gitweb: add $prevent_xss option to prevent XSS by repository content

diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index 95988fba4ab743e26b246aa2c22c6e36ef50efaf..bdaa4e9463460a149a5c7f13881e5373257bc4e5 100755 (executable)
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -132,6 +132,10 @@ BEGIN
 # - one might want to include '-B' option, e.g. '-B', '-M'
 our @diff_opts = ('-M'); # taken from git_commit
 
+# Disables features that would allow repository owners to inject script into
+# the gitweb domain.
+our $prevent_xss = 0;
+
 # information about snapshot formats that gitweb is capable of serving
 our %known_snapshot_formats = (
        # name => {
@@ -241,6 +245,7 @@ BEGIN
        # $feature{'grep'}{'override'} = 1;
        # and in project config gitweb.grep = 0|1;
        'grep' => {
+               'sub' => \&feature_grep,
                'override' => 0,
                'default' => [1]},
 
@@ -2146,8 +2151,9 @@ sub git_get_projects_list {
 
                                my $subdir = substr($File::Find::name, $pfxlen + 1);
                                # we check related file in $projectroot
-                               if (check_export_ok("$projectroot/$filter/$subdir")) {
-                                       push @list, { path => ($filter ? "$filter/" : '') . $subdir };
+                               my $path = ($filter ? "$filter/" : '') . $subdir;
+                               if (check_export_ok("$projectroot/$path")) {
+                                       push @list, { path => $path };
                                        $File::Find::prune = 1;
                                }
                        },
@@ -2763,7 +2769,7 @@ sub insert_file {
        my $filename = shift;
 
        open my $fd, '<', $filename;
-       print map(to_utf8, <$fd>);
+       print map { to_utf8($_) } <$fd>;
        close $fd;
 }
 
@@ -4492,7 +4498,9 @@ sub git_summary {
 
        print "</table>\n";
 
-       if (-s "$projectroot/$project/README.html") {
+       # If XSS prevention is on, we don't include README.html.
+       # TODO: Allow a readme in some safe format.
+       if (!$prevent_xss && -s "$projectroot/$project/README.html") {
                print "<div class=\"title\">readme</div>\n" .
                      "<div class=\"readme\">\n";
                insert_file("$projectroot/$project/README.html");
@@ -4737,10 +4745,21 @@ sub git_blob_plain {
                $save_as .= '.txt';
        }
 
+       # With XSS prevention on, blobs of all types except a few known safe
+       # ones are served with "Content-Disposition: attachment" to make sure
+       # they don't run in our security domain.  For certain image types,
+       # blob view writes an <img> tag referring to blob_plain view, and we
+       # want to be sure not to break that by serving the image as an
+       # attachment (though Firefox 3 doesn't seem to care).
+       my $sandbox = $prevent_xss &&
+               $type !~ m!^(?:text/plain|image/(?:gif|png|jpeg))$!;
+
        print $cgi->header(
                -type => $type,
                -expires => $expires,
-               -content_disposition => 'inline; filename="' . $save_as . '"');
+               -content_disposition =>
+                       ($sandbox ? 'attachment' : 'inline')
+                       . '; filename="' . $save_as . '"');
        undef $/;
        binmode STDOUT, ':raw';
        print <$fd>;
@@ -5284,43 +5303,9 @@ sub git_blobdiff {
                        or die_error(500, "Open git-diff-tree failed");
        }
 
-       # old/legacy style URI
-       if (!%diffinfo && # if new style URI failed
-           defined $hash && defined $hash_parent) {
-               # fake git-diff-tree raw output
-               $diffinfo{'from_mode'} = $diffinfo{'to_mode'} = "blob";
-               $diffinfo{'from_id'} = $hash_parent;
-               $diffinfo{'to_id'}   = $hash;
-               if (defined $file_name) {
-                       if (defined $file_parent) {
-                               $diffinfo{'status'} = '2';
-                               $diffinfo{'from_file'} = $file_parent;
-                               $diffinfo{'to_file'}   = $file_name;
-                       } else { # assume not renamed
-                               $diffinfo{'status'} = '1';
-                               $diffinfo{'from_file'} = $file_name;
-                               $diffinfo{'to_file'}   = $file_name;
-                       }
-               } else { # no filename given
-                       $diffinfo{'status'} = '2';
-                       $diffinfo{'from_file'} = $hash_parent;
-                       $diffinfo{'to_file'}   = $hash;
-               }
-
-               # non-textual hash id's can be cached
-               if ($hash =~ m/^[0-9a-fA-F]{40}$/ &&
-                   $hash_parent =~ m/^[0-9a-fA-F]{40}$/) {
-                       $expires = '+1d';
-               }
-
-               # open patch output
-               open $fd, "-|", git_cmd(), "diff", @diff_opts,
-                       '-p', ($format eq 'html' ? "--full-index" : ()),
-                       $hash_parent, $hash, "--"
-                       or die_error(500, "Open git-diff failed");
-       } else  {
-               die_error(400, "Missing one of the blob diff parameters")
-                       unless %diffinfo;
+       # old/legacy style URI -- not generated anymore since 1.4.3.
+       if (!%diffinfo) {
+               die_error('404 Not Found', "Missing one of the blob diff parameters")
        }
 
        # header