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 CERTFP_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 static void
 117 LogOpenSSLError( const char *msg, const char *msg2 )
 118 {
 119         unsigned long err = ERR_get_error();
 120         char * errmsg = err ? ERR_error_string(err, NULL) : "Unable to determine error";
 121
 122         if (!msg) msg = "SSL Error";
 123         if (msg2)
 124                 Log( LOG_ERR, "%s: %s: %s", msg, msg2, errmsg);
 125         else
 126                 Log( LOG_ERR, "%s: %s", msg, errmsg);
 127 }
 128
 129
 130 static int
 131 pem_passwd_cb(char *buf, int size, int rwflag, void *password)
 132 {
 133         array *pass = password;
 134         int passlen;
 135
 136         (void)rwflag;           /* rwflag is unused if DEBUG is not set. */
 137         assert(rwflag == 0);    /* 0 -> callback used for decryption.
 138                                  * See SSL_CTX_set_default_passwd_cb(3) */
 139
 140         passlen = (int) array_bytes(pass);
 141
 142         LogDebug("pem_passwd_cb buf size %d, array size %d", size, passlen);
 143         assert(passlen >= 0);
 144         if (passlen <= 0) {
 145                 Log(LOG_ERR, "pem_passwd_cb: password required, but not set");
 146                 return 0;
 147         }
 148         size = passlen > size ? size : passlen;
 149         memcpy(buf, (char *)(array_start(pass)), size);
 150         return size;
 151 }
 152
 153
 154 static int
 155 Verify_openssl(UNUSED int preverify_ok, UNUSED X509_STORE_CTX *x509_ctx)
 156 {
 157         return 1;
 158 }
 159 #endif
 160
 161
 162 static bool
 163 Load_DH_params(void)
 164 {
 165 #ifdef HAVE_LIBSSL
 166         FILE *fp;
 167         bool ret = true;
 168
 169         if (!Conf_SSLOptions.DHFile) {
 170                 Log(LOG_NOTICE, "Configuration option \"DHFile\" not set!");
 171                 return false;
 172         }
 173         fp = fopen(Conf_SSLOptions.DHFile, "r");
 174         if (!fp) {
 175                 Log(LOG_ERR, "%s: %s", Conf_SSLOptions.DHFile, strerror(errno));
 176                 return false;
 177         }
 178         dh_params = PEM_read_DHparams(fp, NULL, NULL, NULL);
 179         if (!dh_params) {
 180                 Log(LOG_ERR, "%s: PEM_read_DHparams failed!",
 181                     Conf_SSLOptions.DHFile);
 182                 ret = false;
 183         }
 184         fclose(fp);
 185         return ret;
 186 #endif
 187 #ifdef HAVE_LIBGNUTLS
 188         bool need_dhgenerate = true;
 189         int err;
 190         gnutls_dh_params_t tmp_dh_params;
 191
 192         err = gnutls_dh_params_init(&tmp_dh_params);
 193         if (err < 0) {
 194                 Log(LOG_ERR, "gnutls_dh_params_init: %s", gnutls_strerror(err));
 195                 return false;
 196         }
 197         if (Conf_SSLOptions.DHFile) {
 198                 gnutls_datum_t dhparms;
 199                 size_t size;
 200                 dhparms.data = (unsigned char *) openreadclose(Conf_SSLOptions.DHFile, &size);
 201                 if (dhparms.data) {
 202                         dhparms.size = size;
 203                         err = gnutls_dh_params_import_pkcs3(tmp_dh_params, &dhparms, GNUTLS_X509_FMT_PEM);
 204                         if (err == 0)
 205                                 need_dhgenerate = false;
 206                         else
 207                                 Log(LOG_ERR, "gnutls_dh_params_init: %s", gnutls_strerror(err));
 208
 209                         memset(dhparms.data, 0, size);
 210                         free(dhparms.data);
 211                 }
 212         }
 213         if (need_dhgenerate) {
 214                 Log(LOG_WARNING,
 215                     "DHFile not set, generating %u bit DH parameters. This may take a while ...",
 216                     DH_BITS);
 217                 err = gnutls_dh_params_generate2(tmp_dh_params, DH_BITS);
 218                 if (err < 0) {
 219                         Log(LOG_ERR, "gnutls_dh_params_generate2: %s", gnutls_strerror(err));
 220                         return false;
 221                 }
 222         }
 223         dh_params = tmp_dh_params;
 224         return true;
 225 #endif
 226 }
 227
 228
 229 void ConnSSL_Free(CONNECTION *c)
 230 {
 231 #ifdef HAVE_LIBSSL
 232         SSL *ssl = c->ssl_state.ssl;
 233         if (ssl) {
 234                 SSL_shutdown(ssl);
 235                 SSL_free(ssl);
 236                 c->ssl_state.ssl = NULL;
 237                 if (c->ssl_state.fingerprint) {
 238                         free(c->ssl_state.fingerprint);
 239                         c->ssl_state.fingerprint = NULL;
 240                 }
 241         }
 242 #endif
 243 #ifdef HAVE_LIBGNUTLS
 244         gnutls_session_t sess = c->ssl_state.gnutls_session;
 245         if (Conn_OPTION_ISSET(c, CONN_SSL)) {
 246                 gnutls_bye(sess, GNUTLS_SHUT_RDWR);
 247                 gnutls_deinit(sess);
 248         }
 249 #endif
 250         assert(Conn_OPTION_ISSET(c, CONN_SSL));
 251         /* can't just set bitmask to 0 -- there are other, non-ssl related flags, e.g. CONN_ZIP. */
 252         Conn_OPTION_DEL(c, CONN_SSL_FLAGS_ALL);
 253 }
 254
 255
 256 bool
 257 ConnSSL_InitLibrary( void )
 258 {
 259         if (!Conf_SSLInUse()) {
 260                 LogDebug("SSL not in use, skipping initialization.");
 261                 return true;
 262         }
 263
 264 #ifdef HAVE_LIBSSL
 265         SSL_CTX *newctx;
 266
 267         if (!ssl_ctx) {
 268                 SSL_library_init();
 269                 SSL_load_error_strings();
 270         }
 271
 272         if (!RAND_status()) {
 273                 Log(LOG_ERR, "OpenSSL PRNG not seeded: /dev/urandom missing?");
 274                 /*
 275                  * it is probably best to fail and let the user install EGD or a similar program if no kernel random device is available.
 276                  * According to OpenSSL RAND_egd(3): "The automatic query of /var/run/egd-pool et al was added in OpenSSL 0.9.7";
 277                  * so it makes little sense to deal with PRNGD seeding ourselves.
 278                  */
 279                 array_free(&Conf_SSLOptions.ListenPorts);
 280                 return false;
 281         }
 282
 283         newctx = SSL_CTX_new(SSLv23_method());
 284         if (!newctx) {
 285                 LogOpenSSLError("SSL_CTX_new()", NULL);
 286                 array_free(&Conf_SSLOptions.ListenPorts);
 287                 return false;
 288         }
 289
 290         if (!ConnSSL_LoadServerKey_openssl(newctx))
 291                 goto out;
 292
 293         SSL_CTX_set_options(newctx, SSL_OP_SINGLE_DH_USE|SSL_OP_NO_SSLv2);
 294         SSL_CTX_set_mode(newctx, SSL_MODE_ENABLE_PARTIAL_WRITE);
 295         SSL_CTX_set_verify(newctx, SSL_VERIFY_PEER|SSL_VERIFY_CLIENT_ONCE, Verify_openssl);
 296         SSL_CTX_free(ssl_ctx);
 297         ssl_ctx = newctx;
 298         Log(LOG_INFO, "%s initialized.", SSLeay_version(SSLEAY_VERSION));
 299         return true;
 300 out:
 301         SSL_CTX_free(newctx);
 302         array_free(&Conf_SSLOptions.ListenPorts);
 303         return false;
 304 #endif
 305 #ifdef HAVE_LIBGNUTLS
 306         int err;
 307         static bool initialized;
 308         if (initialized) /* TODO: cannot reload gnutls keys: can't simply free x509 context -- it may still be in use */
 309                 return false;
 310
 311         err = gnutls_global_init();
 312         if (err) {
 313                 Log(LOG_ERR, "gnutls_global_init(): %s", gnutls_strerror(err));
 314                 array_free(&Conf_SSLOptions.ListenPorts);
 315                 return false;
 316         }
 317         if (!ConnSSL_LoadServerKey_gnutls()) {
 318                 array_free(&Conf_SSLOptions.ListenPorts);
 319                 return false;
 320         }
 321         Log(LOG_INFO, "gnutls %s initialized.", gnutls_check_version(NULL));
 322         initialized = true;
 323         return true;
 324 #endif
 325 }
 326
 327
 328 #ifdef HAVE_LIBGNUTLS
 329 static bool
 330 ConnSSL_LoadServerKey_gnutls(void)
 331 {
 332         int err;
 333         const char *cert_file;
 334
 335         err = gnutls_certificate_allocate_credentials(&x509_cred);
 336         if (err < 0) {
 337                 Log(LOG_ERR, "gnutls_certificate_allocate_credentials: %s", gnutls_strerror(err));
 338                 return false;
 339         }
 340
 341         cert_file = Conf_SSLOptions.CertFile ? Conf_SSLOptions.CertFile:Conf_SSLOptions.KeyFile;
 342         if (!cert_file) {
 343                 Log(LOG_ERR, "No SSL server key configured!");
 344                 return false;
 345         }
 346
 347         if (array_bytes(&Conf_SSLOptions.KeyFilePassword))
 348                 Log(LOG_WARNING,
 349                     "Ignoring KeyFilePassword: Not supported by GNUTLS.");
 350
 351         if (!Load_DH_params())
 352                 return false;
 353
 354         gnutls_certificate_set_dh_params(x509_cred, dh_params);
 355         err = gnutls_certificate_set_x509_key_file(x509_cred, cert_file, Conf_SSLOptions.KeyFile, GNUTLS_X509_FMT_PEM);
 356         if (err < 0) {
 357                 Log(LOG_ERR, "gnutls_certificate_set_x509_key_file (cert %s, key %s): %s",
 358                                 cert_file, Conf_SSLOptions.KeyFile ? Conf_SSLOptions.KeyFile : "(NULL)", gnutls_strerror(err));
 359                 return false;
 360         }
 361         return true;
 362 }
 363 #endif
 364
 365
 366 #ifdef HAVE_LIBSSL
 367 static bool
 368 ConnSSL_LoadServerKey_openssl(SSL_CTX *ctx)
 369 {
 370         char *cert_key;
 371
 372         assert(ctx);
 373         if (!Conf_SSLOptions.KeyFile) {
 374                 Log(LOG_ERR, "No SSL server key configured!");
 375                 return false;
 376         }
 377
 378         SSL_CTX_set_default_passwd_cb(ctx, pem_passwd_cb);
 379         SSL_CTX_set_default_passwd_cb_userdata(ctx, &Conf_SSLOptions.KeyFilePassword);
 380
 381         if (SSL_CTX_use_PrivateKey_file(ctx, Conf_SSLOptions.KeyFile, SSL_FILETYPE_PEM) != 1) {
 382                 array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 383                 LogOpenSSLError("SSL_CTX_use_PrivateKey_file",  Conf_SSLOptions.KeyFile);
 384                 return false;
 385         }
 386
 387         cert_key = Conf_SSLOptions.CertFile ? Conf_SSLOptions.CertFile:Conf_SSLOptions.KeyFile;
 388         if (SSL_CTX_use_certificate_chain_file(ctx, cert_key) != 1) {
 389                 array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 390                 LogOpenSSLError("SSL_CTX_use_certificate_file", cert_key);
 391                 return false;
 392         }
 393
 394         array_free_wipe(&Conf_SSLOptions.KeyFilePassword);
 395
 396         if (!SSL_CTX_check_private_key(ctx)) {
 397                 LogOpenSSLError("Server Private Key does not match certificate", NULL);
 398                 return false;
 399         }
 400         if (Load_DH_params()) {
 401                 if (SSL_CTX_set_tmp_dh(ctx, dh_params) != 1)
 402                         LogOpenSSLError("Error setting DH Parameters", Conf_SSLOptions.DHFile);
 403                 /* don't return false here: the non-DH modes will still work */
 404                 DH_free(dh_params);
 405                 dh_params = NULL;
 406         }
 407         return true;
 408 }
 409
 410
 411 #endif
 412 static bool
 413 ConnSSL_Init_SSL(CONNECTION *c)
 414 {
 415         int ret;
 416         assert(c != NULL);
 417 #ifdef HAVE_LIBSSL
 418         if (!ssl_ctx) {
 419                 Log(LOG_ERR, "Cannot init ssl_ctx: OpenSSL initialization failed at startup");
 420                 return false;
 421         }
 422         assert(c->ssl_state.ssl == NULL);
 423         assert(c->ssl_state.fingerprint == NULL);
 424
 425         c->ssl_state.ssl = SSL_new(ssl_ctx);
 426         if (!c->ssl_state.ssl) {
 427                 LogOpenSSLError("SSL_new()", NULL);
 428                 return false;
 429         }
 430
 431         ret = SSL_set_fd(c->ssl_state.ssl, c->sock);
 432         if (ret != 1) {
 433                 LogOpenSSLError("SSL_set_fd()", NULL);
 434                 ConnSSL_Free(c);
 435                 return false;
 436         }
 437 #endif
 438 #ifdef HAVE_LIBGNUTLS
 439         ret = gnutls_set_default_priority(c->ssl_state.gnutls_session);
 440         if (ret < 0) {
 441                 Log(LOG_ERR, "gnutls_set_default_priority: %s", gnutls_strerror(ret));
 442                 ConnSSL_Free(c);
 443                 return false;
 444         }
 445         /*
 446          * The intermediate (long) cast is here to avoid a warning like:
 447          * "cast to pointer from integer of different size" on 64-bit platforms.
 448          * There doesn't seem to be an alternate GNUTLS API we could use instead, see e.g.
 449          * http://www.mail-archive.com/help-gnutls@gnu.org/msg00286.html
 450          */
 451         gnutls_transport_set_ptr(c->ssl_state.gnutls_session, (gnutls_transport_ptr_t) (long) c->sock);
 452         gnutls_certificate_server_set_request(c->ssl_state.gnutls_session, GNUTLS_CERT_REQUEST);
 453         ret = gnutls_credentials_set(c->ssl_state.gnutls_session, GNUTLS_CRD_CERTIFICATE, x509_cred);
 454         if (ret < 0) {
 455                 Log(LOG_ERR, "gnutls_credentials_set: %s", gnutls_strerror(ret));
 456                 ConnSSL_Free(c);
 457                 return false;
 458         }
 459         gnutls_dh_set_prime_bits(c->ssl_state.gnutls_session, DH_BITS_MIN);
 460 #endif
 461         Conn_OPTION_ADD(c, CONN_SSL);
 462         return true;
 463 }
 464
 465
 466 bool
 467 ConnSSL_PrepareConnect(CONNECTION *c, UNUSED CONF_SERVER *s)
 468 {
 469         bool ret;
 470 #ifdef HAVE_LIBGNUTLS
 471         int err;
 472
 473         err = gnutls_init(&c->ssl_state.gnutls_session, GNUTLS_CLIENT);
 474         if (err) {
 475                 Log(LOG_ERR, "gnutls_init: %s", gnutls_strerror(err));
 476                 return false;
 477         }
 478 #endif
 479         ret = ConnSSL_Init_SSL(c);
 480         if (!ret)
 481                 return false;
 482         Conn_OPTION_ADD(c, CONN_SSL_CONNECT);
 483 #ifdef HAVE_LIBSSL
 484         assert(c->ssl_state.ssl);
 485         SSL_set_verify(c->ssl_state.ssl, SSL_VERIFY_NONE, NULL);
 486 #endif
 487         return true;
 488 }
 489
 490
 491 /**
 492  * Check and handle error return codes after failed calls to SSL/TLS functions.
 493  *
 494  * OpenSSL:
 495  * SSL_connect(), SSL_accept(), SSL_do_handshake(), SSL_read(), SSL_peek(), or
 496  * SSL_write() on ssl.
 497  *
 498  * GNUTLS:
 499  * gnutlsssl_read(), gnutls_write() or gnutls_handshake().
 500  *
 501  * @param c The connection handle.
 502  * @prarm code The return code.
 503  * @param fname The name of the function in which the error occurred.
 504  * @return -1 on fatal errors, 0 if we can try again later.
 505  */
 506 static int
 507 ConnSSL_HandleError(CONNECTION * c, const int code, const char *fname)
 508 {
 509 #ifdef HAVE_LIBSSL
 510         int ret = SSL_ERROR_SYSCALL;
 511         unsigned long sslerr;
 512         int real_errno = errno;
 513
 514         ret = SSL_get_error(c->ssl_state.ssl, code);
 515         switch (ret) {
 516         case SSL_ERROR_WANT_READ:
 517                 io_event_del(c->sock, IO_WANTWRITE);
 518                 Conn_OPTION_ADD(c, CONN_SSL_WANT_READ);
 519                 return 0;       /* try again later */
 520         case SSL_ERROR_WANT_WRITE:
 521                 io_event_del(c->sock, IO_WANTREAD);
 522                 Conn_OPTION_ADD(c, CONN_SSL_WANT_WRITE); /* fall through */
 523         case SSL_ERROR_NONE:
 524                 return 0;       /* try again later */
 525         case SSL_ERROR_ZERO_RETURN:
 526                 LogDebug("TLS/SSL connection shut down normally");
 527                 break;
 528         case SSL_ERROR_SYSCALL:
 529                 /* SSL_ERROR_WANT_CONNECT, SSL_ERROR_WANT_ACCEPT,
 530                  * and SSL_ERROR_WANT_X509_LOOKUP */
 531                 sslerr = ERR_get_error();
 532                 if (sslerr) {
 533                         Log(LOG_ERR, "%s: %s", fname,
 534                             ERR_error_string(sslerr, NULL));
 535                 } else {
 536
 537                         switch (code) { /* EOF that violated protocol */
 538                         case 0:
 539                                 Log(LOG_ERR, "%s: Client Disconnected", fname);
 540                                 break;
 541                         case -1:        /* low level socket I/O error, check errno */
 542                                 Log(LOG_ERR, "%s: %s", fname,
 543                                     strerror(real_errno));
 544                         }
 545                 }
 546                 break;
 547         case SSL_ERROR_SSL:
 548                 LogOpenSSLError("TLS/SSL Protocol Error", fname);
 549                 break;
 550         default:
 551                 Log(LOG_ERR, "%s: Unknown error %d!", fname, ret);
 552         }
 553         ConnSSL_Free(c);
 554         return -1;
 555 #endif
 556 #ifdef HAVE_LIBGNUTLS
 557         switch (code) {
 558         case GNUTLS_E_AGAIN:
 559         case GNUTLS_E_INTERRUPTED:
 560                 if (gnutls_record_get_direction(c->ssl_state.gnutls_session)) {
 561                         Conn_OPTION_ADD(c, CONN_SSL_WANT_WRITE);
 562                         io_event_del(c->sock, IO_WANTREAD);
 563                 } else {
 564                         Conn_OPTION_ADD(c, CONN_SSL_WANT_READ);
 565                         io_event_del(c->sock, IO_WANTWRITE);
 566                 }
 567                 break;
 568         default:
 569                 assert(code < 0);
 570                 if (gnutls_error_is_fatal(code)) {
 571                         Log(LOG_ERR, "%s: %s", fname, gnutls_strerror(code));
 572                         ConnSSL_Free(c);
 573                         return -1;
 574                 }
 575         }
 576         return 0;
 577 #endif
 578 }
 579
 580
 581 static void
 582 ConnSSL_LogCertInfo( CONNECTION *c )
 583 {
 584 #ifdef HAVE_LIBSSL
 585         SSL *ssl = c->ssl_state.ssl;
 586
 587         assert(ssl);
 588
 589         Log(LOG_INFO, "Connection %d: initialized %s using cipher %s.",
 590                 c->sock, SSL_get_version(ssl), SSL_get_cipher(ssl));
 591 #endif
 592 #ifdef HAVE_LIBGNUTLS
 593         gnutls_session_t sess = c->ssl_state.gnutls_session;
 594         gnutls_cipher_algorithm_t cipher = gnutls_cipher_get(sess);
 595
 596         Log(LOG_INFO, "Connection %d: initialized %s using cipher %s-%s.",
 597             c->sock,
 598             gnutls_protocol_get_name(gnutls_protocol_get_version(sess)),
 599             gnutls_cipher_get_name(cipher),
 600             gnutls_mac_get_name(gnutls_mac_get(sess)));
 601 #endif
 602 }
 603
 604
 605 /*
 606  Accept incoming SSL connection.
 607  Return Values:
 608          1: SSL Connection established
 609          0: try again
 610         -1: SSL Connection not established due to fatal error.
 611 */
 612 int
 613 ConnSSL_Accept( CONNECTION *c )
 614 {
 615         assert(c != NULL);
 616         if (!Conn_OPTION_ISSET(c, CONN_SSL)) {
 617 #ifdef HAVE_LIBGNUTLS
 618                 int err = gnutls_init(&c->ssl_state.gnutls_session, GNUTLS_SERVER);
 619                 if (err) {
 620                         Log(LOG_ERR, "gnutls_init: %s", gnutls_strerror(err));
 621                         return false;
 622                 }
 623 #endif
 624                 LogDebug("ConnSSL_Accept: Initializing SSL data");
 625                 if (!ConnSSL_Init_SSL(c))
 626                         return -1;
 627         }
 628         return ConnectAccept(c, false );
 629 }
 630
 631
 632 int
 633 ConnSSL_Connect( CONNECTION *c )
 634 {
 635         assert(c != NULL);
 636 #ifdef HAVE_LIBSSL
 637         assert(c->ssl_state.ssl);
 638 #endif
 639         assert(Conn_OPTION_ISSET(c, CONN_SSL));
 640         return ConnectAccept(c, true);
 641 }
 642
 643 static int
 644 ConnSSL_InitCertFp( CONNECTION *c )
 645 {
 646         const char hex[] = "0123456789abcdef";
 647         int i;
 648
 649 #ifdef HAVE_LIBSSL
 650         unsigned char digest[EVP_MAX_MD_SIZE];
 651         unsigned int digest_size;
 652         X509 *cert;
 653
 654         cert = SSL_get_peer_certificate(c->ssl_state.ssl);
 655         if (!cert)
 656                 return 0;
 657
 658         if (!X509_digest(cert, EVP_sha1(), digest, &digest_size)) {
 659                 X509_free(cert);
 660                 return 0;
 661         }
 662
 663         X509_free(cert);
 664 #endif /* HAVE_LIBSSL */
 665 #ifdef HAVE_LIBGNUTLS
 666         gnutls_x509_crt_t cert;
 667         unsigned int cert_list_size;
 668         const gnutls_datum_t *cert_list;
 669         unsigned char digest[MAX_HASH_SIZE];
 670         size_t digest_size;
 671
 672         if (gnutls_certificate_type_get(c->ssl_state.gnutls_session) != GNUTLS_CRT_X509)
 673                 return 0;
 674
 675         if (gnutls_x509_crt_init(&cert) != GNUTLS_E_SUCCESS)
 676                 return 0;
 677
 678         cert_list_size = 0;
 679         cert_list = gnutls_certificate_get_peers(c->ssl_state.gnutls_session,
 680                                                  &cert_list_size);
 681         if (!cert_list) {
 682                 gnutls_x509_crt_deinit(cert);
 683                 return 0;
 684         }
 685
 686         if (gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER) != GNUTLS_E_SUCCESS) {
 687                 gnutls_x509_crt_deinit(cert);
 688                 return 0;
 689         }
 690
 691         digest_size = sizeof(digest);
 692         if (gnutls_x509_crt_get_fingerprint(cert, GNUTLS_DIG_SHA1, digest, &digest_size)) {
 693                 gnutls_x509_crt_deinit(cert);
 694                 return 0;
 695         }
 696
 697         gnutls_x509_crt_deinit(cert);
 698 #endif /* HAVE_LIBGNUTLS */
 699
 700         assert(c->ssl_state.fingerprint == NULL);
 701
 702         c->ssl_state.fingerprint = malloc(CERTFP_LEN);
 703         if (!c->ssl_state.fingerprint)
 704                 return 0;
 705
 706         for (i = 0; i < (int)digest_size; i++) {
 707                 c->ssl_state.fingerprint[i * 2] = hex[digest[i] / 16];
 708                 c->ssl_state.fingerprint[i * 2 + 1] = hex[digest[i] % 16];
 709         }
 710         c->ssl_state.fingerprint[i * 2] = '\0';
 711
 712         return 1;
 713 }
 714
 715 /* accept/connect wrapper. if connect is true, connect to peer, otherwise wait for incoming connection */
 716 static int
 717 ConnectAccept( CONNECTION *c, bool connect)
 718 {
 719         int ret;
 720 #ifdef HAVE_LIBSSL
 721         SSL *ssl = c->ssl_state.ssl;
 722         assert(ssl != NULL);
 723
 724         ret = connect ? SSL_connect(ssl) : SSL_accept(ssl);
 725         if (1 != ret)
 726                 return ConnSSL_HandleError(c, ret, connect ? "SSL_connect": "SSL_accept");
 727 #endif
 728 #ifdef HAVE_LIBGNUTLS
 729         (void) connect;
 730         ret = gnutls_handshake(c->ssl_state.gnutls_session);
 731         if (ret)
 732                 return ConnSSL_HandleError(c, ret, "gnutls_handshake");
 733 #endif /* _GNUTLS */
 734         (void)ConnSSL_InitCertFp(c);
 735
 736         Conn_OPTION_DEL(c, (CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ|CONN_SSL_CONNECT));
 737         ConnSSL_LogCertInfo(c);
 738
 739         Conn_StartLogin(CONNECTION2ID(c));
 740         return 1;
 741 }
 742
 743
 744 ssize_t
 745 ConnSSL_Write(CONNECTION *c, const void *buf, size_t count)
 746 {
 747         ssize_t bw;
 748
 749         Conn_OPTION_DEL(c, CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ);
 750
 751         assert(count > 0);
 752 #ifdef HAVE_LIBSSL
 753         bw = (ssize_t) SSL_write(c->ssl_state.ssl, buf, count);
 754 #endif
 755 #ifdef HAVE_LIBGNUTLS
 756         bw = gnutls_write(c->ssl_state.gnutls_session, buf, count);
 757 #endif
 758         if (bw > 0)
 759                 return bw;
 760         if (ConnSSL_HandleError( c, bw, "ConnSSL_Write") == 0)
 761                 errno = EAGAIN; /* try again */
 762         return -1;
 763 }
 764
 765
 766 ssize_t
 767 ConnSSL_Read(CONNECTION *c, void * buf, size_t count)
 768 {
 769         ssize_t br;
 770
 771         Conn_OPTION_DEL(c, CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ);
 772 #ifdef HAVE_LIBSSL
 773         br = (ssize_t) SSL_read(c->ssl_state.ssl, buf, count);
 774         if (br > 0)     /* on EOF we have to call ConnSSL_HandleError(), see SSL_read(3) */
 775                 return br;
 776 #endif
 777 #ifdef HAVE_LIBGNUTLS
 778         br = gnutls_read(c->ssl_state.gnutls_session, buf, count);
 779         if (br >= 0)    /* on EOF we must _not_ call ConnSSL_HandleError, see gnutls_record_recv(3) */
 780                 return br;
 781 #endif
 782         /* error on read: switch ConnSSL_HandleError() return values -> 0 is "try again", so return -1 and set EAGAIN */
 783         if (ConnSSL_HandleError(c, br, "ConnSSL_Read") == 0) {
 784                 errno = EAGAIN;
 785                 return -1;
 786         }
 787         return 0;
 788 }
 789
 790
 791 bool
 792 ConnSSL_GetCipherInfo(CONNECTION *c, char *buf, size_t len)
 793 {
 794 #ifdef HAVE_LIBSSL
 795         char *nl;
 796         SSL *ssl = c->ssl_state.ssl;
 797
 798         if (!ssl)
 799                 return false;
 800         *buf = 0;
 801         SSL_CIPHER_description(SSL_get_current_cipher(ssl), buf, len);
 802         nl = strchr(buf, '\n');
 803         if (nl)
 804                 *nl = 0;
 805         return true;
 806 #endif
 807 #ifdef HAVE_LIBGNUTLS
 808         if (Conn_OPTION_ISSET(c, CONN_SSL)) {
 809                 const char *name_cipher, *name_mac, *name_proto, *name_keyexchange;
 810                 unsigned keysize;
 811
 812                 gnutls_session_t sess = c->ssl_state.gnutls_session;
 813                 gnutls_cipher_algorithm_t cipher = gnutls_cipher_get(sess);
 814                 name_cipher = gnutls_cipher_get_name(cipher);
 815                 name_mac = gnutls_mac_get_name(gnutls_mac_get(sess));
 816                 keysize = gnutls_cipher_get_key_size(cipher) * 8;
 817                 name_proto = gnutls_protocol_get_name(gnutls_protocol_get_version(sess));
 818                 name_keyexchange = gnutls_kx_get_name(gnutls_kx_get(sess));
 819
 820                 return snprintf(buf, len, "%s-%s%15s Kx=%s      Enc=%s(%u) Mac=%s",
 821                         name_cipher, name_mac, name_proto, name_keyexchange, name_cipher, keysize, name_mac) > 0;
 822         }
 823         return false;
 824 #endif
 825 }
 826
 827 char *
 828 ConnSSL_GetCertFp(CONNECTION *c)
 829 {
 830         return c->ssl_state.fingerprint;
 831 }
 832
 833 bool
 834 ConnSSL_SetCertFp(CONNECTION *c, const char *fingerprint)
 835 {
 836         assert (c != NULL);
 837         c->ssl_state.fingerprint = strdup(fingerprint);
 838         return c->ssl_state.fingerprint != NULL;
 839 }
 840 #else
 841
 842 bool
 843 ConnSSL_InitLibrary(void)
 844 {
 845         return true;
 846 }
 847
 848 #endif /* SSL_SUPPORT */
 849 /* -eof- */
 850
 851