From a506e02edd068748cf2a1d42be946f8c67807ec2 Mon Sep 17 00:00:00 2001
From: Adam Silverstein <adamsilverstein@earthboundhosting.com>
Date: Tue, 2 Feb 2021 20:55:05 +0000
Subject: [PATCH] Security: add  Content-Security-Policy script loaders.

Add new functions `wp_get_script_tag`, `wp_print_script_tag`, `wp_print_inline_script_tag` and `wp_get_inline_script_tag` that support script attributes. Enables passing attributes such as `async` or `nonce`, creating a path forward for enabling a Content-Security-Policy in core, plugins and themes.

Props tomdxw, johnbillion, jadeddragoon, jrchamp, mallorydxw, epicfaace, alinod, enricocarraro, ocean90.
Fixes #39941.



Built from https://develop.svn.wordpress.org/trunk@50167


git-svn-id: http://core.svn.wordpress.org/trunk@49846 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/functions.php | 120 ++++++++++++++++++++++++++++++++++++++
 wp-includes/version.php   |   2 +-
 2 files changed, 121 insertions(+), 1 deletion(-)

diff --git a/wp-includes/functions.php b/wp-includes/functions.php
index 5935f781fb..56f50ce2de 100644
--- a/wp-includes/functions.php
+++ b/wp-includes/functions.php
@@ -7866,3 +7866,123 @@ function is_php_version_compatible( $required ) {
 function wp_fuzzy_number_match( $expected, $actual, $precision = 1 ) {
 	return abs( (float) $expected - (float) $actual ) <= $precision;
 }
+
+/**
+ * Sanitizes an attributes array into an attributes string to be placed inside a `<script>` tag.
+ *
+ * Automatically injects type attribute if needed.
+ * Used by {@see wp_get_script_tag()} and {@see wp_get_inline_script_tag()}.
+ *
+ * @since 5.7.0
+ *
+ * @param array $attributes Key-value pairs representing `<script>` tag attributes.
+ * @return string String made of sanitized `<script>` tag attributes.
+ */
+function wp_sanitize_script_attributes( $attributes ) {
+	$html5_script_support = ! is_admin() && ! current_theme_supports( 'html5', 'script' );
+	$attributes_string    = '';
+
+	// If HTML5 script tag is supported, only the attribute name is added
+	// to $attributes_string for entries with a boolean value, and that are true.
+	foreach ( $attributes as $attribute_name => $attribute_value ) {
+		if ( is_bool( $attribute_value ) ) {
+			if ( $attribute_value ) {
+				$attributes_string .= $html5_script_support ? sprintf( ' %1$s="%2$s"', esc_attr( $attribute_name ), esc_attr( $attribute_name ) ) : ' ' . $attribute_name;
+			}
+		} else {
+			$attributes_string .= sprintf( ' %1$s="%2$s"', esc_attr( $attribute_name ), esc_attr( $attribute_value ) );
+		}
+	}
+
+	return $attributes_string;
+}
+
+/**
+ * Formats `<script>` loader tags.
+ *
+ * It is possible to inject attributes in the `<script>` tag via the {@see 'wp_script_attributes'} filter.
+ * Automatically injects type attribute if needed.
+ *
+ * @since 5.7.0
+ *
+ * @param array $attributes Key-value pairs representing `<script>` tag attributes.
+ * @return string String containing `<script>` opening and closing tags.
+ */
+function wp_get_script_tag( $attributes ) {
+	if ( ! isset( $attributes['type'] ) && ! is_admin() && ! current_theme_supports( 'html5', 'script' ) ) {
+		$attributes['type'] = 'text/javascript';
+	}
+	/**
+	 * Filters attributes to be added to a script tag.
+	 *
+	 * @since 5.7.0
+	 *
+	 * @param array $attributes Key-value pairs representing `<script>` tag attributes.
+	 *                          Only the attribute name is added to the `<script>` tag for
+	 *                          entries with a boolean value, and that are true.
+	 */
+	$attributes = apply_filters( 'wp_script_attributes', $attributes );
+
+	return sprintf( "<script%s></script>\n", wp_sanitize_script_attributes( $attributes ) );
+}
+
+/**
+ * Prints formatted `<script>` loader tag.
+ *
+ * It is possible to inject attributes in the `<script>` tag via the  {@see 'wp_script_attributes'}  filter.
+ * Automatically injects type attribute if needed.
+ *
+ * @since 5.7.0
+ *
+ * @param array $attributes Key-value pairs representing `<script>` tag attributes.
+ */
+function wp_print_script_tag( $attributes ) {
+	echo wp_get_script_tag( $attributes );
+}
+
+/**
+ * Wraps inline JavaScript in `<script>` tag.
+ *
+ * It is possible to inject attributes in the `<script>` tag via the  {@see 'wp_script_attributes'}  filter.
+ * Automatically injects type attribute if needed.
+ *
+ * @since 5.7.0
+ *
+ * @param string $javascript Inline JavaScript code.
+ * @param array  $attributes  Optional. Key-value pairs representing `<script>` tag attributes.
+ * @return string String containing inline JavaScript code wrapped around `<script>` tag.
+ */
+function wp_get_inline_script_tag( $javascript, $attributes = array() ) {
+	if ( ! isset( $attributes['type'] ) && ! is_admin() && ! current_theme_supports( 'html5', 'script' ) ) {
+		$attributes['type'] = 'text/javascript';
+	}
+	/**
+	 * Filters attributes to be added to a script tag.
+	 *
+	 * @since 5.7.0
+	 *
+	 * @param array $attributes Key-value pairs representing `<script>` tag attributes.
+	 *                          Only the attribute name is added to the `<script>` tag for
+	 *                          entries with a boolean value, and that are true.
+	 */
+	$attributes = apply_filters( 'wp_inline_script_attributes', $attributes, $javascript );
+
+	$javascript = "\n" . trim( $javascript, "\n\r " ) . "\n";
+
+	return sprintf( "<script%s>%s</script>\n", wp_sanitize_script_attributes( $attributes ), $javascript );
+}
+
+/**
+ * Prints inline JavaScript wrapped in `<script>` tag.
+ *
+ * It is possible to inject attributes in the `<script>` tag via the  {@see 'wp_script_attributes'}  filter.
+ * Automatically injects type attribute if needed.
+ *
+ * @since 5.7.0
+ *
+ * @param string $javascript Inline JavaScript code.
+ * @param array  $attributes Optional. Key-value pairs representing `<script>` tag attributes.
+ */
+function wp_print_inline_script_tag( $javascript, $attributes = array() ) {
+	echo wp_get_inline_script_tag( $javascript, $attributes );
+}
diff --git a/wp-includes/version.php b/wp-includes/version.php
index f2306d1608..8a5ebbf989 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.7-alpha-50166';
+$wp_version = '5.7-alpha-50167';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.