                     Conf_SSLOptions.DHFile);
 198                 ret = false;
 199         }
 200         fclose(fp);
 201         return ret;
 202 #endif
 203 #ifdef HAVE_LIBGNUTLS
 204         bool need_dhgenerate = true;
 205         int err;
 206         gnutls_dh_params_t tmp_dh_params;
 207
 208         err = gnutls_dh_params_init(&tmp_dh_params);
 209         if (err < 0) {
 210                 Log(LOG_ERR, "Failed to initialize SSL DH parameters: %s",
 211                     gnutls_strerror(err));
 212                 return false;
 213         }
 214         if (Conf_SSLOptions.DHFile) {
 215                 gnutls_datum_t dhparms;
 216                 size_t size;
 217                 dhparms.data = (unsigned char *) openreadclose(Conf_SSLOptions.DHFile, &size);
 218                 if (dhparms.data) {
 219                         dhparms.size = size;
 220                         err = gnutls_dh_params_import_pkcs3(tmp_dh_params, &dhparms, GNUTLS_X509_FMT_PEM);
 221                         if (err == 0)
 222                                 need_dhgenerate = false;
 223                         else
 224                                 Log(LOG_ERR,
 225                                     "Failed to initialize SSL DH parameters: %s",
 226                                     gnutls_strerror(err));
 227
 228                         memset(dhparms.data, 0, size);
 229                         free(dhparms.data);
 230                 }
 231         }
 232         if (need_dhgenerate) {
 233                 Log(LOG_WARNING,
 234                     "DHFile not set, generating %u bit DH parameters. This may take a while ...",
 235                     DH_BITS);
 236                 err = gnutls_dh_params_generate2(tmp_dh_params, DH_BITS);
 237                 if (err < 0) {
 238                         Log(LOG_ERR, "Failed to generate SSL DH parameters: %s",
 239                             gnutls_strerror(err));
 240                         return false;
 241                 }
 242         }
 243         dh_params = tmp_dh_params;
 244         return true;
 245 #endif
 246 }
 247
 248
 249 void ConnSSL_Free(CONNECTION *c)
 250 {
 251 #ifdef HAVE_LIBSSL
 252         SSL *ssl = c->ssl_state.ssl;
 253         if (ssl) {
 254                 SSL_shutdown(ssl);
 255                 SSL_free(ssl);
 256                 c->ssl_state.ssl = NULL;
 257                 if (c->ssl_state.fingerprint) {
 258                         free(c->ssl_state.fingerprint);
 259                         c->ssl_state.fingerprint = NULL;
 260                 }
 261         }
 262 #endif
 263 #ifdef HAVE_LIBGNUTLS
 264         gnutls_session_t sess = c->ssl_state.gnutls_session;
 265         if (Conn_OPTION_ISSET(c, CONN_SSL)) {
 266                 gnutls_bye(sess, GNUTLS_SHUT_RDWR);
 267                 gnutls_deinit(sess);
 268         }
 269 #endif
 270         assert(Conn_OPTION_ISSET(c, CONN_SSL));
 271         /* can't just set bitmask to 0 -- there are other, non-ssl related flags, e.g. CONN_ZIP. */
 272         Conn_OPTION_DEL(c, CONN_SSL_FLAGS_ALL);
 273 }
 274
 275
 276 bool
 277 ConnSSL_InitLibrary( void )
 278 {
 279         if (!Conf_SSLInUse()) {
 280                 LogDebug("SSL not in use, skipping initialization.");
 281                 return true;
 282         }
 283
 284 #ifdef HAVE_LIBSSL
 285         SSL_CTX *newctx;
 286
 287 #if OPENSSL_API_COMPAT < 0x10100000L
 288         if (!ssl_ctx) {
 289                 SSL_library_init();
 290                 SSL_load_error_strings();
 291         }
 292 #endif
 293
 294         if (!RAND_status()) {
 295                 Log(LOG_ERR, "OpenSSL PRNG not seeded: /dev/urandom missing?");
 296                 /*
 297                  * it is probably best to fail and let the user install EGD or
 298                  * a similar program if no kernel random device is available.
 299                  * According to OpenSSL RAND_egd(3): "The automatic query of
 300                  * /var/run/egd-pool et al was added in OpenSSL 0.9.7";
 301                  * so it makes little sense to deal with PRNGD seeding ourselves.
 302                  */
 303                 array_free(&Conf_SSLOptions.ListenPorts);
 304                 return false;
 305         }
 306
 307         newctx = SSL_CTX_new(SSLv23_method());
 308         if (!newctx) {
 309                 LogOpenSSLError("Failed to create SSL context", NULL);
 310                 array_free(&Conf_SSLOptions.ListenPorts);
 311                 return false;
 312         }
 313
 314         if (!ConnSSL_LoadServerKey_openssl(newctx)) {
 315                 /* Failed to read new key but an old ssl context
 316                  * already exists -> reuse old context */
 317                 if (ssl_ctx) {
 318                         SSL_CTX_free(newctx);
 319                         Log(LOG_WARNING,
 320                         "Re-Initializing of SSL failed, using old keys!");
 321                         return true;
 322                 }
 323                 /* No preexisting old context -> error. */
 324                 goto out;
 325         }
 326
 327         if (SSL_CTX_set_cipher_list(newctx, Conf_SSLOptions.CipherList) == 0) {
 328                 Log(LOG_ERR, "Failed to apply OpenSSL cipher list \"%s\"!",
 329                     Conf_SSLOptions.CipherList);
 330                 goto out;
 331         }
 332
 333         SSL_CTX_set_session_id_context(newctx, (unsigned char *)"ngircd", 6);
 334         SSL_CTX_set_options(newctx, SSL_OP_SINGLE_DH_USE|SSL_OP_NO_SSLv2);
 335         SSL_CTX_set_mode(newctx, SSL_MODE_ENABLE_PARTIAL_WRITE);
 336         SSL_CTX_set_verify(newctx, SSL_VERIFY_PEER|SSL_VERIFY_CLIENT_ONCE,
 337                            Verify_openssl);
 338         SSL_CTX_free(ssl_ctx);
 339         ssl_ctx = newctx;
 340         Log(LOG_INFO, "%s initialized.", OpenSSL_version(OPENSSL_VERSION));
 341         return true;
 342 out:
 343         SSL_CTX_free(newctx);
 344         array_free(&Conf_SSLOptions.ListenPorts);
 345         return false;
 346 #endif
 347 #ifdef HAVE_LIBGNUTLS
 348         int err;
 349         static bool initialized;
 350
 351         if (initialized) {
 352                 /* TODO: cannot reload gnutls keys: can't simply free x509
 353                  * context -- it may still be in use */
 354                 return false;
 355         }
 356
 357         err = gnutls_global_init();
 358         if (err) {
 359                 Log(LOG_ERR, "Failed to initialize GnuTLS: %s",
 360                     gnutls_strerror(err));
 361                 goto out;
 362         }
 363
 364         if (!ConnSSL_LoadServerKey_gnutls())
 365                 goto out;
 366
 367         if (gnutls_priority_init(&priorities_cache, Conf_SSLOptions.CipherList,
 368                                  NULL) != GNUTLS_E_SUCCESS) {
 369                 Log(LOG_ERR,
 370                     "Failed to apply GnuTLS cipher list \"%s\"!",
 371                     Conf_SSLOptions.CipherList);
 372                 goto out;
 373         }
 374
 375         Log(LOG_INFO, "GnuTLS %s initialized.", gnutls_check_version(NULL));
 376         initialized = true;
 377         return true;
 378 out:
 379         array_free(&Conf_SSLOptions.ListenPorts);
 380         return false;
 381 #endif
 382 }
 383
 384
 385 #ifdef HAVE_LIBGNUTLS
 386 static bool
 387 ConnSSL_LoadServerKey_gnutls(void)
 388 {
 389         int err;
 390         const char *cert_file;
 391
 392         err = gnutls_certificate_allocate_credentials(&x509_cred);
 393         if (err < 0) {
 394                 Log(LOG_ERR, "Failed to allocate certificate credentials: %s",
 395                     gnutls_strerror(err));
 396                 return false;
 397         }
 398
 399         cert_file = Conf_SSLOptions.CertFile ? Conf_SSLOptions.CertFile:Conf_SSLOptions.KeyFile;
 400         if (!cert_file) {
 401                 Log(LOG_ERR, "No SSL server key configured!");
 402                 return false;
 403         }
 404
 405         if (array_bytes(&Conf_SSLOptions.KeyFilePassword))
 406                 Log(LOG_WARNING,
 407                     "Ignoring SSL \"KeyFilePassword\": Not supported by GnuTLS.");
 408
 409         if (!Load_DH_params())
 410                 return false;
 411
 412         gnutls_certificate_set_dh_params(x509_cred, dh_params);
 413         err = gnutls_certificate_set_x509_key_file(x509_cred, cert_file, Conf_SSLOptions.KeyFile, GNUTLS_X509_FMT_PEM);
 414         if (err < 0) {
 415                 Log(LOG_ERR,
 416                     "Failed to set certificate key file (cert %s, key %s): %s",
 417                     cert_file,
 418                     Conf_SSLOptions.KeyFile ? Conf_SSLOptions.KeyFile : "(NULL)",
 419                     gnutls_strerror(err));
 420                 return false;
 421         }
 422         return true;
 423 }
 424 #endif
 425
 426
 427 #ifdef HAVE_LIBSSL
 428 static bool
 429 ConnSSL_LoadServerKey_openssl(SSL_CTX *ctx)
 430 {
 431         char *cert_key;
 432
 433         assert(ctx);
 434         if (!Conf_SSLOptions.KeyFile) {
 435                 Log(LOG_ERR, "No SSL server key configured!");
 436                 return false;
 437         }
 438
 439         SSL_CTX_set_default_passwd_cb(ctx, pem_passwd_cb);
 440         SSL_CTX_set_default_passwd_cb_userdata(ctx, &Conf_SSLOptions.KeyFilePassword);
 441
 442         if (SSL_CTX_use_PrivateKey_file(ctx, Conf_SSLOptions.KeyFile, SSL_FILETYPE_PEM) != 1) {
 443                 array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 444                 LogOpenSSLError("Failed to add private key", Conf_SSLOptions.KeyFile);
 445                 return false;
 446         }
 447
 448         cert_key = Conf_SSLOptions.CertFile ? Conf_SSLOptions.CertFile:Conf_SSLOptions.KeyFile;
 449         if (SSL_CTX_use_certificate_chain_file(ctx, cert_key) != 1) {
 450                 array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 451                 LogOpenSSLError("Failed to load certificate chain", cert_key);
 452                 return false;
 453         }
 454
 455         array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 456
 457         if (!SSL_CTX_check_private_key(ctx)) {
 458                 LogOpenSSLError("Server private key does not match certificate", NULL);
 459                 return false;
 460         }
 461         if (Load_DH_params()) {
 462                 if (SSL_CTX_set_tmp_dh(ctx, dh_params) != 1)
 463                         LogOpenSSLError("Error setting DH parameters", Conf_SSLOptions.DHFile);
 464                 /* don't return false here: the non-DH modes will still work */
 465                 DH_free(dh_params);
 466                 dh_params = NULL;
 467         }
 468         return true;
 469 }
 470
 471
 472 #endif
 473 static bool
 474 ConnSSL_Init_SSL(CONNECTION *c)
 475 {
 476         int ret;
 477
 478         LogDebug("Initializing SSL ...");
 479         assert(c != NULL);
 480
 481 #ifdef HAVE_LIBSSL
 482         if (!ssl_ctx) {
 483                 Log(LOG_ERR,
 484                     "Can't initialize SSL context, OpenSSL initialization failed at startup!");
 485                 return false;
 486         }
 487         assert(c->ssl_state.ssl == NULL);
 488         assert(c->ssl_state.fingerprint == NULL);
 489
 490         c->ssl_state.ssl = SSL_new(ssl_ctx);
 491         if (!c->ssl_state.ssl) {
 492                 LogOpenSSLError("Failed to create SSL structure", NULL);
 493                 return false;
 494         }
 495         Conn_OPTION_ADD(c, CONN_SSL);
 496
 497         ret = SSL_set_fd(c->ssl_state.ssl, c->sock);
 498         if (ret != 1) {
 499                 LogOpenSSLError("Failed to set SSL file descriptor", NULL);
 500                 ConnSSL_Free(c);
 501                 return false;
 502         }
 503 #endif
 504 #ifdef HAVE_LIBGNUTLS
 505         Conn_OPTION_ADD(c, CONN_SSL);
 506         ret = gnutls_priority_set(c->ssl_state.gnutls_session, priorities_cache);
 507         if (ret != GNUTLS_E_SUCCESS) {
 508                 Log(LOG_ERR, "Failed to set GnuTLS session priorities: %s",
 509                     gnutls_strerror(ret));
 510                 ConnSSL_Free(c);
 511                 return false;
 512         }
 513         /*
 514          * The intermediate (long) cast is here to avoid a warning like:
 515          * "cast to pointer from integer of different size" on 64-bit platforms.
 516          * There doesn't seem to be an alternate GNUTLS API we could use instead, see e.g.
 517          * http://www.mail-archive.com/help-gnutls@gnu.org/msg00286.html
 518          */
 519         gnutls_transport_set_ptr(c->ssl_state.gnutls_session,
 520                                  (gnutls_transport_ptr_t) (long) c->sock);
 521         gnutls_certificate_server_set_request(c->ssl_state.gnutls_session,
 522                                               GNUTLS_CERT_REQUEST);
 523         ret = gnutls_credentials_set(c->ssl_state.gnutls_session,
 524                                      GNUTLS_CRD_CERTIFICATE, x509_cred);
 525         if (ret != 0) {
 526                 Log(LOG_ERR, "Failed to set SSL credentials: %s",
 527                     gnutls_strerror(ret));
 528                 ConnSSL_Free(c);
 529                 return false;
 530         }
 531         gnutls_dh_set_prime_bits(c->ssl_state.gnutls_session, DH_BITS_MIN);
 532 #endif
 533         return true;
 534 }
 535
 536
 537 bool
 538 ConnSSL_PrepareConnect(CONNECTION *c, UNUSED CONF_SERVER *s)
 539 {
 540         bool ret;
 541 #ifdef HAVE_LIBGNUTLS
 542         int err;
 543
 544         err = gnutls_init(&c->ssl_state.gnutls_session, GNUTLS_CLIENT);
 545         if (err) {
 546                 Log(LOG_ERR, "Failed to initialize new SSL session: %s",
 547                     gnutls_strerror(err));
 548                 return false;
 549         }
 550 #endif
 551         ret = ConnSSL_Init_SSL(c);
 552         if (!ret)
 553                 return false;
 554         Conn_OPTION_ADD(c, CONN_SSL_CONNECT);
 555 #ifdef HAVE_LIBSSL
 556         assert(c->ssl_state.ssl);
 557         SSL_set_verify(c->ssl_state.ssl, SSL_VERIFY_NONE, NULL);
 558 #endif
 559         return true;
 560 }
 561
 562
 563 /**
 564  * Check and handle error return codes after failed calls to SSL functions.
 565  *
 566  * OpenSSL:
 567  * SSL_connect(), SSL_accept(), SSL_do_handshake(), SSL_read(), SSL_peek(), or
 568  * SSL_write() on ssl.
 569  *
 570  * GnuTLS:
 571  * gnutlsssl_read(), gnutls_write() or gnutls_handshake().
 572  *
 573  * @param c The connection handle.
 574  * @prarm code The return code.
 575  * @param fname The name of the function in which the error occurred.
 576  * @return -1 on fatal errors, 0 if we can try again later.
 577  */
 578 static int
 579 ConnSSL_HandleError(CONNECTION * c, const int code, const char *fname)
 580 {
 581 #ifdef HAVE_LIBSSL
 582         int ret = SSL_ERROR_SYSCALL;
 583         unsigned long sslerr;
 584         int real_errno = errno;
 585
 586         ret = SSL_get_error(c->ssl_state.ssl, code);
 587
 588         switch (ret) {
 589         case SSL_ERROR_WANT_READ:
 590                 io_event_del(c->sock, IO_WANTWRITE);
 591                 Conn_OPTION_ADD(c, CONN_SSL_WANT_READ);
 592                 return 0;       /* try again later */
 593         case SSL_ERROR_WANT_WRITE:
 594                 io_event_del(c->sock, IO_WANTREAD);
 595                 Conn_OPTION_ADD(c, CONN_SSL_WANT_WRITE); /* fall through */
 596         case SSL_ERROR_NONE:
 597                 return 0;       /* try again later */
 598         case SSL_ERROR_ZERO_RETURN:
 599                 LogDebug("SSL connection shut down normally.");
 600                 break;
 601         case SSL_ERROR_SYSCALL:
 602                 /* SSL_ERROR_WANT_CONNECT, SSL_ERROR_WANT_ACCEPT,
 603                  * and SSL_ERROR_WANT_X509_LOOKUP */
 604                 sslerr = ERR_get_error();
 605                 if (sslerr) {
 606                         Log(LOG_ERR, "SSL error: %s [in %s()]!",
 607                             ERR_error_string(sslerr, NULL), fname);
 608                 } else {
 609                         switch (code) { /* EOF that violated protocol */
 610                         case 0:
 611                                 Log(LOG_ERR,
 612                                     "SSL error, client disconnected [in %s()]!",
 613                                     fname);
 614                                 break;
 615                         case -1:        /* low level socket I/O error, check errno */
 616                                 Log(LOG_ERR, "SSL error: %s [in %s()]!",
 617                                     strerror(real_errno), fname);
 618                         }
 619                 }
 620                 break;
 621         case SSL_ERROR_SSL:
 622                 LogOpenSSLError("SSL protocol error", fname);
 623                 break;
 624         default:
 625                 Log(LOG_ERR, "Unknown SSL error %d [in %s()]!", ret, fname);
 626         }
 627         ConnSSL_Free(c);
 628         return -1;
 629 #endif
 630 #ifdef HAVE_LIBGNUTLS
 631         switch (code) {
 632         case GNUTLS_E_AGAIN:
 633         case GNUTLS_E_INTERRUPTED:
 634                 if (gnutls_record_get_direction(c->ssl_state.gnutls_session)) {
 635                         Conn_OPTION_ADD(c, CONN_SSL_WANT_WRITE);
 636                         io_event_del(c->sock, IO_WANTREAD);
 637                 } else {
 638                         Conn_OPTION_ADD(c, CONN_SSL_WANT_READ);
 639                         io_event_del(c->sock, IO_WANTWRITE);
 640                 }
 641                 break;
 642         default:
 643                 assert(code < 0);
 644                 if (gnutls_error_is_fatal(code)) {
 645                         Log(LOG_ERR, "SSL error: %s [%s].",
 646                             gnutls_strerror(code), fname);
 647                         ConnSSL_Free(c);
 648                         return -1;
 649                 }
 650         }
 651         return 0;
 652 #endif
 653 }
 654
 655
 656 static void
 657 ConnSSL_LogCertInfo( CONNECTION *c )
 658 {
 659 #ifdef HAVE_LIBSSL
 660         SSL *ssl = c->ssl_state.ssl;
 661
 662         assert(ssl);
 663
 664         Log(LOG_INFO, "Connection %d: initialized %s using cipher %s.",
 665                 c->sock, SSL_get_version(ssl), SSL_get_cipher(ssl));
 666 #endif
 667 #ifdef HAVE_LIBGNUTLS
 668         gnutls_session_t sess = c->ssl_state.gnutls_session;
 669         gnutls_cipher_algorithm_t cipher = gnutls_cipher_get(sess);
 670
 671         Log(LOG_INFO, "Connection %d: initialized %s using cipher %s-%s.",
 672             c->sock,
 673             gnutls_protocol_get_name(gnutls_protocol_get_version(sess)),
 674             gnutls_cipher_get_name(cipher),
 675             gnutls_mac_get_name(gnutls_mac_get(sess)));
 676 #endif
 677 }
 678
 679
 680 /*
 681  Accept incoming SSL connection.
 682  Return Values:
 683          1: SSL Connection established
 684          0: try again
 685         -1: SSL Connection not established due to fatal error.
 686 */
 687 int
 688 ConnSSL_Accept( CONNECTION *c )
 689 {
 690         assert(c != NULL);
 691         if (!Conn_OPTION_ISSET(c, CONN_SSL)) {
 692 #ifdef HAVE_LIBGNUTLS
 693                 int err = gnutls_init(&c->ssl_state.gnutls_session, GNUTLS_SERVER);
 694                 if (err) {
 695                         Log(LOG_ERR, "Failed to initialize new SSL session: %s",
 696                             gnutls_strerror(err));
 697                         return false;
 698                 }
 699 #endif
 700                 if (!ConnSSL_Init_SSL(c))
 701                         return -1;
 702         }
 703         return ConnectAccept(c, false );
 704 }
 705
 706
 707 int
 708 ConnSSL_Connect( CONNECTION *c )
 709 {
 710         assert(c != NULL);
 711 #ifdef HAVE_LIBSSL
 712         assert(c->ssl_state.ssl);
 713 #endif
 714         assert(Conn_OPTION_ISSET(c, CONN_SSL));
 715         return ConnectAccept(c, true);
 716 }
 717
 718 static int
 719 ConnSSL_InitCertFp( CONNECTION *c )
 720 {
 721         const char hex[] = "0123456789abcdef";
 722         int i;
 723
 724 #ifdef HAVE_LIBSSL
 725         unsigned char digest[EVP_MAX_MD_SIZE];
 726         unsigned int digest_size;
 727         X509 *cert;
 728
 729         cert = SSL_get_peer_certificate(c->ssl_state.ssl);
 730         if (!cert)
 731                 return 0;
 732
 733         if (!X509_digest(cert, EVP_sha256(), digest, &digest_size)) {
 734                 X509_free(cert);
 735                 return 0;
 736         }
 737
 738         X509_free(cert);
 739 #endif /* HAVE_LIBSSL */
 740 #ifdef HAVE_LIBGNUTLS
 741         gnutls_x509_crt_t cert;
 742         unsigned int cert_list_size;
 743         const gnutls_datum_t *cert_list;
 744         unsigned char digest[MAX_HASH_SIZE];
 745         size_t digest_size;
 746
 747         if (gnutls_certificate_type_get(c->ssl_state.gnutls_session) !=
 748                                         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],
 763                                    GNUTLS_X509_FMT_DER) != GNUTLS_E_SUCCESS) {
 764                 gnutls_x509_crt_deinit(cert);
 765                 return 0;
 766         }
 767
 768         digest_size = sizeof(digest);
 769         if (gnutls_x509_crt_get_fingerprint(cert, GNUTLS_DIG_SHA256, digest,
 770                                             &digest_size)) {
 771                 gnutls_x509_crt_deinit(cert);
 772                 return 0;
 773         }
 774
 775         gnutls_x509_crt_deinit(cert);
 776 #endif /* HAVE_LIBGNUTLS */
 777
 778         assert(c->ssl_state.fingerprint == NULL);
 779
 780         c->ssl_state.fingerprint = malloc(SHA256_STRING_LEN);
 781         if (!c->ssl_state.fingerprint)
 782                 return 0;
 783
 784         for (i = 0; i < (int)digest_size; i++) {
 785                 c->ssl_state.fingerprint[i * 2] = hex[digest[i] / 16];
 786                 c->ssl_state.fingerprint[i * 2 + 1] = hex[digest[i] % 16];
 787         }
 788         c->ssl_state.fingerprint[i * 2] = '\0';
 789
 790         return 1;
 791 }
 792
 793 /* accept/connect wrapper. if connect is true, connect to peer, otherwise wait for incoming connection */
 794 static int
 795 ConnectAccept( CONNECTION *c, bool connect)
 796 {
 797         int ret;
 798 #ifdef HAVE_LIBSSL
 799         SSL *ssl = c->ssl_state.ssl;
 800         assert(ssl != NULL);
 801
 802         ret = connect ? SSL_connect(ssl) : SSL_accept(ssl);
 803         if (1 != ret)
 804                 return ConnSSL_HandleError(c, ret, connect ? "SSL_connect": "SSL_accept");
 805 #endif
 806 #ifdef HAVE_LIBGNUTLS
 807         (void) connect;
 808         ret = gnutls_handshake(c->ssl_state.gnutls_session);
 809         if (ret)
 810                 return ConnSSL_HandleError(c, ret, "gnutls_handshake");
 811 #endif /* _GNUTLS */
 812         (void)ConnSSL_InitCertFp(c);
 813
 814         Conn_OPTION_DEL(c, (CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ|CONN_SSL_CONNECT));
 815         ConnSSL_LogCertInfo(c);
 816
 817         Conn_StartLogin(CONNECTION2ID(c));
 818         return 1;
 819 }
 820
 821
 822 ssize_t
 823 ConnSSL_Write(CONNECTION *c, const void *buf, size_t count)
 824 {
 825         ssize_t bw;
 826
 827         Conn_OPTION_DEL(c, CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ);
 828
 829         assert(count > 0);
 830 #ifdef HAVE_LIBSSL
 831         bw = (ssize_t) SSL_write(c->ssl_state.ssl, buf, count);
 832 #endif
 833 #ifdef HAVE_LIBGNUTLS
 834         bw = gnutls_write(c->ssl_state.gnutls_session, buf, count);
 835 #endif
 836         if (bw > 0)
 837                 return bw;
 838         if (ConnSSL_HandleError( c, bw, "ConnSSL_Write") == 0)
 839                 errno = EAGAIN; /* try again */
 840         return -1;
 841 }
 842
 843
 844 ssize_t
 845 ConnSSL_Read(CONNECTION *c, void * buf, size_t count)
 846 {
 847         ssize_t br;
 848
 849         Conn_OPTION_DEL(c, CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ);
 850 #ifdef HAVE_LIBSSL
 851         br = (ssize_t) SSL_read(c->ssl_state.ssl, buf, count);
 852         if (br > 0)     /* on EOF we have to call ConnSSL_HandleError(), see SSL_read(3) */
 853                 return br;
 854 #endif
 855 #ifdef HAVE_LIBGNUTLS
 856         br = gnutls_read(c->ssl_state.gnutls_session, buf, count);
 857         if (br >= 0)    /* on EOF we must _not_ call ConnSSL_HandleError, see gnutls_record_recv(3) */
 858                 return br;
 859 #endif
 860         /* error on read: switch ConnSSL_HandleError() return values -> 0 is "try again", so return -1 and set EAGAIN */
 861         if (ConnSSL_HandleError(c, br, "ConnSSL_Read") == 0) {
 862                 errno = EAGAIN;
 863                 return -1;
 864         }
 865         return 0;
 866 }
 867
 868
 869 bool
 870 ConnSSL_GetCipherInfo(CONNECTION *c, char *buf, size_t len)
 871 {
 872 #ifdef HAVE_LIBSSL
 873         char *nl;
 874         SSL *ssl = c->ssl_state.ssl;
 875
 876         if (!ssl)
 877                 return false;
 878         *buf = 0;
 879         SSL_CIPHER_description(SSL_get_current_cipher(ssl), buf, len);
 880         nl = strchr(buf, '\n');
 881         if (nl)
 882                 *nl = 0;
 883         return true;
 884 #endif
 885 #ifdef HAVE_LIBGNUTLS
 886         if (Conn_OPTION_ISSET(c, CONN_SSL)) {
 887                 const char *name_cipher, *name_mac, *name_proto, *name_keyexchange;
 888                 unsigned keysize;
 889
 890                 gnutls_session_t sess = c->ssl_state.gnutls_session;
 891                 gnutls_cipher_algorithm_t cipher = gnutls_cipher_get(sess);
 892                 name_cipher = gnutls_cipher_get_name(cipher);
 893                 name_mac = gnutls_mac_get_name(gnutls_mac_get(sess));
 894                 keysize = gnutls_cipher_get_key_size(cipher) * 8;
 895                 name_proto = gnutls_protocol_get_name(gnutls_protocol_get_version(sess));
 896                 name_keyexchange = gnutls_kx_get_name(gnutls_kx_get(sess));
 897
 898                 return snprintf(buf, len, "%s-%s%15s Kx=%s      Enc=%s(%u) Mac=%s",
 899                         name_cipher, name_mac, name_proto, name_keyexchange, name_cipher, keysize, name_mac) > 0;
 900         }
 901         return false;
 902 #endif
 903 }
 904
 905 char *
 906 ConnSSL_GetCertFp(CONNECTION *c)
 907 {
 908         return c->ssl_state.fingerprint;
 909 }
 910
 911 bool
 912 ConnSSL_SetCertFp(CONNECTION *c, const char *fingerprint)
 913 {
 914         assert (c != NULL);
 915         c->ssl_state.fingerprint = strndup(fingerprint, SHA256_STRING_LEN - 1);
 916         return c->ssl_state.fingerprint != NULL;
 917 }
 918 #else
 919
 920 bool
 921 ConnSSL_InitLibrary(void)
 922 {
 923         return true;
 924 }
 925
 926 #endif /* SSL_SUPPORT */
 927 /* -eof- */