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CGIProxy Ban Extensions Hack

A simple hack to ban only specified extensions in CGIProxy

I figured out a hacky way to ban on extensions based on the TEXT_ONLY thing. Unfortunately text only strips images and everything else, which is unacceptable for most common uses.

Open nph-proxy.pl for editing.

Find "use vars qw(". After, add:

$MY_BANNED_EXTENSIONS

Find "$NON_TEXT_EXTENSIONS=". After the file types for NON_TEXT_EXTENSIONS, add:

$MY_BANNED_EXTENSIONS=
      '|mp2|mp3|wav|aif|aiff|au|snd'            # audios
	. '|avi|qt|mov|mpeg|mpg|mpe'                # videos
	. '|gz|Z|exe|gtar|tar|zip|sit|hqx|pdf'      # applications
	. '|ram|rm|ra|swf' ;                        # others[/code]

Find "if ($TEXT_ONLY)". Before, add:

# Forbid requests for filenames with non-text-type extensions
&my_die if ($path=~ /\.($MY_BANNED_EXTENSIONS)(;|\?|$)/i);

Find "sub non_text_die {". After, add:

# If images are forbidden, return either a "403 Forbidden" message or a
#   1x1 transparent GIF.
sub my_die {

    my($date_header)= &rfc1123_date($now, 0) ;

    print <<EOF ;
    $HTTP_1_X 403 Forbidden
    $Date: $date_header
    Content-type: text/html

    <html>
    <head><title>Proxy cannot forward media files</title></head>
    <body>
    <h1>Proxy cannot forward media files</h1>
    <p>Due to bandwidth limitations, the owner of this proxy has disallowed media files.
    EOF
    goto EXIT ;
}

You can customize the file types set for $MY_BANNED_EXTENSIONS, as well as the message/response in sub my_die.

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