testing/rssh: new aport

http://www.pizzashack.org/rssh/
Restricted shell for use with OpenSSH, allowing only scp, sftp, and/or rsync

1 files changed, 130 insertions, 0 deletions

diff --git a/testing/rssh/handle-rsync-v3-e-option.patch b/testing/rssh/handle-rsync-v3-e-option.patch
new file mode 100644
index 00000000000..e1694ee0adc
--- /dev/null
+++ b/testing/rssh/handle-rsync-v3-e-option.patch
@@ -0,0 +1,130 @@
+From: Russ Allbery <rra@stanford.edu>
+Subject: [PATCH] Handle the rsync v3 -e option for protocol information
+
+As of rsync 3, rsync reused the -e option to pass protocol information
+from the client to the server.  We therefore cannot reject all -e
+options to rsync, only ones not sent with --server or containing
+something other than protocol information as an argument.
+
+Also scan the rsync command line for any --rsh option and reject it as
+well.  This replaces and improves the upstream strategy for rejecting
+that command-line option, taking advantage of the parsing added to
+check the -e option.
+
+Based on work by Robert Hardy.
+
+Debian Bug#471803
+
+Signed-off-by: Russ Allbery <rra@stanford.edu>
+
+---
+ util.c |   80 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++-------
+ 1 file changed, 72 insertions(+), 8 deletions(-)
+
+diff --git a/util.c b/util.c
+index f98d2bc..a257b06 100644
+--- a/util.c
++++ b/util.c
+@@ -56,6 +56,7 @@
+ #ifdef HAVE_LIBGEN_H
+ #include <libgen.h>
+ #endif /* HAVE_LIBGEN_H */
++#include <regex.h>
+ 
+ /* LOCAL INCLUDES */
+ #include "pathnames.h"
+@@ -198,6 +199,73 @@ bool check_command( char *cl, ShellOptions_t *opts, char *cmd, int cmdflag )
+ 
+ 
+ /*
++ * rsync_e_okay() - take the command line passed to rssh and look for an -e
++ *		    option.  If one is found, make sure --server is provided
++ *		    and the option contains only the protocol information.
++ *		    Also check for and reject any --rsh option.	 Returns FALSE
++ *		    if the command line should not be allowed, TRUE if it is
++ *		    okay.
++ */
++static int rsync_e_okay( char **vec )
++{
++	regex_t	re;
++	int	server = FALSE;
++	int	e_found = FALSE;
++
++	/*
++	 * rsync will send -e, followed by either just "." (meaning no special
++	 * protocol) or "N.N" (meaning a pre-release protocol version),
++	 * followed by some number of alphabetic flags indicating various
++	 * supported options.  There may be other options between - and the e,
++	 * but -e will always be the last option in the string.	 A typical
++	 * option passed by the client is "-ltpre.iL".
++	 *
++	 * Note that if --server is given, this should never be parsed as a
++	 * shell, but we'll tightly verify it anyway, just in case.
++	 *
++	 * This regex matches the acceptable flags containing -e, so if it
++	 * does not match, the command line should be rejected.
++	 */
++	static const char pattern[]
++	    = "^-[a-df-zA-Z]*e[0-9]*\\.[0-9]*[a-zA-Z]*$";
++
++	/*
++	 * Only recognize --server if it's the first option.  rsync itself
++	 * always passes it that way, and if it's not the first argument, it
++	 * could be hidden from the server as an argument to some other
++	 * option.
++	 */
++	if ( vec && vec[0] && vec[1] && strcmp(vec[1], "--server") == 0 ){
++		server = TRUE;
++	}
++
++	/* Check the remaining options for -e or --rsh. */
++	if ( regcomp(&re, pattern, REG_EXTENDED | REG_NOSUB) != 0 ){
++		return FALSE;
++	}
++	while (vec && *vec){
++		if ( strcmp(*vec, "--") == 0 ) break;
++		if ( strcmp(*vec, "--rsh") == 0
++		     || strncmp(*vec, "--rsh=", strlen("--rsh=")) == 0 ){
++			regfree(&re);
++			return FALSE;
++		}
++		if ( strncmp(*vec, "--", 2) != 0 && opt_exist(*vec, 'e') ){
++			e_found = TRUE;
++			if ( regexec(&re, *vec, 0, NULL, 0) != 0 ){
++				regfree(&re);
++				return FALSE;
++			}
++		}
++		vec++;
++	}
++	regfree(&re);
++	if ( e_found && !server ) return FALSE;
++	return TRUE;
++}
++
++
++/*
+  * check_command_line() - take the command line passed to rssh, and verify
+  *			  that the specified command is one the user is
+  *			  allowed to run and validate the arguments.  Return the
+@@ -230,14 +298,10 @@ char *check_command_line( char **cl, ShellOptions_t *opts )
+ 
+ 	if ( check_command(*cl, opts, PATH_RSYNC, RSSH_ALLOW_RSYNC) ){
+ 		/* filter -e option */
+-		if ( opt_filter(cl, 'e') ) return NULL;
+-		while (cl && *cl){
+-			if ( strstr(*cl, "--rsh" ) ){
+-				fprintf(stderr, "\ninsecure --rsh= not allowed.");
+-				log_msg("insecure --rsh option in rsync command line!");
+-				return NULL;
+-			}
+-			cl++;
++		if ( !rsync_e_okay(cl) ){
++			fprintf(stderr, "\ninsecure -e or --rsh option not allowed.");
++			log_msg("insecure -e or --rsh option in rsync command line!");
++			return NULL;
+ 		}
+ 		return PATH_RSYNC;
+ 	}
+-- 
+tg: (f8b36e2..) fixes/rsync-protocol (depends on: upstream)