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 a similar program if no kernel random device is available.
 289                  * According to OpenSSL RAND_egd(3): "The automatic query of /var/run/egd-pool et al was added in OpenSSL 0.9.7";
 290                  * so it makes little sense to deal with PRNGD seeding ourselves.
 291                  */
 292                 array_free(&Conf_SSLOptions.ListenPorts);
 293                 return false;
 294         }
 295
 296         newctx = SSL_CTX_new(SSLv23_method());
 297         if (!newctx) {
 298                 LogOpenSSLError("Failed to create SSL context", NULL);
 299                 array_free(&Conf_SSLOptions.ListenPorts);
 300                 return false;
 301         }
 302
 303         if (!ConnSSL_LoadServerKey_openssl(newctx))
 304                 goto out;
 305
 306         SSL_CTX_set_options(newctx, SSL_OP_SINGLE_DH_USE|SSL_OP_NO_SSLv2);
 307         SSL_CTX_set_mode(newctx, SSL_MODE_ENABLE_PARTIAL_WRITE);
 308         SSL_CTX_set_verify(newctx, SSL_VERIFY_PEER|SSL_VERIFY_CLIENT_ONCE, Verify_openssl);
 309         SSL_CTX_free(ssl_ctx);
 310         ssl_ctx = newctx;
 311         Log(LOG_INFO, "%s initialized.", SSLeay_version(SSLEAY_VERSION));
 312         return true;
 313 out:
 314         SSL_CTX_free(newctx);
 315         array_free(&Conf_SSLOptions.ListenPorts);
 316         return false;
 317 #endif
 318 #ifdef HAVE_LIBGNUTLS
 319         int err;
 320         static bool initialized;
 321         if (initialized) /* TODO: cannot reload gnutls keys: can't simply free x509 context -- it may still be in use */
 322                 return false;
 323
 324         err = gnutls_global_init();
 325         if (err) {
 326                 Log(LOG_ERR, "Failed to initialize GnuTLS: %s", gnutls_strerror(err));
 327                 array_free(&Conf_SSLOptions.ListenPorts);
 328                 return false;
 329         }
 330         if (!ConnSSL_LoadServerKey_gnutls()) {
 331                 array_free(&Conf_SSLOptions.ListenPorts);
 332                 return false;
 333         }
 334         Log(LOG_INFO, "GnuTLS %s initialized.", gnutls_check_version(NULL));
 335         initialized = true;
 336         return true;
 337 #endif
 338 }
 339
 340
 341 #ifdef HAVE_LIBGNUTLS
 342 static bool
 343 ConnSSL_LoadServerKey_gnutls(void)
 344 {
 345         int err;
 346         const char *cert_file;
 347
 348         err = gnutls_certificate_allocate_credentials(&x509_cred);
 349         if (err < 0) {
 350                 Log(LOG_ERR, "Failed to allocate certificate credentials: %s",
 351                     gnutls_strerror(err));
 352                 return false;
 353         }
 354
 355         cert_file = Conf_SSLOptions.CertFile ? Conf_SSLOptions.CertFile:Conf_SSLOptions.KeyFile;
 356         if (!cert_file) {
 357                 Log(LOG_ERR, "No SSL server key configured!");
 358                 return false;
 359         }
 360
 361         if (array_bytes(&Conf_SSLOptions.KeyFilePassword))
 362                 Log(LOG_WARNING,
 363                     "Ignoring KeyFilePassword: Not supported by GnuTLS.");
 364
 365         if (!Load_DH_params())
 366                 return false;
 367
 368         gnutls_certificate_set_dh_params(x509_cred, dh_params);
 369         err = gnutls_certificate_set_x509_key_file(x509_cred, cert_file, Conf_SSLOptions.KeyFile, GNUTLS_X509_FMT_PEM);
 370         if (err < 0) {
 371                 Log(LOG_ERR,
 372                     "Failed to set certificate key file (cert %s, key %s): %s",
 373                     cert_file,
 374                     Conf_SSLOptions.KeyFile ? Conf_SSLOptions.KeyFile : "(NULL)",
 375                     gnutls_strerror(err));
 376                 return false;
 377         }
 378         return true;
 379 }
 380 #endif
 381
 382
 383 #ifdef HAVE_LIBSSL
 384 static bool
 385 ConnSSL_LoadServerKey_openssl(SSL_CTX *ctx)
 386 {
 387         char *cert_key;
 388
 389         assert(ctx);
 390         if (!Conf_SSLOptions.KeyFile) {
 391                 Log(LOG_ERR, "No SSL server key configured!");
 392                 return false;
 393         }
 394
 395         SSL_CTX_set_default_passwd_cb(ctx, pem_passwd_cb);
 396         SSL_CTX_set_default_passwd_cb_userdata(ctx, &Conf_SSLOptions.KeyFilePassword);
 397
 398         if (SSL_CTX_use_PrivateKey_file(ctx, Conf_SSLOptions.KeyFile, SSL_FILETYPE_PEM) != 1) {
 399                 array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 400                 LogOpenSSLError("Failed to add private key", Conf_SSLOptions.KeyFile);
 401                 return false;
 402         }
 403
 404         cert_key = Conf_SSLOptions.CertFile ? Conf_SSLOptions.CertFile:Conf_SSLOptions.KeyFile;
 405         if (SSL_CTX_use_certificate_chain_file(ctx, cert_key) != 1) {
 406                 array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 407                 LogOpenSSLError("Failed to load certificate chain", cert_key);
 408                 return false;
 409         }
 410
 411         array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 412
 413         if (!SSL_CTX_check_private_key(ctx)) {
 414                 LogOpenSSLError("Server private key does not match certificate", NULL);
 415                 return false;
 416         }
 417         if (Load_DH_params()) {
 418                 if (SSL_CTX_set_tmp_dh(ctx, dh_params) != 1)
 419                         LogOpenSSLError("Error setting DH parameters", Conf_SSLOptions.DHFile);
 420                 /* don't return false here: the non-DH modes will still work */
 421                 DH_free(dh_params);
 422                 dh_params = NULL;
 423         }
 424         return true;
 425 }
 426
 427
 428 #endif
 429 static bool
 430 ConnSSL_Init_SSL(CONNECTION *c)
 431 {
 432         int ret;
 433         assert(c != NULL);
 434 #ifdef HAVE_LIBSSL
 435         if (!ssl_ctx) {
 436                 Log(LOG_ERR,
 437                     "Can't initialize SSL context, OpenSSL initialization failed at startup!");
 438                 return false;
 439         }
 440         assert(c->ssl_state.ssl == NULL);
 441         assert(c->ssl_state.fingerprint == NULL);
 442
 443         c->ssl_state.ssl = SSL_new(ssl_ctx);
 444         if (!c->ssl_state.ssl) {
 445                 LogOpenSSLError("Failed to create SSL structure", NULL);
 446                 return false;
 447         }
 448
 449         ret = SSL_set_fd(c->ssl_state.ssl, c->sock);
 450         if (ret != 1) {
 451                 LogOpenSSLError("Failed to set SSL file descriptor", NULL);
 452                 ConnSSL_Free(c);
 453                 return false;
 454         }
 455 #endif
 456 #ifdef HAVE_LIBGNUTLS
 457         ret = gnutls_set_default_priority(c->ssl_state.gnutls_session);
 458         if (ret < 0) {
 459                 Log(LOG_ERR, "Failed to set GnuTLS default priority: %s",
 460                     gnutls_strerror(ret));
 461                 ConnSSL_Free(c);
 462                 return false;
 463         }
 464         /*
 465          * The intermediate (long) cast is here to avoid a warning like:
 466          * "cast to pointer from integer of different size" on 64-bit platforms.
 467          * There doesn't seem to be an alternate GNUTLS API we could use instead, see e.g.
 468          * http://www.mail-archive.com/help-gnutls@gnu.org/msg00286.html
 469          */
 470         gnutls_transport_set_ptr(c->ssl_state.gnutls_session, (gnutls_transport_ptr_t) (long) c->sock);
 471         gnutls_certificate_server_set_request(c->ssl_state.gnutls_session, GNUTLS_CERT_REQUEST);
 472         ret = gnutls_credentials_set(c->ssl_state.gnutls_session, GNUTLS_CRD_CERTIFICATE, x509_cred);
 473         if (ret < 0) {
 474                 Log(LOG_ERR, "Failed to set SSL credentials: %s", gnutls_strerror(ret));
 475                 ConnSSL_Free(c);
 476                 return false;
 477         }
 478         gnutls_dh_set_prime_bits(c->ssl_state.gnutls_session, DH_BITS_MIN);
 479 #endif
 480         Conn_OPTION_ADD(c, CONN_SSL);
 481         return true;
 482 }
 483
 484
 485 bool
 486 ConnSSL_PrepareConnect(CONNECTION *c, UNUSED CONF_SERVER *s)
 487 {
 488         bool ret;
 489 #ifdef HAVE_LIBGNUTLS
 490         int err;
 491
 492         err = gnutls_init(&c->ssl_state.gnutls_session, GNUTLS_CLIENT);
 493         if (err) {
 494                 Log(LOG_ERR, "Failed to initialize new SSL session: %s",
 495                     gnutls_strerror(err));
 496                 return false;
 497         }
 498 #endif
 499         ret = ConnSSL_Init_SSL(c);
 500         if (!ret)
 501                 return false;
 502         Conn_OPTION_ADD(c, CONN_SSL_CONNECT);
 503 #ifdef HAVE_LIBSSL
 504         assert(c->ssl_state.ssl);
 505         SSL_set_verify(c->ssl_state.ssl, SSL_VERIFY_NONE, NULL);
 506 #endif
 507         return true;
 508 }
 509
 510
 511 /**
 512  * Check and handle error return codes after failed calls to SSL functions.
 513  *
 514  * OpenSSL:
 515  * SSL_connect(), SSL_accept(), SSL_do_handshake(), SSL_read(), SSL_peek(), or
 516  * SSL_write() on ssl.
 517  *
 518  * GnuTLS:
 519  * gnutlsssl_read(), gnutls_write() or gnutls_handshake().
 520  *
 521  * @param c The connection handle.
 522  * @prarm code The return code.
 523  * @param fname The name of the function in which the error occurred.
 524  * @return -1 on fatal errors, 0 if we can try again later.
 525  */
 526 static int
 527 ConnSSL_HandleError(CONNECTION * c, const int code, const char *fname)
 528 {
 529 #ifdef HAVE_LIBSSL
 530         int ret = SSL_ERROR_SYSCALL;
 531         unsigned long sslerr;
 532         int real_errno = errno;
 533
 534         ret = SSL_get_error(c->ssl_state.ssl, code);
 535
 536         switch (ret) {
 537         case SSL_ERROR_WANT_READ:
 538                 io_event_del(c->sock, IO_WANTWRITE);
 539                 Conn_OPTION_ADD(c, CONN_SSL_WANT_READ);
 540                 return 0;       /* try again later */
 541         case SSL_ERROR_WANT_WRITE:
 542                 io_event_del(c->sock, IO_WANTREAD);
 543                 Conn_OPTION_ADD(c, CONN_SSL_WANT_WRITE); /* fall through */
 544         case SSL_ERROR_NONE:
 545                 return 0;       /* try again later */
 546         case SSL_ERROR_ZERO_RETURN:
 547                 LogDebug("SSL connection shut down normally.");
 548                 break;
 549         case SSL_ERROR_SYSCALL:
 550                 /* SSL_ERROR_WANT_CONNECT, SSL_ERROR_WANT_ACCEPT,
 551                  * and SSL_ERROR_WANT_X509_LOOKUP */
 552                 sslerr = ERR_get_error();
 553                 if (sslerr) {
 554                         Log(LOG_ERR, "SSL error: %s [in %s()]!",
 555                             ERR_error_string(sslerr, NULL), fname);
 556                 } else {
 557                         switch (code) { /* EOF that violated protocol */
 558                         case 0:
 559                                 Log(LOG_ERR,
 560                                     "SSL error, client disconnected [in %s()]!",
 561                                     fname);
 562                                 break;
 563                         case -1:        /* low level socket I/O error, check errno */
 564                                 Log(LOG_ERR, "SSL error: %s [in %s()]!",
 565                                     strerror(real_errno), fname);
 566                         }
 567                 }
 568                 break;
 569         case SSL_ERROR_SSL:
 570                 LogOpenSSLError("SSL protocol error", fname);
 571                 break;
 572         default:
 573                 Log(LOG_ERR, "Unknown SSL error %d [in %s()]!", ret, fname);
 574         }
 575         ConnSSL_Free(c);
 576         return -1;
 577 #endif
 578 #ifdef HAVE_LIBGNUTLS
 579         switch (code) {
 580         case GNUTLS_E_AGAIN:
 581         case GNUTLS_E_INTERRUPTED:
 582                 if (gnutls_record_get_direction(c->ssl_state.gnutls_session)) {
 583                         Conn_OPTION_ADD(c, CONN_SSL_WANT_WRITE);
 584                         io_event_del(c->sock, IO_WANTREAD);
 585                 } else {
 586                         Conn_OPTION_ADD(c, CONN_SSL_WANT_READ);
 587                         io_event_del(c->sock, IO_WANTWRITE);
 588                 }
 589                 break;
 590         default:
 591                 assert(code < 0);
 592                 if (gnutls_error_is_fatal(code)) {
 593                         Log(LOG_ERR, "SSL error: %s [%s].",
 594                             gnutls_strerror(code), fname);
 595                         ConnSSL_Free(c);
 596                         return -1;
 597                 }
 598         }
 599         return 0;
 600 #endif
 601 }
 602
 603
 604 static void
 605 ConnSSL_LogCertInfo( CONNECTION *c )
 606 {
 607 #ifdef HAVE_LIBSSL
 608         SSL *ssl = c->ssl_state.ssl;
 609
 610         assert(ssl);
 611
 612         Log(LOG_INFO, "Connection %d: initialized %s using cipher %s.",
 613                 c->sock, SSL_get_version(ssl), SSL_get_cipher(ssl));
 614 #endif
 615 #ifdef HAVE_LIBGNUTLS
 616         gnutls_session_t sess = c->ssl_state.gnutls_session;
 617         gnutls_cipher_algorithm_t cipher = gnutls_cipher_get(sess);
 618
 619         Log(LOG_INFO, "Connection %d: initialized %s using cipher %s-%s.",
 620             c->sock,
 621             gnutls_protocol_get_name(gnutls_protocol_get_version(sess)),
 622             gnutls_cipher_get_name(cipher),
 623             gnutls_mac_get_name(gnutls_mac_get(sess)));
 624 #endif
 625 }
 626
 627
 628 /*
 629  Accept incoming SSL connection.
 630  Return Values:
 631          1: SSL Connection established
 632          0: try again
 633         -1: SSL Connection not established due to fatal error.
 634 */
 635 int
 636 ConnSSL_Accept( CONNECTION *c )
 637 {
 638         assert(c != NULL);
 639         if (!Conn_OPTION_ISSET(c, CONN_SSL)) {
 640 #ifdef HAVE_LIBGNUTLS
 641                 int err = gnutls_init(&c->ssl_state.gnutls_session, GNUTLS_SERVER);
 642                 if (err) {
 643                         Log(LOG_ERR, "Failed to initialize new SSL session: %s",
 644                             gnutls_strerror(err));
 645                         return false;
 646                 }
 647 #endif
 648                 LogDebug("Initializing SSL data ...");
 649                 if (!ConnSSL_Init_SSL(c))
 650                         return -1;
 651         }
 652         return ConnectAccept(c, false );
 653 }
 654
 655
 656 int
 657 ConnSSL_Connect( CONNECTION *c )
 658 {
 659         assert(c != NULL);
 660 #ifdef HAVE_LIBSSL
 661         assert(c->ssl_state.ssl);
 662 #endif
 663         assert(Conn_OPTION_ISSET(c, CONN_SSL));
 664         return ConnectAccept(c, true);
 665 }
 666
 667 static int
 668 ConnSSL_InitCertFp( CONNECTION *c )
 669 {
 670         const char hex[] = "0123456789abcdef";
 671         int i;
 672
 673 #ifdef HAVE_LIBSSL
 674         unsigned char digest[EVP_MAX_MD_SIZE];
 675         unsigned int digest_size;
 676         X509 *cert;
 677
 678         cert = SSL_get_peer_certificate(c->ssl_state.ssl);
 679         if (!cert)
 680                 return 0;
 681
 682         if (!X509_digest(cert, EVP_sha1(), digest, &digest_size)) {
 683                 X509_free(cert);
 684                 return 0;
 685         }
 686
 687         X509_free(cert);
 688 #endif /* HAVE_LIBSSL */
 689 #ifdef HAVE_LIBGNUTLS
 690         gnutls_x509_crt_t cert;
 691         unsigned int cert_list_size;
 692         const gnutls_datum_t *cert_list;
 693         unsigned char digest[MAX_HASH_SIZE];
 694         size_t digest_size;
 695
 696         if (gnutls_certificate_type_get(c->ssl_state.gnutls_session) != GNUTLS_CRT_X509)
 697                 return 0;
 698
 699         if (gnutls_x509_crt_init(&cert) != GNUTLS_E_SUCCESS)
 700                 return 0;
 701
 702         cert_list_size = 0;
 703         cert_list = gnutls_certificate_get_peers(c->ssl_state.gnutls_session,
 704                                                  &cert_list_size);
 705         if (!cert_list) {
 706                 gnutls_x509_crt_deinit(cert);
 707                 return 0;
 708         }
 709
 710         if (gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER) != GNUTLS_E_SUCCESS) {
 711                 gnutls_x509_crt_deinit(cert);
 712                 return 0;
 713         }
 714
 715         digest_size = sizeof(digest);
 716         if (gnutls_x509_crt_get_fingerprint(cert, GNUTLS_DIG_SHA1, digest, &digest_size)) {
 717                 gnutls_x509_crt_deinit(cert);
 718                 return 0;
 719         }
 720
 721         gnutls_x509_crt_deinit(cert);
 722 #endif /* HAVE_LIBGNUTLS */
 723
 724         assert(c->ssl_state.fingerprint == NULL);
 725
 726         c->ssl_state.fingerprint = malloc(SHA1_STRING_LEN);
 727         if (!c->ssl_state.fingerprint)
 728                 return 0;
 729
 730         for (i = 0; i < (int)digest_size; i++) {
 731                 c->ssl_state.fingerprint[i * 2] = hex[digest[i] / 16];
 732                 c->ssl_state.fingerprint[i * 2 + 1] = hex[digest[i] % 16];
 733         }
 734         c->ssl_state.fingerprint[i * 2] = '\0';
 735
 736         return 1;
 737 }
 738
 739 /* accept/connect wrapper. if connect is true, connect to peer, otherwise wait for incoming connection */
 740 static int
 741 ConnectAccept( CONNECTION *c, bool connect)
 742 {
 743         int ret;
 744 #ifdef HAVE_LIBSSL
 745         SSL *ssl = c->ssl_state.ssl;
 746         assert(ssl != NULL);
 747
 748         ret = connect ? SSL_connect(ssl) : SSL_accept(ssl);
 749         if (1 != ret)
 750                 return ConnSSL_HandleError(c, ret, connect ? "SSL_connect": "SSL_accept");
 751 #endif
 752 #ifdef HAVE_LIBGNUTLS
 753         (void) connect;
 754         ret = gnutls_handshake(c->ssl_state.gnutls_session);
 755         if (ret)
 756                 return ConnSSL_HandleError(c, ret, "gnutls_handshake");
 757 #endif /* _GNUTLS */
 758         (void)ConnSSL_InitCertFp(c);
 759
 760         Conn_OPTION_DEL(c, (CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ|CONN_SSL_CONNECT));
 761         ConnSSL_LogCertInfo(c);
 762
 763         Conn_StartLogin(CONNECTION2ID(c));
 764         return 1;
 765 }
 766
 767
 768 ssize_t
 769 ConnSSL_Write(CONNECTION *c, const void *buf, size_t count)
 770 {
 771         ssize_t bw;
 772
 773         Conn_OPTION_DEL(c, CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ);
 774
 775         assert(count > 0);
 776 #ifdef HAVE_LIBSSL
 777         bw = (ssize_t) SSL_write(c->ssl_state.ssl, buf, count);
 778 #endif
 779 #ifdef HAVE_LIBGNUTLS
 780         bw = gnutls_write(c->ssl_state.gnutls_session, buf, count);
 781 #endif
 782         if (bw > 0)
 783                 return bw;
 784         if (ConnSSL_HandleError( c, bw, "ConnSSL_Write") == 0)
 785                 errno = EAGAIN; /* try again */
 786         return -1;
 787 }
 788
 789
 790 ssize_t
 791 ConnSSL_Read(CONNECTION *c, void * buf, size_t count)
 792 {
 793         ssize_t br;
 794
 795         Conn_OPTION_DEL(c, CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ);
 796 #ifdef HAVE_LIBSSL
 797         br = (ssize_t) SSL_read(c->ssl_state.ssl, buf, count);
 798         if (br > 0)     /* on EOF we have to call ConnSSL_HandleError(), see SSL_read(3) */
 799                 return br;
 800 #endif
 801 #ifdef HAVE_LIBGNUTLS
 802         br = gnutls_read(c->ssl_state.gnutls_session, buf, count);
 803         if (br >= 0)    /* on EOF we must _not_ call ConnSSL_HandleError, see gnutls_record_recv(3) */
 804                 return br;
 805 #endif
 806         /* error on read: switch ConnSSL_HandleError() return values -> 0 is "try again", so return -1 and set EAGAIN */
 807         if (ConnSSL_HandleError(c, br, "ConnSSL_Read") == 0) {
 808                 errno = EAGAIN;
 809                 return -1;
 810         }
 811         return 0;
 812 }
 813
 814
 815 bool
 816 ConnSSL_GetCipherInfo(CONNECTION *c, char *buf, size_t len)
 817 {
 818 #ifdef HAVE_LIBSSL
 819         char *nl;
 820         SSL *ssl = c->ssl_state.ssl;
 821
 822         if (!ssl)
 823                 return false;
 824         *buf = 0;
 825         SSL_CIPHER_description(SSL_get_current_cipher(ssl), buf, len);
 826         nl = strchr(buf, '\n');
 827         if (nl)
 828                 *nl = 0;
 829         return true;
 830 #endif
 831 #ifdef HAVE_LIBGNUTLS
 832         if (Conn_OPTION_ISSET(c, CONN_SSL)) {
 833                 const char *name_cipher, *name_mac, *name_proto, *name_keyexchange;
 834                 unsigned keysize;
 835
 836                 gnutls_session_t sess = c->ssl_state.gnutls_session;
 837                 gnutls_cipher_algorithm_t cipher = gnutls_cipher_get(sess);
 838                 name_cipher = gnutls_cipher_get_name(cipher);
 839                 name_mac = gnutls_mac_get_name(gnutls_mac_get(sess));
 840                 keysize = gnutls_cipher_get_key_size(cipher) * 8;
 841                 name_proto = gnutls_protocol_get_name(gnutls_protocol_get_version(sess));
 842                 name_keyexchange = gnutls_kx_get_name(gnutls_kx_get(sess));
 843
 844                 return snprintf(buf, len, "%s-%s%15s Kx=%s      Enc=%s(%u) Mac=%s",
 845                         name_cipher, name_mac, name_proto, name_keyexchange, name_cipher, keysize, name_mac) > 0;
 846         }
 847         return false;
 848 #endif
 849 }
 850
 851 char *
 852 ConnSSL_GetCertFp(CONNECTION *c)
 853 {
 854         return c->ssl_state.fingerprint;
 855 }
 856
 857 bool
 858 ConnSSL_SetCertFp(CONNECTION *c, const char *fingerprint)
 859 {
 860         assert (c != NULL);
 861         c->ssl_state.fingerprint = strndup(fingerprint, SHA1_STRING_LEN - 1);
 862         return c->ssl_state.fingerprint != NULL;
 863 }
 864 #else
 865
 866 bool
 867 ConnSSL_InitLibrary(void)
 868 {
 869         return true;
 870 }
 871
 872 #endif /* SSL_SUPPORT */
 873 /* -eof- */
 874
 875