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                 goto out;
 316
 317         if (SSL_CTX_set_cipher_list(newctx, Conf_SSLOptions.CipherList) == 0) {
 318                 Log(LOG_ERR, "Failed to apply OpenSSL cipher list \"%s\"!",
 319                     Conf_SSLOptions.CipherList);
 320                 goto out;
 321         }
 322
 323         SSL_CTX_set_session_id_context(newctx, (unsigned char *)"ngircd", 6);
 324         SSL_CTX_set_options(newctx, SSL_OP_SINGLE_DH_USE|SSL_OP_NO_SSLv2);
 325         SSL_CTX_set_mode(newctx, SSL_MODE_ENABLE_PARTIAL_WRITE);
 326         SSL_CTX_set_verify(newctx, SSL_VERIFY_PEER|SSL_VERIFY_CLIENT_ONCE,
 327                            Verify_openssl);
 328         SSL_CTX_free(ssl_ctx);
 329         ssl_ctx = newctx;
 330         Log(LOG_INFO, "%s initialized.", OpenSSL_version(OPENSSL_VERSION));
 331         return true;
 332 out:
 333         SSL_CTX_free(newctx);
 334         array_free(&Conf_SSLOptions.ListenPorts);
 335         return false;
 336 #endif
 337 #ifdef HAVE_LIBGNUTLS
 338         int err;
 339         static bool initialized;
 340
 341         if (initialized) {
 342                 /* TODO: cannot reload gnutls keys: can't simply free x509
 343                  * context -- it may still be in use */
 344                 return false;
 345         }
 346
 347         err = gnutls_global_init();
 348         if (err) {
 349                 Log(LOG_ERR, "Failed to initialize GnuTLS: %s",
 350                     gnutls_strerror(err));
 351                 goto out;
 352         }
 353
 354         if (!ConnSSL_LoadServerKey_gnutls())
 355                 goto out;
 356
 357         if (gnutls_priority_init(&priorities_cache, Conf_SSLOptions.CipherList,
 358                                  NULL) != GNUTLS_E_SUCCESS) {
 359                 Log(LOG_ERR,
 360                     "Failed to apply GnuTLS cipher list \"%s\"!",
 361                     Conf_SSLOptions.CipherList);
 362                 goto out;
 363         }
 364
 365         Log(LOG_INFO, "GnuTLS %s initialized.", gnutls_check_version(NULL));
 366         initialized = true;
 367         return true;
 368 out:
 369         array_free(&Conf_SSLOptions.ListenPorts);
 370         return false;
 371 #endif
 372 }
 373
 374
 375 #ifdef HAVE_LIBGNUTLS
 376 static bool
 377 ConnSSL_LoadServerKey_gnutls(void)
 378 {
 379         int err;
 380         const char *cert_file;
 381
 382         err = gnutls_certificate_allocate_credentials(&x509_cred);
 383         if (err < 0) {
 384                 Log(LOG_ERR, "Failed to allocate certificate credentials: %s",
 385                     gnutls_strerror(err));
 386                 return false;
 387         }
 388
 389         cert_file = Conf_SSLOptions.CertFile ? Conf_SSLOptions.CertFile:Conf_SSLOptions.KeyFile;
 390         if (!cert_file) {
 391                 Log(LOG_ERR, "No SSL server key configured!");
 392                 return false;
 393         }
 394
 395         if (array_bytes(&Conf_SSLOptions.KeyFilePassword))
 396                 Log(LOG_WARNING,
 397                     "Ignoring SSL \"KeyFilePassword\": Not supported by GnuTLS.");
 398
 399         if (!Load_DH_params())
 400                 return false;
 401
 402         gnutls_certificate_set_dh_params(x509_cred, dh_params);
 403         err = gnutls_certificate_set_x509_key_file(x509_cred, cert_file, Conf_SSLOptions.KeyFile, GNUTLS_X509_FMT_PEM);
 404         if (err < 0) {
 405                 Log(LOG_ERR,
 406                     "Failed to set certificate key file (cert %s, key %s): %s",
 407                     cert_file,
 408                     Conf_SSLOptions.KeyFile ? Conf_SSLOptions.KeyFile : "(NULL)",
 409                     gnutls_strerror(err));
 410                 return false;
 411         }
 412         return true;
 413 }
 414 #endif
 415
 416
 417 #ifdef HAVE_LIBSSL
 418 static bool
 419 ConnSSL_LoadServerKey_openssl(SSL_CTX *ctx)
 420 {
 421         char *cert_key;
 422
 423         assert(ctx);
 424         if (!Conf_SSLOptions.KeyFile) {
 425                 Log(LOG_ERR, "No SSL server key configured!");
 426                 return false;
 427         }
 428
 429         SSL_CTX_set_default_passwd_cb(ctx, pem_passwd_cb);
 430         SSL_CTX_set_default_passwd_cb_userdata(ctx, &Conf_SSLOptions.KeyFilePassword);
 431
 432         if (SSL_CTX_use_PrivateKey_file(ctx, Conf_SSLOptions.KeyFile, SSL_FILETYPE_PEM) != 1) {
 433                 array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 434                 LogOpenSSLError("Failed to add private key", Conf_SSLOptions.KeyFile);
 435                 return false;
 436         }
 437
 438         cert_key = Conf_SSLOptions.CertFile ? Conf_SSLOptions.CertFile:Conf_SSLOptions.KeyFile;
 439         if (SSL_CTX_use_certificate_chain_file(ctx, cert_key) != 1) {
 440                 array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 441                 LogOpenSSLError("Failed to load certificate chain", cert_key);
 442                 return false;
 443         }
 444
 445         array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 446
 447         if (!SSL_CTX_check_private_key(ctx)) {
 448                 LogOpenSSLError("Server private key does not match certificate", NULL);
 449                 return false;
 450         }
 451         if (Load_DH_params()) {
 452                 if (SSL_CTX_set_tmp_dh(ctx, dh_params) != 1)
 453                         LogOpenSSLError("Error setting DH parameters", Conf_SSLOptions.DHFile);
 454                 /* don't return false here: the non-DH modes will still work */
 455                 DH_free(dh_params);
 456                 dh_params = NULL;
 457         }
 458         return true;
 459 }
 460
 461
 462 #endif
 463 static bool
 464 ConnSSL_Init_SSL(CONNECTION *c)
 465 {
 466         int ret;
 467
 468         LogDebug("Initializing SSL ...");
 469         assert(c != NULL);
 470
 471 #ifdef HAVE_LIBSSL
 472         if (!ssl_ctx) {
 473                 Log(LOG_ERR,
 474                     "Can't initialize SSL context, OpenSSL initialization failed at startup!");
 475                 return false;
 476         }
 477         assert(c->ssl_state.ssl == NULL);
 478         assert(c->ssl_state.fingerprint == NULL);
 479
 480         c->ssl_state.ssl = SSL_new(ssl_ctx);
 481         if (!c->ssl_state.ssl) {
 482                 LogOpenSSLError("Failed to create SSL structure", NULL);
 483                 return false;
 484         }
 485         Conn_OPTION_ADD(c, CONN_SSL);
 486
 487         ret = SSL_set_fd(c->ssl_state.ssl, c->sock);
 488         if (ret != 1) {
 489                 LogOpenSSLError("Failed to set SSL file descriptor", NULL);
 490                 ConnSSL_Free(c);
 491                 return false;
 492         }
 493 #endif
 494 #ifdef HAVE_LIBGNUTLS
 495         Conn_OPTION_ADD(c, CONN_SSL);
 496         ret = gnutls_priority_set(c->ssl_state.gnutls_session, priorities_cache);
 497         if (ret != GNUTLS_E_SUCCESS) {
 498                 Log(LOG_ERR, "Failed to set GnuTLS session priorities: %s",
 499                     gnutls_strerror(ret));
 500                 ConnSSL_Free(c);
 501                 return false;
 502         }
 503         /*
 504          * The intermediate (long) cast is here to avoid a warning like:
 505          * "cast to pointer from integer of different size" on 64-bit platforms.
 506          * There doesn't seem to be an alternate GNUTLS API we could use instead, see e.g.
 507          * http://www.mail-archive.com/help-gnutls@gnu.org/msg00286.html
 508          */
 509         gnutls_transport_set_ptr(c->ssl_state.gnutls_session,
 510                                  (gnutls_transport_ptr_t) (long) c->sock);
 511         gnutls_certificate_server_set_request(c->ssl_state.gnutls_session,
 512                                               GNUTLS_CERT_REQUEST);
 513         ret = gnutls_credentials_set(c->ssl_state.gnutls_session,
 514                                      GNUTLS_CRD_CERTIFICATE, x509_cred);
 515         if (ret != 0) {
 516                 Log(LOG_ERR, "Failed to set SSL credentials: %s",
 517                     gnutls_strerror(ret));
 518                 ConnSSL_Free(c);
 519                 return false;
 520         }
 521         gnutls_dh_set_prime_bits(c->ssl_state.gnutls_session, DH_BITS_MIN);
 522 #endif
 523         return true;
 524 }
 525
 526
 527 bool
 528 ConnSSL_PrepareConnect(CONNECTION *c, UNUSED CONF_SERVER *s)
 529 {
 530         bool ret;
 531 #ifdef HAVE_LIBGNUTLS
 532         int err;
 533
 534         err = gnutls_init(&c->ssl_state.gnutls_session, GNUTLS_CLIENT);
 535         if (err) {
 536                 Log(LOG_ERR, "Failed to initialize new SSL session: %s",
 537                     gnutls_strerror(err));
 538                 return false;
 539         }
 540 #endif
 541         ret = ConnSSL_Init_SSL(c);
 542         if (!ret)
 543                 return false;
 544         Conn_OPTION_ADD(c, CONN_SSL_CONNECT);
 545 #ifdef HAVE_LIBSSL
 546         assert(c->ssl_state.ssl);
 547         SSL_set_verify(c->ssl_state.ssl, SSL_VERIFY_NONE, NULL);
 548 #endif
 549         return true;
 550 }
 551
 552
 553 /**
 554  * Check and handle error return codes after failed calls to SSL functions.
 555  *
 556  * OpenSSL:
 557  * SSL_connect(), SSL_accept(), SSL_do_handshake(), SSL_read(), SSL_peek(), or
 558  * SSL_write() on ssl.
 559  *
 560  * GnuTLS:
 561  * gnutlsssl_read(), gnutls_write() or gnutls_handshake().
 562  *
 563  * @param c The connection handle.
 564  * @prarm code The return code.
 565  * @param fname The name of the function in which the error occurred.
 566  * @return -1 on fatal errors, 0 if we can try again later.
 567  */
 568 static int
 569 ConnSSL_HandleError(CONNECTION * c, const int code, const char *fname)
 570 {
 571 #ifdef HAVE_LIBSSL
 572         int ret = SSL_ERROR_SYSCALL;
 573         unsigned long sslerr;
 574         int real_errno = errno;
 575
 576         ret = SSL_get_error(c->ssl_state.ssl, code);
 577
 578         switch (ret) {
 579         case SSL_ERROR_WANT_READ:
 580                 io_event_del(c->sock, IO_WANTWRITE);
 581                 Conn_OPTION_ADD(c, CONN_SSL_WANT_READ);
 582                 return 0;       /* try again later */
 583         case SSL_ERROR_WANT_WRITE:
 584                 io_event_del(c->sock, IO_WANTREAD);
 585                 Conn_OPTION_ADD(c, CONN_SSL_WANT_WRITE); /* fall through */
 586         case SSL_ERROR_NONE:
 587                 return 0;       /* try again later */
 588         case SSL_ERROR_ZERO_RETURN:
 589                 LogDebug("SSL connection shut down normally.");
 590                 break;
 591         case SSL_ERROR_SYSCALL:
 592                 /* SSL_ERROR_WANT_CONNECT, SSL_ERROR_WANT_ACCEPT,
 593                  * and SSL_ERROR_WANT_X509_LOOKUP */
 594                 sslerr = ERR_get_error();
 595                 if (sslerr) {
 596                         Log(LOG_ERR, "SSL error: %s [in %s()]!",
 597                             ERR_error_string(sslerr, NULL), fname);
 598                 } else {
 599                         switch (code) { /* EOF that violated protocol */
 600                         case 0:
 601                                 Log(LOG_ERR,
 602                                     "SSL error, client disconnected [in %s()]!",
 603                                     fname);
 604                                 break;
 605                         case -1:        /* low level socket I/O error, check errno */
 606                                 Log(LOG_ERR, "SSL error: %s [in %s()]!",
 607                                     strerror(real_errno), fname);
 608                         }
 609                 }
 610                 break;
 611         case SSL_ERROR_SSL:
 612                 LogOpenSSLError("SSL protocol error", fname);
 613                 break;
 614         default:
 615                 Log(LOG_ERR, "Unknown SSL error %d [in %s()]!", ret, fname);
 616         }
 617         ConnSSL_Free(c);
 618         return -1;
 619 #endif
 620 #ifdef HAVE_LIBGNUTLS
 621         switch (code) {
 622         case GNUTLS_E_AGAIN:
 623         case GNUTLS_E_INTERRUPTED:
 624                 if (gnutls_record_get_direction(c->ssl_state.gnutls_session)) {
 625                         Conn_OPTION_ADD(c, CONN_SSL_WANT_WRITE);
 626                         io_event_del(c->sock, IO_WANTREAD);
 627                 } else {
 628                         Conn_OPTION_ADD(c, CONN_SSL_WANT_READ);
 629                         io_event_del(c->sock, IO_WANTWRITE);
 630                 }
 631                 break;
 632         default:
 633                 assert(code < 0);
 634                 if (gnutls_error_is_fatal(code)) {
 635                         Log(LOG_ERR, "SSL error: %s [%s].",
 636                             gnutls_strerror(code), fname);
 637                         ConnSSL_Free(c);
 638                         return -1;
 639                 }
 640         }
 641         return 0;
 642 #endif
 643 }
 644
 645
 646 static void
 647 ConnSSL_LogCertInfo( CONNECTION *c )
 648 {
 649 #ifdef HAVE_LIBSSL
 650         SSL *ssl = c->ssl_state.ssl;
 651
 652         assert(ssl);
 653
 654         Log(LOG_INFO, "Connection %d: initialized %s using cipher %s.",
 655                 c->sock, SSL_get_version(ssl), SSL_get_cipher(ssl));
 656 #endif
 657 #ifdef HAVE_LIBGNUTLS
 658         gnutls_session_t sess = c->ssl_state.gnutls_session;
 659         gnutls_cipher_algorithm_t cipher = gnutls_cipher_get(sess);
 660
 661         Log(LOG_INFO, "Connection %d: initialized %s using cipher %s-%s.",
 662             c->sock,
 663             gnutls_protocol_get_name(gnutls_protocol_get_version(sess)),
 664             gnutls_cipher_get_name(cipher),
 665             gnutls_mac_get_name(gnutls_mac_get(sess)));
 666 #endif
 667 }
 668
 669
 670 /*
 671  Accept incoming SSL connection.
 672  Return Values:
 673          1: SSL Connection established
 674          0: try again
 675         -1: SSL Connection not established due to fatal error.
 676 */
 677 int
 678 ConnSSL_Accept( CONNECTION *c )
 679 {
 680         assert(c != NULL);
 681         if (!Conn_OPTION_ISSET(c, CONN_SSL)) {
 682 #ifdef HAVE_LIBGNUTLS
 683                 int err = gnutls_init(&c->ssl_state.gnutls_session, GNUTLS_SERVER);
 684                 if (err) {
 685                         Log(LOG_ERR, "Failed to initialize new SSL session: %s",
 686                             gnutls_strerror(err));
 687                         return false;
 688                 }
 689 #endif
 690                 if (!ConnSSL_Init_SSL(c))
 691                         return -1;
 692         }
 693         return ConnectAccept(c, false );
 694 }
 695
 696
 697 int
 698 ConnSSL_Connect( CONNECTION *c )
 699 {
 700         assert(c != NULL);
 701 #ifdef HAVE_LIBSSL
 702         assert(c->ssl_state.ssl);
 703 #endif
 704         assert(Conn_OPTION_ISSET(c, CONN_SSL));
 705         return ConnectAccept(c, true);
 706 }
 707
 708 static int
 709 ConnSSL_InitCertFp( CONNECTION *c )
 710 {
 711         const char hex[] = "0123456789abcdef";
 712         int i;
 713
 714 #ifdef HAVE_LIBSSL
 715         unsigned char digest[EVP_MAX_MD_SIZE];
 716         unsigned int digest_size;
 717         X509 *cert;
 718
 719         cert = SSL_get_peer_certificate(c->ssl_state.ssl);
 720         if (!cert)
 721                 return 0;
 722
 723         if (!X509_digest(cert, EVP_sha256(), digest, &digest_size)) {
 724                 X509_free(cert);
 725                 return 0;
 726         }
 727
 728         X509_free(cert);
 729 #endif /* HAVE_LIBSSL */
 730 #ifdef HAVE_LIBGNUTLS
 731         gnutls_x509_crt_t cert;
 732         unsigned int cert_list_size;
 733         const gnutls_datum_t *cert_list;
 734         unsigned char digest[MAX_HASH_SIZE];
 735         size_t digest_size;
 736
 737         if (gnutls_certificate_type_get(c->ssl_state.gnutls_session) !=
 738                                         GNUTLS_CRT_X509)
 739                 return 0;
 740
 741         if (gnutls_x509_crt_init(&cert) != GNUTLS_E_SUCCESS)
 742                 return 0;
 743
 744         cert_list_size = 0;
 745         cert_list = gnutls_certificate_get_peers(c->ssl_state.gnutls_session,
 746                                                  &cert_list_size);
 747         if (!cert_list) {
 748                 gnutls_x509_crt_deinit(cert);
 749                 return 0;
 750         }
 751
 752         if (gnutls_x509_crt_import(cert, &cert_list[0],
 753                                    GNUTLS_X509_FMT_DER) != GNUTLS_E_SUCCESS) {
 754                 gnutls_x509_crt_deinit(cert);
 755                 return 0;
 756         }
 757
 758         digest_size = sizeof(digest);
 759         if (gnutls_x509_crt_get_fingerprint(cert, GNUTLS_DIG_SHA256, digest,
 760                                             &digest_size)) {
 761                 gnutls_x509_crt_deinit(cert);
 762                 return 0;
 763         }
 764
 765         gnutls_x509_crt_deinit(cert);
 766 #endif /* HAVE_LIBGNUTLS */
 767
 768         assert(c->ssl_state.fingerprint == NULL);
 769
 770         c->ssl_state.fingerprint = malloc(SHA256_STRING_LEN);
 771         if (!c->ssl_state.fingerprint)
 772                 return 0;
 773
 774         for (i = 0; i < (int)digest_size; i++) {
 775                 c->ssl_state.fingerprint[i * 2] = hex[digest[i] / 16];
 776                 c->ssl_state.fingerprint[i * 2 + 1] = hex[digest[i] % 16];
 777         }
 778         c->ssl_state.fingerprint[i * 2] = '\0';
 779
 780         return 1;
 781 }
 782
 783 /* accept/connect wrapper. if connect is true, connect to peer, otherwise wait for incoming connection */
 784 static int
 785 ConnectAccept( CONNECTION *c, bool connect)
 786 {
 787         int ret;
 788 #ifdef HAVE_LIBSSL
 789         SSL *ssl = c->ssl_state.ssl;
 790         assert(ssl != NULL);
 791
 792         ret = connect ? SSL_connect(ssl) : SSL_accept(ssl);
 793         if (1 != ret)
 794                 return ConnSSL_HandleError(c, ret, connect ? "SSL_connect": "SSL_accept");
 795 #endif
 796 #ifdef HAVE_LIBGNUTLS
 797         (void) connect;
 798         ret = gnutls_handshake(c->ssl_state.gnutls_session);
 799         if (ret)
 800                 return ConnSSL_HandleError(c, ret, "gnutls_handshake");
 801 #endif /* _GNUTLS */
 802         (void)ConnSSL_InitCertFp(c);
 803
 804         Conn_OPTION_DEL(c, (CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ|CONN_SSL_CONNECT));
 805         ConnSSL_LogCertInfo(c);
 806
 807         Conn_StartLogin(CONNECTION2ID(c));
 808         return 1;
 809 }
 810
 811
 812 ssize_t
 813 ConnSSL_Write(CONNECTION *c, const void *buf, size_t count)
 814 {
 815         ssize_t bw;
 816
 817         Conn_OPTION_DEL(c, CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ);
 818
 819         assert(count > 0);
 820 #ifdef HAVE_LIBSSL
 821         bw = (ssize_t) SSL_write(c->ssl_state.ssl, buf, count);
 822 #endif
 823 #ifdef HAVE_LIBGNUTLS
 824         bw = gnutls_write(c->ssl_state.gnutls_session, buf, count);
 825 #endif
 826         if (bw > 0)
 827                 return bw;
 828         if (ConnSSL_HandleError( c, bw, "ConnSSL_Write") == 0)
 829                 errno = EAGAIN; /* try again */
 830         return -1;
 831 }
 832
 833
 834 ssize_t
 835 ConnSSL_Read(CONNECTION *c, void * buf, size_t count)
 836 {
 837         ssize_t br;
 838
 839         Conn_OPTION_DEL(c, CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ);
 840 #ifdef HAVE_LIBSSL
 841         br = (ssize_t) SSL_read(c->ssl_state.ssl, buf, count);
 842         if (br > 0)     /* on EOF we have to call ConnSSL_HandleError(), see SSL_read(3) */
 843                 return br;
 844 #endif
 845 #ifdef HAVE_LIBGNUTLS
 846         br = gnutls_read(c->ssl_state.gnutls_session, buf, count);
 847         if (br >= 0)    /* on EOF we must _not_ call ConnSSL_HandleError, see gnutls_record_recv(3) */
 848                 return br;
 849 #endif
 850         /* error on read: switch ConnSSL_HandleError() return values -> 0 is "try again", so return -1 and set EAGAIN */
 851         if (ConnSSL_HandleError(c, br, "ConnSSL_Read") == 0) {
 852                 errno = EAGAIN;
 853                 return -1;
 854         }
 855         return 0;
 856 }
 857
 858
 859 bool
 860 ConnSSL_GetCipherInfo(CONNECTION *c, char *buf, size_t len)
 861 {
 862 #ifdef HAVE_LIBSSL
 863         char *nl;
 864         SSL *ssl = c->ssl_state.ssl;
 865
 866         if (!ssl)
 867                 return false;
 868         *buf = 0;
 869         SSL_CIPHER_description(SSL_get_current_cipher(ssl), buf, len);
 870         nl = strchr(buf, '\n');
 871         if (nl)
 872                 *nl = 0;
 873         return true;
 874 #endif
 875 #ifdef HAVE_LIBGNUTLS
 876         if (Conn_OPTION_ISSET(c, CONN_SSL)) {
 877                 const char *name_cipher, *name_mac, *name_proto, *name_keyexchange;
 878                 unsigned keysize;
 879
 880                 gnutls_session_t sess = c->ssl_state.gnutls_session;
 881                 gnutls_cipher_algorithm_t cipher = gnutls_cipher_get(sess);
 882                 name_cipher = gnutls_cipher_get_name(cipher);
 883                 name_mac = gnutls_mac_get_name(gnutls_mac_get(sess));
 884                 keysize = gnutls_cipher_get_key_size(cipher) * 8;
 885                 name_proto = gnutls_protocol_get_name(gnutls_protocol_get_version(sess));
 886                 name_keyexchange = gnutls_kx_get_name(gnutls_kx_get(sess));
 887
 888                 return snprintf(buf, len, "%s-%s%15s Kx=%s      Enc=%s(%u) Mac=%s",
 889                         name_cipher, name_mac, name_proto, name_keyexchange, name_cipher, keysize, name_mac) > 0;
 890         }
 891         return false;
 892 #endif
 893 }
 894
 895 char *
 896 ConnSSL_GetCertFp(CONNECTION *c)
 897 {
 898         return c->ssl_state.fingerprint;
 899 }
 900
 901 bool
 902 ConnSSL_SetCertFp(CONNECTION *c, const char *fingerprint)
 903 {
 904         assert (c != NULL);
 905         c->ssl_state.fingerprint = strndup(fingerprint, SHA256_STRING_LEN - 1);
 906         return c->ssl_state.fingerprint != NULL;
 907 }
 908 #else
 909
 910 bool
 911 ConnSSL_InitLibrary(void)
 912 {
 913         return true;
 914 }
 915
 916 #endif /* SSL_SUPPORT */
 917 /* -eof- */