Add pre-save content filter to make target=_blank always secure.

Props notnownikki, iseulde, azaozz
Fixes #43187

git-svn-id: https://develop.svn.wordpress.org/trunk@42770 602fd350-edb4-49c9-b593-d223f7449a82
This commit is contained in:
Andrew Ozz 2018-03-02 14:41:04 +00:00
parent c3615b2688
commit 6d094f61bb
5 changed files with 160 additions and 8 deletions

View File

@ -104,6 +104,21 @@ foreach ( array( 'content_save_pre', 'excerpt_save_pre', 'comment_save_pre', 'pr
add_filter( $filter, 'balanceTags', 50 );
}
// Add proper rel values for links with target.
foreach ( array(
'title_save_pre',
'content_save_pre',
'excerpt_save_pre',
'content_filtered_save_pre',
'pre_comment_content',
'pre_term_description',
'pre_link_description',
'pre_link_notes',
'pre_user_description',
) as $filter ) {
add_filter( $filter, 'wp_targeted_link_rel' );
};
// Format strings for display.
foreach ( array( 'comment_author', 'term_name', 'link_name', 'link_description', 'link_notes', 'bloginfo', 'wp_title', 'widget_title' ) as $filter ) {
add_filter( $filter, 'wptexturize' );

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@ -3023,6 +3023,69 @@ function wp_rel_nofollow_callback( $matches ) {
return "<a $text rel=\"$rel\">";
}
/**
* Adds rel noreferrer and noopener to all HTML A elements that have a target.
*
* @param string $text Content that may contain HTML A elements.
* @return string Converted content.
*/
function wp_targeted_link_rel( $text ) {
// Don't run (more expensive) regex if no links with targets.
if ( stripos( $text, 'target' ) !== false && stripos( $text, '<a ' ) !== false ) {
$text = preg_replace_callback( '|<a\s([^>]*target\s*=[^>]*)>|i', 'wp_targeted_link_rel_callback', $text );
}
return $text;
}
/**
* Callback to add rel="noreferrer noopener" string to HTML A element.
*
* Will not duplicate existing noreferrer and noopener values
* to prevent from invalidating the HTML.
*
* @param array $matches Single Match
* @return string HTML A Element with rel noreferrer noopener in addition to any existing values
*/
function wp_targeted_link_rel_callback( $matches ) {
$link_html = $matches[1];
$rel_match = array();
/**
* Filters the rel values that are added to links with `target` attribute.
*
* @since 5.0.0
*
* @param string The rel values.
* @param string $link_html The matched content of the link tag including all HTML attributes.
*/
$rel = apply_filters( 'wp_targeted_link_rel', 'noopener noreferrer', $link_html );
// Value with delimiters, spaces around are optional.
$attr_regex = '|rel\s*=\s*?(\\\\{0,1}["\'])(.*?)\\1|i';
preg_match( $attr_regex, $link_html, $rel_match );
if ( empty( $rel_match[0] ) ) {
// No delimiters, try with a single value and spaces, because `rel = va"lue` is totally fine...
$attr_regex = '|rel\s*=(\s*)([^\s]*)|i';
preg_match( $attr_regex, $link_html, $rel_match );
}
if ( ! empty( $rel_match[0] ) ) {
$parts = preg_split( '|\s+|', strtolower( $rel_match[2] ) );
$parts = array_map( 'esc_attr', $parts );
$needed = explode( ' ', $rel );
$parts = array_unique( array_merge( $parts, $needed ) );
$delimiter = trim( $rel_match[1] ) ? $rel_match[1] : '"';
$rel = 'rel=' . $delimiter . trim( implode( ' ', $parts ) ) . $delimiter;
$link_html = str_replace( $rel_match[0], $rel, $link_html );
} else {
$link_html .= " rel=\"$rel\"";
}
return "<a $link_html>";
}
/**
* Convert one smiley code to the icon graphic file equivalent.
*

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@ -0,0 +1,74 @@
<?php
/**
* @group formatting
* @ticket 43187
*/
class Tests_Targeted_Link_Rel extends WP_UnitTestCase {
public function test_add_to_links_with_target_blank() {
$content = '<p>Links: <a href="/" target="_blank">No rel</a></p>';
$expected = '<p>Links: <a href="/" target="_blank" rel="noopener noreferrer">No rel</a></p>';
$this->assertEquals( $expected, wp_targeted_link_rel( $content ) );
}
public function test_add_to_links_with_target_foo() {
$content = '<p>Links: <a href="/" target="foo">No rel</a></p>';
$expected = '<p>Links: <a href="/" target="foo" rel="noopener noreferrer">No rel</a></p>';
$this->assertEquals( $expected, wp_targeted_link_rel( $content ) );
}
public function test_target_as_first_attribute() {
$content = '<p>Links: <a target="_blank" href="#">No rel</a></p>';
$expected = '<p>Links: <a target="_blank" href="#" rel="noopener noreferrer">No rel</a></p>';
$this->assertEquals( $expected, wp_targeted_link_rel( $content ) );
}
public function test_add_to_existing_rel() {
$content = '<p>Links: <a href="/" rel="existing values" target="_blank">Existing rel</a></p>';
$expected = '<p>Links: <a href="/" rel="existing values noopener noreferrer" target="_blank">Existing rel</a></p>';
$this->assertEquals( $expected, wp_targeted_link_rel( $content ) );
}
public function test_no_duplicate_values_added() {
$content = '<p>Links: <a href="/" rel="existing noopener values" target="_blank">Existing rel</a></p>';
$expected = '<p>Links: <a href="/" rel="existing noopener values noreferrer" target="_blank">Existing rel</a></p>';
$this->assertEquals( $expected, wp_targeted_link_rel( $content ) );
}
public function test_rel_with_single_quote_delimiter() {
$content = '<p>Links: <a href="/" rel=\'existing values\' target="_blank">Existing rel</a></p>';
$expected = '<p>Links: <a href="/" rel=\'existing values noopener noreferrer\' target="_blank">Existing rel</a></p>';
$this->assertEquals( $expected, wp_targeted_link_rel( $content ) );
}
public function test_rel_with_no_delimiter() {
$content = '<p>Links: <a href="/" rel=existing target="_blank">Existing rel</a></p>';
$expected = '<p>Links: <a href="/" rel="existing noopener noreferrer" target="_blank">Existing rel</a></p>';
$this->assertEquals( $expected, wp_targeted_link_rel( $content ) );
}
public function test_rel_value_spaced_and_no_delimiter() {
$content = '<p>Links: <a href="/" rel = existing target="_blank">Existing rel</a></p>';
$expected = '<p>Links: <a href="/" rel="existing noopener noreferrer" target="_blank">Existing rel</a></p>';
$this->assertEquals( $expected, wp_targeted_link_rel( $content ) );
}
public function test_rel_value_spaced_and_no_delimiter_and_values_to_escape() {
$content = '<p>Links: <a href="/" rel = existing"value target="_blank">Existing rel</a></p>';
$expected = '<p>Links: <a href="/" rel="existing&quot;value noopener noreferrer" target="_blank">Existing rel</a></p>';
$this->assertEquals( $expected, wp_targeted_link_rel( $content ) );
}
public function test_escaped_quotes() {
$content = '<p>Links: <a href=\"/\" rel=\"existing values\" target=\"_blank\">Existing rel</a></p>';
$expected = '<p>Links: <a href=\"/\" rel=\"existing values noopener noreferrer\" target=\"_blank\">Existing rel</a></p>';
$this->assertEquals( $expected, wp_targeted_link_rel( $content ) );
}
public function test_ignore_links_with_no_target() {
$content = '<p>Links: <a href="/" target="_blank">Change me</a> <a href="/">Do not change me</a></p>';
$expected = '<p>Links: <a href="/" target="_blank" rel="noopener noreferrer">Change me</a> <a href="/">Do not change me</a></p>';
$this->assertEquals( $expected, wp_targeted_link_rel( $content ) );
}
}

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@ -1015,12 +1015,12 @@ class WP_Test_REST_Attachments_Controller extends WP_Test_REST_Post_Type_Control
'rendered' => '<a href="#">link</a>',
),
'description' => array(
'raw' => '<a href="#" target="_blank">link</a>',
'rendered' => '<p><a href="#" target="_blank">link</a></p>',
'raw' => '<a href="#" target="_blank" rel="noopener noreferrer">link</a>',
'rendered' => '<p><a href="#" target="_blank" rel="noopener noreferrer">link</a></p>',
),
'caption' => array(
'raw' => '<a href="#" target="_blank">link</a>',
'rendered' => '<p><a href="#" target="_blank">link</a></p>',
'raw' => '<a href="#" target="_blank" rel="noopener noreferrer">link</a>',
'rendered' => '<p><a href="#" target="_blank" rel="noopener noreferrer">link</a></p>',
),
),
),

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@ -3185,12 +3185,12 @@ class WP_Test_REST_Posts_Controller extends WP_Test_REST_Post_Type_Controller_Te
'rendered' => '<a href="#">link</a>',
),
'content' => array(
'raw' => '<a href="#" target="_blank">link</a>',
'rendered' => '<p><a href="#" target="_blank">link</a></p>',
'raw' => '<a href="#" target="_blank" rel="noopener noreferrer">link</a>',
'rendered' => '<p><a href="#" target="_blank" rel="noopener noreferrer">link</a></p>',
),
'excerpt' => array(
'raw' => '<a href="#" target="_blank">link</a>',
'rendered' => '<p><a href="#" target="_blank">link</a></p>',
'raw' => '<a href="#" target="_blank" rel="noopener noreferrer">link</a>',
'rendered' => '<p><a href="#" target="_blank" rel="noopener noreferrer">link</a></p>',
),
),
),