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:
7 1. The SSL code is added as a "layer" that is forked into its own
10 2. An SSL connection is established by the client issuing the
15 And, if the daemon allows SSL, it replies with
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.
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.
26 4. There are a number of details not implemented.
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.
31 To use this patch, run these commands for a successful build:
33 patch -p1 <patches/openssl-support.diff
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@
47 TLS_OBJ = tls.o syscall.o lib/compat.o lib/snprintf.o lib/permstring.o lib/sysxattrs.o @BUILD_POPT@
58 extern int keep_partial;
59 extern int log_got_error;
60 extern char *partial_dir;
61 @@ -121,6 +124,14 @@ NORETURN void _exit_cleanup(int code, co
76 --- old/clientserver.c
77 +++ new/clientserver.c
78 @@ -29,6 +29,9 @@ extern int am_sender;
85 extern int rsync_port;
86 extern int ignore_errors;
87 extern int kluge_around_eof;
88 @@ -112,8 +115,18 @@ int start_socket_client(char *host, int
89 set_socket_options(fd, sockopts);
91 ret = start_inband_exchange(fd, fd, user, remote_argc, remote_argv);
95 - return ret ? ret : client_run(fd, fd, -1, argc, argv);
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);
104 + return client_run(fd, fd, -1, argc, argv);
107 static int exchange_protocols(int f_in, int f_out, char *buf, size_t bufsiz, int am_client)
108 @@ -244,6 +257,32 @@ int start_inband_exchange(int f_in, int
110 print_child_argv("sending daemon args:", sargs);
114 + io_printf(f_out, "#starttls\n");
116 + if (!read_line_old(f_in, line, sizeof line)) {
117 + rprintf(FERROR, "rsync: did not receive reply to #starttls\n");
120 + if (strncmp(line, "@ERROR", 6) == 0) {
121 + rprintf(FERROR, "%s\n", line);
124 + if (strcmp(line, "@RSYNCD: starttls") == 0)
126 + rprintf(FINFO, "%s\n", line);
128 + if (start_tls(f_in, f_out)) {
129 + rprintf(FERROR, "rsync: error during SSL handshake: %s\n",
133 + f_in = get_tls_rfd();
134 + f_out = get_tls_wfd();
138 p = strchr(path, '/');
140 io_printf(f_out, "%s\n", path);
141 @@ -272,6 +311,10 @@ int start_inband_exchange(int f_in, int
142 * server to terminate the listing of modules.
143 * We don't want to go on and transfer
144 * anything; just exit. */
152 @@ -279,6 +322,10 @@ int start_inband_exchange(int f_in, int
153 rprintf(FERROR, "%s\n", line);
154 /* This is always fatal; the server will now
155 * close the socket. */
163 @@ -807,6 +854,9 @@ int start_daemon(int f_in, int f_out)
164 if (exchange_protocols(f_in, f_out, line, sizeof line, 0) < 0)
171 if (!read_line_old(f_in, line, sizeof line))
173 @@ -818,6 +868,20 @@ int start_daemon(int f_in, int f_out)
178 + if (use_ssl && strcmp(line, "#starttls") == 0) {
179 + io_printf(f_out, "@RSYNCD: starttls\n");
180 + if (start_tls(f_in, f_out)) {
181 + rprintf(FLOG, "SSL connection failed: %s\n",
185 + f_in = get_tls_rfd();
186 + f_out = get_tls_wfd();
192 /* it's some sort of command that I don't understand */
193 io_printf(f_out, "@ERROR: Unknown command '%s'\n", line);
196 @@ -290,6 +290,21 @@ if test x"$enable_locale" != x"no"; then
197 AC_DEFINE(CONFIG_LOCALE)
200 +AC_ARG_ENABLE(openssl,
201 + AC_HELP_STRING([--enable-openssl], [compile SSL support with OpenSSL.]))
203 +if test "x$enable_openssl" != xno
206 + AC_CHECK_LIB(ssl, SSL_library_init, , [have_ssl=no])
207 + if test "x$have_ssl" = xyes
209 + AC_DEFINE(HAVE_OPENSSL, 1, [true if you want to use SSL.])
215 AC_MSG_CHECKING([whether to call shutdown on all sockets])
217 *cygwin* ) AC_MSG_RESULT(yes)
220 @@ -182,6 +182,14 @@ int logfile_format_has_o_or_i = 0;
221 int always_checksum = 0;
226 +char *ssl_cert_path = NULL;
227 +char *ssl_key_path = NULL;
228 +char *ssl_key_passwd = NULL;
229 +char *ssl_ca_path = NULL;
232 #define MAX_BATCH_NAME_LEN 256 /* Must be less than MAXPATHLEN-13 */
233 char *batch_name = NULL;
235 @@ -221,6 +229,7 @@ static void print_rsync_version(enum log
236 char const *links = "no ";
237 char const *iconv = "no ";
238 char const *ipv6 = "no ";
239 + char const *ssl = "no ";
240 STRUCT_STAT *dumstat;
242 #if SUBPROTOCOL_VERSION != 0
243 @@ -250,6 +259,9 @@ static void print_rsync_version(enum log
251 rprintf(f, "%s version %s protocol version %d%s\n",
252 RSYNC_NAME, RSYNC_VERSION, PROTOCOL_VERSION, subprotocol);
253 @@ -263,8 +275,8 @@ static void print_rsync_version(enum log
254 (int)(sizeof (int64) * 8));
255 rprintf(f, " %ssocketpairs, %shardlinks, %ssymlinks, %sIPv6, batchfiles, %sinplace,\n",
256 got_socketpair, hardlinks, links, ipv6, have_inplace);
257 - rprintf(f, " %sappend, %sACLs, %sxattrs, %siconv\n",
258 - have_inplace, acls, xattrs, iconv);
259 + rprintf(f, " %sappend, %sACLs, %sxattrs, %siconv, %sSSL\n",
260 + have_inplace, acls, xattrs, iconv, ssl);
262 #ifdef MAINTAINER_MODE
263 rprintf(f, "Panic Action: \"%s\"\n", get_panic_action());
264 @@ -425,6 +437,13 @@ void usage(enum logcode F)
266 rprintf(F," -4, --ipv4 prefer IPv4\n");
267 rprintf(F," -6, --ipv6 prefer IPv6\n");
269 + rprintf(F," --ssl allow socket connections to use SSL\n");
270 + rprintf(F," --ssl-cert=FILE path to daemon's SSL certificate\n");
271 + rprintf(F," --ssl-key=FILE path to daemon's SSL private key\n");
272 + rprintf(F," --ssl-key-passwd=PASS password for PEM-encoded private key\n");
273 + rprintf(F," --ssl-ca-certs=FILE path to trusted CA certificates\n");
275 rprintf(F," --version print version number\n");
276 rprintf(F,"(-h) --help show this help (-h works with no other options)\n");
278 @@ -438,7 +457,7 @@ enum {OPT_VERSION = 1000, OPT_DAEMON, OP
279 OPT_FILTER, OPT_COMPARE_DEST, OPT_COPY_DEST, OPT_LINK_DEST, OPT_HELP,
280 OPT_INCLUDE, OPT_INCLUDE_FROM, OPT_MODIFY_WINDOW, OPT_MIN_SIZE, OPT_CHMOD,
281 OPT_READ_BATCH, OPT_WRITE_BATCH, OPT_ONLY_WRITE_BATCH, OPT_MAX_SIZE,
282 - OPT_NO_D, OPT_APPEND,
283 + OPT_NO_D, OPT_APPEND, OPT_USE_SSL,
284 OPT_SERVER, OPT_REFUSED_BASE = 9000};
286 static struct poptOption long_options[] = {
287 @@ -623,6 +642,13 @@ static struct poptOption long_options[]
288 {"checksum-seed", 0, POPT_ARG_INT, &checksum_seed, 0, 0, 0 },
289 {"server", 0, POPT_ARG_NONE, 0, OPT_SERVER, 0, 0 },
290 {"sender", 0, POPT_ARG_NONE, 0, OPT_SENDER, 0, 0 },
292 + {"ssl", 0, POPT_ARG_NONE, 0, OPT_USE_SSL, 0, 0},
293 + {"ssl-cert", 0, POPT_ARG_STRING, &ssl_cert_path, OPT_USE_SSL, 0, 0},
294 + {"ssl-key", 0, POPT_ARG_STRING, &ssl_key_path, OPT_USE_SSL, 0, 0},
295 + {"ssl-key-passwd", 0, POPT_ARG_STRING, &ssl_key_passwd, OPT_USE_SSL, 0, 0},
296 + {"ssl-ca-certs", 0, POPT_ARG_STRING, &ssl_ca_path, OPT_USE_SSL, 0, 0},
298 /* All the following options switch us into daemon-mode option-parsing. */
299 {"config", 0, POPT_ARG_STRING, 0, OPT_DAEMON, 0, 0 },
300 {"daemon", 0, POPT_ARG_NONE, 0, OPT_DAEMON, 0, 0 },
301 @@ -648,6 +674,13 @@ static void daemon_usage(enum logcode F)
302 rprintf(F," -v, --verbose increase verbosity\n");
303 rprintf(F," -4, --ipv4 prefer IPv4\n");
304 rprintf(F," -6, --ipv6 prefer IPv6\n");
306 + rprintf(F," --ssl allow socket connections to use SSL\n");
307 + rprintf(F," --ssl-cert=FILE path to daemon's SSL certificate\n");
308 + rprintf(F," --ssl-key=FILE path to daemon's SSL private key\n");
309 + rprintf(F," --ssl-key-passwd=PASS password for PEM-encoded private key\n");
310 + rprintf(F," --ssl-ca-certs=FILE path to trusted CA certificates\n");
312 rprintf(F," --help show this help screen\n");
315 @@ -672,6 +705,13 @@ static struct poptOption long_daemon_opt
316 {"protocol", 0, POPT_ARG_INT, &protocol_version, 0, 0, 0 },
317 {"server", 0, POPT_ARG_NONE, &am_server, 0, 0, 0 },
318 {"temp-dir", 'T', POPT_ARG_STRING, &tmpdir, 0, 0, 0 },
320 + {"ssl", 0, POPT_ARG_NONE, 0, OPT_USE_SSL, 0, 0},
321 + {"ssl-cert", 0, POPT_ARG_STRING, &ssl_cert_path, OPT_USE_SSL, 0, 0},
322 + {"ssl-key", 0, POPT_ARG_STRING, &ssl_key_path, OPT_USE_SSL, 0, 0},
323 + {"ssl-key-passwd", 0, POPT_ARG_STRING, &ssl_key_passwd, OPT_USE_SSL, 0, 0},
324 + {"ssl-ca-certs", 0, POPT_ARG_STRING, &ssl_ca_path, OPT_USE_SSL, 0, 0},
326 {"verbose", 'v', POPT_ARG_NONE, 0, 'v', 0, 0 },
327 {"no-verbose", 0, POPT_ARG_VAL, &verbose, 0, 0, 0 },
328 {"no-v", 0, POPT_ARG_VAL, &verbose, 0, 0, 0 },
329 @@ -946,6 +986,12 @@ int parse_arguments(int *argc_p, const c
341 "rsync: %s: %s (in daemon mode)\n",
342 @@ -969,6 +1015,17 @@ int parse_arguments(int *argc_p, const c
343 exit_cleanup(RERR_SYNTAX);
349 + snprintf(err_buf, sizeof(err_buf),
350 + "Openssl error: %s\n",
357 *argv_p = argv = poptGetArgs(pc);
358 *argc_p = argc = count_args(argv);
360 @@ -1221,6 +1278,12 @@ int parse_arguments(int *argc_p, const c
371 /* A large opt value means that set_refuse_options()
372 * turned this option off. */
373 @@ -1536,6 +1599,17 @@ int parse_arguments(int *argc_p, const c
374 if (delay_updates && !partial_dir)
375 partial_dir = tmp_partialdir;
380 + snprintf(err_buf, sizeof(err_buf),
381 + "Openssl error: %s\n",
389 #ifdef HAVE_FTRUNCATE
391 @@ -2011,10 +2085,27 @@ char *check_for_hostspec(char *s, char *
395 + int url_prefix_len = sizeof URL_PREFIX - 1;
397 - if (port_ptr && strncasecmp(URL_PREFIX, s, strlen(URL_PREFIX)) == 0) {
399 + url_prefix_len = 0;
400 + else if (strncasecmp(URL_PREFIX, s, url_prefix_len) != 0) {
402 + url_prefix_len = sizeof SSL_URL_PREFIX - 1;
403 + if (strncasecmp(SSL_URL_PREFIX, s, url_prefix_len) != 0)
404 + url_prefix_len = 0;
411 + url_prefix_len = 0;
414 + if (url_prefix_len) {
416 - s += strlen(URL_PREFIX);
417 + s += url_prefix_len;
418 if ((p = strchr(s, '/')) != NULL) {
425 #define DEFAULT_LOCK_FILE "/var/run/rsyncd.lock"
426 #define URL_PREFIX "rsync://"
427 +#define SSL_URL_PREFIX "rsyncs://"
429 #define BACKUP_SUFFIX "~"
431 @@ -500,6 +501,11 @@ enum msgcode {
432 # define SIZEOF_INT64 SIZEOF_OFF_T
436 +#include <openssl/ssl.h>
437 +#include <openssl/err.h>
446 +/* -*- c-file-style: "linux" -*-
447 + * ssl.c: operations for negotiating SSL rsync connections.
449 + * Copyright (C) 2003 Casey Marshall <rsdio@metastatic.org>
451 + * This program is free software; you can redistribute it and/or modify
452 + * it under the terms of the GNU General Public License as published by
453 + * the Free Software Foundation; either version 2 of the License, or
454 + * (at your option) any later version.
456 + * This program is distributed in the hope that it will be useful,
457 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
458 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
459 + * GNU General Public License for more details.
461 + * You should have received a copy of the GNU General Public License
462 + * along with this program; if not, write to the Free Software
463 + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
468 +#ifdef HAVE_SYS_SELECT_H
469 +#include <sys/select.h>
471 +#include <sys/time.h>
472 +#include <sys/types.h>
477 +#define BUF_SIZE 1024
480 +extern int am_daemon;
481 +extern int am_server;
483 +extern char *ssl_cert_path;
484 +extern char *ssl_key_path;
485 +extern char *ssl_key_passwd;
486 +extern char *ssl_ca_path;
488 +static SSL_CTX *ssl_ctx;
490 +static int tls_read[2] = { -1, -1 };
491 +static int tls_write[2] = { -1, -1 };
492 +static int ssl_running;
493 +static int ssl_pid = -1;
495 +#ifdef HAVE_SIGACTION
496 +static struct sigaction sigact;
500 + * A non-interactive callback to be passed to SSL_CTX_set_default_password_cb,
501 + * which merely copies the value of ssl_key_passwd into buf. This is
502 + * used for when the private key password is supplied via an option.
504 +static int default_password_cb(char *buf, int n, UNUSED(int f), UNUSED(void *u))
506 + if (ssl_key_passwd == NULL || n < (int)strlen(ssl_key_passwd))
508 + strncpy(buf, ssl_key_passwd, n-1);
509 + return strlen(ssl_key_passwd);
513 + * If verbose, this method traces the status of the SSL handshake.
515 +static void info_callback(const SSL *ssl, int cb, int val)
522 + cbs = "SSL_CB_LOOP";
525 + cbs = "SSL_CB_EXIT";
528 + cbs = "SSL_CB_READ";
531 + cbs = "SSL_CB_WRITE";
534 + cbs = "SSL_CB_ALERT";
536 + case SSL_CB_READ_ALERT:
537 + cbs = "SSL_CB_READ_ALERT";
539 + case SSL_CB_WRITE_ALERT:
540 + cbs = "SSL_CB_WRITE_ALERT";
542 + case SSL_CB_ACCEPT_LOOP:
543 + cbs = "SSL_CB_ACCEPT_LOOP";
545 + case SSL_CB_ACCEPT_EXIT:
546 + cbs = "SSL_CB_ACCEPT_EXIT";
548 + case SSL_CB_CONNECT_LOOP:
549 + cbs = "SSL_CB_CONNECT_LOOP";
551 + case SSL_CB_CONNECT_EXIT:
552 + cbs = "SSL_CB_CONNECT_EXIT";
554 + case SSL_CB_HANDSHAKE_START:
555 + cbs = "SSL_CB_HANDSHAKE_START";
557 + case SSL_CB_HANDSHAKE_DONE:
558 + cbs = "SSL_CB_HANDSHAKE_DONE";
561 + snprintf(buf, sizeof buf, "??? (%d)", cb);
566 + rprintf(FLOG, "SSL: info_callback(%p,%s,%d)\n", ssl, cbs, val);
567 + if (cb == SSL_CB_HANDSHAKE_DONE) {
568 + SSL_CIPHER_description(SSL_get_current_cipher((SSL*)ssl),
570 + rprintf(FLOG, "SSL: cipher: %s", buf);
576 + * Initializes the SSL context for TLSv1 connections; returns zero on
583 + SSL_library_init();
584 + SSL_load_error_strings();
585 + ssl_ctx = SSL_CTX_new(TLSv1_method());
588 + SSL_CTX_set_info_callback(ssl_ctx, info_callback);
590 + /* Sets the certificate sent to the other party. */
591 + if (ssl_cert_path != NULL
592 + && SSL_CTX_use_certificate_file(ssl_ctx, ssl_cert_path,
593 + SSL_FILETYPE_PEM) != 1)
595 + /* Set up the simple non-interactive callback if the password
596 + * was supplied on the command line. */
597 + if (ssl_key_passwd != NULL)
598 + SSL_CTX_set_default_passwd_cb(ssl_ctx, default_password_cb);
599 + /* Sets the private key that matches the public certificate. */
600 + if (ssl_key_path != NULL) {
601 + if (SSL_CTX_use_PrivateKey_file(ssl_ctx, ssl_key_path,
602 + SSL_FILETYPE_PEM) != 1)
604 + if (SSL_CTX_check_private_key(ssl_ctx) != 1)
607 + if (ssl_ca_path != NULL
608 + && !SSL_CTX_load_verify_locations(ssl_ctx, ssl_ca_path, NULL))
615 + * Returns the error string for the current SSL error, if any.
617 +char *get_ssl_error(void)
619 + return ERR_error_string(ERR_get_error(), NULL);
623 + * Returns the input file descriptor for the SSL connection.
625 +int get_tls_rfd(void)
627 + return tls_read[0];
631 + * Returns the output file descriptor for the SSL connection.
633 +int get_tls_wfd(void)
635 + return tls_write[1];
639 + * Signal handler that ends the SSL connection.
641 +static RETSIGTYPE tls_sigusr1(int UNUSED(val))
652 + * Negotiates the TLS connection, creates a socket pair for communicating
653 + * with the rsync process, then forks into a new process that will handle
654 + * the communication.
656 + * 0 is returned on success.
658 +int start_tls(int f_in, int f_out)
662 + unsigned char buf1[BUF_SIZE], buf2[BUF_SIZE];
663 + int avail1 = 0, avail2 = 0, write1 = 0, write2 = 0;
666 + if (fd_pair(tls_read))
668 + if (fd_pair(tls_write))
671 + set_blocking(tls_read[0]);
672 + set_blocking(tls_read[1]);
673 + set_blocking(tls_write[0]);
674 + set_blocking(tls_write[1]);
675 + set_blocking(f_in);
676 + set_blocking(f_out);
678 + ssl_pid = do_fork();
681 + if (ssl_pid != 0) {
682 + close(tls_write[0]);
683 + close(tls_read[1]);
687 + SIGACTION(SIGUSR1, tls_sigusr1);
688 + ssl = SSL_new(ssl_ctx);
691 + if (am_daemon || am_server)
692 + SSL_set_accept_state(ssl);
694 + SSL_set_connect_state(ssl);
695 + SSL_set_rfd(ssl, f_in);
696 + SSL_set_wfd(ssl, f_out);
698 + tls_fd = SSL_get_fd(ssl);
700 + n = MAX(tls_read[1], n);
701 + n = MAX(tls_fd, n) + 1;
704 + while (ssl_running) {
707 + FD_SET(tls_write[0], &rd);
708 + FD_SET(tls_read[1], &wd);
709 + FD_SET(tls_fd, &rd);
710 + FD_SET(tls_fd, &wd);
712 + r = select(n, &rd, &wd, NULL, NULL);
714 + if (r == -1 && errno == EINTR)
716 + if (FD_ISSET(tls_write[0], &rd)) {
717 + r = read(tls_write[0], buf1+avail1, BUF_SIZE-avail1);
721 + rprintf(FERROR, "pipe read error: %s\n",
726 + if (FD_ISSET(tls_fd, &rd)) {
727 + r = SSL_read(ssl, buf2+avail2, BUF_SIZE-avail2);
731 + switch (SSL_get_error(ssl, r)) {
732 + case SSL_ERROR_ZERO_RETURN:
734 + case SSL_ERROR_WANT_READ:
735 + case SSL_ERROR_WANT_WRITE:
737 + case SSL_ERROR_SYSCALL:
739 + rprintf(FERROR, "SSL spurious EOF\n");
741 + rprintf(FERROR, "SSL I/O error: %s\n",
744 + case SSL_ERROR_SSL:
745 + rprintf(FERROR, "SSL: %s\n",
746 + ERR_error_string(ERR_get_error(), NULL));
749 + rprintf(FERROR, "unexpected ssl error %d\n", r);
754 + if (FD_ISSET(tls_read[1], &wd) && write2 < avail2) {
755 + r = write(tls_read[1], buf2+write2, avail2-write2);
759 + rprintf(FERROR, "pipe write error: %s\n",
764 + if (FD_ISSET(tls_fd, &wd) && write1 < avail1) {
765 + r = SSL_write(ssl, buf1+write1, avail1-write1);
769 + switch (SSL_get_error(ssl, r)) {
770 + case SSL_ERROR_ZERO_RETURN:
772 + case SSL_ERROR_WANT_READ:
773 + case SSL_ERROR_WANT_WRITE:
775 + case SSL_ERROR_SYSCALL:
777 + rprintf(FERROR, "SSL: spurious EOF\n");
779 + rprintf(FERROR, "SSL: I/O error: %s\n",
782 + case SSL_ERROR_SSL:
783 + rprintf(FERROR, "SSL: %s\n",
784 + ERR_error_string(ERR_get_error(), NULL));
787 + rprintf(FERROR, "unexpected ssl error %d\n", r);
792 + if (avail1 == write1)
793 + avail1 = write1 = 0;
794 + if (avail2 == write2)
795 + avail2 = write2 = 0;
798 + /* XXX I'm pretty sure that there is a lot that I am not considering
799 + here. Bugs? Yes, probably. */
801 + /* We're finished. */
803 + close(tls_read[1]);
804 + close(tls_write[0]);
809 + * Ends the TLS connection.
814 + kill(ssl_pid, SIGUSR1);