From 6d094f61bb014fafff882536ecc2aab3e799422c Mon Sep 17 00:00:00 2001
From: Andrew Ozz
Date: Fri, 2 Mar 2018 14:41:04 +0000
Subject: [PATCH] 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
---
src/wp-includes/default-filters.php | 15 ++++
src/wp-includes/formatting.php | 63 ++++++++++++++++
.../tests/formatting/WPTargetedLinkRel.php | 74 +++++++++++++++++++
.../rest-api/rest-attachments-controller.php | 8 +-
.../tests/rest-api/rest-posts-controller.php | 8 +-
5 files changed, 160 insertions(+), 8 deletions(-)
create mode 100644 tests/phpunit/tests/formatting/WPTargetedLinkRel.php
diff --git a/src/wp-includes/default-filters.php b/src/wp-includes/default-filters.php
index 53f1d7b247..6b60625545 100644
--- a/src/wp-includes/default-filters.php
+++ b/src/wp-includes/default-filters.php
@@ -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' );
diff --git a/src/wp-includes/formatting.php b/src/wp-includes/formatting.php
index 8648287f81..0d7b9f931e 100644
--- a/src/wp-includes/formatting.php
+++ b/src/wp-includes/formatting.php
@@ -3023,6 +3023,69 @@ function wp_rel_nofollow_callback( $matches ) {
return "";
}
+/**
+ * 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, ']*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 "";
+}
+
/**
* Convert one smiley code to the icon graphic file equivalent.
*
diff --git a/tests/phpunit/tests/formatting/WPTargetedLinkRel.php b/tests/phpunit/tests/formatting/WPTargetedLinkRel.php
new file mode 100644
index 0000000000..49c843ec2c
--- /dev/null
+++ b/tests/phpunit/tests/formatting/WPTargetedLinkRel.php
@@ -0,0 +1,74 @@
+Links: No rel
';
+ $expected = 'Links: No rel
';
+ $this->assertEquals( $expected, wp_targeted_link_rel( $content ) );
+ }
+
+ public function test_add_to_links_with_target_foo() {
+ $content = 'Links: No rel
';
+ $expected = 'Links: No rel
';
+ $this->assertEquals( $expected, wp_targeted_link_rel( $content ) );
+ }
+
+ public function test_target_as_first_attribute() {
+ $content = 'Links: No rel
';
+ $expected = 'Links: No rel
';
+ $this->assertEquals( $expected, wp_targeted_link_rel( $content ) );
+ }
+
+ public function test_add_to_existing_rel() {
+ $content = 'Links: Existing rel
';
+ $expected = 'Links: Existing rel
';
+ $this->assertEquals( $expected, wp_targeted_link_rel( $content ) );
+ }
+
+ public function test_no_duplicate_values_added() {
+ $content = 'Links: Existing rel
';
+ $expected = 'Links: Existing rel
';
+ $this->assertEquals( $expected, wp_targeted_link_rel( $content ) );
+ }
+
+ public function test_rel_with_single_quote_delimiter() {
+ $content = 'Links: Existing rel
';
+ $expected = 'Links: Existing rel
';
+ $this->assertEquals( $expected, wp_targeted_link_rel( $content ) );
+ }
+
+ public function test_rel_with_no_delimiter() {
+ $content = 'Links: Existing rel
';
+ $expected = 'Links: Existing rel
';
+ $this->assertEquals( $expected, wp_targeted_link_rel( $content ) );
+ }
+
+ public function test_rel_value_spaced_and_no_delimiter() {
+ $content = 'Links: Existing rel
';
+ $expected = 'Links: Existing rel
';
+ $this->assertEquals( $expected, wp_targeted_link_rel( $content ) );
+ }
+
+ public function test_rel_value_spaced_and_no_delimiter_and_values_to_escape() {
+ $content = 'Links: Existing rel
';
+ $expected = 'Links: Existing rel
';
+ $this->assertEquals( $expected, wp_targeted_link_rel( $content ) );
+ }
+
+ public function test_escaped_quotes() {
+ $content = 'Links: Existing rel
';
+ $expected = 'Links: Existing rel
';
+ $this->assertEquals( $expected, wp_targeted_link_rel( $content ) );
+ }
+
+ public function test_ignore_links_with_no_target() {
+ $content = 'Links: Change me Do not change me
';
+ $expected = 'Links: Change me Do not change me
';
+ $this->assertEquals( $expected, wp_targeted_link_rel( $content ) );
+ }
+}
diff --git a/tests/phpunit/tests/rest-api/rest-attachments-controller.php b/tests/phpunit/tests/rest-api/rest-attachments-controller.php
index c93b8b09ab..1136ac2cf2 100644
--- a/tests/phpunit/tests/rest-api/rest-attachments-controller.php
+++ b/tests/phpunit/tests/rest-api/rest-attachments-controller.php
@@ -1015,12 +1015,12 @@ class WP_Test_REST_Attachments_Controller extends WP_Test_REST_Post_Type_Control
'rendered' => 'link',
),
'description' => array(
- 'raw' => 'link',
- 'rendered' => 'link
',
+ 'raw' => 'link',
+ 'rendered' => 'link
',
),
'caption' => array(
- 'raw' => 'link',
- 'rendered' => 'link
',
+ 'raw' => 'link',
+ 'rendered' => 'link
',
),
),
),
diff --git a/tests/phpunit/tests/rest-api/rest-posts-controller.php b/tests/phpunit/tests/rest-api/rest-posts-controller.php
index bc820a8796..c0a5397aa0 100644
--- a/tests/phpunit/tests/rest-api/rest-posts-controller.php
+++ b/tests/phpunit/tests/rest-api/rest-posts-controller.php
@@ -3185,12 +3185,12 @@ class WP_Test_REST_Posts_Controller extends WP_Test_REST_Post_Type_Controller_Te
'rendered' => 'link',
),
'content' => array(
- 'raw' => 'link',
- 'rendered' => 'link
',
+ 'raw' => 'link',
+ 'rendered' => 'link
',
),
'excerpt' => array(
- 'raw' => 'link',
- 'rendered' => 'link
',
+ 'raw' => 'link',
+ 'rendered' => 'link
',
),
),
),