#!/usr/bin/perl
+use strict;
# Name: /usr/local/bin/rrsync (should also have a symlink in /usr/bin)
# Purpose: Restricts rsync to subdirectory declared in .ssh/authorized_keys
# Author: Joe Smith <js-cgi@inwap.com> 30-Sep-2004
-# Modified by Wayne Davison <wayned@samba.org> 12-Jan-2005
+# Modified by: Wayne Davison <wayned@samba.org>
use Socket;
+use File::Glob ':glob';
+use constant RSYNC => 'rsync'; # Optionally set the path of rsync here.
use constant LOGFILE => 'rrsync.log';
my $Usage = <<EOM;
Use 'command="$0 [-ro] SUBDIR"'
in front of lines in $ENV{HOME}/.ssh/authorized_keys
EOM
-my $ro = (@ARGV and $ARGV[0] eq '-ro') ? shift : ''; # -ro = Read-Only
-my $subdir = shift;
-die "No subdirectory specified\n$Usage" unless defined $subdir;
+our $ro = (@ARGV && $ARGV[0] eq '-ro') ? shift : ''; # -ro = Read-Only
+our $subdir = shift;
+die "$0: No subdirectory specified\n$Usage" unless defined $subdir;
+die "$0: Restricted subdirectory does not exist!\n" if $subdir ne '/' && !-d $subdir;
# The client uses "rsync -av -e ssh src/ server:dir/", and sshd on the server
# executes this program when .ssh/authorized_keys has 'command="..."'.
# command="rrsync -ro results" ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAIEAmkHG1WCjC...
#
# Format of the envrionment variables set by sshd:
-# SSH_ORIGINAL_COMMAND=rsync --server -vlogDtpr --partial . dir # push
-# SSH_ORIGINAL_COMMAND=rsync --server --sender -vlogDtpr --partial . dir # pull
+# SSH_ORIGINAL_COMMAND=rsync --server -vlogDtpr --partial . ARG # push
+# SSH_ORIGINAL_COMMAND=rsync --server --sender -vlogDtpr --partial . ARGS # pull
# SSH_CONNECTION=client_addr client_port server_port
my $command = $ENV{SSH_ORIGINAL_COMMAND};
-die "Not invoked via sshd\n$Usage" unless defined $command;
-die "SSH_ORIGINAL_COMMAND='$command' is not rsync\n" unless $command =~ /^rsync\s/;
-die "$0 -ro: sending to read-only server not allowed\n"
- if $ro and $command !~ /^rsync --server --sender /;
-die "$0 -ro: use of $1 with read-only server not allowed\n"
- if $ro and $command =~ /\s(--remove-\S+)/;
-
-my ($cmd,$dir) = $command =~ /^(rsync\s+(?:-[-a-zA-Z]+\s+)+\.) ?("[^"]*"|[^\s"]*)$/;
-die "$0: invalid rsync-command syntax or options\n" if !defined $cmd;
-
-# Enforce default of $subdir instead of the normal $HOME default.
-my $orig = $dir;
-my @dirs;
-$dir =~ s/^"(.*?)"$/$1/;
-$dir =~ s/^\s+//;
-$dir =~ s/\s+$//;
-foreach (split(/(?<!\\)\s+/, $dir)) {
- s/\\(\s)/$1/g; # Unescape any escaped whitespace
- if ($subdir eq '/') { # Less checking for '/' access
- $dir = '/' if $dir eq '';
+die "$0: Not invoked via sshd\n$Usage" unless defined $command;
+die "$0: SSH_ORIGINAL_COMMAND='$command' is not rsync\n" unless $command =~ s/^rsync\s+//;
+our $am_sender = $command =~ /\s--sender\s/;
+die "$0 -ro: sending to read-only server not allowed\n" if $ro && !$am_sender;
+
+# These options are only the options that rsync might send to the
+# server, and only in the arg format that the stock rsync uses.
+### START of options data output by the cull-options script. ###
+our $short_no_arg = 'CDHIKLORSWbcdglnoprtuvxz';
+our $short_with_num = 'B';
+# To disable a short-named option, add its letter to this string:
+our $short_disabled = '';
+# To disable a long-named option, change its value to a 0. A value of -1
+# means the arg doesn't need checking, a 2 means only check when receiving.
+our %long_no_arg = (
+ 'copy-unsafe-links' => -1,
+ 'daemon' => -1,
+ 'delay-updates' => -1,
+ 'delete' => -1,
+ 'delete-after' => -1,
+ 'delete-before' => -1,
+ 'delete-during' => -1,
+ 'delete-excluded' => -1,
+ 'existing' => -1,
+ 'force' => -1,
+ 'from0' => -1,
+ 'fuzzy' => -1,
+ 'ignore-errors' => -1,
+ 'ignore-existing' => -1,
+ 'inplace' => -1,
+ 'list-only' => -1,
+ 'no-implied-dirs' => -1,
+ 'no-relative' => -1,
+ 'numeric-ids' => -1,
+ 'partial' => -1,
+ 'remove-sent-files' => $ro ? 0 : -1,
+ 'safe-links' => -1,
+ 'sender' => -1,
+ 'server' => -1,
+ 'size-only' => -1,
+);
+our %long_with_arg = (
+ 'bwlimit' => -1,
+ 'checksum-seed' => -1,
+ 'files-from' => 1,
+ 'log-format' => -1,
+ 'max-delete' => -1,
+ 'modify-window' => -1,
+ 'only-write-batch' => -1,
+ 'suffix' => -1,
+ 'timeout' => -1,
+);
+our %long_before_arg = (
+ 'backup-dir' => 2,
+ 'files-from' => 1,
+ 'max-size' => -1,
+ 'partial-dir' => 2,
+ 'temp-dir' => 2,
+);
+### END of options data output by the cull-options script. ###
+
+if ($short_disabled ne '') {
+ $short_no_arg =~ s/[$short_disabled]//go;
+ $short_with_num =~ s/[$short_disabled]//go;
+}
+
+my(@opts, @args);
+my $in_options = 1;
+my $last_opt = '';
+my $check_type;
+foreach (split(/(?<!\\)\s+/, $command)) {
+ if ($check_type) {
+ s/\\(.)/$1/g;
+ push(@opts, check_arg($last_opt, $_, $check_type));
+ $check_type = 0;
+ } elsif ($in_options) {
+ s/\\(.)/$1/g;
+ push(@opts, $_);
+ if ($_ eq '.') {
+ $in_options = 0;
+ } else {
+ next if /^-[$short_no_arg]+$/o || /^-[$short_with_num]\d+$/o;
+
+ my($opt,$arg) = /^--([^=]+)(?:=(.*))?$/;
+ my $disabled;
+ if (defined $arg) {
+ my $ct = $long_with_arg{$opt};
+ if ($ct) {
+ $arg = check_arg($opt, $arg, $ct);
+ $opts[-1] =~ s/=.*/=$arg/;
+ next;
+ }
+ $disabled = defined $long_with_arg{$opt};
+ $opt = "--$opt";
+ } elsif (defined $opt) {
+ if (defined $long_no_arg{$opt}) {
+ next if $long_no_arg{$opt};
+ $disabled = 1;
+ } else {
+ $check_type = $long_before_arg{$opt};
+ if ($check_type) {
+ $last_opt = $opt;
+ next;
+ }
+ $disabled = defined $check_type;
+ }
+ $opt = "--$opt";
+ } elsif ($short_disabled ne '') {
+ $disabled = /^-[$short_no_arg]*([$short_disabled])/o;
+ $opt = "-$1" if $disabled;
+ }
+
+ die "$0: option $opt has been disabled on this server.\n" if $disabled;
+ die "$0: invalid rsync-command syntax or options\n";
+ }
} else {
- s#^/##; # Don't allow absolute paths
- $_ = "$subdir/$_" unless m#^\Q$subdir\E(/|$)#;
- 1 while s#/\.\.(/|$)#/__/#g; # Don't allow foo/../../etc
+ push(@args, $_);
}
- tr#-_/a-zA-Z0-9.,+@^%: #_#c; # Don't allow '"&;|!=()[]{}<>*?#\$
- s/(\s)/\\$1/g; # Re-escape whitespace
- push(@dirs, $_);
}
-push(@dirs, $subdir) unless @dirs;
-$dir = join(' ', @dirs);
-if (-f LOGFILE and open LOG,'>>',LOGFILE) {
+my $write_log = -f LOGFILE && open(LOG, '>>', LOGFILE);
+
+chdir($subdir) or die "$0: Unable to chdir to $subdir: $!\n";
+
+# Validate args to ensure they don't try to leave our restricted dir.
+if ($subdir ne '/') {
+ my @new;
+ foreach (@args) {
+ s#//+#/#g; # Turn multiple slashes into a single slash
+ s#^/##; # Don't allow absolute paths
+ s#^$#.#; # Turn empty arg into "."
+ die "Do not use .. in any path!\n" if m#(^|/)\.\.(/|$)#;
+ push(@new, bsd_glob($_, GLOB_LIMIT | GLOB_NOCHECK | GLOB_BRACE | GLOB_QUOTE));
+ }
+ @args = @new;
+}
+
+@args = ( '.' ) if !@args;
+
+if ($write_log) {
my ($mm,$hh) = (localtime)[1,2];
my $host = $ENV{SSH_CONNECTION} || 'unknown';
$host =~ s/ .*//; # Keep only the client's IP addr
$host =~ s/^::ffff://;
$host = gethostbyaddr(inet_aton($host),AF_INET) || $host;
- my $dir_result = $dir eq $orig ? " OK" : "> \"$dir\"";
- printf LOG "%02d:%02d %-13s [%s] =%s\n", $hh, $mm, $host, $command, $dir_result;
+ printf LOG "%02d:%02d %-13s [%s]\n", $hh, $mm, $host, "@opts @args";
close LOG;
}
-exec "$cmd \"$dir\"" or die "exec($cmd \"$dir\") failed: $? $!";
# Note: This assumes that the rsync protocol will not be maliciously hijacked.
+exec(RSYNC, @opts, @args) or die "exec(rsync @opts @args) failed: $? $!";
+
+sub check_arg
+{
+ my($opt, $arg, $type) = @_;
+ if ($subdir ne '/' && $type > 0 && ($type < 2 || !$am_sender)) {
+ $arg =~ s#//#/#g;
+ die "Do not use .. in --$opt; anchor the path at the root of your restricted dir.\n"
+ if $arg =~ m#(^|/)\.\.(/|$)#;
+ $arg =~ s#^/#$subdir/#;
+ }
+ $arg;
+}
git.samba.org / rsync.git / commitdiff