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 "conf-ssl.h"
  14
  15 #ifdef SSL_SUPPORT
  16
  17 #include "io.h"
  18 #include <assert.h>
  19 #include <stdio.h>
  20 #include <string.h>
  21 #include <stdlib.h>
  22 #include <errno.h>
  23
  24 #define CONN_MODULE
  25 #include "conn.h"
  26 #include "conf.h"
  27 #include "conn-func.h"
  28 #include "conn-ssl.h"
  29 #include "log.h"
  30
  31 #include "defines.h"
  32
  33 extern struct SSLOptions Conf_SSLOptions;
  34
  35 #ifdef HAVE_LIBSSL
  36 #include <openssl/err.h>
  37 #include <openssl/rand.h>
  38
  39 static SSL_CTX * ssl_ctx;
  40 static DH *dh_params;
  41
  42 static bool ConnSSL_LoadServerKey_openssl PARAMS(( SSL_CTX *c ));
  43 #endif
  44
  45 #ifdef HAVE_LIBGNUTLS
  46 #include <sys/types.h>
  47 #include <sys/stat.h>
  48 #include <fcntl.h>
  49 #include <unistd.h>
  50 #include <gnutls/x509.h>
  51
  52 #define DH_BITS 2048
  53 #define DH_BITS_MIN 1024
  54
  55 #define MAX_HASH_SIZE   64      /* from gnutls-int.h */
  56
  57 static gnutls_certificate_credentials_t x509_cred;
  58 static gnutls_dh_params_t dh_params;
  59 static gnutls_priority_t priorities_cache;
  60 static bool ConnSSL_LoadServerKey_gnutls PARAMS(( void ));
  61 #endif
  62
  63 #define SHA256_STRING_LEN       (32 * 2 + 1)
  64
  65 static bool ConnSSL_Init_SSL PARAMS(( CONNECTION *c ));
  66 static int ConnectAccept PARAMS(( CONNECTION *c, bool connect ));
  67 static int ConnSSL_HandleError PARAMS(( CONNECTION *c, const int code, const char *fname ));
  68
  69 #ifdef HAVE_LIBGNUTLS
  70 static char * openreadclose(const char *name, size_t *len)
  71 {
  72         char *buf = NULL;
  73         struct stat s;
  74         ssize_t br;
  75         int fd = open(name, O_RDONLY);
  76         if (fd < 0) {
  77                 Log(LOG_ERR, "Could not open %s: %s", name, strerror(errno));
  78                 return NULL;
  79         }
  80         if (fstat(fd, &s)) {
  81                 Log(LOG_ERR, "Could not fstat %s: %s", name, strerror(errno));
  82                 goto out;
  83         }
  84         if (!S_ISREG(s.st_mode)) {
  85                 Log(LOG_ERR, "%s: Not a regular file", name);
  86                 goto out;
  87         }
  88         if (s.st_size <= 0) {
  89                 Log(LOG_ERR, "%s: invalid file length (size %ld <= 0)", name, (long) s.st_size);
  90                 goto out;
  91         }
  92         buf = malloc(s.st_size);
  93         if (!buf) {
  94                 Log(LOG_ERR, "Could not malloc %lu bytes for file %s: %s", s.st_size, name, strerror(errno));
  95                 goto out;
  96         }
  97         br = read(fd, buf, s.st_size);
  98         if (br != (ssize_t)s.st_size) {
  99                 Log(LOG_ERR, "Could not read file %s: read returned %ld, expected %ld: %s",
 100                         name, (long) br, (long) s.st_size, br == -1 ? strerror(errno):"short read?!");
 101                 memset(buf, 0, s.st_size);
 102                 free(buf);
 103                 buf = NULL;
 104         } else {
 105                 *len = br;
 106         }
 107 out:
 108         close(fd);
 109         return buf;
 110 }
 111 #endif
 112
 113
 114 #ifdef HAVE_LIBSSL
 115 /**
 116  * Log OpenSSL error message.
 117  *
 118  * @param msg The error message.
 119  * @param info Additional information text or NULL.
 120  */
 121 static void
 122 LogOpenSSLError(const char *error, const char *info)
 123 {
 124         unsigned long err = ERR_get_error();
 125         char * errmsg = err
 126                 ? ERR_error_string(err, NULL)
 127                 : "Unable to determine error";
 128
 129         assert(error != NULL);
 130
 131         if (info)
 132                 Log(LOG_ERR, "%s: %s (%s)", error, info, errmsg);
 133         else
 134                 Log(LOG_ERR, "%s: %s", error, errmsg);
 135 }
 136
 137
 138 static int
 139 pem_passwd_cb(char *buf, int size, int rwflag, void *password)
 140 {
 141         array *pass = password;
 142         int passlen;
 143
 144         (void)rwflag;           /* rwflag is unused if DEBUG is not set. */
 145         assert(rwflag == 0);    /* 0 -> callback used for decryption.
 146                                  * See SSL_CTX_set_default_passwd_cb(3) */
 147
 148         passlen = (int) array_bytes(pass);
 149
 150         LogDebug("pem_passwd_cb buf size %d, array size %d", size, passlen);
 151         assert(passlen >= 0);
 152         if (passlen <= 0) {
 153                 Log(LOG_ERR, "PEM password required but not set [in pem_passwd_cb()]!");
 154                 return 0;
 155         }
 156         size = passlen > size ? size : passlen;
 157         memcpy(buf, (char *)(array_start(pass)), size);
 158         return size;
 159 }
 160
 161
 162 static int
 163 Verify_openssl(UNUSED int preverify_ok, UNUSED X509_STORE_CTX *x509_ctx)
 164 {
 165         return 1;
 166 }
 167 #endif
 168
 169
 170 static bool
 171 Load_DH_params(void)
 172 {
 173 #ifdef HAVE_LIBSSL
 174         FILE *fp;
 175         bool ret = true;
 176
 177         if (!Conf_SSLOptions.DHFile) {
 178                 Log(LOG_NOTICE, "Configuration option \"DHFile\" not set!");
 179                 return false;
 180         }
 181         fp = fopen(Conf_SSLOptions.DHFile, "r");
 182         if (!fp) {
 183                 Log(LOG_ERR, "%s: %s", Conf_SSLOptions.DHFile, strerror(errno));
 184                 return false;
 185         }
 186         dh_params = PEM_read_DHparams(fp, NULL, NULL, NULL);
 187         if (!dh_params) {
 188                 Log(LOG_ERR, "%s: Failed to read SSL DH parameters!",
 189                     Conf_SSLOptions.DHFile);
 190                 ret = false;
 191         }
 192         fclose(fp);
 193         return ret;
 194 #endif
 195 #ifdef HAVE_LIBGNUTLS
 196         bool need_dhgenerate = true;
 197         int err;
 198         gnutls_dh_params_t tmp_dh_params;
 199
 200         err = gnutls_dh_params_init(&tmp_dh_params);
 201         if (err < 0) {
 202                 Log(LOG_ERR, "Failed to initialize SSL DH parameters: %s",
 203                     gnutls_strerror(err));
 204                 return false;
 205         }
 206         if (Conf_SSLOptions.DHFile) {
 207                 gnutls_datum_t dhparms;
 208                 size_t size;
 209                 dhparms.data = (unsigned char *) openreadclose(Conf_SSLOptions.DHFile, &size);
 210                 if (dhparms.data) {
 211                         dhparms.size = size;
 212                         err = gnutls_dh_params_import_pkcs3(tmp_dh_params, &dhparms, GNUTLS_X509_FMT_PEM);
 213                         if (err == 0)
 214                                 need_dhgenerate = false;
 215                         else
 216                                 Log(LOG_ERR,
 217                                     "Failed to initialize SSL DH parameters: %s",
 218                                     gnutls_strerror(err));
 219
 220                         memset(dhparms.data, 0, size);
 221                         free(dhparms.data);
 222                 }
 223         }
 224         if (need_dhgenerate) {
 225                 Log(LOG_WARNING,
 226                     "DHFile not set, generating %u bit DH parameters. This may take a while ...",
 227                     DH_BITS);
 228                 err = gnutls_dh_params_generate2(tmp_dh_params, DH_BITS);
 229                 if (err < 0) {
 230                         Log(LOG_ERR, "Failed to generate SSL DH parameters: %s",
 231                             gnutls_strerror(err));
 232                         return false;
 233                 }
 234         }
 235         dh_params = tmp_dh_params;
 236         return true;
 237 #endif
 238 }
 239
 240
 241 void ConnSSL_Free(CONNECTION *c)
 242 {
 243 #ifdef HAVE_LIBSSL
 244         SSL *ssl = c->ssl_state.ssl;
 245         if (ssl) {
 246                 SSL_shutdown(ssl);
 247                 SSL_free(ssl);
 248                 c->ssl_state.ssl = NULL;
 249                 if (c->ssl_state.fingerprint) {
 250                         free(c->ssl_state.fingerprint);
 251                         c->ssl_state.fingerprint = NULL;
 252                 }
 253         }
 254 #endif
 255 #ifdef HAVE_LIBGNUTLS
 256         gnutls_session_t sess = c->ssl_state.gnutls_session;
 257         if (Conn_OPTION_ISSET(c, CONN_SSL)) {
 258                 gnutls_bye(sess, GNUTLS_SHUT_RDWR);
 259                 gnutls_deinit(sess);
 260         }
 261 #endif
 262         assert(Conn_OPTION_ISSET(c, CONN_SSL));
 263         /* can't just set bitmask to 0 -- there are other, non-ssl related flags, e.g. CONN_ZIP. */
 264         Conn_OPTION_DEL(c, CONN_SSL_FLAGS_ALL);
 265 }
 266
 267
 268 bool
 269 ConnSSL_InitLibrary( void )
 270 {
 271         if (!Conf_SSLInUse()) {
 272                 LogDebug("SSL not in use, skipping initialization.");
 273                 return true;
 274         }
 275
 276 #ifdef HAVE_LIBSSL
 277         SSL_CTX *newctx;
 278
 279         if (!ssl_ctx) {
 280                 SSL_library_init();
 281                 SSL_load_error_strings();
 282         }
 283
 284         if (!RAND_status()) {
 285                 Log(LOG_ERR, "OpenSSL PRNG not seeded: /dev/urandom missing?");
 286                 /*
 287                  * it is probably best to fail and let the user install EGD or
 288                  * a similar program if no kernel random device is available.
 289                  * According to OpenSSL RAND_egd(3): "The automatic query of
 290                  * /var/run/egd-pool et al was added in OpenSSL 0.9.7";
 291                  * so it makes little sense to deal with PRNGD seeding ourselves.
 292                  */
 293                 array_free(&Conf_SSLOptions.ListenPorts);
 294                 return false;
 295         }
 296
 297         newctx = SSL_CTX_new(SSLv23_method());
 298         if (!newctx) {
 299                 LogOpenSSLError("Failed to create SSL context", NULL);
 300                 array_free(&Conf_SSLOptions.ListenPorts);
 301                 return false;
 302         }
 303
 304         if (!ConnSSL_LoadServerKey_openssl(newctx))
 305                 goto out;
 306
 307         if (SSL_CTX_set_cipher_list(newctx, Conf_SSLOptions.CipherList) == 0) {
 308                 Log(LOG_ERR, "Failed to apply OpenSSL cipher list \"%s\"!",
 309                     Conf_SSLOptions.CipherList);
 310                 goto out;
 311         }
 312
 313         SSL_CTX_set_options(newctx, SSL_OP_SINGLE_DH_USE|SSL_OP_NO_SSLv2);
 314         SSL_CTX_set_mode(newctx, SSL_MODE_ENABLE_PARTIAL_WRITE);
 315         SSL_CTX_set_verify(newctx, SSL_VERIFY_PEER|SSL_VERIFY_CLIENT_ONCE,
 316                            Verify_openssl);
 317         SSL_CTX_free(ssl_ctx);
 318         ssl_ctx = newctx;
 319         Log(LOG_INFO, "%s initialized.", SSLeay_version(SSLEAY_VERSION));
 320         return true;
 321 out:
 322         SSL_CTX_free(newctx);
 323         array_free(&Conf_SSLOptions.ListenPorts);
 324         return false;
 325 #endif
 326 #ifdef HAVE_LIBGNUTLS
 327         int err;
 328         static bool initialized;
 329
 330         if (initialized) {
 331                 /* TODO: cannot reload gnutls keys: can't simply free x509
 332                  * context -- it may still be in use */
 333                 return false;
 334         }
 335
 336         err = gnutls_global_init();
 337         if (err) {
 338                 Log(LOG_ERR, "Failed to initialize GnuTLS: %s",
 339                     gnutls_strerror(err));
 340                 goto out;
 341         }
 342
 343         if (!ConnSSL_LoadServerKey_gnutls())
 344                 goto out;
 345
 346         if (gnutls_priority_init(&priorities_cache, Conf_SSLOptions.CipherList,
 347                                  NULL) != GNUTLS_E_SUCCESS) {
 348                 Log(LOG_ERR,
 349                     "Failed to apply GnuTLS cipher list \"%s\"!",
 350                     Conf_SSLOptions.CipherList);
 351                 goto out;
 352         }
 353
 354         Log(LOG_INFO, "GnuTLS %s initialized.", gnutls_check_version(NULL));
 355         initialized = true;
 356         return true;
 357 out:
 358         array_free(&Conf_SSLOptions.ListenPorts);
 359         return false;
 360 #endif
 361 }
 362
 363
 364 #ifdef HAVE_LIBGNUTLS
 365 static bool
 366 ConnSSL_LoadServerKey_gnutls(void)
 367 {
 368         int err;
 369         const char *cert_file;
 370
 371         err = gnutls_certificate_allocate_credentials(&x509_cred);
 372         if (err < 0) {
 373                 Log(LOG_ERR, "Failed to allocate certificate credentials: %s",
 374                     gnutls_strerror(err));
 375                 return false;
 376         }
 377
 378         cert_file = Conf_SSLOptions.CertFile ? Conf_SSLOptions.CertFile:Conf_SSLOptions.KeyFile;
 379         if (!cert_file) {
 380                 Log(LOG_ERR, "No SSL server key configured!");
 381                 return false;
 382         }
 383
 384         if (array_bytes(&Conf_SSLOptions.KeyFilePassword))
 385                 Log(LOG_WARNING,
 386                     "Ignoring SSL \"KeyFilePassword\": Not supported by GnuTLS.");
 387
 388         if (!Load_DH_params())
 389                 return false;
 390
 391         gnutls_certificate_set_dh_params(x509_cred, dh_params);
 392         err = gnutls_certificate_set_x509_key_file(x509_cred, cert_file, Conf_SSLOptions.KeyFile, GNUTLS_X509_FMT_PEM);
 393         if (err < 0) {
 394                 Log(LOG_ERR,
 395                     "Failed to set certificate key file (cert %s, key %s): %s",
 396                     cert_file,
 397                     Conf_SSLOptions.KeyFile ? Conf_SSLOptions.KeyFile : "(NULL)",
 398                     gnutls_strerror(err));
 399                 return false;
 400         }
 401         return true;
 402 }
 403 #endif
 404
 405
 406 #ifdef HAVE_LIBSSL
 407 static bool
 408 ConnSSL_LoadServerKey_openssl(SSL_CTX *ctx)
 409 {
 410         char *cert_key;
 411
 412         assert(ctx);
 413         if (!Conf_SSLOptions.KeyFile) {
 414                 Log(LOG_ERR, "No SSL server key configured!");
 415                 return false;
 416         }
 417
 418         SSL_CTX_set_default_passwd_cb(ctx, pem_passwd_cb);
 419         SSL_CTX_set_default_passwd_cb_userdata(ctx, &Conf_SSLOptions.KeyFilePassword);
 420
 421         if (SSL_CTX_use_PrivateKey_file(ctx, Conf_SSLOptions.KeyFile, SSL_FILETYPE_PEM) != 1) {
 422                 array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 423                 LogOpenSSLError("Failed to add private key", Conf_SSLOptions.KeyFile);
 424                 return false;
 425         }
 426
 427         cert_key = Conf_SSLOptions.CertFile ? Conf_SSLOptions.CertFile:Conf_SSLOptions.KeyFile;
 428         if (SSL_CTX_use_certificate_chain_file(ctx, cert_key) != 1) {
 429                 array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 430                 LogOpenSSLError("Failed to load certificate chain", cert_key);
 431                 return false;
 432         }
 433
 434         array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 435
 436         if (!SSL_CTX_check_private_key(ctx)) {
 437                 LogOpenSSLError("Server private key does not match certificate", NULL);
 438                 return false;
 439         }
 440         if (Load_DH_params()) {
 441                 if (SSL_CTX_set_tmp_dh(ctx, dh_params) != 1)
 442                         LogOpenSSLError("Error setting DH parameters", Conf_SSLOptions.DHFile);
 443                 /* don't return false here: the non-DH modes will still work */
 444                 DH_free(dh_params);
 445                 dh_params = NULL;
 446         }
 447         return true;
 448 }
 449
 450
 451 #endif
 452 static bool
 453 ConnSSL_Init_SSL(CONNECTION *c)
 454 {
 455         int ret;
 456
 457         LogDebug("Initializing SSL ...");
 458         assert(c != NULL);
 459
 460 #ifdef HAVE_LIBSSL
 461         if (!ssl_ctx) {
 462                 Log(LOG_ERR,
 463                     "Can't initialize SSL context, OpenSSL initialization failed at startup!");
 464                 return false;
 465         }
 466         assert(c->ssl_state.ssl == NULL);
 467         assert(c->ssl_state.fingerprint == NULL);
 468
 469         c->ssl_state.ssl = SSL_new(ssl_ctx);
 470         if (!c->ssl_state.ssl) {
 471                 LogOpenSSLError("Failed to create SSL structure", NULL);
 472                 return false;
 473         }
 474         Conn_OPTION_ADD(c, CONN_SSL);
 475
 476         ret = SSL_set_fd(c->ssl_state.ssl, c->sock);
 477         if (ret != 1) {
 478                 LogOpenSSLError("Failed to set SSL file descriptor", NULL);
 479                 ConnSSL_Free(c);
 480                 return false;
 481         }
 482 #endif
 483 #ifdef HAVE_LIBGNUTLS
 484         Conn_OPTION_ADD(c, CONN_SSL);
 485         ret = gnutls_priority_set(c->ssl_state.gnutls_session, priorities_cache);
 486         if (ret != GNUTLS_E_SUCCESS) {
 487                 Log(LOG_ERR, "Failed to set GnuTLS session priorities: %s",
 488                     gnutls_strerror(ret));
 489                 ConnSSL_Free(c);
 490                 return false;
 491         }
 492         /*
 493          * The intermediate (long) cast is here to avoid a warning like:
 494          * "cast to pointer from integer of different size" on 64-bit platforms.
 495          * There doesn't seem to be an alternate GNUTLS API we could use instead, see e.g.
 496          * http://www.mail-archive.com/help-gnutls@gnu.org/msg00286.html
 497          */
 498         gnutls_transport_set_ptr(c->ssl_state.gnutls_session,
 499                                  (gnutls_transport_ptr_t) (long) c->sock);
 500         gnutls_certificate_server_set_request(c->ssl_state.gnutls_session,
 501                                               GNUTLS_CERT_REQUEST);
 502         ret = gnutls_credentials_set(c->ssl_state.gnutls_session,
 503                                      GNUTLS_CRD_CERTIFICATE, x509_cred);
 504         if (ret != 0) {
 505                 Log(LOG_ERR, "Failed to set SSL credentials: %s",
 506                     gnutls_strerror(ret));
 507                 ConnSSL_Free(c);
 508                 return false;
 509         }
 510         gnutls_dh_set_prime_bits(c->ssl_state.gnutls_session, DH_BITS_MIN);
 511 #endif
 512         return true;
 513 }
 514
 515
 516 bool
 517 ConnSSL_PrepareConnect(CONNECTION *c, UNUSED CONF_SERVER *s)
 518 {
 519         bool ret;
 520 #ifdef HAVE_LIBGNUTLS
 521         int err;
 522
 523         err = gnutls_init(&c->ssl_state.gnutls_session, GNUTLS_CLIENT);
 524         if (err) {
 525                 Log(LOG_ERR, "Failed to initialize new SSL session: %s",
 526                     gnutls_strerror(err));
 527                 return false;
 528         }
 529 #endif
 530         ret = ConnSSL_Init_SSL(c);
 531         if (!ret)
 532                 return false;
 533         Conn_OPTION_ADD(c, CONN_SSL_CONNECT);
 534 #ifdef HAVE_LIBSSL
 535         assert(c->ssl_state.ssl);
 536         SSL_set_verify(c->ssl_state.ssl, SSL_VERIFY_NONE, NULL);
 537 #endif
 538         return true;
 539 }
 540
 541
 542 /**
 543  * Check and handle error return codes after failed calls to SSL functions.
 544  *
 545  * OpenSSL:
 546  * SSL_connect(), SSL_accept(), SSL_do_handshake(), SSL_read(), SSL_peek(), or
 547  * SSL_write() on ssl.
 548  *
 549  * GnuTLS:
 550  * gnutlsssl_read(), gnutls_write() or gnutls_handshake().
 551  *
 552  * @param c The connection handle.
 553  * @prarm code The return code.
 554  * @param fname The name of the function in which the error occurred.
 555  * @return -1 on fatal errors, 0 if we can try again later.
 556  */
 557 static int
 558 ConnSSL_HandleError(CONNECTION * c, const int code, const char *fname)
 559 {
 560 #ifdef HAVE_LIBSSL
 561         int ret = SSL_ERROR_SYSCALL;
 562         unsigned long sslerr;
 563         int real_errno = errno;
 564
 565         ret = SSL_get_error(c->ssl_state.ssl, code);
 566
 567         switch (ret) {
 568         case SSL_ERROR_WANT_READ:
 569                 io_event_del(c->sock, IO_WANTWRITE);
 570                 Conn_OPTION_ADD(c, CONN_SSL_WANT_READ);
 571                 return 0;       /* try again later */
 572         case SSL_ERROR_WANT_WRITE:
 573                 io_event_del(c->sock, IO_WANTREAD);
 574                 Conn_OPTION_ADD(c, CONN_SSL_WANT_WRITE); /* fall through */
 575         case SSL_ERROR_NONE:
 576                 return 0;       /* try again later */
 577         case SSL_ERROR_ZERO_RETURN:
 578                 LogDebug("SSL connection shut down normally.");
 579                 break;
 580         case SSL_ERROR_SYSCALL:
 581                 /* SSL_ERROR_WANT_CONNECT, SSL_ERROR_WANT_ACCEPT,
 582                  * and SSL_ERROR_WANT_X509_LOOKUP */
 583                 sslerr = ERR_get_error();
 584                 if (sslerr) {
 585                         Log(LOG_ERR, "SSL error: %s [in %s()]!",
 586                             ERR_error_string(sslerr, NULL), fname);
 587                 } else {
 588                         switch (code) { /* EOF that violated protocol */
 589                         case 0:
 590                                 Log(LOG_ERR,
 591                                     "SSL error, client disconnected [in %s()]!",
 592                                     fname);
 593                                 break;
 594                         case -1:        /* low level socket I/O error, check errno */
 595                                 Log(LOG_ERR, "SSL error: %s [in %s()]!",
 596                                     strerror(real_errno), fname);
 597                         }
 598                 }
 599                 break;
 600         case SSL_ERROR_SSL:
 601                 LogOpenSSLError("SSL protocol error", fname);
 602                 break;
 603         default:
 604                 Log(LOG_ERR, "Unknown SSL error %d [in %s()]!", ret, fname);
 605         }
 606         ConnSSL_Free(c);
 607         return -1;
 608 #endif
 609 #ifdef HAVE_LIBGNUTLS
 610         switch (code) {
 611         case GNUTLS_E_AGAIN:
 612         case GNUTLS_E_INTERRUPTED:
 613                 if (gnutls_record_get_direction(c->ssl_state.gnutls_session)) {
 614                         Conn_OPTION_ADD(c, CONN_SSL_WANT_WRITE);
 615                         io_event_del(c->sock, IO_WANTREAD);
 616                 } else {
 617                         Conn_OPTION_ADD(c, CONN_SSL_WANT_READ);
 618                         io_event_del(c->sock, IO_WANTWRITE);
 619                 }
 620                 break;
 621         default:
 622                 assert(code < 0);
 623                 if (gnutls_error_is_fatal(code)) {
 624                         Log(LOG_ERR, "SSL error: %s [%s].",
 625                             gnutls_strerror(code), fname);
 626                         ConnSSL_Free(c);
 627                         return -1;
 628                 }
 629         }
 630         return 0;
 631 #endif
 632 }
 633
 634
 635 static void
 636 ConnSSL_LogCertInfo( CONNECTION *c )
 637 {
 638 #ifdef HAVE_LIBSSL
 639         SSL *ssl = c->ssl_state.ssl;
 640
 641         assert(ssl);
 642
 643         Log(LOG_INFO, "Connection %d: initialized %s using cipher %s.",
 644                 c->sock, SSL_get_version(ssl), SSL_get_cipher(ssl));
 645 #endif
 646 #ifdef HAVE_LIBGNUTLS
 647         gnutls_session_t sess = c->ssl_state.gnutls_session;
 648         gnutls_cipher_algorithm_t cipher = gnutls_cipher_get(sess);
 649
 650         Log(LOG_INFO, "Connection %d: initialized %s using cipher %s-%s.",
 651             c->sock,
 652             gnutls_protocol_get_name(gnutls_protocol_get_version(sess)),
 653             gnutls_cipher_get_name(cipher),
 654             gnutls_mac_get_name(gnutls_mac_get(sess)));
 655 #endif
 656 }
 657
 658
 659 /*
 660  Accept incoming SSL connection.
 661  Return Values:
 662          1: SSL Connection established
 663          0: try again
 664         -1: SSL Connection not established due to fatal error.
 665 */
 666 int
 667 ConnSSL_Accept( CONNECTION *c )
 668 {
 669         assert(c != NULL);
 670         if (!Conn_OPTION_ISSET(c, CONN_SSL)) {
 671 #ifdef HAVE_LIBGNUTLS
 672                 int err = gnutls_init(&c->ssl_state.gnutls_session, GNUTLS_SERVER);
 673                 if (err) {
 674                         Log(LOG_ERR, "Failed to initialize new SSL session: %s",
 675                             gnutls_strerror(err));
 676                         return false;
 677                 }
 678 #endif
 679                 if (!ConnSSL_Init_SSL(c))
 680                         return -1;
 681         }
 682         return ConnectAccept(c, false );
 683 }
 684
 685
 686 int
 687 ConnSSL_Connect( CONNECTION *c )
 688 {
 689         assert(c != NULL);
 690 #ifdef HAVE_LIBSSL
 691         assert(c->ssl_state.ssl);
 692 #endif
 693         assert(Conn_OPTION_ISSET(c, CONN_SSL));
 694         return ConnectAccept(c, true);
 695 }
 696
 697 static int
 698 ConnSSL_InitCertFp( CONNECTION *c )
 699 {
 700         const char hex[] = "0123456789abcdef";
 701         int i;
 702
 703 #ifdef HAVE_LIBSSL
 704         unsigned char digest[EVP_MAX_MD_SIZE];
 705         unsigned int digest_size;
 706         X509 *cert;
 707
 708         cert = SSL_get_peer_certificate(c->ssl_state.ssl);
 709         if (!cert)
 710                 return 0;
 711
 712         if (!X509_digest(cert, EVP_sha256(), digest, &digest_size)) {
 713                 X509_free(cert);
 714                 return 0;
 715         }
 716
 717         X509_free(cert);
 718 #endif /* HAVE_LIBSSL */
 719 #ifdef HAVE_LIBGNUTLS
 720         gnutls_x509_crt_t cert;
 721         unsigned int cert_list_size;
 722         const gnutls_datum_t *cert_list;
 723         unsigned char digest[MAX_HASH_SIZE];
 724         size_t digest_size;
 725
 726         if (gnutls_certificate_type_get(c->ssl_state.gnutls_session) !=
 727                                         GNUTLS_CRT_X509)
 728                 return 0;
 729
 730         if (gnutls_x509_crt_init(&cert) != GNUTLS_E_SUCCESS)
 731                 return 0;
 732
 733         cert_list_size = 0;
 734         cert_list = gnutls_certificate_get_peers(c->ssl_state.gnutls_session,
 735                                                  &cert_list_size);
 736         if (!cert_list) {
 737                 gnutls_x509_crt_deinit(cert);
 738                 return 0;
 739         }
 740
 741         if (gnutls_x509_crt_import(cert, &cert_list[0],
 742                                    GNUTLS_X509_FMT_DER) != GNUTLS_E_SUCCESS) {
 743                 gnutls_x509_crt_deinit(cert);
 744                 return 0;
 745         }
 746
 747         digest_size = sizeof(digest);
 748         if (gnutls_x509_crt_get_fingerprint(cert, GNUTLS_DIG_SHA256, digest,
 749                                             &digest_size)) {
 750                 gnutls_x509_crt_deinit(cert);
 751                 return 0;
 752         }
 753
 754         gnutls_x509_crt_deinit(cert);
 755 #endif /* HAVE_LIBGNUTLS */
 756
 757         assert(c->ssl_state.fingerprint == NULL);
 758
 759         c->ssl_state.fingerprint = malloc(SHA256_STRING_LEN);
 760         if (!c->ssl_state.fingerprint)
 761                 return 0;
 762
 763         for (i = 0; i < (int)digest_size; i++) {
 764                 c->ssl_state.fingerprint[i * 2] = hex[digest[i] / 16];
 765                 c->ssl_state.fingerprint[i * 2 + 1] = hex[digest[i] % 16];
 766         }
 767         c->ssl_state.fingerprint[i * 2] = '\0';
 768
 769         return 1;
 770 }
 771
 772 /* accept/connect wrapper. if connect is true, connect to peer, otherwise wait for incoming connection */
 773 static int
 774 ConnectAccept( CONNECTION *c, bool connect)
 775 {
 776         int ret;
 777 #ifdef HAVE_LIBSSL
 778         SSL *ssl = c->ssl_state.ssl;
 779         assert(ssl != NULL);
 780
 781         ret = connect ? SSL_connect(ssl) : SSL_accept(ssl);
 782         if (1 != ret)
 783                 return ConnSSL_HandleError(c, ret, connect ? "SSL_connect": "SSL_accept");
 784 #endif
 785 #ifdef HAVE_LIBGNUTLS
 786         (void) connect;
 787         ret = gnutls_handshake(c->ssl_state.gnutls_session);
 788         if (ret)
 789                 return ConnSSL_HandleError(c, ret, "gnutls_handshake");
 790 #endif /* _GNUTLS */
 791         (void)ConnSSL_InitCertFp(c);
 792
 793         Conn_OPTION_DEL(c, (CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ|CONN_SSL_CONNECT));
 794         ConnSSL_LogCertInfo(c);
 795
 796         Conn_StartLogin(CONNECTION2ID(c));
 797         return 1;
 798 }
 799
 800
 801 ssize_t
 802 ConnSSL_Write(CONNECTION *c, const void *buf, size_t count)
 803 {
 804         ssize_t bw;
 805
 806         Conn_OPTION_DEL(c, CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ);
 807
 808         assert(count > 0);
 809 #ifdef HAVE_LIBSSL
 810         bw = (ssize_t) SSL_write(c->ssl_state.ssl, buf, count);
 811 #endif
 812 #ifdef HAVE_LIBGNUTLS
 813         bw = gnutls_write(c->ssl_state.gnutls_session, buf, count);
 814 #endif
 815         if (bw > 0)
 816                 return bw;
 817         if (ConnSSL_HandleError( c, bw, "ConnSSL_Write") == 0)
 818                 errno = EAGAIN; /* try again */
 819         return -1;
 820 }
 821
 822
 823 ssize_t
 824 ConnSSL_Read(CONNECTION *c, void * buf, size_t count)
 825 {
 826         ssize_t br;
 827
 828         Conn_OPTION_DEL(c, CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ);
 829 #ifdef HAVE_LIBSSL
 830         br = (ssize_t) SSL_read(c->ssl_state.ssl, buf, count);
 831         if (br > 0)     /* on EOF we have to call ConnSSL_HandleError(), see SSL_read(3) */
 832                 return br;
 833 #endif
 834 #ifdef HAVE_LIBGNUTLS
 835         br = gnutls_read(c->ssl_state.gnutls_session, buf, count);
 836         if (br >= 0)    /* on EOF we must _not_ call ConnSSL_HandleError, see gnutls_record_recv(3) */
 837                 return br;
 838 #endif
 839         /* error on read: switch ConnSSL_HandleError() return values -> 0 is "try again", so return -1 and set EAGAIN */
 840         if (ConnSSL_HandleError(c, br, "ConnSSL_Read") == 0) {
 841                 errno = EAGAIN;
 842                 return -1;
 843         }
 844         return 0;
 845 }
 846
 847
 848 bool
 849 ConnSSL_GetCipherInfo(CONNECTION *c, char *buf, size_t len)
 850 {
 851 #ifdef HAVE_LIBSSL
 852         char *nl;
 853         SSL *ssl = c->ssl_state.ssl;
 854
 855         if (!ssl)
 856                 return false;
 857         *buf = 0;
 858         SSL_CIPHER_description(SSL_get_current_cipher(ssl), buf, len);
 859         nl = strchr(buf, '\n');
 860         if (nl)
 861                 *nl = 0;
 862         return true;
 863 #endif
 864 #ifdef HAVE_LIBGNUTLS
 865         if (Conn_OPTION_ISSET(c, CONN_SSL)) {
 866                 const char *name_cipher, *name_mac, *name_proto, *name_keyexchange;
 867                 unsigned keysize;
 868
 869                 gnutls_session_t sess = c->ssl_state.gnutls_session;
 870                 gnutls_cipher_algorithm_t cipher = gnutls_cipher_get(sess);
 871                 name_cipher = gnutls_cipher_get_name(cipher);
 872                 name_mac = gnutls_mac_get_name(gnutls_mac_get(sess));
 873                 keysize = gnutls_cipher_get_key_size(cipher) * 8;
 874                 name_proto = gnutls_protocol_get_name(gnutls_protocol_get_version(sess));
 875                 name_keyexchange = gnutls_kx_get_name(gnutls_kx_get(sess));
 876
 877                 return snprintf(buf, len, "%s-%s%15s Kx=%s      Enc=%s(%u) Mac=%s",
 878                         name_cipher, name_mac, name_proto, name_keyexchange, name_cipher, keysize, name_mac) > 0;
 879         }
 880         return false;
 881 #endif
 882 }
 883
 884 char *
 885 ConnSSL_GetCertFp(CONNECTION *c)
 886 {
 887         return c->ssl_state.fingerprint;
 888 }
 889
 890 bool
 891 ConnSSL_SetCertFp(CONNECTION *c, const char *fingerprint)
 892 {
 893         assert (c != NULL);
 894         c->ssl_state.fingerprint = strndup(fingerprint, SHA256_STRING_LEN - 1);
 895         return c->ssl_state.fingerprint != NULL;
 896 }
 897 #else
 898
 899 bool
 900 ConnSSL_InitLibrary(void)
 901 {
 902         return true;
 903 }
 904
 905 #endif /* SSL_SUPPORT */
 906 /* -eof- */
 907
 908