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
  46 static SSL_CTX * ssl_ctx;
  47 static DH *dh_params;
  48
  49 static bool ConnSSL_LoadServerKey_openssl PARAMS(( SSL_CTX *c ));
  50 #endif
  51
  52 #ifdef HAVE_LIBGNUTLS
  53 #include <sys/types.h>
  54 #include <sys/stat.h>
  55 #include <fcntl.h>
  56 #include <unistd.h>
  57 #include <gnutls/x509.h>
  58
  59 #define DH_BITS 2048
  60 #define DH_BITS_MIN 1024
  61
  62 #define MAX_HASH_SIZE   64      /* from gnutls-int.h */
  63
  64 static gnutls_certificate_credentials_t x509_cred;
  65 static gnutls_dh_params_t dh_params;
  66 static gnutls_priority_t priorities_cache;
  67 static bool ConnSSL_LoadServerKey_gnutls PARAMS(( void ));
  68 #endif
  69
  70 #define SHA256_STRING_LEN       (32 * 2 + 1)
  71
  72 static bool ConnSSL_Init_SSL PARAMS(( CONNECTION *c ));
  73 static int ConnectAccept PARAMS(( CONNECTION *c, bool connect ));
  74 static int ConnSSL_HandleError PARAMS(( CONNECTION *c, const int code, const char *fname ));
  75
  76 #ifdef HAVE_LIBGNUTLS
  77 static char * openreadclose(const char *name, size_t *len)
  78 {
  79         char *buf = NULL;
  80         struct stat s;
  81         ssize_t br;
  82         int fd = open(name, O_RDONLY);
  83         if (fd < 0) {
  84                 Log(LOG_ERR, "Could not open %s: %s", name, strerror(errno));
  85                 return NULL;
  86         }
  87         if (fstat(fd, &s)) {
  88                 Log(LOG_ERR, "Could not fstat %s: %s", name, strerror(errno));
  89                 goto out;
  90         }
  91         if (!S_ISREG(s.st_mode)) {
  92                 Log(LOG_ERR, "%s: Not a regular file", name);
  93                 goto out;
  94         }
  95         if (s.st_size <= 0) {
  96                 Log(LOG_ERR, "%s: invalid file length (size %ld <= 0)", name, (long) s.st_size);
  97                 goto out;
  98         }
  99         buf = malloc(s.st_size);
 100         if (!buf) {
 101                 Log(LOG_ERR, "Could not malloc %lu bytes for file %s: %s", s.st_size, name, strerror(errno));
 102                 goto out;
 103         }
 104         br = read(fd, buf, s.st_size);
 105         if (br != (ssize_t)s.st_size) {
 106                 Log(LOG_ERR, "Could not read file %s: read returned %ld, expected %ld: %s",
 107                         name, (long) br, (long) s.st_size, br == -1 ? strerror(errno):"short read?!");
 108                 memset(buf, 0, s.st_size);
 109                 free(buf);
 110                 buf = NULL;
 111         } else {
 112                 *len = br;
 113         }
 114 out:
 115         close(fd);
 116         return buf;
 117 }
 118 #endif
 119
 120
 121 #ifdef HAVE_LIBSSL
 122 /**
 123  * Log OpenSSL error message.
 124  *
 125  * @param msg The error message.
 126  * @param info Additional information text or NULL.
 127  */
 128 static void
 129 LogOpenSSLError(const char *error, const char *info)
 130 {
 131         unsigned long err = ERR_get_error();
 132         char * errmsg = err
 133                 ? ERR_error_string(err, NULL)
 134                 : "Unable to determine error";
 135
 136         assert(error != NULL);
 137
 138         if (info)
 139                 Log(LOG_ERR, "%s: %s (%s)", error, info, errmsg);
 140         else
 141                 Log(LOG_ERR, "%s: %s", error, errmsg);
 142 }
 143
 144
 145 static int
 146 pem_passwd_cb(char *buf, int size, int rwflag, void *password)
 147 {
 148         array *pass = password;
 149         int passlen;
 150
 151         (void)rwflag;           /* rwflag is unused if DEBUG is not set. */
 152         assert(rwflag == 0);    /* 0 -> callback used for decryption.
 153                                  * See SSL_CTX_set_default_passwd_cb(3) */
 154
 155         passlen = (int) array_bytes(pass);
 156
 157         LogDebug("pem_passwd_cb buf size %d, array size %d", size, passlen);
 158         assert(passlen >= 0);
 159         if (passlen <= 0) {
 160                 Log(LOG_ERR, "PEM password required but not set [in pem_passwd_cb()]!");
 161                 return 0;
 162         }
 163         size = passlen > size ? size : passlen;
 164         memcpy(buf, (char *)(array_start(pass)), size);
 165         return size;
 166 }
 167
 168
 169 static int
 170 Verify_openssl(UNUSED int preverify_ok, UNUSED X509_STORE_CTX *x509_ctx)
 171 {
 172         return 1;
 173 }
 174 #endif
 175
 176
 177 static bool
 178 Load_DH_params(void)
 179 {
 180 #ifdef HAVE_LIBSSL
 181         FILE *fp;
 182         bool ret = true;
 183
 184         if (!Conf_SSLOptions.DHFile) {
 185                 Log(LOG_NOTICE, "Configuration option \"DHFile\" not set!");
 186                 return false;
 187         }
 188         fp = fopen(Conf_SSLOptions.DHFile, "r");
 189         if (!fp) {
 190                 Log(LOG_ERR, "%s: %s", Conf_SSLOptions.DHFile, strerror(errno));
 191                 return false;
 192         }
 193         dh_params = PEM_read_DHparams(fp, NULL, NULL, NULL);
 194         if (!dh_params) {
 195                 Log(LOG_ERR, "%s: Failed to read SSL DH parameters!",
 196                     Conf_SSLOptions.DHFile);
 197                 ret = false;
 198         }
 199         fclose(fp);
 200         return ret;
 201 #endif
 202 #ifdef HAVE_LIBGNUTLS
 203         bool need_dhgenerate = true;
 204         int err;
 205         gnutls_dh_params_t tmp_dh_params;
 206
 207         err = gnutls_dh_params_init(&tmp_dh_params);
 208         if (err < 0) {
 209                 Log(LOG_ERR, "Failed to initialize SSL DH parameters: %s",
 210                     gnutls_strerror(err));
 211                 return false;
 212         }
 213         if (Conf_SSLOptions.DHFile) {
 214                 gnutls_datum_t dhparms;
 215                 size_t size;
 216                 dhparms.data = (unsigned char *) openreadclose(Conf_SSLOptions.DHFile, &size);
 217                 if (dhparms.data) {
 218                         dhparms.size = size;
 219                         err = gnutls_dh_params_import_pkcs3(tmp_dh_params, &dhparms, GNUTLS_X509_FMT_PEM);
 220                         if (err == 0)
 221                                 need_dhgenerate = false;
 222                         else
 223                                 Log(LOG_ERR,
 224                                     "Failed to initialize SSL DH parameters: %s",
 225                                     gnutls_strerror(err));
 226
 227                         memset(dhparms.data, 0, size);
 228                         free(dhparms.data);
 229                 }
 230         }
 231         if (need_dhgenerate) {
 232                 Log(LOG_WARNING,
 233                     "DHFile not set, generating %u bit DH parameters. This may take a while ...",
 234                     DH_BITS);
 235                 err = gnutls_dh_params_generate2(tmp_dh_params, DH_BITS);
 236                 if (err < 0) {
 237                         Log(LOG_ERR, "Failed to generate SSL DH parameters: %s",
 238                             gnutls_strerror(err));
 239                         return false;
 240                 }
 241         }
 242         dh_params = tmp_dh_params;
 243         return true;
 244 #endif
 245 }
 246
 247
 248 void ConnSSL_Free(CONNECTION *c)
 249 {
 250 #ifdef HAVE_LIBSSL
 251         SSL *ssl = c->ssl_state.ssl;
 252         if (ssl) {
 253                 SSL_shutdown(ssl);
 254                 SSL_free(ssl);
 255                 c->ssl_state.ssl = NULL;
 256                 if (c->ssl_state.fingerprint) {
 257                         free(c->ssl_state.fingerprint);
 258                         c->ssl_state.fingerprint = NULL;
 259                 }
 260         }
 261 #endif
 262 #ifdef HAVE_LIBGNUTLS
 263         gnutls_session_t sess = c->ssl_state.gnutls_session;
 264         if (Conn_OPTION_ISSET(c, CONN_SSL)) {
 265                 gnutls_bye(sess, GNUTLS_SHUT_RDWR);
 266                 gnutls_deinit(sess);
 267         }
 268 #endif
 269         assert(Conn_OPTION_ISSET(c, CONN_SSL));
 270         /* can't just set bitmask to 0 -- there are other, non-ssl related flags, e.g. CONN_ZIP. */
 271         Conn_OPTION_DEL(c, CONN_SSL_FLAGS_ALL);
 272 }
 273
 274
 275 bool
 276 ConnSSL_InitLibrary( void )
 277 {
 278         if (!Conf_SSLInUse()) {
 279                 LogDebug("SSL not in use, skipping initialization.");
 280                 return true;
 281         }
 282
 283 #ifdef HAVE_LIBSSL
 284         SSL_CTX *newctx;
 285
 286         if (!ssl_ctx) {
 287                 SSL_library_init();
 288                 SSL_load_error_strings();
 289         }
 290
 291         if (!RAND_status()) {
 292                 Log(LOG_ERR, "OpenSSL PRNG not seeded: /dev/urandom missing?");
 293                 /*
 294                  * it is probably best to fail and let the user install EGD or
 295                  * a similar program if no kernel random device is available.
 296                  * According to OpenSSL RAND_egd(3): "The automatic query of
 297                  * /var/run/egd-pool et al was added in OpenSSL 0.9.7";
 298                  * so it makes little sense to deal with PRNGD seeding ourselves.
 299                  */
 300                 array_free(&Conf_SSLOptions.ListenPorts);
 301                 return false;
 302         }
 303
 304         newctx = SSL_CTX_new(SSLv23_method());
 305         if (!newctx) {
 306                 LogOpenSSLError("Failed to create SSL context", NULL);
 307                 array_free(&Conf_SSLOptions.ListenPorts);
 308                 return false;
 309         }
 310
 311         if (!ConnSSL_LoadServerKey_openssl(newctx))
 312                 goto out;
 313
 314         if (SSL_CTX_set_cipher_list(newctx, Conf_SSLOptions.CipherList) == 0) {
 315                 Log(LOG_ERR, "Failed to apply OpenSSL cipher list \"%s\"!",
 316                     Conf_SSLOptions.CipherList);
 317                 goto out;
 318         }
 319
 320         SSL_CTX_set_options(newctx, SSL_OP_SINGLE_DH_USE|SSL_OP_NO_SSLv2);
 321         SSL_CTX_set_mode(newctx, SSL_MODE_ENABLE_PARTIAL_WRITE);
 322         SSL_CTX_set_verify(newctx, SSL_VERIFY_PEER|SSL_VERIFY_CLIENT_ONCE,
 323                            Verify_openssl);
 324         SSL_CTX_free(ssl_ctx);
 325         ssl_ctx = newctx;
 326         Log(LOG_INFO, "%s initialized.", SSLeay_version(SSLEAY_VERSION));
 327         return true;
 328 out:
 329         SSL_CTX_free(newctx);
 330         array_free(&Conf_SSLOptions.ListenPorts);
 331         return false;
 332 #endif
 333 #ifdef HAVE_LIBGNUTLS
 334         int err;
 335         static bool initialized;
 336
 337         if (initialized) {
 338                 /* TODO: cannot reload gnutls keys: can't simply free x509
 339                  * context -- it may still be in use */
 340                 return false;
 341         }
 342
 343         err = gnutls_global_init();
 344         if (err) {
 345                 Log(LOG_ERR, "Failed to initialize GnuTLS: %s",
 346                     gnutls_strerror(err));
 347                 goto out;
 348         }
 349
 350         if (!ConnSSL_LoadServerKey_gnutls())
 351                 goto out;
 352
 353         if (gnutls_priority_init(&priorities_cache, Conf_SSLOptions.CipherList,
 354                                  NULL) != GNUTLS_E_SUCCESS) {
 355                 Log(LOG_ERR,
 356                     "Failed to apply GnuTLS cipher list \"%s\"!",
 357                     Conf_SSLOptions.CipherList);
 358                 goto out;
 359         }
 360
 361         Log(LOG_INFO, "GnuTLS %s initialized.", gnutls_check_version(NULL));
 362         initialized = true;
 363         return true;
 364 out:
 365         array_free(&Conf_SSLOptions.ListenPorts);
 366         return false;
 367 #endif
 368 }
 369
 370
 371 #ifdef HAVE_LIBGNUTLS
 372 static bool
 373 ConnSSL_LoadServerKey_gnutls(void)
 374 {
 375         int err;
 376         const char *cert_file;
 377
 378         err = gnutls_certificate_allocate_credentials(&x509_cred);
 379         if (err < 0) {
 380                 Log(LOG_ERR, "Failed to allocate certificate credentials: %s",
 381                     gnutls_strerror(err));
 382                 return false;
 383         }
 384
 385         cert_file = Conf_SSLOptions.CertFile ? Conf_SSLOptions.CertFile:Conf_SSLOptions.KeyFile;
 386         if (!cert_file) {
 387                 Log(LOG_ERR, "No SSL server key configured!");
 388                 return false;
 389         }
 390
 391         if (array_bytes(&Conf_SSLOptions.KeyFilePassword))
 392                 Log(LOG_WARNING,
 393                     "Ignoring SSL \"KeyFilePassword\": Not supported by GnuTLS.");
 394
 395         if (!Load_DH_params())
 396                 return false;
 397
 398         gnutls_certificate_set_dh_params(x509_cred, dh_params);
 399         err = gnutls_certificate_set_x509_key_file(x509_cred, cert_file, Conf_SSLOptions.KeyFile, GNUTLS_X509_FMT_PEM);
 400         if (err < 0) {
 401                 Log(LOG_ERR,
 402                     "Failed to set certificate key file (cert %s, key %s): %s",
 403                     cert_file,
 404                     Conf_SSLOptions.KeyFile ? Conf_SSLOptions.KeyFile : "(NULL)",
 405                     gnutls_strerror(err));
 406                 return false;
 407         }
 408         return true;
 409 }
 410 #endif
 411
 412
 413 #ifdef HAVE_LIBSSL
 414 static bool
 415 ConnSSL_LoadServerKey_openssl(SSL_CTX *ctx)
 416 {
 417         char *cert_key;
 418
 419         assert(ctx);
 420         if (!Conf_SSLOptions.KeyFile) {
 421                 Log(LOG_ERR, "No SSL server key configured!");
 422                 return false;
 423         }
 424
 425         SSL_CTX_set_default_passwd_cb(ctx, pem_passwd_cb);
 426         SSL_CTX_set_default_passwd_cb_userdata(ctx, &Conf_SSLOptions.KeyFilePassword);
 427
 428         if (SSL_CTX_use_PrivateKey_file(ctx, Conf_SSLOptions.KeyFile, SSL_FILETYPE_PEM) != 1) {
 429                 array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 430                 LogOpenSSLError("Failed to add private key", Conf_SSLOptions.KeyFile);
 431                 return false;
 432         }
 433
 434         cert_key = Conf_SSLOptions.CertFile ? Conf_SSLOptions.CertFile:Conf_SSLOptions.KeyFile;
 435         if (SSL_CTX_use_certificate_chain_file(ctx, cert_key) != 1) {
 436                 array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 437                 LogOpenSSLError("Failed to load certificate chain", cert_key);
 438                 return false;
 439         }
 440
 441         array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 442
 443         if (!SSL_CTX_check_private_key(ctx)) {
 444                 LogOpenSSLError("Server private key does not match certificate", NULL);
 445                 return false;
 446         }
 447         if (Load_DH_params()) {
 448                 if (SSL_CTX_set_tmp_dh(ctx, dh_params) != 1)
 449                         LogOpenSSLError("Error setting DH parameters", Conf_SSLOptions.DHFile);
 450                 /* don't return false here: the non-DH modes will still work */
 451                 DH_free(dh_params);
 452                 dh_params = NULL;
 453         }
 454         return true;
 455 }
 456
 457
 458 #endif
 459 static bool
 460 ConnSSL_Init_SSL(CONNECTION *c)
 461 {
 462         int ret;
 463
 464         LogDebug("Initializing SSL ...");
 465         assert(c != NULL);
 466
 467 #ifdef HAVE_LIBSSL
 468         if (!ssl_ctx) {
 469                 Log(LOG_ERR,
 470                     "Can't initialize SSL context, OpenSSL initialization failed at startup!");
 471                 return false;
 472         }
 473         assert(c->ssl_state.ssl == NULL);
 474         assert(c->ssl_state.fingerprint == NULL);
 475
 476         c->ssl_state.ssl = SSL_new(ssl_ctx);
 477         if (!c->ssl_state.ssl) {
 478                 LogOpenSSLError("Failed to create SSL structure", NULL);
 479                 return false;
 480         }
 481         Conn_OPTION_ADD(c, CONN_SSL);
 482
 483         ret = SSL_set_fd(c->ssl_state.ssl, c->sock);
 484         if (ret != 1) {
 485                 LogOpenSSLError("Failed to set SSL file descriptor", NULL);
 486                 ConnSSL_Free(c);
 487                 return false;
 488         }
 489 #endif
 490 #ifdef HAVE_LIBGNUTLS
 491         Conn_OPTION_ADD(c, CONN_SSL);
 492         ret = gnutls_priority_set(c->ssl_state.gnutls_session, priorities_cache);
 493         if (ret != GNUTLS_E_SUCCESS) {
 494                 Log(LOG_ERR, "Failed to set GnuTLS session priorities: %s",
 495                     gnutls_strerror(ret));
 496                 ConnSSL_Free(c);
 497                 return false;
 498         }
 499         /*
 500          * The intermediate (long) cast is here to avoid a warning like:
 501          * "cast to pointer from integer of different size" on 64-bit platforms.
 502          * There doesn't seem to be an alternate GNUTLS API we could use instead, see e.g.
 503          * http://www.mail-archive.com/help-gnutls@gnu.org/msg00286.html
 504          */
 505         gnutls_transport_set_ptr(c->ssl_state.gnutls_session,
 506                                  (gnutls_transport_ptr_t) (long) c->sock);
 507         gnutls_certificate_server_set_request(c->ssl_state.gnutls_session,
 508                                               GNUTLS_CERT_REQUEST);
 509         ret = gnutls_credentials_set(c->ssl_state.gnutls_session,
 510                                      GNUTLS_CRD_CERTIFICATE, x509_cred);
 511         if (ret != 0) {
 512                 Log(LOG_ERR, "Failed to set SSL credentials: %s",
 513                     gnutls_strerror(ret));
 514                 ConnSSL_Free(c);
 515                 return false;
 516         }
 517         gnutls_dh_set_prime_bits(c->ssl_state.gnutls_session, DH_BITS_MIN);
 518 #endif
 519         return true;
 520 }
 521
 522
 523 bool
 524 ConnSSL_PrepareConnect(CONNECTION *c, UNUSED CONF_SERVER *s)
 525 {
 526         bool ret;
 527 #ifdef HAVE_LIBGNUTLS
 528         int err;
 529
 530         err = gnutls_init(&c->ssl_state.gnutls_session, GNUTLS_CLIENT);
 531         if (err) {
 532                 Log(LOG_ERR, "Failed to initialize new SSL session: %s",
 533                     gnutls_strerror(err));
 534                 return false;
 535         }
 536 #endif
 537         ret = ConnSSL_Init_SSL(c);
 538         if (!ret)
 539                 return false;
 540         Conn_OPTION_ADD(c, CONN_SSL_CONNECT);
 541 #ifdef HAVE_LIBSSL
 542         assert(c->ssl_state.ssl);
 543         SSL_set_verify(c->ssl_state.ssl, SSL_VERIFY_NONE, NULL);
 544 #endif
 545         return true;
 546 }
 547
 548
 549 /**
 550  * Check and handle error return codes after failed calls to SSL functions.
 551  *
 552  * OpenSSL:
 553  * SSL_connect(), SSL_accept(), SSL_do_handshake(), SSL_read(), SSL_peek(), or
 554  * SSL_write() on ssl.
 555  *
 556  * GnuTLS:
 557  * gnutlsssl_read(), gnutls_write() or gnutls_handshake().
 558  *
 559  * @param c The connection handle.
 560  * @prarm code The return code.
 561  * @param fname The name of the function in which the error occurred.
 562  * @return -1 on fatal errors, 0 if we can try again later.
 563  */
 564 static int
 565 ConnSSL_HandleError(CONNECTION * c, const int code, const char *fname)
 566 {
 567 #ifdef HAVE_LIBSSL
 568         int ret = SSL_ERROR_SYSCALL;
 569         unsigned long sslerr;
 570         int real_errno = errno;
 571
 572         ret = SSL_get_error(c->ssl_state.ssl, code);
 573
 574         switch (ret) {
 575         case SSL_ERROR_WANT_READ:
 576                 io_event_del(c->sock, IO_WANTWRITE);
 577                 Conn_OPTION_ADD(c, CONN_SSL_WANT_READ);
 578                 return 0;       /* try again later */
 579         case SSL_ERROR_WANT_WRITE:
 580                 io_event_del(c->sock, IO_WANTREAD);
 581                 Conn_OPTION_ADD(c, CONN_SSL_WANT_WRITE); /* fall through */
 582         case SSL_ERROR_NONE:
 583                 return 0;       /* try again later */
 584         case SSL_ERROR_ZERO_RETURN:
 585                 LogDebug("SSL connection shut down normally.");
 586                 break;
 587         case SSL_ERROR_SYSCALL:
 588                 /* SSL_ERROR_WANT_CONNECT, SSL_ERROR_WANT_ACCEPT,
 589                  * and SSL_ERROR_WANT_X509_LOOKUP */
 590                 sslerr = ERR_get_error();
 591                 if (sslerr) {
 592                         Log(LOG_ERR, "SSL error: %s [in %s()]!",
 593                             ERR_error_string(sslerr, NULL), fname);
 594                 } else {
 595                         switch (code) { /* EOF that violated protocol */
 596                         case 0:
 597                                 Log(LOG_ERR,
 598                                     "SSL error, client disconnected [in %s()]!",
 599                                     fname);
 600                                 break;
 601                         case -1:        /* low level socket I/O error, check errno */
 602                                 Log(LOG_ERR, "SSL error: %s [in %s()]!",
 603                                     strerror(real_errno), fname);
 604                         }
 605                 }
 606                 break;
 607         case SSL_ERROR_SSL:
 608                 LogOpenSSLError("SSL protocol error", fname);
 609                 break;
 610         default:
 611                 Log(LOG_ERR, "Unknown SSL error %d [in %s()]!", ret, fname);
 612         }
 613         ConnSSL_Free(c);
 614         return -1;
 615 #endif
 616 #ifdef HAVE_LIBGNUTLS
 617         switch (code) {
 618         case GNUTLS_E_AGAIN:
 619         case GNUTLS_E_INTERRUPTED:
 620                 if (gnutls_record_get_direction(c->ssl_state.gnutls_session)) {
 621                         Conn_OPTION_ADD(c, CONN_SSL_WANT_WRITE);
 622                         io_event_del(c->sock, IO_WANTREAD);
 623                 } else {
 624                         Conn_OPTION_ADD(c, CONN_SSL_WANT_READ);
 625                         io_event_del(c->sock, IO_WANTWRITE);
 626                 }
 627                 break;
 628         default:
 629                 assert(code < 0);
 630                 if (gnutls_error_is_fatal(code)) {
 631                         Log(LOG_ERR, "SSL error: %s [%s].",
 632                             gnutls_strerror(code), fname);
 633                         ConnSSL_Free(c);
 634                         return -1;
 635                 }
 636         }
 637         return 0;
 638 #endif
 639 }
 640
 641
 642 static void
 643 ConnSSL_LogCertInfo( CONNECTION *c )
 644 {
 645 #ifdef HAVE_LIBSSL
 646         SSL *ssl = c->ssl_state.ssl;
 647
 648         assert(ssl);
 649
 650         Log(LOG_INFO, "Connection %d: initialized %s using cipher %s.",
 651                 c->sock, SSL_get_version(ssl), SSL_get_cipher(ssl));
 652 #endif
 653 #ifdef HAVE_LIBGNUTLS
 654         gnutls_session_t sess = c->ssl_state.gnutls_session;
 655         gnutls_cipher_algorithm_t cipher = gnutls_cipher_get(sess);
 656
 657         Log(LOG_INFO, "Connection %d: initialized %s using cipher %s-%s.",
 658             c->sock,
 659             gnutls_protocol_get_name(gnutls_protocol_get_version(sess)),
 660             gnutls_cipher_get_name(cipher),
 661             gnutls_mac_get_name(gnutls_mac_get(sess)));
 662 #endif
 663 }
 664
 665
 666 /*
 667  Accept incoming SSL connection.
 668  Return Values:
 669          1: SSL Connection established
 670          0: try again
 671         -1: SSL Connection not established due to fatal error.
 672 */
 673 int
 674 ConnSSL_Accept( CONNECTION *c )
 675 {
 676         assert(c != NULL);
 677         if (!Conn_OPTION_ISSET(c, CONN_SSL)) {
 678 #ifdef HAVE_LIBGNUTLS
 679                 int err = gnutls_init(&c->ssl_state.gnutls_session, GNUTLS_SERVER);
 680                 if (err) {
 681                         Log(LOG_ERR, "Failed to initialize new SSL session: %s",
 682                             gnutls_strerror(err));
 683                         return false;
 684                 }
 685 #endif
 686                 if (!ConnSSL_Init_SSL(c))
 687                         return -1;
 688         }
 689         return ConnectAccept(c, false );
 690 }
 691
 692
 693 int
 694 ConnSSL_Connect( CONNECTION *c )
 695 {
 696         assert(c != NULL);
 697 #ifdef HAVE_LIBSSL
 698         assert(c->ssl_state.ssl);
 699 #endif
 700         assert(Conn_OPTION_ISSET(c, CONN_SSL));
 701         return ConnectAccept(c, true);
 702 }
 703
 704 static int
 705 ConnSSL_InitCertFp( CONNECTION *c )
 706 {
 707         const char hex[] = "0123456789abcdef";
 708         int i;
 709
 710 #ifdef HAVE_LIBSSL
 711         unsigned char digest[EVP_MAX_MD_SIZE];
 712         unsigned int digest_size;
 713         X509 *cert;
 714
 715         cert = SSL_get_peer_certificate(c->ssl_state.ssl);
 716         if (!cert)
 717                 return 0;
 718
 719         if (!X509_digest(cert, EVP_sha256(), digest, &digest_size)) {
 720                 X509_free(cert);
 721                 return 0;
 722         }
 723
 724         X509_free(cert);
 725 #endif /* HAVE_LIBSSL */
 726 #ifdef HAVE_LIBGNUTLS
 727         gnutls_x509_crt_t cert;
 728         unsigned int cert_list_size;
 729         const gnutls_datum_t *cert_list;
 730         unsigned char digest[MAX_HASH_SIZE];
 731         size_t digest_size;
 732
 733         if (gnutls_certificate_type_get(c->ssl_state.gnutls_session) !=
 734                                         GNUTLS_CRT_X509)
 735                 return 0;
 736
 737         if (gnutls_x509_crt_init(&cert) != GNUTLS_E_SUCCESS)
 738                 return 0;
 739
 740         cert_list_size = 0;
 741         cert_list = gnutls_certificate_get_peers(c->ssl_state.gnutls_session,
 742                                                  &cert_list_size);
 743         if (!cert_list) {
 744                 gnutls_x509_crt_deinit(cert);
 745                 return 0;
 746         }
 747
 748         if (gnutls_x509_crt_import(cert, &cert_list[0],
 749                                    GNUTLS_X509_FMT_DER) != GNUTLS_E_SUCCESS) {
 750                 gnutls_x509_crt_deinit(cert);
 751                 return 0;
 752         }
 753
 754         digest_size = sizeof(digest);
 755         if (gnutls_x509_crt_get_fingerprint(cert, GNUTLS_DIG_SHA256, digest,
 756                                             &digest_size)) {
 757                 gnutls_x509_crt_deinit(cert);
 758                 return 0;
 759         }
 760
 761         gnutls_x509_crt_deinit(cert);
 762 #endif /* HAVE_LIBGNUTLS */
 763
 764         assert(c->ssl_state.fingerprint == NULL);
 765
 766         c->ssl_state.fingerprint = malloc(SHA256_STRING_LEN);
 767         if (!c->ssl_state.fingerprint)
 768                 return 0;
 769
 770         for (i = 0; i < (int)digest_size; i++) {
 771                 c->ssl_state.fingerprint[i * 2] = hex[digest[i] / 16];
 772                 c->ssl_state.fingerprint[i * 2 + 1] = hex[digest[i] % 16];
 773         }
 774         c->ssl_state.fingerprint[i * 2] = '\0';
 775
 776         return 1;
 777 }
 778
 779 /* accept/connect wrapper. if connect is true, connect to peer, otherwise wait for incoming connection */
 780 static int
 781 ConnectAccept( CONNECTION *c, bool connect)
 782 {
 783         int ret;
 784 #ifdef HAVE_LIBSSL
 785         SSL *ssl = c->ssl_state.ssl;
 786         assert(ssl != NULL);
 787
 788         ret = connect ? SSL_connect(ssl) : SSL_accept(ssl);
 789         if (1 != ret)
 790                 return ConnSSL_HandleError(c, ret, connect ? "SSL_connect": "SSL_accept");
 791 #endif
 792 #ifdef HAVE_LIBGNUTLS
 793         (void) connect;
 794         ret = gnutls_handshake(c->ssl_state.gnutls_session);
 795         if (ret)
 796                 return ConnSSL_HandleError(c, ret, "gnutls_handshake");
 797 #endif /* _GNUTLS */
 798         (void)ConnSSL_InitCertFp(c);
 799
 800         Conn_OPTION_DEL(c, (CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ|CONN_SSL_CONNECT));
 801         ConnSSL_LogCertInfo(c);
 802
 803         Conn_StartLogin(CONNECTION2ID(c));
 804         return 1;
 805 }
 806
 807
 808 ssize_t
 809 ConnSSL_Write(CONNECTION *c, const void *buf, size_t count)
 810 {
 811         ssize_t bw;
 812
 813         Conn_OPTION_DEL(c, CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ);
 814
 815         assert(count > 0);
 816 #ifdef HAVE_LIBSSL
 817         bw = (ssize_t) SSL_write(c->ssl_state.ssl, buf, count);
 818 #endif
 819 #ifdef HAVE_LIBGNUTLS
 820         bw = gnutls_write(c->ssl_state.gnutls_session, buf, count);
 821 #endif
 822         if (bw > 0)
 823                 return bw;
 824         if (ConnSSL_HandleError( c, bw, "ConnSSL_Write") == 0)
 825                 errno = EAGAIN; /* try again */
 826         return -1;
 827 }
 828
 829
 830 ssize_t
 831 ConnSSL_Read(CONNECTION *c, void * buf, size_t count)
 832 {
 833         ssize_t br;
 834
 835         Conn_OPTION_DEL(c, CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ);
 836 #ifdef HAVE_LIBSSL
 837         br = (ssize_t) SSL_read(c->ssl_state.ssl, buf, count);
 838         if (br > 0)     /* on EOF we have to call ConnSSL_HandleError(), see SSL_read(3) */
 839                 return br;
 840 #endif
 841 #ifdef HAVE_LIBGNUTLS
 842         br = gnutls_read(c->ssl_state.gnutls_session, buf, count);
 843         if (br >= 0)    /* on EOF we must _not_ call ConnSSL_HandleError, see gnutls_record_recv(3) */
 844                 return br;
 845 #endif
 846         /* error on read: switch ConnSSL_HandleError() return values -> 0 is "try again", so return -1 and set EAGAIN */
 847         if (ConnSSL_HandleError(c, br, "ConnSSL_Read") == 0) {
 848                 errno = EAGAIN;
 849                 return -1;
 850         }
 851         return 0;
 852 }
 853
 854
 855 bool
 856 ConnSSL_GetCipherInfo(CONNECTION *c, char *buf, size_t len)
 857 {
 858 #ifdef HAVE_LIBSSL
 859         char *nl;
 860         SSL *ssl = c->ssl_state.ssl;
 861
 862         if (!ssl)
 863                 return false;
 864         *buf = 0;
 865         SSL_CIPHER_description(SSL_get_current_cipher(ssl), buf, len);
 866         nl = strchr(buf, '\n');
 867         if (nl)
 868                 *nl = 0;
 869         return true;
 870 #endif
 871 #ifdef HAVE_LIBGNUTLS
 872         if (Conn_OPTION_ISSET(c, CONN_SSL)) {
 873                 const char *name_cipher, *name_mac, *name_proto, *name_keyexchange;
 874                 unsigned keysize;
 875
 876                 gnutls_session_t sess = c->ssl_state.gnutls_session;
 877                 gnutls_cipher_algorithm_t cipher = gnutls_cipher_get(sess);
 878                 name_cipher = gnutls_cipher_get_name(cipher);
 879                 name_mac = gnutls_mac_get_name(gnutls_mac_get(sess));
 880                 keysize = gnutls_cipher_get_key_size(cipher) * 8;
 881                 name_proto = gnutls_protocol_get_name(gnutls_protocol_get_version(sess));
 882                 name_keyexchange = gnutls_kx_get_name(gnutls_kx_get(sess));
 883
 884                 return snprintf(buf, len, "%s-%s%15s Kx=%s      Enc=%s(%u) Mac=%s",
 885                         name_cipher, name_mac, name_proto, name_keyexchange, name_cipher, keysize, name_mac) > 0;
 886         }
 887         return false;
 888 #endif
 889 }
 890
 891 char *
 892 ConnSSL_GetCertFp(CONNECTION *c)
 893 {
 894         return c->ssl_state.fingerprint;
 895 }
 896
 897 bool
 898 ConnSSL_SetCertFp(CONNECTION *c, const char *fingerprint)
 899 {
 900         assert (c != NULL);
 901         c->ssl_state.fingerprint = strndup(fingerprint, SHA256_STRING_LEN - 1);
 902         return c->ssl_state.fingerprint != NULL;
 903 }
 904 #else
 905
 906 bool
 907 ConnSSL_InitLibrary(void)
 908 {
 909         return true;
 910 }
 911
 912 #endif /* SSL_SUPPORT */
 913 /* -eof- */
 914
 915