src/ngircd/conn-ssl.c

   1 /*
   2  * ngIRCd -- The Next Generation IRC Daemon
   3  * Copyright (c) 2005-2008 Florian Westphal <fw@strlen.de>
   4  */
   5
   6 #include "portab.h"
   7
   8 /**
   9  * @file
  10  * SSL wrapper functions
  11  */
  12
  13 #include "imp.h"
  14 #include "conf-ssl.h"
  15
  16 #ifdef SSL_SUPPORT
  17
  18 #include "io.h"
  19 #include <assert.h>
  20 #include <stdio.h>
  21 #include <string.h>
  22 #include <stdlib.h>
  23 #include <errno.h>
  24
  25 #define CONN_MODULE
  26 #include "conn.h"
  27 #include "conf.h"
  28 #include "conn-func.h"
  29 #include "conn-ssl.h"
  30 #include "log.h"
  31
  32 #include "exp.h"
  33 #include "defines.h"
  34
  35 extern struct SSLOptions Conf_SSLOptions;
  36
  37 #ifdef HAVE_LIBSSL
  38 #include <openssl/err.h>
  39 #include <openssl/rand.h>
  40
  41 static SSL_CTX * ssl_ctx;
  42 static DH *dh_params;
  43
  44 static bool ConnSSL_LoadServerKey_openssl PARAMS(( SSL_CTX *c ));
  45 #endif
  46
  47 #ifdef HAVE_LIBGNUTLS
  48 #include <sys/types.h>
  49 #include <sys/stat.h>
  50 #include <fcntl.h>
  51 #include <unistd.h>
  52 #include <gnutls/x509.h>
  53
  54 #define DH_BITS 2048
  55 #define DH_BITS_MIN 1024
  56
  57 #define MAX_HASH_SIZE   64      /* from gnutls-int.h */
  58
  59 static gnutls_certificate_credentials_t x509_cred;
  60 static gnutls_dh_params_t dh_params;
  61 static bool ConnSSL_LoadServerKey_gnutls PARAMS(( void ));
  62 #endif
  63
  64 #define SHA1_STRING_LEN (20 * 2 + 1)
  65
  66 static bool ConnSSL_Init_SSL PARAMS(( CONNECTION *c ));
  67 static int ConnectAccept PARAMS(( CONNECTION *c, bool connect ));
  68 static int ConnSSL_HandleError PARAMS(( CONNECTION *c, const int code, const char *fname ));
  69
  70 #ifdef HAVE_LIBGNUTLS
  71 static char * openreadclose(const char *name, size_t *len)
  72 {
  73         char *buf = NULL;
  74         struct stat s;
  75         ssize_t br;
  76         int fd = open(name, O_RDONLY);
  77         if (fd < 0) {
  78                 Log(LOG_ERR, "Could not open %s: %s", name, strerror(errno));
  79                 return NULL;
  80         }
  81         if (fstat(fd, &s)) {
  82                 Log(LOG_ERR, "Could not fstat %s: %s", name, strerror(errno));
  83                 goto out;
  84         }
  85         if (!S_ISREG(s.st_mode)) {
  86                 Log(LOG_ERR, "%s: Not a regular file", name);
  87                 goto out;
  88         }
  89         if (s.st_size <= 0) {
  90                 Log(LOG_ERR, "%s: invalid file length (size %ld <= 0)", name, (long) s.st_size);
  91                 goto out;
  92         }
  93         buf = malloc(s.st_size);
  94         if (!buf) {
  95                 Log(LOG_ERR, "Could not malloc %lu bytes for file %s: %s", s.st_size, name, strerror(errno));
  96                 goto out;
  97         }
  98         br = read(fd, buf, s.st_size);
  99         if (br != (ssize_t)s.st_size) {
 100                 Log(LOG_ERR, "Could not read file %s: read returned %ld, expected %ld: %s",
 101                         name, (long) br, (long) s.st_size, br == -1 ? strerror(errno):"short read?!");
 102                 memset(buf, 0, s.st_size);
 103                 free(buf);
 104                 buf = NULL;
 105         } else {
 106                 *len = br;
 107         }
 108 out:
 109         close(fd);
 110         return buf;
 111 }
 112 #endif
 113
 114
 115 #ifdef HAVE_LIBSSL
 116 /**
 117  * Log OpenSSL error message.
 118  *
 119  * @param msg The error message.
 120  * @param info Additional information text or NULL.
 121  */
 122 static void
 123 LogOpenSSLError(const char *error, const char *info)
 124 {
 125         unsigned long err = ERR_get_error();
 126         char * errmsg = err
 127                 ? ERR_error_string(err, NULL)
 128                 : "Unable to determine error";
 129
 130         assert(error != NULL);
 131
 132         if (info)
 133                 Log(LOG_ERR, "%s: %s (%s)", error, info, errmsg);
 134         else
 135                 Log(LOG_ERR, "%s: %s", error, errmsg);
 136 }
 137
 138
 139 static int
 140 pem_passwd_cb(char *buf, int size, int rwflag, void *password)
 141 {
 142         array *pass = password;
 143         int passlen;
 144
 145         (void)rwflag;           /* rwflag is unused if DEBUG is not set. */
 146         assert(rwflag == 0);    /* 0 -> callback used for decryption.
 147                                  * See SSL_CTX_set_default_passwd_cb(3) */
 148
 149         passlen = (int) array_bytes(pass);
 150
 151         LogDebug("pem_passwd_cb buf size %d, array size %d", size, passlen);
 152         assert(passlen >= 0);
 153         if (passlen <= 0) {
 154                 Log(LOG_ERR, "PEM password required but not set [in pem_passwd_cb()]!");
 155                 return 0;
 156         }
 157         size = passlen > size ? size : passlen;
 158         memcpy(buf, (char *)(array_start(pass)), size);
 159         return size;
 160 }
 161
 162
 163 static int
 164 Verify_openssl(UNUSED int preverify_ok, UNUSED X509_STORE_CTX *x509_ctx)
 165 {
 166         return 1;
 167 }
 168 #endif
 169
 170
 171 static bool
 172 Load_DH_params(void)
 173 {
 174 #ifdef HAVE_LIBSSL
 175         FILE *fp;
 176         bool ret = true;
 177
 178         if (!Conf_SSLOptions.DHFile) {
 179                 Log(LOG_NOTICE, "Configuration option \"DHFile\" not set!");
 180                 return false;
 181         }
 182         fp = fopen(Conf_SSLOptions.DHFile, "r");
 183         if (!fp) {
 184                 Log(LOG_ERR, "%s: %s", Conf_SSLOptions.DHFile, strerror(errno));
 185                 return false;
 186         }
 187         dh_params = PEM_read_DHparams(fp, NULL, NULL, NULL);
 188         if (!dh_params) {
 189                 Log(LOG_ERR, "%s: Failed to read SSL DH parameters!",
 190                     Conf_SSLOptions.DHFile);
 191                 ret = false;
 192         }
 193         fclose(fp);
 194         return ret;
 195 #endif
 196 #ifdef HAVE_LIBGNUTLS
 197         bool need_dhgenerate = true;
 198         int err;
 199         gnutls_dh_params_t tmp_dh_params;
 200
 201         err = gnutls_dh_params_init(&tmp_dh_params);
 202         if (err < 0) {
 203                 Log(LOG_ERR, "Failed to initialize SSL DH parameters: %s",
 204                     gnutls_strerror(err));
 205                 return false;
 206         }
 207         if (Conf_SSLOptions.DHFile) {
 208                 gnutls_datum_t dhparms;
 209                 size_t size;
 210                 dhparms.data = (unsigned char *) openreadclose(Conf_SSLOptions.DHFile, &size);
 211                 if (dhparms.data) {
 212                         dhparms.size = size;
 213                         err = gnutls_dh_params_import_pkcs3(tmp_dh_params, &dhparms, GNUTLS_X509_FMT_PEM);
 214                         if (err == 0)
 215                                 need_dhgenerate = false;
 216                         else
 217                                 Log(LOG_ERR,
 218                                     "Failed to initialize SSL DH parameters: %s",
 219                                     gnutls_strerror(err));
 220
 221                         memset(dhparms.data, 0, size);
 222                         free(dhparms.data);
 223                 }
 224         }
 225         if (need_dhgenerate) {
 226                 Log(LOG_WARNING,
 227                     "DHFile not set, generating %u bit DH parameters. This may take a while ...",
 228                     DH_BITS);
 229                 err = gnutls_dh_params_generate2(tmp_dh_params, DH_BITS);
 230                 if (err < 0) {
 231                         Log(LOG_ERR, "Failed to generate SSL DH parameters: %s",
 232                             gnutls_strerror(err));
 233                         return false;
 234                 }
 235         }
 236         dh_params = tmp_dh_params;
 237         return true;
 238 #endif
 239 }
 240
 241
 242 void ConnSSL_Free(CONNECTION *c)
 243 {
 244 #ifdef HAVE_LIBSSL
 245         SSL *ssl = c->ssl_state.ssl;
 246         if (ssl) {
 247                 SSL_shutdown(ssl);
 248                 SSL_free(ssl);
 249                 c->ssl_state.ssl = NULL;
 250                 if (c->ssl_state.fingerprint) {
 251                         free(c->ssl_state.fingerprint);
 252                         c->ssl_state.fingerprint = NULL;
 253                 }
 254         }
 255 #endif
 256 #ifdef HAVE_LIBGNUTLS
 257         gnutls_session_t sess = c->ssl_state.gnutls_session;
 258         if (Conn_OPTION_ISSET(c, CONN_SSL)) {
 259                 gnutls_bye(sess, GNUTLS_SHUT_RDWR);
 260                 gnutls_deinit(sess);
 261         }
 262 #endif
 263         assert(Conn_OPTION_ISSET(c, CONN_SSL));
 264         /* can't just set bitmask to 0 -- there are other, non-ssl related flags, e.g. CONN_ZIP. */
 265         Conn_OPTION_DEL(c, CONN_SSL_FLAGS_ALL);
 266 }
 267
 268
 269 bool
 270 ConnSSL_InitLibrary( void )
 271 {
 272         if (!Conf_SSLInUse()) {
 273                 LogDebug("SSL not in use, skipping initialization.");
 274                 return true;
 275         }
 276
 277 #ifdef HAVE_LIBSSL
 278         SSL_CTX *newctx;
 279
 280         if (!ssl_ctx) {
 281                 SSL_library_init();
 282                 SSL_load_error_strings();
 283         }
 284
 285         if (!RAND_status()) {
 286                 Log(LOG_ERR, "OpenSSL PRNG not seeded: /dev/urandom missing?");
 287                 /*
 288                  * it is probably best to fail and let the user install EGD or
 289                  * a similar program if no kernel random device is available.
 290                  * According to OpenSSL RAND_egd(3): "The automatic query of
 291                  * /var/run/egd-pool et al was added in OpenSSL 0.9.7";
 292                  * so it makes little sense to deal with PRNGD seeding ourselves.
 293                  */
 294                 array_free(&Conf_SSLOptions.ListenPorts);
 295                 return false;
 296         }
 297
 298         newctx = SSL_CTX_new(SSLv23_method());
 299         if (!newctx) {
 300                 LogOpenSSLError("Failed to create SSL context", NULL);
 301                 array_free(&Conf_SSLOptions.ListenPorts);
 302                 return false;
 303         }
 304
 305         if (!ConnSSL_LoadServerKey_openssl(newctx))
 306                 goto out;
 307
 308         SSL_CTX_set_options(newctx, SSL_OP_SINGLE_DH_USE|SSL_OP_NO_SSLv2);
 309         SSL_CTX_set_mode(newctx, SSL_MODE_ENABLE_PARTIAL_WRITE);
 310         SSL_CTX_set_verify(newctx, SSL_VERIFY_PEER|SSL_VERIFY_CLIENT_ONCE,
 311                            Verify_openssl);
 312         SSL_CTX_free(ssl_ctx);
 313         ssl_ctx = newctx;
 314         Log(LOG_INFO, "%s initialized.", SSLeay_version(SSLEAY_VERSION));
 315         return true;
 316 out:
 317         SSL_CTX_free(newctx);
 318         array_free(&Conf_SSLOptions.ListenPorts);
 319         return false;
 320 #endif
 321 #ifdef HAVE_LIBGNUTLS
 322         int err;
 323         static bool initialized;
 324
 325         if (initialized) {
 326                 /* TODO: cannot reload gnutls keys: can't simply free x509
 327                  * context -- it may still be in use */
 328                 return false;
 329         }
 330
 331         err = gnutls_global_init();
 332         if (err) {
 333                 Log(LOG_ERR, "Failed to initialize GnuTLS: %s",
 334                     gnutls_strerror(err));
 335                 array_free(&Conf_SSLOptions.ListenPorts);
 336                 return false;
 337         }
 338         if (!ConnSSL_LoadServerKey_gnutls()) {
 339                 array_free(&Conf_SSLOptions.ListenPorts);
 340                 return false;
 341         }
 342         Log(LOG_INFO, "GnuTLS %s initialized.", gnutls_check_version(NULL));
 343         initialized = true;
 344         return true;
 345 #endif
 346 }
 347
 348
 349 #ifdef HAVE_LIBGNUTLS
 350 static bool
 351 ConnSSL_LoadServerKey_gnutls(void)
 352 {
 353         int err;
 354         const char *cert_file;
 355
 356         err = gnutls_certificate_allocate_credentials(&x509_cred);
 357         if (err < 0) {
 358                 Log(LOG_ERR, "Failed to allocate certificate credentials: %s",
 359                     gnutls_strerror(err));
 360                 return false;
 361         }
 362
 363         cert_file = Conf_SSLOptions.CertFile ? Conf_SSLOptions.CertFile:Conf_SSLOptions.KeyFile;
 364         if (!cert_file) {
 365                 Log(LOG_ERR, "No SSL server key configured!");
 366                 return false;
 367         }
 368
 369         if (array_bytes(&Conf_SSLOptions.KeyFilePassword))
 370                 Log(LOG_WARNING,
 371                     "Ignoring KeyFilePassword: Not supported by GnuTLS.");
 372
 373         if (!Load_DH_params())
 374                 return false;
 375
 376         gnutls_certificate_set_dh_params(x509_cred, dh_params);
 377         err = gnutls_certificate_set_x509_key_file(x509_cred, cert_file, Conf_SSLOptions.KeyFile, GNUTLS_X509_FMT_PEM);
 378         if (err < 0) {
 379                 Log(LOG_ERR,
 380                     "Failed to set certificate key file (cert %s, key %s): %s",
 381                     cert_file,
 382                     Conf_SSLOptions.KeyFile ? Conf_SSLOptions.KeyFile : "(NULL)",
 383                     gnutls_strerror(err));
 384                 return false;
 385         }
 386         return true;
 387 }
 388 #endif
 389
 390
 391 #ifdef HAVE_LIBSSL
 392 static bool
 393 ConnSSL_LoadServerKey_openssl(SSL_CTX *ctx)
 394 {
 395         char *cert_key;
 396
 397         assert(ctx);
 398         if (!Conf_SSLOptions.KeyFile) {
 399                 Log(LOG_ERR, "No SSL server key configured!");
 400                 return false;
 401         }
 402
 403         SSL_CTX_set_default_passwd_cb(ctx, pem_passwd_cb);
 404         SSL_CTX_set_default_passwd_cb_userdata(ctx, &Conf_SSLOptions.KeyFilePassword);
 405
 406         if (SSL_CTX_use_PrivateKey_file(ctx, Conf_SSLOptions.KeyFile, SSL_FILETYPE_PEM) != 1) {
 407                 array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 408                 LogOpenSSLError("Failed to add private key", Conf_SSLOptions.KeyFile);
 409                 return false;
 410         }
 411
 412         cert_key = Conf_SSLOptions.CertFile ? Conf_SSLOptions.CertFile:Conf_SSLOptions.KeyFile;
 413         if (SSL_CTX_use_certificate_chain_file(ctx, cert_key) != 1) {
 414                 array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 415                 LogOpenSSLError("Failed to load certificate chain", cert_key);
 416                 return false;
 417         }
 418
 419         array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 420
 421         if (!SSL_CTX_check_private_key(ctx)) {
 422                 LogOpenSSLError("Server private key does not match certificate", NULL);
 423                 return false;
 424         }
 425         if (Load_DH_params()) {
 426                 if (SSL_CTX_set_tmp_dh(ctx, dh_params) != 1)
 427                         LogOpenSSLError("Error setting DH parameters", Conf_SSLOptions.DHFile);
 428                 /* don't return false here: the non-DH modes will still work */
 429                 DH_free(dh_params);
 430                 dh_params = NULL;
 431         }
 432         return true;
 433 }
 434
 435
 436 #endif
 437 static bool
 438 ConnSSL_Init_SSL(CONNECTION *c)
 439 {
 440         int ret;
 441         assert(c != NULL);
 442 #ifdef HAVE_LIBSSL
 443         if (!ssl_ctx) {
 444                 Log(LOG_ERR,
 445                     "Can't initialize SSL context, OpenSSL initialization failed at startup!");
 446                 return false;
 447         }
 448         assert(c->ssl_state.ssl == NULL);
 449         assert(c->ssl_state.fingerprint == NULL);
 450
 451         c->ssl_state.ssl = SSL_new(ssl_ctx);
 452         if (!c->ssl_state.ssl) {
 453                 LogOpenSSLError("Failed to create SSL structure", NULL);
 454                 return false;
 455         }
 456
 457         ret = SSL_set_fd(c->ssl_state.ssl, c->sock);
 458         if (ret != 1) {
 459                 LogOpenSSLError("Failed to set SSL file descriptor", NULL);
 460                 ConnSSL_Free(c);
 461                 return false;
 462         }
 463 #endif
 464 #ifdef HAVE_LIBGNUTLS
 465         ret = gnutls_set_default_priority(c->ssl_state.gnutls_session);
 466         if (ret < 0) {
 467                 Log(LOG_ERR, "Failed to set GnuTLS default priority: %s",
 468                     gnutls_strerror(ret));
 469                 ConnSSL_Free(c);
 470                 return false;
 471         }
 472         /*
 473          * The intermediate (long) cast is here to avoid a warning like:
 474          * "cast to pointer from integer of different size" on 64-bit platforms.
 475          * There doesn't seem to be an alternate GNUTLS API we could use instead, see e.g.
 476          * http://www.mail-archive.com/help-gnutls@gnu.org/msg00286.html
 477          */
 478         gnutls_transport_set_ptr(c->ssl_state.gnutls_session, (gnutls_transport_ptr_t) (long) c->sock);
 479         gnutls_certificate_server_set_request(c->ssl_state.gnutls_session, GNUTLS_CERT_REQUEST);
 480         ret = gnutls_credentials_set(c->ssl_state.gnutls_session, GNUTLS_CRD_CERTIFICATE, x509_cred);
 481         if (ret < 0) {
 482                 Log(LOG_ERR, "Failed to set SSL credentials: %s", gnutls_strerror(ret));
 483                 ConnSSL_Free(c);
 484                 return false;
 485         }
 486         gnutls_dh_set_prime_bits(c->ssl_state.gnutls_session, DH_BITS_MIN);
 487 #endif
 488         Conn_OPTION_ADD(c, CONN_SSL);
 489         return true;
 490 }
 491
 492
 493 bool
 494 ConnSSL_PrepareConnect(CONNECTION *c, UNUSED CONF_SERVER *s)
 495 {
 496         bool ret;
 497 #ifdef HAVE_LIBGNUTLS
 498         int err;
 499
 500         err = gnutls_init(&c->ssl_state.gnutls_session, GNUTLS_CLIENT);
 501         if (err) {
 502                 Log(LOG_ERR, "Failed to initialize new SSL session: %s",
 503                     gnutls_strerror(err));
 504                 return false;
 505         }
 506 #endif
 507         ret = ConnSSL_Init_SSL(c);
 508         if (!ret)
 509                 return false;
 510         Conn_OPTION_ADD(c, CONN_SSL_CONNECT);
 511 #ifdef HAVE_LIBSSL
 512         assert(c->ssl_state.ssl);
 513         SSL_set_verify(c->ssl_state.ssl, SSL_VERIFY_NONE, NULL);
 514 #endif
 515         return true;
 516 }
 517
 518
 519 /**
 520  * Check and handle error return codes after failed calls to SSL functions.
 521  *
 522  * OpenSSL:
 523  * SSL_connect(), SSL_accept(), SSL_do_handshake(), SSL_read(), SSL_peek(), or
 524  * SSL_write() on ssl.
 525  *
 526  * GnuTLS:
 527  * gnutlsssl_read(), gnutls_write() or gnutls_handshake().
 528  *
 529  * @param c The connection handle.
 530  * @prarm code The return code.
 531  * @param fname The name of the function in which the error occurred.
 532  * @return -1 on fatal errors, 0 if we can try again later.
 533  */
 534 static int
 535 ConnSSL_HandleError(CONNECTION * c, const int code, const char *fname)
 536 {
 537 #ifdef HAVE_LIBSSL
 538         int ret = SSL_ERROR_SYSCALL;
 539         unsigned long sslerr;
 540         int real_errno = errno;
 541
 542         ret = SSL_get_error(c->ssl_state.ssl, code);
 543
 544         switch (ret) {
 545         case SSL_ERROR_WANT_READ:
 546                 io_event_del(c->sock, IO_WANTWRITE);
 547                 Conn_OPTION_ADD(c, CONN_SSL_WANT_READ);
 548                 return 0;       /* try again later */
 549         case SSL_ERROR_WANT_WRITE:
 550                 io_event_del(c->sock, IO_WANTREAD);
 551                 Conn_OPTION_ADD(c, CONN_SSL_WANT_WRITE); /* fall through */
 552         case SSL_ERROR_NONE:
 553                 return 0;       /* try again later */
 554         case SSL_ERROR_ZERO_RETURN:
 555                 LogDebug("SSL connection shut down normally.");
 556                 break;
 557         case SSL_ERROR_SYSCALL:
 558                 /* SSL_ERROR_WANT_CONNECT, SSL_ERROR_WANT_ACCEPT,
 559                  * and SSL_ERROR_WANT_X509_LOOKUP */
 560                 sslerr = ERR_get_error();
 561                 if (sslerr) {
 562                         Log(LOG_ERR, "SSL error: %s [in %s()]!",
 563                             ERR_error_string(sslerr, NULL), fname);
 564                 } else {
 565                         switch (code) { /* EOF that violated protocol */
 566                         case 0:
 567                                 Log(LOG_ERR,
 568                                     "SSL error, client disconnected [in %s()]!",
 569                                     fname);
 570                                 break;
 571                         case -1:        /* low level socket I/O error, check errno */
 572                                 Log(LOG_ERR, "SSL error: %s [in %s()]!",
 573                                     strerror(real_errno), fname);
 574                         }
 575                 }
 576                 break;
 577         case SSL_ERROR_SSL:
 578                 LogOpenSSLError("SSL protocol error", fname);
 579                 break;
 580         default:
 581                 Log(LOG_ERR, "Unknown SSL error %d [in %s()]!", ret, fname);
 582         }
 583         ConnSSL_Free(c);
 584         return -1;
 585 #endif
 586 #ifdef HAVE_LIBGNUTLS
 587         switch (code) {
 588         case GNUTLS_E_AGAIN:
 589         case GNUTLS_E_INTERRUPTED:
 590                 if (gnutls_record_get_direction(c->ssl_state.gnutls_session)) {
 591                         Conn_OPTION_ADD(c, CONN_SSL_WANT_WRITE);
 592                         io_event_del(c->sock, IO_WANTREAD);
 593                 } else {
 594                         Conn_OPTION_ADD(c, CONN_SSL_WANT_READ);
 595                         io_event_del(c->sock, IO_WANTWRITE);
 596                 }
 597                 break;
 598         default:
 599                 assert(code < 0);
 600                 if (gnutls_error_is_fatal(code)) {
 601                         Log(LOG_ERR, "SSL error: %s [%s].",
 602                             gnutls_strerror(code), fname);
 603                         ConnSSL_Free(c);
 604                         return -1;
 605                 }
 606         }
 607         return 0;
 608 #endif
 609 }
 610
 611
 612 static void
 613 ConnSSL_LogCertInfo( CONNECTION *c )
 614 {
 615 #ifdef HAVE_LIBSSL
 616         SSL *ssl = c->ssl_state.ssl;
 617
 618         assert(ssl);
 619
 620         Log(LOG_INFO, "Connection %d: initialized %s using cipher %s.",
 621                 c->sock, SSL_get_version(ssl), SSL_get_cipher(ssl));
 622 #endif
 623 #ifdef HAVE_LIBGNUTLS
 624         gnutls_session_t sess = c->ssl_state.gnutls_session;
 625         gnutls_cipher_algorithm_t cipher = gnutls_cipher_get(sess);
 626
 627         Log(LOG_INFO, "Connection %d: initialized %s using cipher %s-%s.",
 628             c->sock,
 629             gnutls_protocol_get_name(gnutls_protocol_get_version(sess)),
 630             gnutls_cipher_get_name(cipher),
 631             gnutls_mac_get_name(gnutls_mac_get(sess)));
 632 #endif
 633 }
 634
 635
 636 /*
 637  Accept incoming SSL connection.
 638  Return Values:
 639          1: SSL Connection established
 640          0: try again
 641         -1: SSL Connection not established due to fatal error.
 642 */
 643 int
 644 ConnSSL_Accept( CONNECTION *c )
 645 {
 646         assert(c != NULL);
 647         if (!Conn_OPTION_ISSET(c, CONN_SSL)) {
 648 #ifdef HAVE_LIBGNUTLS
 649                 int err = gnutls_init(&c->ssl_state.gnutls_session, GNUTLS_SERVER);
 650                 if (err) {
 651                         Log(LOG_ERR, "Failed to initialize new SSL session: %s",
 652                             gnutls_strerror(err));
 653                         return false;
 654                 }
 655 #endif
 656                 LogDebug("Initializing SSL data ...");
 657                 if (!ConnSSL_Init_SSL(c))
 658                         return -1;
 659         }
 660         return ConnectAccept(c, false );
 661 }
 662
 663
 664 int
 665 ConnSSL_Connect( CONNECTION *c )
 666 {
 667         assert(c != NULL);
 668 #ifdef HAVE_LIBSSL
 669         assert(c->ssl_state.ssl);
 670 #endif
 671         assert(Conn_OPTION_ISSET(c, CONN_SSL));
 672         return ConnectAccept(c, true);
 673 }
 674
 675 static int
 676 ConnSSL_InitCertFp( CONNECTION *c )
 677 {
 678         const char hex[] = "0123456789abcdef";
 679         int i;
 680
 681 #ifdef HAVE_LIBSSL
 682         unsigned char digest[EVP_MAX_MD_SIZE];
 683         unsigned int digest_size;
 684         X509 *cert;
 685
 686         cert = SSL_get_peer_certificate(c->ssl_state.ssl);
 687         if (!cert)
 688                 return 0;
 689
 690         if (!X509_digest(cert, EVP_sha1(), digest, &digest_size)) {
 691                 X509_free(cert);
 692                 return 0;
 693         }
 694
 695         X509_free(cert);
 696 #endif /* HAVE_LIBSSL */
 697 #ifdef HAVE_LIBGNUTLS
 698         gnutls_x509_crt_t cert;
 699         unsigned int cert_list_size;
 700         const gnutls_datum_t *cert_list;
 701         unsigned char digest[MAX_HASH_SIZE];
 702         size_t digest_size;
 703
 704         if (gnutls_certificate_type_get(c->ssl_state.gnutls_session) != GNUTLS_CRT_X509)
 705                 return 0;
 706
 707         if (gnutls_x509_crt_init(&cert) != GNUTLS_E_SUCCESS)
 708                 return 0;
 709
 710         cert_list_size = 0;
 711         cert_list = gnutls_certificate_get_peers(c->ssl_state.gnutls_session,
 712                                                  &cert_list_size);
 713         if (!cert_list) {
 714                 gnutls_x509_crt_deinit(cert);
 715                 return 0;
 716         }
 717
 718         if (gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER) != GNUTLS_E_SUCCESS) {
 719                 gnutls_x509_crt_deinit(cert);
 720                 return 0;
 721         }
 722
 723         digest_size = sizeof(digest);
 724         if (gnutls_x509_crt_get_fingerprint(cert, GNUTLS_DIG_SHA1, digest, &digest_size)) {
 725                 gnutls_x509_crt_deinit(cert);
 726                 return 0;
 727         }
 728
 729         gnutls_x509_crt_deinit(cert);
 730 #endif /* HAVE_LIBGNUTLS */
 731
 732         assert(c->ssl_state.fingerprint == NULL);
 733
 734         c->ssl_state.fingerprint = malloc(SHA1_STRING_LEN);
 735         if (!c->ssl_state.fingerprint)
 736                 return 0;
 737
 738         for (i = 0; i < (int)digest_size; i++) {
 739                 c->ssl_state.fingerprint[i * 2] = hex[digest[i] / 16];
 740                 c->ssl_state.fingerprint[i * 2 + 1] = hex[digest[i] % 16];
 741         }
 742         c->ssl_state.fingerprint[i * 2] = '\0';
 743
 744         return 1;
 745 }
 746
 747 /* accept/connect wrapper. if connect is true, connect to peer, otherwise wait for incoming connection */
 748 static int
 749 ConnectAccept( CONNECTION *c, bool connect)
 750 {
 751         int ret;
 752 #ifdef HAVE_LIBSSL
 753         SSL *ssl = c->ssl_state.ssl;
 754         assert(ssl != NULL);
 755
 756         ret = connect ? SSL_connect(ssl) : SSL_accept(ssl);
 757         if (1 != ret)
 758                 return ConnSSL_HandleError(c, ret, connect ? "SSL_connect": "SSL_accept");
 759 #endif
 760 #ifdef HAVE_LIBGNUTLS
 761         (void) connect;
 762         ret = gnutls_handshake(c->ssl_state.gnutls_session);
 763         if (ret)
 764                 return ConnSSL_HandleError(c, ret, "gnutls_handshake");
 765 #endif /* _GNUTLS */
 766         (void)ConnSSL_InitCertFp(c);
 767
 768         Conn_OPTION_DEL(c, (CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ|CONN_SSL_CONNECT));
 769         ConnSSL_LogCertInfo(c);
 770
 771         Conn_StartLogin(CONNECTION2ID(c));
 772         return 1;
 773 }
 774
 775
 776 ssize_t
 777 ConnSSL_Write(CONNECTION *c, const void *buf, size_t count)
 778 {
 779         ssize_t bw;
 780
 781         Conn_OPTION_DEL(c, CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ);
 782
 783         assert(count > 0);
 784 #ifdef HAVE_LIBSSL
 785         bw = (ssize_t) SSL_write(c->ssl_state.ssl, buf, count);
 786 #endif
 787 #ifdef HAVE_LIBGNUTLS
 788         bw = gnutls_write(c->ssl_state.gnutls_session, buf, count);
 789 #endif
 790         if (bw > 0)
 791                 return bw;
 792         if (ConnSSL_HandleError( c, bw, "ConnSSL_Write") == 0)
 793                 errno = EAGAIN; /* try again */
 794         return -1;
 795 }
 796
 797
 798 ssize_t
 799 ConnSSL_Read(CONNECTION *c, void * buf, size_t count)
 800 {
 801         ssize_t br;
 802
 803         Conn_OPTION_DEL(c, CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ);
 804 #ifdef HAVE_LIBSSL
 805         br = (ssize_t) SSL_read(c->ssl_state.ssl, buf, count);
 806         if (br > 0)     /* on EOF we have to call ConnSSL_HandleError(), see SSL_read(3) */
 807                 return br;
 808 #endif
 809 #ifdef HAVE_LIBGNUTLS
 810         br = gnutls_read(c->ssl_state.gnutls_session, buf, count);
 811         if (br >= 0)    /* on EOF we must _not_ call ConnSSL_HandleError, see gnutls_record_recv(3) */
 812                 return br;
 813 #endif
 814         /* error on read: switch ConnSSL_HandleError() return values -> 0 is "try again", so return -1 and set EAGAIN */
 815         if (ConnSSL_HandleError(c, br, "ConnSSL_Read") == 0) {
 816                 errno = EAGAIN;
 817                 return -1;
 818         }
 819         return 0;
 820 }
 821
 822
 823 bool
 824 ConnSSL_GetCipherInfo(CONNECTION *c, char *buf, size_t len)
 825 {
 826 #ifdef HAVE_LIBSSL
 827         char *nl;
 828         SSL *ssl = c->ssl_state.ssl;
 829
 830         if (!ssl)
 831                 return false;
 832         *buf = 0;
 833         SSL_CIPHER_description(SSL_get_current_cipher(ssl), buf, len);
 834         nl = strchr(buf, '\n');
 835         if (nl)
 836                 *nl = 0;
 837         return true;
 838 #endif
 839 #ifdef HAVE_LIBGNUTLS
 840         if (Conn_OPTION_ISSET(c, CONN_SSL)) {
 841                 const char *name_cipher, *name_mac, *name_proto, *name_keyexchange;
 842                 unsigned keysize;
 843
 844                 gnutls_session_t sess = c->ssl_state.gnutls_session;
 845                 gnutls_cipher_algorithm_t cipher = gnutls_cipher_get(sess);
 846                 name_cipher = gnutls_cipher_get_name(cipher);
 847                 name_mac = gnutls_mac_get_name(gnutls_mac_get(sess));
 848                 keysize = gnutls_cipher_get_key_size(cipher) * 8;
 849                 name_proto = gnutls_protocol_get_name(gnutls_protocol_get_version(sess));
 850                 name_keyexchange = gnutls_kx_get_name(gnutls_kx_get(sess));
 851
 852                 return snprintf(buf, len, "%s-%s%15s Kx=%s      Enc=%s(%u) Mac=%s",
 853                         name_cipher, name_mac, name_proto, name_keyexchange, name_cipher, keysize, name_mac) > 0;
 854         }
 855         return false;
 856 #endif
 857 }
 858
 859 char *
 860 ConnSSL_GetCertFp(CONNECTION *c)
 861 {
 862         return c->ssl_state.fingerprint;
 863 }
 864
 865 bool
 866 ConnSSL_SetCertFp(CONNECTION *c, const char *fingerprint)
 867 {
 868         assert (c != NULL);
 869         c->ssl_state.fingerprint = strndup(fingerprint, SHA1_STRING_LEN - 1);
 870         return c->ssl_state.fingerprint != NULL;
 871 }
 872 #else
 873
 874 bool
 875 ConnSSL_InitLibrary(void)
 876 {
 877         return true;
 878 }
 879
 880 #endif /* SSL_SUPPORT */
 881 /* -eof- */
 882
 883