JavaScript::Value::Escape(3)

NAME
JavaScript::Value::Escape - Avoid XSS with JavaScript value interpolation

SYNOPSIS
  use JavaScript::Value::Escape;

  my $escaped = javascript_value_escape(q!&foo"bar'</script>!);
  # $escaped is "\u0026foo\u0022bar\u0027\u003c\/script\u003e"

  my $html_escaped = javascript_value_escape(Text::Xslate::Util::escape_html(q!&foo"bar'</script>!));

  print <<EOF;
  <script>
  var param = '$escaped';
  alert(param);

  document.write('$html_escaped');

  </script>
  EOF

DESCRIPTION
There are a lot of XSS, a security hole typically found in web applications, caused by incorrect (or lack of) JavaScript escaping. This module aims to provide secure JavaScript escaping to avoid XSS with JavaScript values.

The escaping routine JavaScript::Value::Escape provides escapes for q!"!, q!'!, q!&!, q!=!, q!-!, q!+!, q!;!, q!<!, q!>!, q!/!, q!\! and control characters to JavaScript unicode entities like "\u0026".

EXPORT FUNCTION

javascript_value_escape($value :Str) :Str
    Escape a string. The argument of this function must be a text string (a.k.a. UTF-8 flagged string, Perl's internal form).

    This is exported by default.

js($value :Str) :Str
    Alias to javascript_value_escape() for convenience.

    This is exported by your request.

AUTHOR
Masahiro Nagano <kazeburo {at} gmail.com>

THANKS TO
Fuji, Goro (gfx)

SEE ALSO
<http://subtech.g.hatena.ne.jp/mala/20100222/1266843093> - About XSS caused by buggy JavaScript escaping for HTML script sections (Japanese)

<http://blog.nomadscafe.jp/2010/11/htmlscript.html> - Wrote a module (JavaScript::Value::Escape) to escape data for HTML script sections (Japanese)

<https://www.owasp.org/index.php/XSS_%28Cross_Site_Scripting%29_Prevention_Cheat_Sheet> - Preventing XSS (Cross Site Scripting) (English)

RFC4627 - The application/json Media Type for JSON

LICENSE
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.