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 SHA256_STRING_LEN       (32 * 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 (SSL_CTX_set_cipher_list(newctx, Conf_SSLOptions.CipherList) == 0) {
 310                 Log(LOG_ERR, "Failed to apply OpenSSL cipher list \"%s\"!",
 311                     Conf_SSLOptions.CipherList);
 312                 goto out;
 313         }
 314
 315         SSL_CTX_set_options(newctx, SSL_OP_SINGLE_DH_USE|SSL_OP_NO_SSLv2);
 316         SSL_CTX_set_mode(newctx, SSL_MODE_ENABLE_PARTIAL_WRITE);
 317         SSL_CTX_set_verify(newctx, SSL_VERIFY_PEER|SSL_VERIFY_CLIENT_ONCE,
 318                            Verify_openssl);
 319         SSL_CTX_free(ssl_ctx);
 320         ssl_ctx = newctx;
 321         Log(LOG_INFO, "%s initialized.", SSLeay_version(SSLEAY_VERSION));
 322         return true;
 323 out:
 324         SSL_CTX_free(newctx);
 325         array_free(&Conf_SSLOptions.ListenPorts);
 326         return false;
 327 #endif
 328 #ifdef HAVE_LIBGNUTLS
 329         int err;
 330         static bool initialized;
 331
 332         if (initialized) {
 333                 /* TODO: cannot reload gnutls keys: can't simply free x509
 334                  * context -- it may still be in use */
 335                 return false;
 336         }
 337
 338         err = gnutls_global_init();
 339         if (err) {
 340                 Log(LOG_ERR, "Failed to initialize GnuTLS: %s",
 341                     gnutls_strerror(err));
 342                 goto out;
 343         }
 344
 345         if (!ConnSSL_LoadServerKey_gnutls())
 346                 goto out;
 347
 348         if (gnutls_priority_init(&priorities_cache, Conf_SSLOptions.CipherList,
 349                                  NULL) != GNUTLS_E_SUCCESS) {
 350                 Log(LOG_ERR,
 351                     "Failed to apply GnuTLS cipher list \"%s\"!",
 352                     Conf_SSLOptions.CipherList);
 353                 goto out;
 354         }
 355
 356         Log(LOG_INFO, "GnuTLS %s initialized.", gnutls_check_version(NULL));
 357         initialized = true;
 358         return true;
 359 out:
 360         array_free(&Conf_SSLOptions.ListenPorts);
 361         return false;
 362 #endif
 363 }
 364
 365
 366 #ifdef HAVE_LIBGNUTLS
 367 static bool
 368 ConnSSL_LoadServerKey_gnutls(void)
 369 {
 370         int err;
 371         const char *cert_file;
 372
 373         err = gnutls_certificate_allocate_credentials(&x509_cred);
 374         if (err < 0) {
 375                 Log(LOG_ERR, "Failed to allocate certificate credentials: %s",
 376                     gnutls_strerror(err));
 377                 return false;
 378         }
 379
 380         cert_file = Conf_SSLOptions.CertFile ? Conf_SSLOptions.CertFile:Conf_SSLOptions.KeyFile;
 381         if (!cert_file) {
 382                 Log(LOG_ERR, "No SSL server key configured!");
 383                 return false;
 384         }
 385
 386         if (array_bytes(&Conf_SSLOptions.KeyFilePassword))
 387                 Log(LOG_WARNING,
 388                     "Ignoring SSL \"KeyFilePassword\": Not supported by GnuTLS.");
 389
 390         if (!Load_DH_params())
 391                 return false;
 392
 393         gnutls_certificate_set_dh_params(x509_cred, dh_params);
 394         err = gnutls_certificate_set_x509_key_file(x509_cred, cert_file, Conf_SSLOptions.KeyFile, GNUTLS_X509_FMT_PEM);
 395         if (err < 0) {
 396                 Log(LOG_ERR,
 397                     "Failed to set certificate key file (cert %s, key %s): %s",
 398                     cert_file,
 399                     Conf_SSLOptions.KeyFile ? Conf_SSLOptions.KeyFile : "(NULL)",
 400                     gnutls_strerror(err));
 401                 return false;
 402         }
 403         return true;
 404 }
 405 #endif
 406
 407
 408 #ifdef HAVE_LIBSSL
 409 static bool
 410 ConnSSL_LoadServerKey_openssl(SSL_CTX *ctx)
 411 {
 412         char *cert_key;
 413
 414         assert(ctx);
 415         if (!Conf_SSLOptions.KeyFile) {
 416                 Log(LOG_ERR, "No SSL server key configured!");
 417                 return false;
 418         }
 419
 420         SSL_CTX_set_default_passwd_cb(ctx, pem_passwd_cb);
 421         SSL_CTX_set_default_passwd_cb_userdata(ctx, &Conf_SSLOptions.KeyFilePassword);
 422
 423         if (SSL_CTX_use_PrivateKey_file(ctx, Conf_SSLOptions.KeyFile, SSL_FILETYPE_PEM) != 1) {
 424                 array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 425                 LogOpenSSLError("Failed to add private key", Conf_SSLOptions.KeyFile);
 426                 return false;
 427         }
 428
 429         cert_key = Conf_SSLOptions.CertFile ? Conf_SSLOptions.CertFile:Conf_SSLOptions.KeyFile;
 430         if (SSL_CTX_use_certificate_chain_file(ctx, cert_key) != 1) {
 431                 array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 432                 LogOpenSSLError("Failed to load certificate chain", cert_key);
 433                 return false;
 434         }
 435
 436         array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 437
 438         if (!SSL_CTX_check_private_key(ctx)) {
 439                 LogOpenSSLError("Server private key does not match certificate", NULL);
 440                 return false;
 441         }
 442         if (Load_DH_params()) {
 443                 if (SSL_CTX_set_tmp_dh(ctx, dh_params) != 1)
 444                         LogOpenSSLError("Error setting DH parameters", Conf_SSLOptions.DHFile);
 445                 /* don't return false here: the non-DH modes will still work */
 446                 DH_free(dh_params);
 447                 dh_params = NULL;
 448         }
 449         return true;
 450 }
 451
 452
 453 #endif
 454 static bool
 455 ConnSSL_Init_SSL(CONNECTION *c)
 456 {
 457         int ret;
 458
 459         LogDebug("Initializing SSL ...");
 460         assert(c != NULL);
 461
 462 #ifdef HAVE_LIBSSL
 463         if (!ssl_ctx) {
 464                 Log(LOG_ERR,
 465                     "Can't initialize SSL context, OpenSSL initialization failed at startup!");
 466                 return false;
 467         }
 468         assert(c->ssl_state.ssl == NULL);
 469         assert(c->ssl_state.fingerprint == NULL);
 470
 471         c->ssl_state.ssl = SSL_new(ssl_ctx);
 472         if (!c->ssl_state.ssl) {
 473                 LogOpenSSLError("Failed to create SSL structure", NULL);
 474                 return false;
 475         }
 476         Conn_OPTION_ADD(c, CONN_SSL);
 477
 478         ret = SSL_set_fd(c->ssl_state.ssl, c->sock);
 479         if (ret != 1) {
 480                 LogOpenSSLError("Failed to set SSL file descriptor", NULL);
 481                 ConnSSL_Free(c);
 482                 return false;
 483         }
 484 #endif
 485 #ifdef HAVE_LIBGNUTLS
 486         Conn_OPTION_ADD(c, CONN_SSL);
 487         ret = gnutls_priority_set(c->ssl_state.gnutls_session, priorities_cache);
 488         if (ret != GNUTLS_E_SUCCESS) {
 489                 Log(LOG_ERR, "Failed to set GnuTLS session priorities: %s",
 490                     gnutls_strerror(ret));
 491                 ConnSSL_Free(c);
 492                 return false;
 493         }
 494         /*
 495          * The intermediate (long) cast is here to avoid a warning like:
 496          * "cast to pointer from integer of different size" on 64-bit platforms.
 497          * There doesn't seem to be an alternate GNUTLS API we could use instead, see e.g.
 498          * http://www.mail-archive.com/help-gnutls@gnu.org/msg00286.html
 499          */
 500         gnutls_transport_set_ptr(c->ssl_state.gnutls_session,
 501                                  (gnutls_transport_ptr_t) (long) c->sock);
 502         gnutls_certificate_server_set_request(c->ssl_state.gnutls_session,
 503                                               GNUTLS_CERT_REQUEST);
 504         ret = gnutls_credentials_set(c->ssl_state.gnutls_session,
 505                                      GNUTLS_CRD_CERTIFICATE, x509_cred);
 506         if (ret != 0) {
 507                 Log(LOG_ERR, "Failed to set SSL credentials: %s",
 508                     gnutls_strerror(ret));
 509                 ConnSSL_Free(c);
 510                 return false;
 511         }
 512         gnutls_dh_set_prime_bits(c->ssl_state.gnutls_session, DH_BITS_MIN);
 513 #endif
 514         return true;
 515 }
 516
 517
 518 bool
 519 ConnSSL_PrepareConnect(CONNECTION *c, UNUSED CONF_SERVER *s)
 520 {
 521         bool ret;
 522 #ifdef HAVE_LIBGNUTLS
 523         int err;
 524
 525         err = gnutls_init(&c->ssl_state.gnutls_session, GNUTLS_CLIENT);
 526         if (err) {
 527                 Log(LOG_ERR, "Failed to initialize new SSL session: %s",
 528                     gnutls_strerror(err));
 529                 return false;
 530         }
 531 #endif
 532         ret = ConnSSL_Init_SSL(c);
 533         if (!ret)
 534                 return false;
 535         Conn_OPTION_ADD(c, CONN_SSL_CONNECT);
 536 #ifdef HAVE_LIBSSL
 537         assert(c->ssl_state.ssl);
 538         SSL_set_verify(c->ssl_state.ssl, SSL_VERIFY_NONE, NULL);
 539 #endif
 540         return true;
 541 }
 542
 543
 544 /**
 545  * Check and handle error return codes after failed calls to SSL functions.
 546  *
 547  * OpenSSL:
 548  * SSL_connect(), SSL_accept(), SSL_do_handshake(), SSL_read(), SSL_peek(), or
 549  * SSL_write() on ssl.
 550  *
 551  * GnuTLS:
 552  * gnutlsssl_read(), gnutls_write() or gnutls_handshake().
 553  *
 554  * @param c The connection handle.
 555  * @prarm code The return code.
 556  * @param fname The name of the function in which the error occurred.
 557  * @return -1 on fatal errors, 0 if we can try again later.
 558  */
 559 static int
 560 ConnSSL_HandleError(CONNECTION * c, const int code, const char *fname)
 561 {
 562 #ifdef HAVE_LIBSSL
 563         int ret = SSL_ERROR_SYSCALL;
 564         unsigned long sslerr;
 565         int real_errno = errno;
 566
 567         ret = SSL_get_error(c->ssl_state.ssl, code);
 568
 569         switch (ret) {
 570         case SSL_ERROR_WANT_READ:
 571                 io_event_del(c->sock, IO_WANTWRITE);
 572                 Conn_OPTION_ADD(c, CONN_SSL_WANT_READ);
 573                 return 0;       /* try again later */
 574         case SSL_ERROR_WANT_WRITE:
 575                 io_event_del(c->sock, IO_WANTREAD);
 576                 Conn_OPTION_ADD(c, CONN_SSL_WANT_WRITE); /* fall through */
 577         case SSL_ERROR_NONE:
 578                 return 0;       /* try again later */
 579         case SSL_ERROR_ZERO_RETURN:
 580                 LogDebug("SSL connection shut down normally.");
 581                 break;
 582         case SSL_ERROR_SYSCALL:
 583                 /* SSL_ERROR_WANT_CONNECT, SSL_ERROR_WANT_ACCEPT,
 584                  * and SSL_ERROR_WANT_X509_LOOKUP */
 585                 sslerr = ERR_get_error();
 586                 if (sslerr) {
 587                         Log(LOG_ERR, "SSL error: %s [in %s()]!",
 588                             ERR_error_string(sslerr, NULL), fname);
 589                 } else {
 590                         switch (code) { /* EOF that violated protocol */
 591                         case 0:
 592                                 Log(LOG_ERR,
 593                                     "SSL error, client disconnected [in %s()]!",
 594                                     fname);
 595                                 break;
 596                         case -1:        /* low level socket I/O error, check errno */
 597                                 Log(LOG_ERR, "SSL error: %s [in %s()]!",
 598                                     strerror(real_errno), fname);
 599                         }
 600                 }
 601                 break;
 602         case SSL_ERROR_SSL:
 603                 LogOpenSSLError("SSL protocol error", fname);
 604                 break;
 605         default:
 606                 Log(LOG_ERR, "Unknown SSL error %d [in %s()]!", ret, fname);
 607         }
 608         ConnSSL_Free(c);
 609         return -1;
 610 #endif
 611 #ifdef HAVE_LIBGNUTLS
 612         switch (code) {
 613         case GNUTLS_E_AGAIN:
 614         case GNUTLS_E_INTERRUPTED:
 615                 if (gnutls_record_get_direction(c->ssl_state.gnutls_session)) {
 616                         Conn_OPTION_ADD(c, CONN_SSL_WANT_WRITE);
 617                         io_event_del(c->sock, IO_WANTREAD);
 618                 } else {
 619                         Conn_OPTION_ADD(c, CONN_SSL_WANT_READ);
 620                         io_event_del(c->sock, IO_WANTWRITE);
 621                 }
 622                 break;
 623         default:
 624                 assert(code < 0);
 625                 if (gnutls_error_is_fatal(code)) {
 626                         Log(LOG_ERR, "SSL error: %s [%s].",
 627                             gnutls_strerror(code), fname);
 628                         ConnSSL_Free(c);
 629                         return -1;
 630                 }
 631         }
 632         return 0;
 633 #endif
 634 }
 635
 636
 637 static void
 638 ConnSSL_LogCertInfo( CONNECTION *c )
 639 {
 640 #ifdef HAVE_LIBSSL
 641         SSL *ssl = c->ssl_state.ssl;
 642
 643         assert(ssl);
 644
 645         Log(LOG_INFO, "Connection %d: initialized %s using cipher %s.",
 646                 c->sock, SSL_get_version(ssl), SSL_get_cipher(ssl));
 647 #endif
 648 #ifdef HAVE_LIBGNUTLS
 649         gnutls_session_t sess = c->ssl_state.gnutls_session;
 650         gnutls_cipher_algorithm_t cipher = gnutls_cipher_get(sess);
 651
 652         Log(LOG_INFO, "Connection %d: initialized %s using cipher %s-%s.",
 653             c->sock,
 654             gnutls_protocol_get_name(gnutls_protocol_get_version(sess)),
 655             gnutls_cipher_get_name(cipher),
 656             gnutls_mac_get_name(gnutls_mac_get(sess)));
 657 #endif
 658 }
 659
 660
 661 /*
 662  Accept incoming SSL connection.
 663  Return Values:
 664          1: SSL Connection established
 665          0: try again
 666         -1: SSL Connection not established due to fatal error.
 667 */
 668 int
 669 ConnSSL_Accept( CONNECTION *c )
 670 {
 671         assert(c != NULL);
 672         if (!Conn_OPTION_ISSET(c, CONN_SSL)) {
 673 #ifdef HAVE_LIBGNUTLS
 674                 int err = gnutls_init(&c->ssl_state.gnutls_session, GNUTLS_SERVER);
 675                 if (err) {
 676                         Log(LOG_ERR, "Failed to initialize new SSL session: %s",
 677                             gnutls_strerror(err));
 678                         return false;
 679                 }
 680 #endif
 681                 if (!ConnSSL_Init_SSL(c))
 682                         return -1;
 683         }
 684         return ConnectAccept(c, false );
 685 }
 686
 687
 688 int
 689 ConnSSL_Connect( CONNECTION *c )
 690 {
 691         assert(c != NULL);
 692 #ifdef HAVE_LIBSSL
 693         assert(c->ssl_state.ssl);
 694 #endif
 695         assert(Conn_OPTION_ISSET(c, CONN_SSL));
 696         return ConnectAccept(c, true);
 697 }
 698
 699 static int
 700 ConnSSL_InitCertFp( CONNECTION *c )
 701 {
 702         const char hex[] = "0123456789abcdef";
 703         int i;
 704
 705 #ifdef HAVE_LIBSSL
 706         unsigned char digest[EVP_MAX_MD_SIZE];
 707         unsigned int digest_size;
 708         X509 *cert;
 709
 710         cert = SSL_get_peer_certificate(c->ssl_state.ssl);
 711         if (!cert)
 712                 return 0;
 713
 714         if (!X509_digest(cert, EVP_sha256(), digest, &digest_size)) {
 715                 X509_free(cert);
 716                 return 0;
 717         }
 718
 719         X509_free(cert);
 720 #endif /* HAVE_LIBSSL */
 721 #ifdef HAVE_LIBGNUTLS
 722         gnutls_x509_crt_t cert;
 723         unsigned int cert_list_size;
 724         const gnutls_datum_t *cert_list;
 725         unsigned char digest[MAX_HASH_SIZE];
 726         size_t digest_size;
 727
 728         if (gnutls_certificate_type_get(c->ssl_state.gnutls_session) !=
 729                                         GNUTLS_CRT_X509)
 730                 return 0;
 731
 732         if (gnutls_x509_crt_init(&cert) != GNUTLS_E_SUCCESS)
 733                 return 0;
 734
 735         cert_list_size = 0;
 736         cert_list = gnutls_certificate_get_peers(c->ssl_state.gnutls_session,
 737                                                  &cert_list_size);
 738         if (!cert_list) {
 739                 gnutls_x509_crt_deinit(cert);
 740                 return 0;
 741         }
 742
 743         if (gnutls_x509_crt_import(cert, &cert_list[0],
 744                                    GNUTLS_X509_FMT_DER) != GNUTLS_E_SUCCESS) {
 745                 gnutls_x509_crt_deinit(cert);
 746                 return 0;
 747         }
 748
 749         digest_size = sizeof(digest);
 750         if (gnutls_x509_crt_get_fingerprint(cert, GNUTLS_DIG_SHA256, digest,
 751                                             &digest_size)) {
 752                 gnutls_x509_crt_deinit(cert);
 753                 return 0;
 754         }
 755
 756         gnutls_x509_crt_deinit(cert);
 757 #endif /* HAVE_LIBGNUTLS */
 758
 759         assert(c->ssl_state.fingerprint == NULL);
 760
 761         c->ssl_state.fingerprint = malloc(SHA256_STRING_LEN);
 762         if (!c->ssl_state.fingerprint)
 763                 return 0;
 764
 765         for (i = 0; i < (int)digest_size; i++) {
 766                 c->ssl_state.fingerprint[i * 2] = hex[digest[i] / 16];
 767                 c->ssl_state.fingerprint[i * 2 + 1] = hex[digest[i] % 16];
 768         }
 769         c->ssl_state.fingerprint[i * 2] = '\0';
 770
 771         return 1;
 772 }
 773
 774 /* accept/connect wrapper. if connect is true, connect to peer, otherwise wait for incoming connection */
 775 static int
 776 ConnectAccept( CONNECTION *c, bool connect)
 777 {
 778         int ret;
 779 #ifdef HAVE_LIBSSL
 780         SSL *ssl = c->ssl_state.ssl;
 781         assert(ssl != NULL);
 782
 783         ret = connect ? SSL_connect(ssl) : SSL_accept(ssl);
 784         if (1 != ret)
 785                 return ConnSSL_HandleError(c, ret, connect ? "SSL_connect": "SSL_accept");
 786 #endif
 787 #ifdef HAVE_LIBGNUTLS
 788         (void) connect;
 789         ret = gnutls_handshake(c->ssl_state.gnutls_session);
 790         if (ret)
 791                 return ConnSSL_HandleError(c, ret, "gnutls_handshake");
 792 #endif /* _GNUTLS */
 793         (void)ConnSSL_InitCertFp(c);
 794
 795         Conn_OPTION_DEL(c, (CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ|CONN_SSL_CONNECT));
 796         ConnSSL_LogCertInfo(c);
 797
 798         Conn_StartLogin(CONNECTION2ID(c));
 799         return 1;
 800 }
 801
 802
 803 ssize_t
 804 ConnSSL_Write(CONNECTION *c, const void *buf, size_t count)
 805 {
 806         ssize_t bw;
 807
 808         Conn_OPTION_DEL(c, CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ);
 809
 810         assert(count > 0);
 811 #ifdef HAVE_LIBSSL
 812         bw = (ssize_t) SSL_write(c->ssl_state.ssl, buf, count);
 813 #endif
 814 #ifdef HAVE_LIBGNUTLS
 815         bw = gnutls_write(c->ssl_state.gnutls_session, buf, count);
 816 #endif
 817         if (bw > 0)
 818                 return bw;
 819         if (ConnSSL_HandleError( c, bw, "ConnSSL_Write") == 0)
 820                 errno = EAGAIN; /* try again */
 821         return -1;
 822 }
 823
 824
 825 ssize_t
 826 ConnSSL_Read(CONNECTION *c, void * buf, size_t count)
 827 {
 828         ssize_t br;
 829
 830         Conn_OPTION_DEL(c, CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ);
 831 #ifdef HAVE_LIBSSL
 832         br = (ssize_t) SSL_read(c->ssl_state.ssl, buf, count);
 833         if (br > 0)     /* on EOF we have to call ConnSSL_HandleError(), see SSL_read(3) */
 834                 return br;
 835 #endif
 836 #ifdef HAVE_LIBGNUTLS
 837         br = gnutls_read(c->ssl_state.gnutls_session, buf, count);
 838         if (br >= 0)    /* on EOF we must _not_ call ConnSSL_HandleError, see gnutls_record_recv(3) */
 839                 return br;
 840 #endif
 841         /* error on read: switch ConnSSL_HandleError() return values -> 0 is "try again", so return -1 and set EAGAIN */
 842         if (ConnSSL_HandleError(c, br, "ConnSSL_Read") == 0) {
 843                 errno = EAGAIN;
 844                 return -1;
 845         }
 846         return 0;
 847 }
 848
 849
 850 bool
 851 ConnSSL_GetCipherInfo(CONNECTION *c, char *buf, size_t len)
 852 {
 853 #ifdef HAVE_LIBSSL
 854         char *nl;
 855         SSL *ssl = c->ssl_state.ssl;
 856
 857         if (!ssl)
 858                 return false;
 859         *buf = 0;
 860         SSL_CIPHER_description(SSL_get_current_cipher(ssl), buf, len);
 861         nl = strchr(buf, '\n');
 862         if (nl)
 863                 *nl = 0;
 864         return true;
 865 #endif
 866 #ifdef HAVE_LIBGNUTLS
 867         if (Conn_OPTION_ISSET(c, CONN_SSL)) {
 868                 const char *name_cipher, *name_mac, *name_proto, *name_keyexchange;
 869                 unsigned keysize;
 870
 871                 gnutls_session_t sess = c->ssl_state.gnutls_session;
 872                 gnutls_cipher_algorithm_t cipher = gnutls_cipher_get(sess);
 873                 name_cipher = gnutls_cipher_get_name(cipher);
 874                 name_mac = gnutls_mac_get_name(gnutls_mac_get(sess));
 875                 keysize = gnutls_cipher_get_key_size(cipher) * 8;
 876                 name_proto = gnutls_protocol_get_name(gnutls_protocol_get_version(sess));
 877                 name_keyexchange = gnutls_kx_get_name(gnutls_kx_get(sess));
 878
 879                 return snprintf(buf, len, "%s-%s%15s Kx=%s      Enc=%s(%u) Mac=%s",
 880                         name_cipher, name_mac, name_proto, name_keyexchange, name_cipher, keysize, name_mac) > 0;
 881         }
 882         return false;
 883 #endif
 884 }
 885
 886 char *
 887 ConnSSL_GetCertFp(CONNECTION *c)
 888 {
 889         return c->ssl_state.fingerprint;
 890 }
 891
 892 bool
 893 ConnSSL_SetCertFp(CONNECTION *c, const char *fingerprint)
 894 {
 895         assert (c != NULL);
 896         c->ssl_state.fingerprint = strndup(fingerprint, SHA256_STRING_LEN - 1);
 897         return c->ssl_state.fingerprint != NULL;
 898 }
 899 #else
 900
 901 bool
 902 ConnSSL_InitLibrary(void)
 903 {
 904         return true;
 905 }
 906
 907 #endif /* SSL_SUPPORT */
 908 /* -eof- */
 909
 910