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lib/CSS/Adaptor/Whitelist.pm  view on Meta::CPAN

    | rgb\(  # rgb(255,0,255), rgb(255,0,255,0.3)
        (?: \d{1,3} | $re_percent ),
        (?: \d{1,3} | $re_percent ),
        (?: \d{1,3} | $re_percent )
        (?: , (?:$re_zero_to_one | $re_percent) )?
      \)
)/x;
my $re_url = qr{url\((?:http://[-\w+.]+/[-/\w.?%#]+)\)};
sub set_url_re {
    my ($new_re) = @_;
    if (ref($new_re) ne 'Regexp') {
        die 'set_url_re requires a compiled regular expression, e.g. qr/url(http:.*?)/'
    }
    else {
        $re_url = $new_re;
    }
}

# background
my $re_image = qr/(?:
      none \b
    | $re_url
)/x;
my $re_xy_pos = qr/(?:
    (?: left | center | right | $re_ndim ) \b
    (?: \s+
        (?: top | center | bottom | $re_ndim ) \b
    )?
)/x;
my $re_bg_attach = qr/(?:scroll\b|fixed\b)/;
my $re_bg_repeat = qr/(?:repeat(?:-[xy])?\b|no-repeat\b)/;

# border
my $re_border_width = qr/(?: thin\b | medium\b | thick\b | $re_dim )/x;
my $re_border_style = qr/(?: (?:none|hidden|dotted|dashed|solid|double|groove|ridge|inset|outset) \b )/x;
sub ck_border {
    space_sep_res(shift, $re_border_width, $re_border_style, $re_color)
}
my $re_border_radius = qr/(?: $re_dim ( \s+ $re_dim )? )/x;

# margin, padding
my $re_margin = qr/(?: auto \b | $re_ndim )/x;
my $re_margin_all = qr/(?: $re_margin ( \s+ $re_margin ){0,3} )/x;
my $re_padding_all = qr/(?: $re_ndim ( \s+ $re_ndim ){0,3} )/x;

# font
my $re_font_family = qr/(?: [-a-zA-Z0-9 ,"']+ \b )/x;  # maybe too generous, should we list possible families?
my $re_font_size = qr/(?: (?:x?x-)?(?:small|large)\b | small(?:er)? \b | larger? \b | medium \b | $re_dim )/x;
my $re_font_style = qr/(?: normal \b | oblique \b | italic \b )/x;
my $re_font_variant = qr/(?: normal \b | small-caps \b )/x;
my $re_font_weight = qr/(?: (?: normal | lighter | bold(?:er)? | \d{3} ) \b )/x;

# list style
my $re_list_style_position = qr/(?: (?:in|out)side \b )/x;
my $re_list_style_type = qr/(?: (?:
      none | circle | disc | square | armenian
    | decimal(?:-leading-zero)? | georgian | lower-greek | (?:lower|upper)-(?:alpha|latin|roman)
) \b )/x;

# various
my $re_cursor = qr/(?:
    (?: $re_url (?: \s*,\s* $re_url )* \s* , )?
    (?: auto | crosshair | default | help | move | pointer | progress | text | wait
        | (?:[news]|[ns][ew])-resize
    ) \b
)/x;

our %whitelist = (
    background => sub {
        space_sep_res(shift, $re_color, $re_image, $re_bg_repeat, $re_bg_attach, $re_xy_pos)
    },
    'background-color' => qr/^$re_color$/,
    'background-image' => qr/^$re_image$/,
    'background-position' => qr/^$re_xy_pos$/,
    'background-attachment' => qr/^$re_bg_attach$/,
    'background-repeat' => qr/^$re_bg_repeat$/,
    
    border => \&ck_border,
    'border-color'    => qr/^$re_color$/,
    'border-style'    => qr/^$re_border_style$/,
    'border-width'    => qr/^$re_border_width$/,
    'border-collapse' => list2hash(qw(collapse separate)),
    'border-spacing'  => qr/^ $re_dim (?: \s+ $re_dim )? $/x,
    'border-top' => \&ck_border,
    'border-top-color' => qr/^$re_color$/,
    'border-top-style' => qr/^$re_border_style$/,
    'border-top-width' => qr/^$re_border_width$/,
    'border-bottom' => \&ck_border,
    'border-bottom-color' => qr/^$re_color$/,
    'border-bottom-style' => qr/^$re_border_style$/,
    'border-bottom-width' => qr/^$re_border_width$/,
    'border-left' => \&ck_border,
    'border-left-color' => qr/^$re_color$/,
    'border-left-style' => qr/^$re_border_style$/,
    'border-left-width' => qr/^$re_border_width$/,
    'border-right' => \&ck_border,
    'border-right-color' => qr/^$re_color$/,
    'border-right-style' => qr/^$re_border_style$/,
    'border-right-width' => qr/^$re_border_width$/,
    '-webkit-border-radius' => qr/^$re_border_radius$/,
       '-moz-border-radius' => qr/^$re_border_radius$/,
         '-o-border-radius' => qr/^$re_border_radius$/,
            'border-radius' => qr/^$re_border_radius$/,
    
    outline => \&ck_border,
    'outline-color' => qr/^$re_color$/,
    'outline-style' => qr/^$re_border_style$/,
    'outline-width' => qr/^$re_border_width$/,
    
    margin => qr/^$re_margin_all$/x,
    'margin-top'    => qr/$re_margin$/,
    'margin-bottom' => qr/$re_margin$/,
    'margin-left'   => qr/$re_margin$/,
    'margin-right'  => qr/$re_margin$/,
    
    padding => qr/^$re_padding_all$/,
    'padding-top'    => qr/^$re_ndim$/,
    'padding-bottom' => qr/^$re_ndim$/,
    'padding-left'   => qr/^$re_ndim$/,
    'padding-right'  => qr/^$re_ndim$/,
    
    color => qr/^$re_color$/,
    font => sub {
        my $str = shift;
        return (
            list2hash(
                qw/caption icon menu message-box small-caption status-bar/
            )->{$str}
            ||
            space_sep_res(
                $str, $re_font_style, $re_font_variant, $re_font_weight, $re_font_size
            )
        )
    },
    'font-family'  => qr/^$re_font_family$/,
    'font-size'    => qr/^$re_font_size$/,
    'font-style'   => qr/^$re_font_style$/,
    'font-variant' => qr/^$re_font_variant$/,
    'font-weight'  => qr/^$re_font_weight$/,
    
    'list-style' => sub {
        space_sep_res(shift, $re_list_style_type, $re_list_style_position, $re_image)
    },
    'list-style-image' => qr/^$re_image$/,
    'list-style-type' => qr/^$re_list_style_type$/,
    'list-style-position' => qr/^$re_list_style_position$/,

    position => list2hash(qw/absolute fixed relative static/),
    top      => qr/^$re_ndim$/,
    bottom   => qr/^$re_ndim$/,
    left     => qr/^$re_ndim$/,
    right    => qr/^$re_ndim$/,
    
    display    => qr/^(?: (?:
          none | block | inline(?:-block|-table)? | list-item | run-in
        | table(?:- (:? caption | cell | (?:footer|header)-group | (?:column|row)(?:-group)? ) )?
    ) \b )$/x,
    visibility => list2hash(qw(visible hidden collapse)),
    overflow   => list2hash(qw(visible hidden scroll auto)),
    float      => list2hash(qw(left right none)),
    clear      => list2hash(qw(left right none both)),
    
    clip      => qr/^(?:auto\b|rect\(\s*$re_dim(?:\s*,\s*$re_dim){3}\s*\))$/,
    cursor    => qr/^$re_cursor$/,
    direction => list2hash(qw(ltr trl)),
    
    height => qr/^(?:auto\b|$re_ndim)$/,
    width  => qr/^(?:auto\b|$re_ndim)$/,
    'min-width'  => qr/^$re_ndim$/,
    'min-height' => qr/^$re_ndim$/,
    'max-width'  => qr/^$re_ndim$/,
    'max-height' => qr/^$re_ndim$/,
    'line-height' => qr/^(?:normal\b|$re_frac|$re_dim)$/,
    
    'text-align'      => list2hash(qw(left right center justify)),
    'text-decoration' => sub {
        my $str = shift;
        if ($str !~ /\S/) { return 0 }
        if ($str eq 'none') { return 1 }
        my %vals = %{ list2hash(qw(underline overline line-through blink)) };
        for (split /\s+/, $str) {
            if (not $vals{$_}) { return 0 }
        }
        return 1
    },
    'text-indent'     => qr/^$re_ndim$/,
    'text-shadow'     => qr/^ $re_ndim \s+ $re_ndim (?: \s+ $re_dim )? (?: \s+ $re_color )? $/x,
    'text-transform'  => list2hash(qw(none capitalize uppercase lowercase)),
    
    'letter-spacing' => qr/^(?:normal\b|$re_ndim)$/,
    'word-spacing'   => qr/^(?:normal\b|$re_ndim)$/,
    'caption-side'   => list2hash(qw(top bottom)),
    'empty-cells'    => list2hash(qw(hide show)),
    'table-layout'   => list2hash(qw(auto fixed)),
    'unicode-bidi'   => list2hash(qw(normal embed bidi-override)),
    'vertical-align' => qr/^(?: $re_ndim | baseline \b | middle \b | su(?:b|per) \b | (?:text-)?(?:top|bottom) \b )$/x,
    'white-space'    => list2hash(qw(normal nowrap pre pre-line pre-wrap)),
    'z-index'        => qr/^(?: auto \b | -?\d+ \b )$/x,
    
    orphans => qr/^\d+\b$/,
    widows  => qr/^\d+\b$/,
    'page-break-after'  => list2hash(qw(auto always avoid left right)),
    'page-break-before' => list2hash(qw(auto always avoid left right)),
    'page-break-inside' => list2hash(qw(auto avoid)),
);
sub value_ok {
    my ($value, $property) = @_;
    $value =~ s/\s+!important$//;
    if ($value eq 'inherit') { return 1 }
    my $w = $whitelist{ $property };
    if (ref $w eq 'Regexp') {
        return $value =~ $w
    }
    elsif (ref $w eq 'HASH') {
        return exists($w->{$value}) && $w->{$value}
    }
    elsif (ref $w eq 'CODE') {
        return $w->($value)
    }
    else {
        return 0
    }
}

lib/CSS/Adaptor/Whitelist.pm  view on Meta::CPAN

the C<log> method.

In case of regexp, it is checked against the regexp. If it matches, the value
passes.

In case of subroutine, the value is passed as the only argument to it. If the
sub returns a true value, the CSS value passes.

In case of hash, if the CSS value is a key in the hash, that is associated with
a true value, then it passes.

=head2 Overriding defaults

You are invited to modify the rules, particularly the ones that allow URL's.
See C<set_url_re> for a convenient way.

Also the C<font-family> (and thus also C<font>) properties are quite generous.
Feel free to allow just a list of expected font families:

 $CSS::Adaptor::Whitelist::whitelist{'font-family'} = qr/^arial|verdana|...$/;

=head2 Functions

=over 4

=item list2hash

Simplifies giving values in the hash way. Returns hasref.

 list2hash('foo', 'bar', 'baz') # returns {foo => 1, bar => 1, baz => 1}

=item space_sep_res

 space_sep_res($string, $regex, $regex, ...) # returns 1 or 0

SPACE-SEParated Regular ExpresssionS. Given a string like C<1px solid #CCFF55>
and regular expressions for CSS dimension, border type and CSS color,
checks if the string matches piece by piece to these regexps.

Will fail if some of the regexp matches too small a chunk, for example:

 space_sep_res('solid #CCFF55', qr/solid|dotted/, qr/#[A-F\d]{3}|#[A-F\d]{6}/)

will return 0 because the latter regexp stops after matching <#CCF>.

Also beware that the regular expressions provided MUST NOT contain capturing
parentheses, otherwise the function will not work. Use C<(?: ... )> for
non-capturing parenthesising.

=item set_url_re

Sets the regular expression that URL's are checked against. Including the
C<url( )> wrapper. You are encouraged to use this method to provide a regexp
that will only allow URL's to domains you control:

 CSS::Adaptor::Whitelist::set_url_re(qr{url(https?://example\.com/[\w/]+)});

Notice that the regexp should not be anchored (no C<^> and C<$> at the edges).
It is being used in these properties:

 cursor
 background
 background-image
 list-style
 list-style-image

=item log

This is a method that stores messages of things being filtered out in
the C<@CSS::Adaptor::Whitelist::message_log> array.

You are encouraged to override or redefine this method to treat the log
messages in accordance with your logging habits.

=back

=head1 AUTHOR

Oldrich Kruza E<lt>sixtease@cpan.orgE<gt>

http://www.sixtease.net/

=head1 COPYRIGHT

Copyright (c) 2009 Oldrich Kruza. All rights reserved.

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