Add configuration to restrict the formats allowed for comments

I want to write my blog posts in a convenient format (Emacs org mode)
but do not want commenters to be able to use this format for security
reasons. This patch allows to configure which formats are allowed for
writing comments.

Effectively, it restricts the formats enabled with add_plugin to those
mentioned in comments_allowformats. If this is empty, all formats are
allowed, which is the behavior without this patch.

diff --git a/IkiWiki/Plugin/comments.pm b/IkiWiki/Plugin/comments.pm
index 285013e49175c8651055bb53e34e71e44115699c..151e839d0bb826a7bda242a9d94b882e79e7cb17 100644 (file)
--- a/IkiWiki/Plugin/comments.pm
+++ b/IkiWiki/Plugin/comments.pm
@@ -90,6 +90,15 @@ sub getsetup () {
                        safe => 0,
                        rebuild => 0,
                },
+               comments_allowformats => {
+                       type => 'string',
+                       default => '',
+                       example => 'mdwn txt',
+                       description => 'Restrict formats for comments to (no restriction if empty)',
+                       safe => 1,
+                       rebuild => 0,
+               },
+
 }
 
 sub checkconfig () {
@@ -101,6 +110,8 @@ sub checkconfig () {
                unless defined $config{comments_closed_pagespec};
        $config{comments_pagename} = 'comment_'
                unless defined $config{comments_pagename};
+       $config{comments_allowformats} = ''
+               unless defined $config{comments_allowformats};
 }
 
 sub htmlize {
@@ -128,12 +139,18 @@ sub safeurl ($) {
        }
 }
 
+sub isallowed ($) {
+    my $format = shift;
+    return ! $config{comments_allowformats} || $config{comments_allowformats} =~ /\b$format\b/;
+}
+
 sub preprocess {
        my %params = @_;
        my $page = $params{page};
 
        my $format = $params{format};
-       if (defined $format && ! exists $IkiWiki::hooks{htmlize}{$format}) {
+       if (defined $format && (! exists $IkiWiki::hooks{htmlize}{$format} ||
+                               ! isallowed($format))) {
                error(sprintf(gettext("unsupported page format %s"), $format));
        }
 
@@ -332,7 +349,7 @@ sub editcomment ($$) {
 
        my @page_types;
        if (exists $IkiWiki::hooks{htmlize}) {
-               foreach my $key (grep { !/^_/ } keys %{$IkiWiki::hooks{htmlize}}) {
+               foreach my $key (grep { !/^_/ && isallowed($_) } keys %{$IkiWiki::hooks{htmlize}}) {
                        push @page_types, [$key, $IkiWiki::hooks{htmlize}{$key}{longname} || $key];
                }
        }