openssl-support.diff

   1 Casey Marshall wrote:
   2
   3 I've been hacking together a way to use rsync with OpenSSL, and have
   4 attached my current patch against a recent CVS tree. The details of
   5 this implementation are:
   6
   7   1. The SSL code is added as a "layer" that is forked into its own
   8      process.
   9
  10   2. An SSL connection is established by the client issuing the
  11      command:
  12
  13        #starttls
  14
  15      And, if the daemon allows SSL, it replies with
  16
  17        @RSYNCD: starttls
  18
  19      At which point both sides begin negotiating the SSL connection.
  20      Servers that can't or don't want to use SSL just treat it as a
  21      normal unknown command.
  22
  23   3. The SSL code is meant to be unobtrusive, and when this patch is
  24      applied the program may still be built with no SSL code.
  25
  26   4. There are a number of details not implemented.
  27
  28 All warnings apply; I don't do C programming all that often, so I
  29 can't say if I've left any cleanup/compatibility errors in the code.
  30
  31 To use this patch, run these commands for a successful build:
  32
  33     patch -p1 <patches/openssl-support.diff
  34     ./prepare-source
  35     ./configure
  36     make
  37
  38 --- old/Makefile.in
  39 +++ new/Makefile.in
  40 @@ -39,7 +39,7 @@ OBJS3=progress.o pipe.o
  41  DAEMON_OBJ = params.o loadparm.o clientserver.o access.o connection.o authenticate.o
  42  popt_OBJS=popt/findme.o  popt/popt.o  popt/poptconfig.o \
  43         popt/popthelp.o popt/poptparse.o
  44 -OBJS=$(OBJS1) $(OBJS2) $(OBJS3) $(DAEMON_OBJ) $(LIBOBJ) $(ZLIBOBJ) @BUILD_POPT@
  45 +OBJS=$(OBJS1) $(OBJS2) $(OBJS3) $(DAEMON_OBJ) $(LIBOBJ) $(ZLIBOBJ) @BUILD_POPT@ @SSL_OBJS@
  46
  47  TLS_OBJ = tls.o syscall.o lib/compat.o lib/snprintf.o lib/permstring.o
  48
  49 --- old/cleanup.c
  50 +++ new/cleanup.c
  51 @@ -25,6 +25,9 @@
  52  extern int am_server;
  53  extern int am_daemon;
  54  extern int io_error;
  55 +#ifdef HAVE_OPENSSL
  56 +extern int use_ssl;
  57 +#endif
  58  extern int keep_partial;
  59  extern int log_got_error;
  60  extern char *partial_dir;
  61 @@ -116,6 +119,14 @@ NORETURN void _exit_cleanup(int code, co
  62                                 code, file, line);
  63                 }
  64
  65 +#ifdef HAVE_OPENSSL
  66 +               /* FALLTHROUGH */
  67 +#include "case_N.h"
  68 +
  69 +               if (use_ssl)
  70 +                       end_tls();
  71 +#endif
  72 +
  73                 /* FALLTHROUGH */
  74  #include "case_N.h"
  75
  76 --- old/clientserver.c
  77 +++ new/clientserver.c
  78 @@ -29,6 +29,9 @@ extern int am_sender;
  79  extern int am_server;
  80  extern int am_daemon;
  81  extern int am_root;
  82 +#ifdef HAVE_OPENSSL
  83 +extern int use_ssl;
  84 +#endif
  85  extern int rsync_port;
  86  extern int ignore_errors;
  87  extern int kluge_around_eof;
  88 @@ -106,8 +109,18 @@ int start_socket_client(char *host, char
  89         set_socket_options(fd, sockopts);
  90
  91         ret = start_inband_exchange(user, path, fd, fd, argc);
  92 +       if (ret)
  93 +               return ret;
  94
  95 -       return ret ? ret : client_run(fd, fd, -1, argc, argv);
  96 +#ifdef HAVE_OPENSSL
  97 +       if (use_ssl) {
  98 +               int f_in = get_tls_rfd();
  99 +               int f_out = get_tls_wfd();
 100 +               return client_run(f_in, f_out, -1, argc, argv);
 101 +       }
 102 +#endif
 103 +
 104 +       return client_run(fd, fd, -1, argc, argv);
 105  }
 106
 107  int start_inband_exchange(const char *user, char *path, int f_in, int f_out,
 108 @@ -168,6 +181,33 @@ int start_inband_exchange(const char *us
 109         if (verbose > 1)
 110                 print_child_argv(sargs);
 111
 112 +#ifdef HAVE_OPENSSL
 113 +       if (use_ssl) {
 114 +               io_printf(f_out, "#starttls\n");
 115 +               while (1) {
 116 +                       if (!read_line(f_in, line, sizeof(line)-1)) {
 117 +                               rprintf(FERROR, "rsync: did not receive reply to #starttls\n");
 118 +                               return -1;
 119 +                       }
 120 +                       if (strncmp(line, "@ERROR", 6) == 0) {
 121 +                               rprintf(FERROR, "%s\n", line);
 122 +                               return -1;
 123 +                       }
 124 +                       if (strcmp(line, "@RSYNCD: starttls") == 0) {
 125 +                               break;
 126 +                       }
 127 +                       rprintf(FINFO, "%s\n", line);
 128 +               }
 129 +               if (start_tls(f_in, f_out)) {
 130 +                       rprintf(FERROR, "rsync: error during SSL handshake: %s\n",
 131 +                               get_ssl_error());
 132 +                       return -1;
 133 +               }
 134 +               f_in = get_tls_rfd();
 135 +               f_out = get_tls_wfd();
 136 +       }
 137 +#endif
 138 +
 139         p = strchr(path,'/');
 140         if (p) *p = 0;
 141         io_printf(f_out, "%s\n", path);
 142 @@ -196,6 +236,10 @@ int start_inband_exchange(const char *us
 143                          * server to terminate the listing of modules.
 144                          * We don't want to go on and transfer
 145                          * anything; just exit. */
 146 +#ifdef HAVE_OPENSSL
 147 +                       if (use_ssl)
 148 +                               end_tls();
 149 +#endif
 150                         exit(0);
 151                 }
 152
 153 @@ -203,6 +247,10 @@ int start_inband_exchange(const char *us
 154                         rprintf(FERROR, "%s\n", line);
 155                         /* This is always fatal; the server will now
 156                          * close the socket. */
 157 +#ifdef HAVE_OPENSSL
 158 +                       if (use_ssl)
 159 +                               end_tls();
 160 +#endif
 161                         return -1;
 162                 }
 163
 164 @@ -785,6 +833,9 @@ int start_daemon(int f_in, int f_out)
 165         if (protocol_version > remote_protocol)
 166                 protocol_version = remote_protocol;
 167
 168 +#ifdef HAVE_OPENSSL
 169 +retry:
 170 +#endif
 171         line[0] = 0;
 172         if (!read_line(f_in, line, sizeof line - 1))
 173                 return -1;
 174 @@ -796,6 +847,20 @@ int start_daemon(int f_in, int f_out)
 175                 return -1;
 176         }
 177
 178 +#ifdef HAVE_OPENSSL
 179 +       if (use_ssl && strcmp(line, "#starttls") == 0) {
 180 +               io_printf(f_out, "@RSYNCD: starttls\n");
 181 +               if (start_tls(f_in, f_out)) {
 182 +                       rprintf(FLOG, "SSL connection failed: %s\n",
 183 +                               get_ssl_error());
 184 +                       return -1;
 185 +               }
 186 +               f_in = get_tls_rfd();
 187 +               f_out = get_tls_wfd();
 188 +               goto retry;
 189 +       }
 190 +#endif
 191 +
 192         if (*line == '#') {
 193                 /* it's some sort of command that I don't understand */
 194                 io_printf(f_out, "@ERROR: Unknown command '%s'\n", line);
 195 --- old/configure.in
 196 +++ new/configure.in
 197 @@ -290,6 +290,21 @@ if test x"$enable_locale" != x"no"; then
 198         AC_DEFINE(CONFIG_LOCALE)
 199  fi
 200
 201 +AC_ARG_ENABLE(openssl,
 202 +              AC_HELP_STRING([--enable-openssl], [compile SSL support with OpenSSL.]))
 203 +
 204 +if test "x$enable_openssl" != xno
 205 +then
 206 +       have_ssl=yes
 207 +       AC_CHECK_LIB(ssl, SSL_library_init, , [have_ssl=no])
 208 +       if test "x$have_ssl" = xyes
 209 +       then
 210 +               AC_DEFINE(HAVE_OPENSSL, 1, [true if you want to use SSL.])
 211 +               SSL_OBJS=ssl.o
 212 +               AC_SUBST(SSL_OBJS)
 213 +       fi
 214 +fi
 215 +
 216  AC_MSG_CHECKING([whether to call shutdown on all sockets])
 217  case $host_os in
 218         *cygwin* ) AC_MSG_RESULT(yes)
 219 --- old/options.c
 220 +++ new/options.c
 221 @@ -172,6 +172,14 @@ int logfile_format_has_o_or_i = 0;
 222  int always_checksum = 0;
 223  int list_only = 0;
 224
 225 +#ifdef HAVE_OPENSSL
 226 +int use_ssl = 0;
 227 +char *ssl_cert_path = NULL;
 228 +char *ssl_key_path = NULL;
 229 +char *ssl_key_passwd = NULL;
 230 +char *ssl_ca_path = NULL;
 231 +#endif
 232 +
 233  #define MAX_BATCH_NAME_LEN 256 /* Must be less than MAXPATHLEN-13 */
 234  char *batch_name = NULL;
 235
 236 @@ -202,6 +210,7 @@ static void print_rsync_version(enum log
 237         char const *acls = "no ";
 238         char const *links = "no ";
 239         char const *ipv6 = "no ";
 240 +       char const *ssl = "no ";
 241         STRUCT_STAT *dumstat;
 242
 243  #ifdef HAVE_SOCKETPAIR
 244 @@ -228,6 +237,10 @@ static void print_rsync_version(enum log
 245         ipv6 = "";
 246  #endif
 247
 248 +#ifdef HAVE_OPENSSL
 249 +       ssl = "";
 250 +#endif
 251 +
 252         rprintf(f, "%s  version %s  protocol version %d\n",
 253                 RSYNC_NAME, RSYNC_VERSION, PROTOCOL_VERSION);
 254         rprintf(f, "Copyright (C) 1996-2007 by Andrew Tridgell, Wayne Davison, and others.\n");
 255 @@ -238,8 +251,8 @@ static void print_rsync_version(enum log
 256                 (int)(sizeof (int64) * 8));
 257         rprintf(f, "    %ssocketpairs, %shardlinks, %ssymlinks, %sIPv6, batchfiles, %sinplace,\n",
 258                 got_socketpair, hardlinks, links, ipv6, have_inplace);
 259 -       rprintf(f, "    %sappend, %sACLs\n",
 260 -               have_inplace, acls);
 261 +       rprintf(f, "    %sappend, %sACLs, %sSSL\n",
 262 +               have_inplace, acls, ssl);
 263
 264  #ifdef MAINTAINER_MODE
 265         rprintf(f, "Panic Action: \"%s\"\n", get_panic_action());
 266 @@ -390,6 +403,13 @@ void usage(enum logcode F)
 267    rprintf(F," -4, --ipv4                  prefer IPv4\n");
 268    rprintf(F," -6, --ipv6                  prefer IPv6\n");
 269  #endif
 270 +#ifdef HAVE_OPENSSL
 271 +  rprintf(F,"     --ssl                   allow socket connections to use SSL\n");
 272 +  rprintf(F,"     --ssl-cert=FILE         path to daemon's SSL certificate\n");
 273 +  rprintf(F,"     --ssl-key=FILE          path to daemon's SSL private key\n");
 274 +  rprintf(F,"     --ssl-key-passwd=PASS   password for PEM-encoded private key\n");
 275 +  rprintf(F,"     --ssl-ca-certs=FILE     path to trusted CA certificates\n");
 276 +#endif
 277    rprintf(F,"     --version               print version number\n");
 278    rprintf(F,"(-h) --help                  show this help (-h works with no other options)\n");
 279
 280 @@ -403,7 +423,7 @@ enum {OPT_VERSION = 1000, OPT_DAEMON, OP
 281        OPT_FILTER, OPT_COMPARE_DEST, OPT_COPY_DEST, OPT_LINK_DEST, OPT_HELP,
 282        OPT_INCLUDE, OPT_INCLUDE_FROM, OPT_MODIFY_WINDOW, OPT_MIN_SIZE, OPT_CHMOD,
 283        OPT_READ_BATCH, OPT_WRITE_BATCH, OPT_ONLY_WRITE_BATCH, OPT_MAX_SIZE,
 284 -      OPT_NO_D,
 285 +      OPT_NO_D, OPT_USE_SSL,
 286        OPT_SERVER, OPT_REFUSED_BASE = 9000};
 287
 288  static struct poptOption long_options[] = {
 289 @@ -554,6 +574,13 @@ static struct poptOption long_options[]
 290    {"checksum-seed",    0,  POPT_ARG_INT,    &checksum_seed, 0, 0, 0 },
 291    {"server",           0,  POPT_ARG_NONE,   0, OPT_SERVER, 0, 0 },
 292    {"sender",           0,  POPT_ARG_NONE,   0, OPT_SENDER, 0, 0 },
 293 +#ifdef HAVE_OPENSSL
 294 +  {"ssl",              0,  POPT_ARG_NONE,   0, OPT_USE_SSL, 0, 0},
 295 +  {"ssl-cert",         0,  POPT_ARG_STRING, &ssl_cert_path, OPT_USE_SSL, 0, 0},
 296 +  {"ssl-key",          0,  POPT_ARG_STRING, &ssl_key_path, OPT_USE_SSL, 0, 0},
 297 +  {"ssl-key-passwd",   0,  POPT_ARG_STRING, &ssl_key_passwd, OPT_USE_SSL, 0, 0},
 298 +  {"ssl-ca-certs",     0,  POPT_ARG_STRING, &ssl_ca_path, OPT_USE_SSL, 0, 0},
 299 +#endif
 300    /* All the following options switch us into daemon-mode option-parsing. */
 301    {"config",           0,  POPT_ARG_STRING, 0, OPT_DAEMON, 0, 0 },
 302    {"daemon",           0,  POPT_ARG_NONE,   0, OPT_DAEMON, 0, 0 },
 303 @@ -581,6 +608,13 @@ static void daemon_usage(enum logcode F)
 304    rprintf(F," -4, --ipv4                  prefer IPv4\n");
 305    rprintf(F," -6, --ipv6                  prefer IPv6\n");
 306  #endif
 307 +#ifdef HAVE_OPENSSL
 308 +  rprintf(F,"     --ssl                   allow socket connections to use SSL\n");
 309 +  rprintf(F,"     --ssl-cert=FILE         path to daemon's SSL certificate\n");
 310 +  rprintf(F,"     --ssl-key=FILE          path to daemon's SSL private key\n");
 311 +  rprintf(F,"     --ssl-key-passwd=PASS   password for PEM-encoded private key\n");
 312 +  rprintf(F,"     --ssl-ca-certs=FILE     path to trusted CA certificates\n");
 313 +#endif
 314    rprintf(F,"     --help                  show this help screen\n");
 315
 316    rprintf(F,"\n");
 317 @@ -607,6 +641,13 @@ static struct poptOption long_daemon_opt
 318    {"protocol",         0,  POPT_ARG_INT,    &protocol_version, 0, 0, 0 },
 319    {"server",           0,  POPT_ARG_NONE,   &am_server, 0, 0, 0 },
 320    {"temp-dir",        'T', POPT_ARG_STRING, &tmpdir, 0, 0, 0 },
 321 +#ifdef HAVE_OPENSSL
 322 +  {"ssl",              0,  POPT_ARG_NONE,   0, OPT_USE_SSL, 0, 0},
 323 +  {"ssl-cert",         0,  POPT_ARG_STRING, &ssl_cert_path, OPT_USE_SSL, 0, 0},
 324 +  {"ssl-key",          0,  POPT_ARG_STRING, &ssl_key_path, OPT_USE_SSL, 0, 0},
 325 +  {"ssl-key-passwd",   0,  POPT_ARG_STRING, &ssl_key_passwd, OPT_USE_SSL, 0, 0},
 326 +  {"ssl-ca-certs",     0,  POPT_ARG_STRING, &ssl_ca_path, OPT_USE_SSL, 0, 0},
 327 +#endif
 328    {"verbose",         'v', POPT_ARG_NONE,   0, 'v', 0, 0 },
 329    {"no-verbose",       0,  POPT_ARG_VAL,    &verbose, 0, 0, 0 },
 330    {"no-v",             0,  POPT_ARG_VAL,    &verbose, 0, 0, 0 },
 331 @@ -866,6 +907,12 @@ int parse_arguments(int *argc, const cha
 332                                         verbose++;
 333                                         break;
 334
 335 +#ifdef HAVE_OPENSSL
 336 +                               case OPT_USE_SSL:
 337 +                                       use_ssl = 1;
 338 +                                       break;
 339 +#endif
 340 +
 341                                 default:
 342                                         rprintf(FERROR,
 343                                             "rsync: %s: %s (in daemon mode)\n",
 344 @@ -889,6 +936,17 @@ int parse_arguments(int *argc, const cha
 345                                 exit_cleanup(RERR_SYNTAX);
 346                         }
 347
 348 +#ifdef HAVE_OPENSSL
 349 +                       if (use_ssl) {
 350 +                               if (init_tls()) {
 351 +                                       snprintf(err_buf, sizeof(err_buf),
 352 +                                                "Openssl error: %s\n",
 353 +                                                get_ssl_error());
 354 +                                       return 0;
 355 +                               }
 356 +                       }
 357 +#endif
 358 +
 359                         *argv = poptGetArgs(pc);
 360                         *argc = count_args(*argv);
 361                         am_starting_up = 0;
 362 @@ -1122,6 +1180,12 @@ int parse_arguments(int *argc, const cha
 363  #endif
 364
 365
 366 +#ifdef HAVE_OPENSSL
 367 +               case OPT_USE_SSL:
 368 +                       use_ssl = 1;
 369 +                       break;
 370 +#endif
 371 +
 372                 default:
 373                         /* A large opt value means that set_refuse_options()
 374                          * turned this option off. */
 375 @@ -1400,6 +1464,17 @@ int parse_arguments(int *argc, const cha
 376         if (delay_updates && !partial_dir)
 377                 partial_dir = tmp_partialdir;
 378
 379 +#ifdef HAVE_OPENSSL
 380 +       if (use_ssl) {
 381 +               if (init_tls()) {
 382 +                       snprintf(err_buf, sizeof(err_buf),
 383 +                                "Openssl error: %s\n",
 384 +                                get_ssl_error());
 385 +                       return 0;
 386 +               }
 387 +       }
 388 +#endif
 389 +
 390         if (inplace) {
 391  #ifdef HAVE_FTRUNCATE
 392                 if (partial_dir) {
 393 @@ -1827,10 +1902,27 @@ char *check_for_hostspec(char *s, char *
 394         char *p;
 395         int not_host;
 396         int hostlen;
 397 +       int url_prefix_len = sizeof URL_PREFIX - 1;
 398
 399 -       if (port_ptr && strncasecmp(URL_PREFIX, s, strlen(URL_PREFIX)) == 0) {
 400 +       if (!port_ptr)
 401 +               url_prefix_len = 0;
 402 +       else if (strncasecmp(URL_PREFIX, s, url_prefix_len) != 0) {
 403 +#ifdef HAVE_OPENSSL
 404 +               url_prefix_len = sizeof SSL_URL_PREFIX - 1;
 405 +               if (strncasecmp(SSL_URL_PREFIX, s, url_prefix_len) != 0)
 406 +                       url_prefix_len = 0;
 407 +               else {
 408 +                       if (!use_ssl)
 409 +                               init_tls();
 410 +                       use_ssl = 1;
 411 +               }
 412 +#else
 413 +               url_prefix_len = 0;
 414 +#endif
 415 +       }
 416 +       if (url_prefix_len) {
 417                 char *path;
 418 -               s += strlen(URL_PREFIX);
 419 +               s += url_prefix_len;
 420                 if ((p = strchr(s, '/')) != NULL) {
 421                         hostlen = p - s;
 422                         path = p + 1;
 423 --- old/rsync.h
 424 +++ new/rsync.h
 425 @@ -31,6 +31,7 @@
 426
 427  #define DEFAULT_LOCK_FILE "/var/run/rsyncd.lock"
 428  #define URL_PREFIX "rsync://"
 429 +#define SSL_URL_PREFIX "rsyncs://"
 430
 431  #define BACKUP_SUFFIX "~"
 432
 433 @@ -474,6 +475,11 @@ enum msgcode {
 434  # define SIZEOF_INT64 SIZEOF_OFF_T
 435  #endif
 436
 437 +#ifdef HAVE_OPENSSL
 438 +#include <openssl/ssl.h>
 439 +#include <openssl/err.h>
 440 +#endif
 441 +
 442  /* Starting from protocol version 26, we always use 64-bit
 443   * ino_t and dev_t internally, even if this platform does not
 444   * allow files to have 64-bit inums.  That's because the
 445 --- old/ssl.c
 446 +++ new/ssl.c
 447 @@ -0,0 +1,370 @@
 448 +/* -*- c-file-style: "linux" -*-
 449 + * ssl.c: operations for negotiating SSL rsync connections.
 450 + *
 451 + * Copyright (C) 2003  Casey Marshall <rsdio@metastatic.org>
 452 + *
 453 + * This program is free software; you can redistribute it and/or modify
 454 + * it under the terms of the GNU General Public License as published by
 455 + * the Free Software Foundation; either version 2 of the License, or
 456 + * (at your option) any later version.
 457 + *
 458 + * This program is distributed in the hope that it will be useful,
 459 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
 460 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 461 + * GNU General Public License for more details.
 462 + *
 463 + * You should have received a copy of the GNU General Public License
 464 + * along with this program; if not, write to the Free Software
 465 + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 466 + */
 467 +
 468 +#include "rsync.h"
 469 +
 470 +#ifdef HAVE_SYS_SELECT_H
 471 +#include <sys/select.h>
 472 +#else
 473 +#include <sys/time.h>
 474 +#include <sys/types.h>
 475 +#include <unistd.h>
 476 +#endif
 477 +#include <string.h>
 478 +
 479 +#define BUF_SIZE 1024
 480 +
 481 +extern int verbose;
 482 +extern int am_daemon;
 483 +extern int am_server;
 484 +
 485 +extern char *ssl_cert_path;
 486 +extern char *ssl_key_path;
 487 +extern char *ssl_key_passwd;
 488 +extern char *ssl_ca_path;
 489 +
 490 +static SSL_CTX *ssl_ctx;
 491 +static SSL *ssl;
 492 +static int tls_read[2] = { -1, -1 };
 493 +static int tls_write[2] = { -1, -1 };
 494 +static int ssl_running;
 495 +static int ssl_pid = -1;
 496 +
 497 +#ifdef HAVE_SIGACTION
 498 +static struct sigaction sigact;
 499 +#endif
 500 +
 501 +/**
 502 + * A non-interactive callback to be passed to SSL_CTX_set_default_password_cb,
 503 + * which merely copies the value of ssl_key_passwd into buf. This is
 504 + * used for when the private key password is supplied via an option.
 505 + */
 506 +static int default_password_cb(char *buf, int n, UNUSED(int f), UNUSED(void *u))
 507 +{
 508 +       if (ssl_key_passwd == NULL || n < (int)strlen(ssl_key_passwd))
 509 +               return 0;
 510 +       strncpy(buf, ssl_key_passwd, n-1);
 511 +       return strlen(ssl_key_passwd);
 512 +}
 513 +
 514 +/**
 515 + * If verbose, this method traces the status of the SSL handshake.
 516 + */
 517 +static void info_callback(const SSL *ssl, int cb, int val)
 518 +{
 519 +       char buf[128];
 520 +       char *cbs;
 521 +
 522 +       switch (cb) {
 523 +       case SSL_CB_LOOP:
 524 +               cbs = "SSL_CB_LOOP";
 525 +               break;
 526 +       case SSL_CB_EXIT:
 527 +               cbs = "SSL_CB_EXIT";
 528 +               break;
 529 +       case SSL_CB_READ:
 530 +               cbs = "SSL_CB_READ";
 531 +               break;
 532 +       case SSL_CB_WRITE:
 533 +               cbs = "SSL_CB_WRITE";
 534 +               break;
 535 +       case SSL_CB_ALERT:
 536 +               cbs = "SSL_CB_ALERT";
 537 +               break;
 538 +       case SSL_CB_READ_ALERT:
 539 +               cbs = "SSL_CB_READ_ALERT";
 540 +               break;
 541 +       case SSL_CB_WRITE_ALERT:
 542 +               cbs = "SSL_CB_WRITE_ALERT";
 543 +               break;
 544 +       case SSL_CB_ACCEPT_LOOP:
 545 +               cbs = "SSL_CB_ACCEPT_LOOP";
 546 +               break;
 547 +       case SSL_CB_ACCEPT_EXIT:
 548 +               cbs = "SSL_CB_ACCEPT_EXIT";
 549 +               break;
 550 +       case SSL_CB_CONNECT_LOOP:
 551 +               cbs = "SSL_CB_CONNECT_LOOP";
 552 +               break;
 553 +       case SSL_CB_CONNECT_EXIT:
 554 +               cbs = "SSL_CB_CONNECT_EXIT";
 555 +               break;
 556 +       case SSL_CB_HANDSHAKE_START:
 557 +               cbs = "SSL_CB_HANDSHAKE_START";
 558 +               break;
 559 +       case SSL_CB_HANDSHAKE_DONE:
 560 +               cbs = "SSL_CB_HANDSHAKE_DONE";
 561 +               break;
 562 +       default:
 563 +               snprintf(buf, sizeof buf, "??? (%d)", cb);
 564 +               cbs = buf;
 565 +               break;
 566 +       }
 567 +       if (verbose > 2) {
 568 +               rprintf(FLOG, "SSL: info_callback(%p,%s,%d)\n", ssl, cbs, val);
 569 +               if (cb == SSL_CB_HANDSHAKE_DONE) {
 570 +                       SSL_CIPHER_description(SSL_get_current_cipher((SSL*)ssl),
 571 +                                              buf, sizeof buf);
 572 +                       rprintf(FLOG, "SSL: cipher: %s", buf);
 573 +               }
 574 +       }
 575 +}
 576 +
 577 +/**
 578 + * Initializes the SSL context for TLSv1 connections; returns zero on
 579 + * success.
 580 + */
 581 +int init_tls(void)
 582 +{
 583 +       if (ssl_ctx)
 584 +               return 0;
 585 +       SSL_library_init();
 586 +       SSL_load_error_strings();
 587 +       ssl_ctx = SSL_CTX_new(TLSv1_method());
 588 +       if (!ssl_ctx)
 589 +               return 1;
 590 +       SSL_CTX_set_info_callback(ssl_ctx, info_callback);
 591 +
 592 +       /* Sets the certificate sent to the other party. */
 593 +       if (ssl_cert_path != NULL
 594 +           && SSL_CTX_use_certificate_file(ssl_ctx, ssl_cert_path,
 595 +                                           SSL_FILETYPE_PEM) != 1)
 596 +               return 1;
 597 +       /* Set up the simple non-interactive callback if the password
 598 +        * was supplied on the command line. */
 599 +       if (ssl_key_passwd != NULL)
 600 +               SSL_CTX_set_default_passwd_cb(ssl_ctx, default_password_cb);
 601 +       /* Sets the private key that matches the public certificate. */
 602 +       if (ssl_key_path != NULL) {
 603 +               if (SSL_CTX_use_PrivateKey_file(ssl_ctx, ssl_key_path,
 604 +                                               SSL_FILETYPE_PEM) != 1)
 605 +                       return 1;
 606 +               if (SSL_CTX_check_private_key(ssl_ctx) != 1)
 607 +                       return 1;
 608 +       }
 609 +       if (ssl_ca_path != NULL
 610 +           && !SSL_CTX_load_verify_locations(ssl_ctx, ssl_ca_path, NULL))
 611 +               return 1;
 612 +
 613 +       return 0;
 614 +}
 615 +
 616 +/**
 617 + * Returns the error string for the current SSL error, if any.
 618 + */
 619 +char *get_ssl_error(void)
 620 +{
 621 +       return ERR_error_string(ERR_get_error(), NULL);
 622 +}
 623 +
 624 +/**
 625 + * Returns the input file descriptor for the SSL connection.
 626 + */
 627 +int get_tls_rfd(void)
 628 +{
 629 +       return tls_read[0];
 630 +}
 631 +
 632 +/**
 633 + * Returns the output file descriptor for the SSL connection.
 634 + */
 635 +int get_tls_wfd(void)
 636 +{
 637 +       return tls_write[1];
 638 +}
 639 +
 640 +/**
 641 + * Signal handler that ends the SSL connection.
 642 + */
 643 +static RETSIGTYPE tls_sigusr1(int UNUSED(val))
 644 +{
 645 +       if (ssl) {
 646 +               SSL_shutdown(ssl);
 647 +               SSL_free(ssl);
 648 +               ssl = NULL;
 649 +       }
 650 +       ssl_running = 0;
 651 +}
 652 +
 653 +/**
 654 + * Negotiates the TLS connection, creates a socket pair for communicating
 655 + * with the rsync process, then forks into a new process that will handle
 656 + * the communication.
 657 + *
 658 + * 0 is returned on success.
 659 + */
 660 +int start_tls(int f_in, int f_out)
 661 +{
 662 +       int tls_fd;
 663 +       int n = 0, r;
 664 +       unsigned char buf1[BUF_SIZE], buf2[BUF_SIZE];
 665 +       int avail1 = 0, avail2 = 0, write1 = 0, write2 = 0;
 666 +       fd_set rd, wd;
 667 +
 668 +       if (fd_pair(tls_read))
 669 +               return 1;
 670 +       if (fd_pair(tls_write))
 671 +               return 1;
 672 +
 673 +       set_blocking(tls_read[0]);
 674 +       set_blocking(tls_read[1]);
 675 +       set_blocking(tls_write[0]);
 676 +       set_blocking(tls_write[1]);
 677 +       set_blocking(f_in);
 678 +       set_blocking(f_out);
 679 +
 680 +       ssl_pid = do_fork();
 681 +       if (ssl_pid < 0)
 682 +               return -1;
 683 +       if (ssl_pid != 0) {
 684 +               close(tls_write[0]);
 685 +               close(tls_read[1]);
 686 +               return 0;
 687 +       }
 688 +
 689 +       SIGACTION(SIGUSR1, tls_sigusr1);
 690 +       ssl = SSL_new(ssl_ctx);
 691 +       if (!ssl)
 692 +               goto closed;
 693 +       if (am_daemon || am_server)
 694 +               SSL_set_accept_state(ssl);
 695 +       else
 696 +               SSL_set_connect_state(ssl);
 697 +       SSL_set_rfd(ssl, f_in);
 698 +       SSL_set_wfd(ssl, f_out);
 699 +
 700 +       tls_fd = SSL_get_fd(ssl);
 701 +       n = tls_write[0];
 702 +       n = MAX(tls_read[1], n);
 703 +       n = MAX(tls_fd, n) + 1;
 704 +
 705 +       ssl_running = 1;
 706 +       while (ssl_running) {
 707 +               FD_ZERO(&rd);
 708 +               FD_ZERO(&wd);
 709 +               FD_SET(tls_write[0], &rd);
 710 +               FD_SET(tls_read[1], &wd);
 711 +               FD_SET(tls_fd, &rd);
 712 +               FD_SET(tls_fd, &wd);
 713 +
 714 +               r = select(n, &rd, &wd, NULL, NULL);
 715 +
 716 +               if (r == -1 && errno == EINTR)
 717 +                       continue;
 718 +               if (FD_ISSET(tls_write[0], &rd)) {
 719 +                       r = read(tls_write[0], buf1+avail1, BUF_SIZE-avail1);
 720 +                       if (r >= 0)
 721 +                               avail1 += r;
 722 +                       else {
 723 +                               rprintf(FERROR, "pipe read error: %s\n",
 724 +                                       strerror(errno));
 725 +                               break;
 726 +                       }
 727 +               }
 728 +               if (FD_ISSET(tls_fd, &rd)) {
 729 +                       r = SSL_read(ssl, buf2+avail2, BUF_SIZE-avail2);
 730 +                       if (r > 0)
 731 +                               avail2 += r;
 732 +                       else {
 733 +                               switch (SSL_get_error(ssl, r)) {
 734 +                               case SSL_ERROR_ZERO_RETURN:
 735 +                                       goto closed;
 736 +                               case SSL_ERROR_WANT_READ:
 737 +                               case SSL_ERROR_WANT_WRITE:
 738 +                                       break;
 739 +                               case SSL_ERROR_SYSCALL:
 740 +                                       if (r == 0)
 741 +                                               rprintf(FERROR, "SSL spurious EOF\n");
 742 +                                       else
 743 +                                               rprintf(FERROR, "SSL I/O error: %s\n",
 744 +                                                       strerror(errno));
 745 +                                       goto closed;
 746 +                               case SSL_ERROR_SSL:
 747 +                                       rprintf(FERROR, "SSL: %s\n",
 748 +                                               ERR_error_string(ERR_get_error(), NULL));
 749 +                                       goto closed;
 750 +                               default:
 751 +                                       rprintf(FERROR, "unexpected ssl error %d\n", r);
 752 +                                       goto closed;
 753 +                               }
 754 +                       }
 755 +               }
 756 +               if (FD_ISSET(tls_read[1], &wd) && write2 < avail2) {
 757 +                       r = write(tls_read[1], buf2+write2, avail2-write2);
 758 +                       if (r >= 0)
 759 +                               write2 += r;
 760 +                       else {
 761 +                               rprintf(FERROR, "pipe write error: %s\n",
 762 +                                       strerror(errno));
 763 +                               break;
 764 +                       }
 765 +               }
 766 +               if (FD_ISSET(tls_fd, &wd) && write1 < avail1) {
 767 +                       r = SSL_write(ssl, buf1+write1, avail1-write1);
 768 +                       if (r > 0)
 769 +                               write1 += r;
 770 +                       else {
 771 +                               switch (SSL_get_error(ssl, r)) {
 772 +                               case SSL_ERROR_ZERO_RETURN:
 773 +                                       goto closed;
 774 +                               case SSL_ERROR_WANT_READ:
 775 +                               case SSL_ERROR_WANT_WRITE:
 776 +                                       break;
 777 +                               case SSL_ERROR_SYSCALL:
 778 +                                       if (r == 0)
 779 +                                               rprintf(FERROR, "SSL: spurious EOF\n");
 780 +                                       else
 781 +                                               rprintf(FERROR, "SSL: I/O error: %s\n",
 782 +                                                       strerror(errno));
 783 +                                       goto closed;
 784 +                               case SSL_ERROR_SSL:
 785 +                                       rprintf(FERROR, "SSL: %s\n",
 786 +                                               ERR_error_string(ERR_get_error(), NULL));
 787 +                                       goto closed;
 788 +                               default:
 789 +                                       rprintf(FERROR, "unexpected ssl error %d\n", r);
 790 +                                       goto closed;
 791 +                               }
 792 +                       }
 793 +               }
 794 +               if (avail1 == write1)
 795 +                       avail1 = write1 = 0;
 796 +               if (avail2 == write2)
 797 +                       avail2 = write2 = 0;
 798 +       }
 799 +
 800 +       /* XXX I'm pretty sure that there is a lot that I am not considering
 801 +          here. Bugs? Yes, probably. */
 802 +
 803 +       /* We're finished. */
 804 +    closed:
 805 +       close(tls_read[1]);
 806 +       close(tls_write[0]);
 807 +       exit(0);
 808 +}
 809 +
 810 +/**
 811 + * Ends the TLS connection.
 812 + */
 813 +void end_tls(void)
 814 +{
 815 +       if (ssl_pid > 0)
 816 +               kill(ssl_pid, SIGUSR1);
 817 +}