From 64e267cf969b78d13c198bca4230cc789778f60b Mon Sep 17 00:00:00 2001
From: Rebecca Hum <16962021+rebeccahum@users.noreply.github.com>
Date: Tue, 23 Feb 2021 12:25:29 -0700
Subject: [PATCH] Add new sniff InlineScriptEscaping

---
 .../Security/InlineScriptEscapingSniff.php    | 82 +++++++++++++++++++
 .../Security/InlineScriptEscapingUnitTest.inc | 30 +++++++
 .../Security/InlineScriptEscapingUnitTest.php | 43 ++++++++++
 3 files changed, 155 insertions(+)
 create mode 100644 WordPressVIPMinimum/Sniffs/Security/InlineScriptEscapingSniff.php
 create mode 100644 WordPressVIPMinimum/Tests/Security/InlineScriptEscapingUnitTest.inc
 create mode 100644 WordPressVIPMinimum/Tests/Security/InlineScriptEscapingUnitTest.php

diff --git a/WordPressVIPMinimum/Sniffs/Security/InlineScriptEscapingSniff.php b/WordPressVIPMinimum/Sniffs/Security/InlineScriptEscapingSniff.php
new file mode 100644
index 00000000..88c8e27f
--- /dev/null
+++ b/WordPressVIPMinimum/Sniffs/Security/InlineScriptEscapingSniff.php
@@ -0,0 +1,82 @@
+<?php
+/**
+ * WordPressVIPMinimum Coding Standard.
+ *
+ * @package VIPCS\WordPressVIPMinimum
+ * @link https://github.com/Automattic/VIP-Coding-Standards
+ */
+
+namespace WordPressVIPMinimum\Sniffs\Security;
+
+use WordPressVIPMinimum\Sniffs\Sniff;
+use PHP_CodeSniffer\Util\Tokens;
+
+/**
+ * Checks whether proper escaping function is used between script tags.
+ *
+ *  @package VIPCS\WordPressVIPMinimum
+ */
+class InlineScriptEscapingSniff extends Sniff {
+
+	/**
+	 * Property to keep track of between script tags.
+	 *
+	 * @var array
+	 */
+	private $in_script = false;
+
+	/**
+	 * Returns an array of tokens this test wants to listen for.
+	 *
+	 * @return array
+	 */
+	public function register() {
+		return [
+			'T_INLINE_HTML' => T_INLINE_HTML,
+			'T_STRING'      => T_STRING,
+		];
+	}
+
+	/**
+	 * Process this test when one of its tokens is encountered
+	 *
+	 * @param int $stackPtr The position of the current token in the stack passed in $tokens.
+	 *
+	 * @return void
+	 */
+	public function process_token( $stackPtr ) {
+		$content = trim( $this->tokens[ $stackPtr ]['content'] );
+
+		if ( $content === '' ) {
+			return;
+		}
+
+		if ( $this->has_open_script_tag( $content ) === true ) {
+			$this->in_script = true;
+		} elseif ( strpos( '</script>', $content ) !== false ) {
+			$this->in_script = false;
+		}
+
+		if ( $this->in_script === true && $this->tokens[ $stackPtr ]['content'] === 'esc_js' ) {
+			$message = 'Please do not use `esc_js()` for inline script escaping. See our code repository for 
+			examples on how to escape within: https://github.com/Automattic/vip-code-samples/blob/master/10-security/js-dynamic.php';
+			$this->phpcsFile->addError( $message, $stackPtr, 'InlineScriptEsc' );
+			return;
+		}
+	}
+
+	/**
+	 * Check if a content string contains <script> tag.
+	 *
+	 * @param string $content Haystack where we look for complete <script> tag.
+	 *
+	 * @return bool True if the string contains <script> tag, false otherwise.
+	 */
+	public function has_open_script_tag( $content = null ) {
+		if ( substr( $content, -1 ) !== '>' ) {
+			return false; // Incomplete tag, bail.
+		}
+
+		return $content !== null && strpos( $content, '<script' ) !== false;
+	}
+}
diff --git a/WordPressVIPMinimum/Tests/Security/InlineScriptEscapingUnitTest.inc b/WordPressVIPMinimum/Tests/Security/InlineScriptEscapingUnitTest.inc
new file mode 100644
index 00000000..cb072b1d
--- /dev/null
+++ b/WordPressVIPMinimum/Tests/Security/InlineScriptEscapingUnitTest.inc
@@ -0,0 +1,30 @@
+<?php
+$color = 'blue';
+$url = 'https://test.com';
+$themeURI = get_template_directory_uri();
+$ga_ua = 'foo';
+$page_title = '<h1>Test</h1>';
+?>
+<script type="text/javascript">
+    var name  = decodeURIComponent( '<?php echo esc_js( $name ); ?>' ); // Error.
+    var html  = document.createElement('h1');
+    html.innerText = name;
+</script>
+<script>
+    window.location.replace('<?php echo esc_js(site_url());?>/foo/#bar'); // Error.
+    ga('create', <?php echo (esc_js($ga_ua)); ?>, 'auto'); // Error.
+</script>
+<script type="text/javascript" src="<?php echo esc_js($themeURI.'/js/lib.min.js' ); // OK - Not in script scope.
+?>"></script> 
+<script>
+var url   = <?php echo wp_json_encode( esc_url( $url ) ) ?>; // OK.
+var title = decodeURIComponent( '<?php echo rawurlencode( (string) $page_title ); ?>' ); // OK.
+</script>
+
+<style>
+h1 {
+  color: <?php echo esc_js( $color ) ?>; /* OK - Not in script scope. */
+  font-family: verdana;
+  font-size: 300%;
+}
+</style>
diff --git a/WordPressVIPMinimum/Tests/Security/InlineScriptEscapingUnitTest.php b/WordPressVIPMinimum/Tests/Security/InlineScriptEscapingUnitTest.php
new file mode 100644
index 00000000..cef1ea7b
--- /dev/null
+++ b/WordPressVIPMinimum/Tests/Security/InlineScriptEscapingUnitTest.php
@@ -0,0 +1,43 @@
+<?php
+/**
+ * Unit test class for WordPressVIPMinimum Coding Standard.
+ *
+ * @package VIPCS\WordPressVIPMinimum
+ */
+
+namespace WordPressVIPMinimum\Tests\Security;
+
+use PHP_CodeSniffer\Tests\Standards\AbstractSniffUnitTest;
+
+/**
+ * Unit test class for the InlineScriptEscaping sniff.
+ *
+ * @package VIPCS\WordPressVIPMinimum
+ *
+ * @covers \WordPressVIPMinimum\Sniffs\Security\InlineScriptEscapingSniff
+ */
+class InlineScriptEscapingUnitTest extends AbstractSniffUnitTest {
+
+	/**
+	 * Returns the lines where errors should occur.
+	 *
+	 * @return array <int line number> => <int number of errors>
+	 */
+	public function getErrorList() {
+		return [
+			9  => 1,
+			14  => 1,
+			15 => 1,
+		];
+	}
+
+	/**
+	 * Returns the lines where warnings should occur.
+	 *
+	 * @return array <int line number> => <int number of warnings>
+	 */
+	public function getWarningList() {
+		return [];
+	}
+
+}