openssl-support.diff

   1 After applying this patch, run these commands for a successful build:
   2
   3     autoconf
   4     autoheader
   5     ./configure
   6     make proto
   7     make
   8
   9 Casey Marshall writes:
  10
  11 I've been hacking together a way to use rsync with OpenSSL, and have
  12 attached my current patch against a recent CVS tree. The details of
  13 this implementation are:
  14
  15   1. The SSL code is added as a "layer" that is forked into its own
  16      process.
  17
  18   2. An SSL connection is established by the client issuing the
  19      command:
  20
  21        #starttls
  22
  23      And, if the server allows SSL, it replies with
  24
  25        @RSYNCD: starttls
  26
  27      At which point both sides begin negotiating the SSL connection.
  28      Servers that can't or don't want to use SSL just treat it as a
  29      normal unknown command.
  30
  31   3. The SSL code is meant to be unobtrusive, and when this patch is
  32      applied the program may still be built with no SSL code.
  33
  34   4. There are a number of details not implemented.
  35
  36 All warnings apply; I don't do C programming all that often, so I
  37 can't say if I've left any cleanup/compatibility errors in the code.
  38
  39
  40 --- orig/Makefile.in    2004-05-15 00:53:53
  41 +++ Makefile.in 2004-07-03 20:22:28
  42 @@ -39,7 +39,7 @@ OBJS3=progress.o pipe.o
  43  DAEMON_OBJ = params.o loadparm.o clientserver.o access.o connection.o authenticate.o
  44  popt_OBJS=popt/findme.o  popt/popt.o  popt/poptconfig.o \
  45         popt/popthelp.o popt/poptparse.o
  46 -OBJS=$(OBJS1) $(OBJS2) $(OBJS3) $(DAEMON_OBJ) $(LIBOBJ) $(ZLIBOBJ) @BUILD_POPT@
  47 +OBJS=$(OBJS1) $(OBJS2) $(OBJS3) $(DAEMON_OBJ) $(LIBOBJ) $(ZLIBOBJ) @BUILD_POPT@ @SSL_OBJS@
  48
  49  TLS_OBJ = tls.o syscall.o lib/permstring.o
  50
  51 --- orig/cleanup.c      2004-07-02 18:11:26
  52 +++ cleanup.c   2004-07-03 20:22:28
  53 @@ -24,6 +24,9 @@
  54  extern int io_error;
  55  extern int keep_partial;
  56  extern int log_got_error;
  57 +#ifdef HAVE_OPENSSL
  58 +extern int use_ssl;
  59 +#endif
  60
  61  /**
  62   * Close all open sockets and files, allowing a (somewhat) graceful
  63 @@ -98,6 +101,11 @@ void _exit_cleanup(int code, const char
  64         signal(SIGUSR1, SIG_IGN);
  65         signal(SIGUSR2, SIG_IGN);
  66
  67 +#ifdef HAVE_OPENSSL
  68 +       if (use_ssl)
  69 +               end_tls();
  70 +#endif
  71 +
  72         if (verbose > 3) {
  73                 rprintf(FINFO,"_exit_cleanup(code=%d, file=%s, line=%d): entered\n",
  74                         code, file, line);
  75 --- orig/clientserver.c 2004-06-18 15:59:19
  76 +++ clientserver.c      2004-07-03 20:22:28
  77 @@ -46,6 +46,9 @@ extern int io_timeout;
  78  extern int orig_umask;
  79  extern int no_detach;
  80  extern int default_af_hint;
  81 +#ifdef HAVE_OPENSSL
  82 +extern int use_ssl;
  83 +#endif
  84  extern char *bind_address;
  85  extern struct exclude_list_struct server_exclude_list;
  86  extern char *exclude_path_prefix;
  87 @@ -93,8 +96,18 @@ int start_socket_client(char *host, char
  88                 exit_cleanup(RERR_SOCKETIO);
  89
  90         ret = start_inband_exchange(user, path, fd, fd, argc);
  91 +       if (ret < 0)
  92 +               return ret;
  93 +
  94 +#ifdef HAVE_OPENSSL
  95 +       if (use_ssl) {
  96 +               int f_in = get_tls_rfd();
  97 +               int f_out = get_tls_wfd();
  98 +               return client_run(f_in, f_out, -1, argc, argv);
  99 +       }
 100 +#endif
 101
 102 -       return ret < 0? ret : client_run(fd, fd, -1, argc, argv);
 103 +       return client_run(fd, fd, -1, argc, argv);
 104  }
 105
 106  int start_inband_exchange(char *user, char *path, int f_in, int f_out, int argc)
 107 @@ -148,6 +161,33 @@ int start_inband_exchange(char *user, ch
 108         if (protocol_version > remote_protocol)
 109                 protocol_version = remote_protocol;
 110
 111 +#ifdef HAVE_OPENSSL
 112 +       if (use_ssl) {
 113 +               io_printf(f_out, "#starttls\n");
 114 +               while (1) {
 115 +                       if (!read_line(f_in, line, sizeof(line)-1)) {
 116 +                               rprintf(FERROR, "rsync: did not receive reply to #starttls\n");
 117 +                               return -1;
 118 +                       }
 119 +                       if (strncmp(line, "@ERROR", 6) == 0) {
 120 +                               rprintf(FERROR, "rsync: ssl connection denied\n");
 121 +                               return -1;
 122 +                       }
 123 +                       if (strcmp(line, "@RSYNCD: starttls") == 0) {
 124 +                               break;
 125 +                       }
 126 +                       rprintf(FINFO, "%s\n", line);
 127 +               }
 128 +               if (start_tls(f_in, f_out)) {
 129 +                       rprintf(FERROR, "rsync: error during SSL handshake: %s\n",
 130 +                               get_ssl_error());
 131 +                       return -1;
 132 +               }
 133 +               f_in = get_tls_rfd();
 134 +               f_out = get_tls_wfd();
 135 +       }
 136 +#endif
 137 +
 138         p = strchr(path,'/');
 139         if (p) *p = 0;
 140         io_printf(f_out, "%s\n", path);
 141 @@ -176,6 +216,10 @@ int start_inband_exchange(char *user, ch
 142                          * server to terminate the listing of modules.
 143                          * We don't want to go on and transfer
 144                          * anything; just exit. */
 145 +#ifdef HAVE_OPENSSL
 146 +                       if (use_ssl)
 147 +                               end_tls();
 148 +#endif
 149                         exit(0);
 150                 }
 151
 152 @@ -183,6 +227,10 @@ int start_inband_exchange(char *user, ch
 153                         rprintf(FERROR, "%s\n", line);
 154                         /* This is always fatal; the server will now
 155                          * close the socket. */
 156 +#ifdef HAVE_OPENSSL
 157 +                       if (use_ssl)
 158 +                               end_tls();
 159 +#endif
 160                         return RERR_STARTCLIENT;
 161                 } else {
 162                         rprintf(FINFO,"%s\n", line);
 163 @@ -487,6 +535,7 @@ static void send_listing(int fd)
 164                 io_printf(fd,"@RSYNCD: EXIT\n");
 165  }
 166
 167 +
 168  /* this is called when a connection is established to a client
 169     and we want to start talking. The setup of the system is done from
 170     here */
 171 @@ -544,6 +593,20 @@ int start_daemon(int f_in, int f_out)
 172                         return -1;
 173                 }
 174
 175 +#if HAVE_OPENSSL
 176 +               if (use_ssl && strcmp(line, "#starttls") == 0) {
 177 +                       io_printf(f_out, "@RSYNCD: starttls\n");
 178 +                       if (start_tls(f_in, f_out)) {
 179 +                               rprintf(FLOG, "SSL connection failed: %s\n",
 180 +                                       get_ssl_error());
 181 +                               return -1;
 182 +                       }
 183 +                       f_in = get_tls_rfd();
 184 +                       f_out = get_tls_wfd();
 185 +                       continue;
 186 +               }
 187 +#endif
 188 +
 189                 if (*line == '#') {
 190                         /* it's some sort of command that I don't understand */
 191                         io_printf(f_out, "@ERROR: Unknown command '%s'\n", line);
 192 --- orig/configure.in   2004-04-30 18:04:07
 193 +++ configure.in        2004-07-03 20:22:28
 194 @@ -271,6 +271,21 @@ yes
 195         AC_SEARCH_LIBS(getaddrinfo, inet6)
 196  fi
 197
 198 +AC_ARG_ENABLE(openssl,
 199 +              AC_HELP_STRING([--enable-openssl], [compile SSL support with OpenSSL.]))
 200 +
 201 +if test "x$enable_openssl" != xno
 202 +then
 203 +       have_ssl=yes
 204 +       AC_CHECK_LIB(ssl, SSL_library_init, , [have_ssl=no])
 205 +       if test "x$have_ssl" = xyes
 206 +       then
 207 +               AC_DEFINE(HAVE_OPENSSL, 1, [true if you want to use SSL.])
 208 +               SSL_OBJS=ssl.o
 209 +               AC_SUBST(SSL_OBJS)
 210 +       fi
 211 +fi
 212 +
 213  AC_MSG_CHECKING([whether to call shutdown on all sockets])
 214  case $host_os in
 215         *cygwin* ) AC_MSG_RESULT(yes)
 216 --- orig/main.c 2004-06-30 07:24:30
 217 +++ main.c      2004-07-03 20:22:28
 218 @@ -52,6 +52,9 @@ extern int rsync_port;
 219  extern int read_batch;
 220  extern int write_batch;
 221  extern int filesfrom_fd;
 222 +#ifdef HAVE_OPENSSL
 223 +extern int use_ssl;
 224 +#endif
 225  extern pid_t cleanup_child_pid;
 226  extern char *files_from;
 227  extern char *remote_filesfrom_file;
 228 @@ -719,17 +722,32 @@ static int start_client(int argc, char *
 229         pid_t pid;
 230         int f_in,f_out;
 231         int rc;
 232 +       int url_prefix = strlen(URL_PREFIX);
 233
 234         /* Don't clobber argv[] so that ps(1) can still show the right
 235          * command line. */
 236         if ((rc = copy_argv(argv)))
 237                 return rc;
 238
 239 +       if (strncasecmp(URL_PREFIX, argv[0], url_prefix) != 0) {
 240 +#ifdef HAVE_OPENSSL
 241 +               url_prefix = strlen(SSL_URL_PREFIX);
 242 +               if (strncasecmp(SSL_URL_PREFIX, argv[0], url_prefix) != 0)
 243 +                       url_prefix = 0;
 244 +               else {
 245 +                       if (!use_ssl)
 246 +                               init_tls();
 247 +                       use_ssl = 1;
 248 +               }
 249 +#else
 250 +               url_prefix = 0;
 251 +#endif
 252 +       }
 253         /* rsync:// always uses rsync server over direct socket connection */
 254 -       if (strncasecmp(URL_PREFIX, argv[0], strlen(URL_PREFIX)) == 0) {
 255 +       if (url_prefix) {
 256                 char *host, *path;
 257
 258 -               host = argv[0] + strlen(URL_PREFIX);
 259 +               host = argv[0] + url_prefix;
 260                 p = strchr(host,'/');
 261                 if (p) {
 262                         *p = 0;
 263 @@ -777,12 +795,27 @@ static int start_client(int argc, char *
 264                         argv++;
 265                 } else { /* source is local */
 266                         am_sender = 1;
 267 +                       url_prefix = strlen(URL_PREFIX);
 268 +                       if (strncasecmp(URL_PREFIX, argv[0], url_prefix) != 0) {
 269 +#ifdef HAVE_OPENSSL
 270 +                               url_prefix = strlen(SSL_URL_PREFIX);
 271 +                               if (strncasecmp(SSL_URL_PREFIX, argv[0], url_prefix) != 0)
 272 +                                       url_prefix = 0;
 273 +                               else {
 274 +                                       if (!use_ssl)
 275 +                                               init_tls();
 276 +                                       use_ssl = 1;
 277 +                               }
 278 +#else
 279 +                               url_prefix = 0;
 280 +#endif
 281 +                       }
 282
 283                         /* rsync:// destination uses rsync server over direct socket */
 284 -                       if (strncasecmp(URL_PREFIX, argv[argc-1], strlen(URL_PREFIX)) == 0) {
 285 +                       if (url_prefix) {
 286                                 char *host, *path;
 287
 288 -                               host = argv[argc-1] + strlen(URL_PREFIX);
 289 +                               host = argv[argc-1] + url_prefix;
 290                                 p = strchr(host,'/');
 291                                 if (p) {
 292                                         *p = 0;
 293 --- orig/options.c      2004-06-20 19:30:00
 294 +++ options.c   2004-07-03 20:22:28
 295 @@ -133,6 +133,14 @@ int quiet = 0;
 296  int always_checksum = 0;
 297  int list_only = 0;
 298
 299 +#ifdef HAVE_OPENSSL
 300 +int use_ssl = 0;
 301 +char *ssl_cert_path = NULL;
 302 +char *ssl_key_path = NULL;
 303 +char *ssl_key_passwd = NULL;
 304 +char *ssl_ca_path = NULL;
 305 +#endif
 306 +
 307  #define FIXED_CHECKSUM_SEED 32761
 308  #define MAX_BATCH_PREFIX_LEN 256       /* Must be less than MAXPATHLEN-13 */
 309  char *batch_prefix = NULL;
 310 @@ -145,13 +153,13 @@ static int modify_window_set;
 311   * address, or a hostname. **/
 312  char *bind_address;
 313
 314 -
 315  static void print_rsync_version(enum logcode f)
 316  {
 317         char const *got_socketpair = "no ";
 318         char const *hardlinks = "no ";
 319         char const *links = "no ";
 320         char const *ipv6 = "no ";
 321 +       char const *ssl = "no ";
 322         STRUCT_STAT *dumstat;
 323
 324  #ifdef HAVE_SOCKETPAIR
 325 @@ -170,6 +178,10 @@ static void print_rsync_version(enum log
 326         ipv6 = "";
 327  #endif
 328
 329 +#ifdef HAVE_OPENSSL
 330 +       ssl = "";
 331 +#endif
 332 +
 333         rprintf(f, "%s  version %s  protocol version %d\n",
 334                 RSYNC_NAME, RSYNC_VERSION, PROTOCOL_VERSION);
 335         rprintf(f,
 336 @@ -183,10 +195,10 @@ static void print_rsync_version(enum log
 337         /* Note that this field may not have type ino_t.  It depends
 338          * on the complicated interaction between largefile feature
 339          * macros. */
 340 -       rprintf(f, "              %sIPv6, %d-bit system inums, %d-bit internal inums\n",
 341 +       rprintf(f, "              %sIPv6, %d-bit system inums, %d-bit internal inums, %sssl\n",
 342                 ipv6,
 343                 (int) (sizeof dumstat->st_ino * 8),
 344 -               (int) (sizeof (uint64) * 8));
 345 +               (int) (sizeof (uint64) * 8), ssl);
 346  #ifdef MAINTAINER_MODE
 347         rprintf(f, "              panic action: \"%s\"\n",
 348                 get_panic_action());
 349 @@ -299,6 +311,13 @@ void usage(enum logcode F)
 350    rprintf(F," -4  --ipv4                  prefer IPv4\n");
 351    rprintf(F," -6  --ipv6                  prefer IPv6\n");
 352  #endif
 353 +#ifdef HAVE_OPENSSL
 354 +  rprintf(F,"     --ssl                   allow socket connections to use SSL\n");
 355 +  rprintf(F,"     --ssl-cert=FILE         path to server's SSL certificate\n");
 356 +  rprintf(F,"     --ssl-key=FILE          path to server's SSL private key\n");
 357 +  rprintf(F,"     --ssl-key-passwd=PASS   password for PEM-encoded private key\n");
 358 +  rprintf(F,"     --ssl-ca-certs=FILE     path to trusted CA certificates\n");
 359 +#endif
 360    rprintf(F," -h, --help                  show this help screen\n");
 361
 362    rprintf(F,"\n");
 363 @@ -310,7 +329,7 @@ void usage(enum logcode F)
 364  enum {OPT_VERSION = 1000, OPT_SENDER, OPT_EXCLUDE, OPT_EXCLUDE_FROM,
 365        OPT_DELETE_AFTER, OPT_DELETE_EXCLUDED, OPT_LINK_DEST,
 366        OPT_INCLUDE, OPT_INCLUDE_FROM, OPT_MODIFY_WINDOW,
 367 -      OPT_READ_BATCH, OPT_WRITE_BATCH, OPT_TIMEOUT,
 368 +      OPT_READ_BATCH, OPT_WRITE_BATCH, OPT_TIMEOUT, OPT_USE_SSL,
 369        OPT_REFUSED_BASE = 9000};
 370
 371  static struct poptOption long_options[] = {
 372 @@ -397,6 +416,13 @@ static struct poptOption long_options[]
 373    {"ipv4",            '4', POPT_ARG_VAL,    &default_af_hint, AF_INET, 0, 0 },
 374    {"ipv6",            '6', POPT_ARG_VAL,    &default_af_hint, AF_INET6, 0, 0 },
 375  #endif
 376 +#ifdef HAVE_OPENSSL
 377 +  {"ssl",              0,  POPT_ARG_NONE,   0,               OPT_USE_SSL, 0, 0},
 378 +  {"ssl-cert",         0,  POPT_ARG_STRING, &ssl_cert_path,  OPT_USE_SSL, 0, 0},
 379 +  {"ssl-key",          0,  POPT_ARG_STRING, &ssl_key_path,   OPT_USE_SSL, 0, 0},
 380 +  {"ssl-key-passwd",   0,  POPT_ARG_STRING, &ssl_key_passwd, OPT_USE_SSL, 0, 0},
 381 +  {"ssl-ca-certs",     0,  POPT_ARG_STRING, &ssl_ca_path,    OPT_USE_SSL, 0, 0},
 382 +#endif
 383    {0,0,0,0, 0, 0, 0}
 384  };
 385
 386 @@ -596,6 +622,12 @@ int parse_arguments(int *argc, const cha
 387                         return 0;
 388  #endif
 389
 390 +               case OPT_USE_SSL:
 391 +#ifdef HAVE_OPENSSL
 392 +                       use_ssl = 1;
 393 +#endif
 394 +                       break;
 395 +
 396                 default:
 397                         /* A large opt value means that set_refuse_options()
 398                          * turned this option off (opt-BASE is its index). */
 399 @@ -733,6 +765,17 @@ int parse_arguments(int *argc, const cha
 400         if (do_progress && !verbose)
 401                 verbose = 1;
 402
 403 +#ifdef HAVE_OPENSSL
 404 +       if (use_ssl) {
 405 +               if (init_tls()) {
 406 +                       snprintf(err_buf, sizeof(err_buf),
 407 +                                "Openssl error: %s\n",
 408 +                                get_ssl_error());
 409 +                       return 0;
 410 +               }
 411 +       }
 412 +#endif
 413 +
 414         if (bwlimit) {
 415                 bwlimit_writemax = (size_t)bwlimit * 128;
 416                 if (bwlimit_writemax < 512)
 417 --- orig/rsync.h        2004-05-16 07:58:12
 418 +++ rsync.h     2004-07-03 20:22:28
 419 @@ -32,6 +32,7 @@
 420
 421  #define DEFAULT_LOCK_FILE "/var/run/rsyncd.lock"
 422  #define URL_PREFIX "rsync://"
 423 +#define SSL_URL_PREFIX "rsyncs://"
 424
 425  #define BACKUP_SUFFIX "~"
 426
 427 @@ -326,6 +327,11 @@ enum msgcode {
 428  #define uint64 unsigned off_t
 429  #endif
 430
 431 +#if HAVE_OPENSSL
 432 +#include <openssl/ssl.h>
 433 +#include <openssl/err.h>
 434 +#endif
 435 +
 436  /* Starting from protocol version 26, we always use 64-bit
 437   * ino_t and dev_t internally, even if this platform does not
 438   * allow files to have 64-bit inums.  That's because the
 439 --- orig/ssl.c  2004-07-02 21:44:19
 440 +++ ssl.c       2004-07-02 21:44:19
 441 @@ -0,0 +1,366 @@
 442 +/* -*- c-file-style: "linux" -*-
 443 + * ssl.c: operations for negotiating SSL rsync connections.
 444 + *
 445 + * Copyright (C) 2003  Casey Marshall <rsdio@metastatic.org>
 446 + *
 447 + * This program is free software; you can redistribute it and/or modify
 448 + * it under the terms of the GNU General Public License as published by
 449 + * the Free Software Foundation; either version 2 of the License, or
 450 + * (at your option) any later version.
 451 + *
 452 + * This program is distributed in the hope that it will be useful,
 453 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
 454 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 455 + * GNU General Public License for more details.
 456 + *
 457 + * You should have received a copy of the GNU General Public License
 458 + * along with this program; if not, write to the Free Software
 459 + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 460 + */
 461 +
 462 +#include "rsync.h"
 463 +
 464 +#ifdef HAVE_SYS_SELECT_H
 465 +#include <sys/select.h>
 466 +#else
 467 +#include <sys/time.h>
 468 +#include <sys/types.h>
 469 +#include <unistd.h>
 470 +#endif
 471 +#include <string.h>
 472 +
 473 +#define BUF_SIZE 1024
 474 +
 475 +extern int verbose;
 476 +extern int am_daemon;
 477 +extern int am_server;
 478 +
 479 +extern char *ssl_cert_path;
 480 +extern char *ssl_key_path;
 481 +extern char *ssl_key_passwd;
 482 +extern char *ssl_ca_path;
 483 +
 484 +static SSL_CTX *ssl_ctx;
 485 +static SSL *ssl;
 486 +static int tls_read[2] = { -1, -1 };
 487 +static int tls_write[2] = { -1, -1 };
 488 +static int ssl_running;
 489 +static int ssl_pid = -1;
 490 +
 491 +/**
 492 + * A non-interactive callback to be passed to SSL_CTX_set_default_password_cb,
 493 + * which merely copies the value of ssl_key_passwd into buf. This is
 494 + * used for when the private key password is supplied via an option.
 495 + */
 496 +static int default_password_cb(char *buf, int n, UNUSED(int f), UNUSED(void *u))
 497 +{
 498 +       if (ssl_key_passwd == NULL || n < strlen(ssl_key_passwd))
 499 +               return 0;
 500 +       strncpy(buf, ssl_key_passwd, n-1);
 501 +       return strlen(ssl_key_passwd);
 502 +}
 503 +
 504 +/**
 505 + * If verbose, this method traces the status of the SSL handshake.
 506 + */
 507 +static void info_callback(SSL *ssl, int cb, int val)
 508 +{
 509 +       char buf[128];
 510 +       char *cbs;
 511 +
 512 +       switch (cb) {
 513 +       case SSL_CB_LOOP:
 514 +               cbs = "SSL_CB_LOOP";
 515 +               break;
 516 +       case SSL_CB_EXIT:
 517 +               cbs = "SSL_CB_EXIT";
 518 +               break;
 519 +       case SSL_CB_READ:
 520 +               cbs = "SSL_CB_READ";
 521 +               break;
 522 +       case SSL_CB_WRITE:
 523 +               cbs = "SSL_CB_WRITE";
 524 +               break;
 525 +       case SSL_CB_ALERT:
 526 +               cbs = "SSL_CB_ALERT";
 527 +               break;
 528 +       case SSL_CB_READ_ALERT:
 529 +               cbs = "SSL_CB_READ_ALERT";
 530 +               break;
 531 +       case SSL_CB_WRITE_ALERT:
 532 +               cbs = "SSL_CB_WRITE_ALERT";
 533 +               break;
 534 +       case SSL_CB_ACCEPT_LOOP:
 535 +               cbs = "SSL_CB_ACCEPT_LOOP";
 536 +               break;
 537 +       case SSL_CB_ACCEPT_EXIT:
 538 +               cbs = "SSL_CB_ACCEPT_EXIT";
 539 +               break;
 540 +       case SSL_CB_CONNECT_LOOP:
 541 +               cbs = "SSL_CB_CONNECT_LOOP";
 542 +               break;
 543 +       case SSL_CB_CONNECT_EXIT:
 544 +               cbs = "SSL_CB_CONNECT_EXIT";
 545 +               break;
 546 +       case SSL_CB_HANDSHAKE_START:
 547 +               cbs = "SSL_CB_HANDSHAKE_START";
 548 +               break;
 549 +       case SSL_CB_HANDSHAKE_DONE:
 550 +               cbs = "SSL_CB_HANDSHAKE_DONE";
 551 +               break;
 552 +       default:
 553 +               snprintf(buf, sizeof buf, "??? (%d)", cb);
 554 +               cbs = buf;
 555 +               break;
 556 +       }
 557 +       if (verbose > 2) {
 558 +               rprintf(FLOG, "SSL: info_callback(%p,%s,%d)\n", ssl, cbs, val);
 559 +               if (cb == SSL_CB_HANDSHAKE_DONE) {
 560 +                       SSL_CIPHER_description(SSL_get_current_cipher(ssl),
 561 +                                              buf, sizeof buf);
 562 +                       rprintf(FLOG, "SSL: cipher: %s", buf);
 563 +               }
 564 +       }
 565 +}
 566 +
 567 +/**
 568 + * Initializes the SSL context for TLSv1 connections; returns zero on
 569 + * success.
 570 + */
 571 +int init_tls(void)
 572 +{
 573 +       if (ssl_ctx)
 574 +               return 0;
 575 +       SSL_library_init();
 576 +       SSL_load_error_strings();
 577 +       ssl_ctx = SSL_CTX_new(TLSv1_method());
 578 +       if (!ssl_ctx)
 579 +               return 1;
 580 +       SSL_CTX_set_info_callback(ssl_ctx, info_callback);
 581 +
 582 +       /* Sets the certificate sent to the other party. */
 583 +       if (ssl_cert_path != NULL
 584 +           && SSL_CTX_use_certificate_file(ssl_ctx, ssl_cert_path,
 585 +                                           SSL_FILETYPE_PEM) != 1)
 586 +               return 1;
 587 +       /* Set up the simple non-interactive callback if the password
 588 +        * was supplied on the command line. */
 589 +       if (ssl_key_passwd != NULL)
 590 +               SSL_CTX_set_default_passwd_cb(ssl_ctx, default_password_cb);
 591 +       /* Sets the private key that matches the public certificate. */
 592 +       if (ssl_key_path != NULL) {
 593 +               if (SSL_CTX_use_PrivateKey_file(ssl_ctx, ssl_key_path,
 594 +                                               SSL_FILETYPE_PEM) != 1)
 595 +                       return 1;
 596 +               if (SSL_CTX_check_private_key(ssl_ctx) != 1)
 597 +                       return 1;
 598 +       }
 599 +       if (ssl_ca_path != NULL
 600 +           && !SSL_CTX_load_verify_locations(ssl_ctx, ssl_ca_path, NULL))
 601 +               return 1;
 602 +
 603 +       return 0;
 604 +}
 605 +
 606 +/**
 607 + * Returns the error string for the current SSL error, if any.
 608 + */
 609 +char *get_ssl_error(void)
 610 +{
 611 +       return ERR_error_string(ERR_get_error(), NULL);
 612 +}
 613 +
 614 +/**
 615 + * Returns the input file descriptor for the SSL connection.
 616 + */
 617 +int get_tls_rfd(void)
 618 +{
 619 +       return tls_read[0];
 620 +}
 621 +
 622 +/**
 623 + * Returns the output file descriptor for the SSL connection.
 624 + */
 625 +int get_tls_wfd(void)
 626 +{
 627 +       return tls_write[1];
 628 +}
 629 +
 630 +/**
 631 + * Signal handler that ends the SSL connection.
 632 + */
 633 +static RETSIGTYPE tls_sigusr1(int UNUSED(val))
 634 +{
 635 +       if (ssl) {
 636 +               SSL_shutdown(ssl);
 637 +               SSL_free(ssl);
 638 +               ssl = NULL;
 639 +       }
 640 +       ssl_running = 0;
 641 +}
 642 +
 643 +/**
 644 + * Negotiates the TLS connection, creates a socket pair for communicating
 645 + * with the rsync process, then forks into a new process that will handle
 646 + * the communication.
 647 + *
 648 + * 0 is returned on success.
 649 + */
 650 +int start_tls(int f_in, int f_out)
 651 +{
 652 +       int tls_fd;
 653 +       int n = 0, r;
 654 +       unsigned char buf1[BUF_SIZE], buf2[BUF_SIZE];
 655 +       int avail1 = 0, avail2 = 0, write1 = 0, write2 = 0;
 656 +       fd_set rd, wd;
 657 +
 658 +       if (fd_pair(tls_read))
 659 +               return 1;
 660 +       if (fd_pair(tls_write))
 661 +               return 1;
 662 +
 663 +       set_blocking(tls_read[0]);
 664 +       set_blocking(tls_read[1]);
 665 +       set_blocking(tls_write[0]);
 666 +       set_blocking(tls_write[1]);
 667 +       set_blocking(f_in);
 668 +       set_blocking(f_out);
 669 +
 670 +       ssl_pid = do_fork();
 671 +       if (ssl_pid < 0)
 672 +               return -1;
 673 +       if (ssl_pid != 0) {
 674 +               close(tls_write[0]);
 675 +               close(tls_read[1]);
 676 +               return 0;
 677 +       }
 678 +
 679 +       signal(SIGUSR1, tls_sigusr1);
 680 +       ssl = SSL_new(ssl_ctx);
 681 +       if (!ssl)
 682 +               goto closed;
 683 +       if (am_daemon || am_server)
 684 +               SSL_set_accept_state(ssl);
 685 +       else
 686 +               SSL_set_connect_state(ssl);
 687 +       SSL_set_rfd(ssl, f_in);
 688 +       SSL_set_wfd(ssl, f_out);
 689 +
 690 +       tls_fd = SSL_get_fd(ssl);
 691 +       n = tls_write[0];
 692 +       n = MAX(tls_read[1], n);
 693 +       n = MAX(tls_fd, n) + 1;
 694 +
 695 +       ssl_running = 1;
 696 +       while (ssl_running) {
 697 +               FD_ZERO(&rd);
 698 +               FD_ZERO(&wd);
 699 +               FD_SET(tls_write[0], &rd);
 700 +               FD_SET(tls_read[1], &wd);
 701 +               FD_SET(tls_fd, &rd);
 702 +               FD_SET(tls_fd, &wd);
 703 +
 704 +               r = select(n, &rd, &wd, NULL, NULL);
 705 +
 706 +               if (r == -1 && errno == EINTR)
 707 +                       continue;
 708 +               if (FD_ISSET(tls_write[0], &rd)) {
 709 +                       r = read(tls_write[0], buf1+avail1, BUF_SIZE-avail1);
 710 +                       if (r >= 0)
 711 +                               avail1 += r;
 712 +                       else {
 713 +                               rprintf(FERROR, "pipe read error: %s\n",
 714 +                                       strerror(errno));
 715 +                               break;
 716 +                       }
 717 +               }
 718 +               if (FD_ISSET(tls_fd, &rd)) {
 719 +                       r = SSL_read(ssl, buf2+avail2, BUF_SIZE-avail2);
 720 +                       if (r > 0)
 721 +                               avail2 += r;
 722 +                       else {
 723 +                               switch (SSL_get_error(ssl, r)) {
 724 +                               case SSL_ERROR_ZERO_RETURN:
 725 +                                       goto closed;
 726 +                               case SSL_ERROR_WANT_READ:
 727 +                               case SSL_ERROR_WANT_WRITE:
 728 +                                       break;
 729 +                               case SSL_ERROR_SYSCALL:
 730 +                                       if (r == 0)
 731 +                                               rprintf(FERROR, "SSL spurious EOF\n");
 732 +                                       else
 733 +                                               rprintf(FERROR, "SSL I/O error: %s\n",
 734 +                                                       strerror(errno));
 735 +                                       goto closed;
 736 +                               case SSL_ERROR_SSL:
 737 +                                       rprintf(FERROR, "SSL: %s\n",
 738 +                                               ERR_error_string(ERR_get_error(), NULL));
 739 +                                       goto closed;
 740 +                               default:
 741 +                                       rprintf(FERROR, "unexpected ssl error %d\n", r);
 742 +                                       goto closed;
 743 +                               }
 744 +                       }
 745 +               }
 746 +               if (FD_ISSET(tls_read[1], &wd) && write2 < avail2) {
 747 +                       r = write(tls_read[1], buf2+write2, avail2-write2);
 748 +                       if (r >= 0)
 749 +                               write2 += r;
 750 +                       else {
 751 +                               rprintf(FERROR, "pipe write error: %s\n",
 752 +                                       strerror(errno));
 753 +                               break;
 754 +                       }
 755 +               }
 756 +               if (FD_ISSET(tls_fd, &wd) && write1 < avail1) {
 757 +                       r = SSL_write(ssl, buf1+write1, avail1-write1);
 758 +                       if (r > 0)
 759 +                               write1 += r;
 760 +                       else {
 761 +                               switch (SSL_get_error(ssl, r)) {
 762 +                               case SSL_ERROR_ZERO_RETURN:
 763 +                                       goto closed;
 764 +                               case SSL_ERROR_WANT_READ:
 765 +                               case SSL_ERROR_WANT_WRITE:
 766 +                                       break;
 767 +                               case SSL_ERROR_SYSCALL:
 768 +                                       if (r == 0)
 769 +                                               rprintf(FERROR, "SSL: spurious EOF\n");
 770 +                                       else
 771 +                                               rprintf(FERROR, "SSL: I/O error: %s\n",
 772 +                                                       strerror(errno));
 773 +                                       goto closed;
 774 +                               case SSL_ERROR_SSL:
 775 +                                       rprintf(FERROR, "SSL: %s\n",
 776 +                                               ERR_error_string(ERR_get_error(), NULL));
 777 +                                       goto closed;
 778 +                               default:
 779 +                                       rprintf(FERROR, "unexpected ssl error %d\n", r);
 780 +                                       goto closed;
 781 +                               }
 782 +                       }
 783 +               }
 784 +               if (avail1 == write1)
 785 +                       avail1 = write1 = 0;
 786 +               if (avail2 == write2)
 787 +                       avail2 = write2 = 0;
 788 +       }
 789 +
 790 +       /* XXX I'm pretty sure that there is a lot that I am not considering
 791 +          here. Bugs? Yes, probably. */
 792 +
 793 +       /* We're finished. */
 794 +    closed:
 795 +       close(tls_read[1]);
 796 +       close(tls_write[0]);
 797 +       exit(0);
 798 +}
 799 +
 800 +/**
 801 + * Ends the TLS connection.
 802 + */
 803 +void end_tls(void)
 804 +{
 805 +       if (ssl_pid > 0)
 806 +               kill(ssl_pid, SIGUSR1);
 807 +}