xarxaprod-wp-theme/vendor/wp-coding-standards/wpcs/WordPress/Sniffs/Security/EscapeOutputSniff.php

506 lines
15 KiB
PHP

<?php
/**
* WordPress Coding Standard.
*
* @package WPCS\WordPressCodingStandards
* @link https://github.com/WordPress/WordPress-Coding-Standards
* @license https://opensource.org/licenses/MIT MIT
*/
namespace WordPressCS\WordPress\Sniffs\Security;
use WordPressCS\WordPress\Sniff;
use PHP_CodeSniffer\Util\Tokens;
/**
* Verifies that all outputted strings are escaped.
*
* @link http://codex.wordpress.org/Data_Validation Data Validation on WordPress Codex
*
* @package WPCS\WordPressCodingStandards
*
* @since 2013-06-11
* @since 0.4.0 This class now extends the WordPressCS native `Sniff` class.
* @since 0.5.0 The various function list properties which used to be contained in this class
* have been moved to the WordPressCS native `Sniff` parent class.
* @since 0.12.0 This sniff will now also check for output escaping when using shorthand
* echo tags `<?=`.
* @since 0.13.0 Class name changed: this class is now namespaced.
* @since 1.0.0 This sniff has been moved from the `XSS` category to the `Security` category.
*/
class EscapeOutputSniff extends Sniff {
/**
* Custom list of functions which escape values for output.
*
* @since 0.5.0
*
* @var string|string[]
*/
public $customEscapingFunctions = array();
/**
* Custom list of functions whose return values are pre-escaped for output.
*
* @since 0.3.0
*
* @var string|string[]
*/
public $customAutoEscapedFunctions = array();
/**
* Custom list of functions which print output incorporating the passed values.
*
* @since 0.4.0
*
* @var string|string[]
*/
public $customPrintingFunctions = array();
/**
* Printing functions that incorporate unsafe values.
*
* @since 0.4.0
* @since 0.11.0 Changed from public static to protected non-static.
*
* @var array
*/
protected $unsafePrintingFunctions = array(
'_e' => 'esc_html_e() or esc_attr_e()',
'_ex' => 'echo esc_html_x() or echo esc_attr_x()',
);
/**
* Cache of previously added custom functions.
*
* Prevents having to do the same merges over and over again.
*
* @since 0.4.0
* @since 0.11.0 - Changed from public static to protected non-static.
* - Changed the format from simple bool to array.
*
* @var array
*/
protected $addedCustomFunctions = array(
'escape' => array(),
'autoescape' => array(),
'sanitize' => array(),
'print' => array(),
);
/**
* List of names of the tokens representing PHP magic constants.
*
* @since 0.10.0
*
* @var array
*/
private $magic_constant_tokens = array(
'T_CLASS_C' => true, // __CLASS__
'T_DIR' => true, // __DIR__
'T_FILE' => true, // __FILE__
'T_FUNC_C' => true, // __FUNCTION__
'T_LINE' => true, // __LINE__
'T_METHOD_C' => true, // __METHOD__
'T_NS_C' => true, // __NAMESPACE__
'T_TRAIT_C' => true, // __TRAIT__
);
/**
* List of names of the native PHP constants which can be considered safe.
*
* @since 1.0.0
*
* @var array
*/
private $safe_php_constants = array(
'PHP_EOL' => true, // String.
'PHP_VERSION' => true, // Integer.
'PHP_MAJOR_VERSION' => true, // Integer.
'PHP_MINOR_VERSION' => true, // Integer.
'PHP_RELEASE_VERSION' => true, // Integer.
'PHP_VERSION_ID' => true, // Integer.
'PHP_EXTRA_VERSION' => true, // String.
'PHP_DEBUG' => true, // Integer.
);
/**
* List of tokens which can be considered as safe when directly part of the output.
*
* @since 0.12.0
*
* @var array
*/
private $safe_components = array(
'T_CONSTANT_ENCAPSED_STRING' => true,
'T_LNUMBER' => true,
'T_MINUS' => true,
'T_PLUS' => true,
'T_MULTIPLY' => true,
'T_DIVIDE' => true,
'T_MODULUS' => true,
'T_TRUE' => true,
'T_FALSE' => true,
'T_NULL' => true,
'T_DNUMBER' => true,
'T_START_NOWDOC' => true,
'T_NOWDOC' => true,
'T_END_NOWDOC' => true,
);
/**
* Returns an array of tokens this test wants to listen for.
*
* @return array
*/
public function register() {
return array(
\T_ECHO,
\T_PRINT,
\T_EXIT,
\T_STRING,
\T_OPEN_TAG_WITH_ECHO,
);
}
/**
* Processes this test, when one of its tokens is encountered.
*
* @param int $stackPtr The position of the current token in the stack.
*
* @return int|void Integer stack pointer to skip forward or void to continue
* normal file processing.
*/
public function process_token( $stackPtr ) {
$this->mergeFunctionLists();
$function = $this->tokens[ $stackPtr ]['content'];
// Find the opening parenthesis (if present; T_ECHO might not have it).
$open_paren = $this->phpcsFile->findNext( Tokens::$emptyTokens, ( $stackPtr + 1 ), null, true );
// If function, not T_ECHO nor T_PRINT.
if ( \T_STRING === $this->tokens[ $stackPtr ]['code'] ) {
// Skip if it is a function but is not one of the printing functions.
if ( ! isset( $this->printingFunctions[ $this->tokens[ $stackPtr ]['content'] ] ) ) {
return;
}
if ( isset( $this->tokens[ $open_paren ]['parenthesis_closer'] ) ) {
$end_of_statement = $this->tokens[ $open_paren ]['parenthesis_closer'];
}
// These functions only need to have the first argument escaped.
if ( \in_array( $function, array( 'trigger_error', 'user_error' ), true ) ) {
$first_param = $this->get_function_call_parameter( $stackPtr, 1 );
$end_of_statement = ( $first_param['end'] + 1 );
unset( $first_param );
}
/*
* If the first param to `_deprecated_file()` follows the typical `basename( __FILE__ )`
* pattern, it doesn't need to be escaped.
*/
if ( '_deprecated_file' === $function ) {
$first_param = $this->get_function_call_parameter( $stackPtr, 1 );
// Quick check. This disregards comments.
if ( preg_match( '`^basename\s*\(\s*__FILE__\s*\)$`', $first_param['raw'] ) === 1 ) {
$stackPtr = ( $first_param['end'] + 2 );
}
unset( $first_param );
}
}
// Checking for the ignore comment, ex: //xss ok.
if ( $this->has_whitelist_comment( 'xss', $stackPtr ) ) {
return;
}
if ( isset( $this->unsafePrintingFunctions[ $function ] ) ) {
$error = $this->phpcsFile->addError(
"All output should be run through an escaping function (like %s), found '%s'.",
$stackPtr,
'UnsafePrintingFunction',
array( $this->unsafePrintingFunctions[ $function ], $function )
);
// If the error was reported, don't bother checking the function's arguments.
if ( $error ) {
return isset( $end_of_statement ) ? $end_of_statement : null;
}
}
$ternary = false;
// This is already determined if this is a function and not T_ECHO.
if ( ! isset( $end_of_statement ) ) {
$end_of_statement = $this->phpcsFile->findNext( array( \T_SEMICOLON, \T_CLOSE_TAG ), $stackPtr );
$last_token = $this->phpcsFile->findPrevious( Tokens::$emptyTokens, ( $end_of_statement - 1 ), null, true );
// Check for the ternary operator. We only need to do this here if this
// echo is lacking parenthesis. Otherwise it will be handled below.
if ( \T_OPEN_PARENTHESIS !== $this->tokens[ $open_paren ]['code'] || \T_CLOSE_PARENTHESIS !== $this->tokens[ $last_token ]['code'] ) {
$ternary = $this->phpcsFile->findNext( \T_INLINE_THEN, $stackPtr, $end_of_statement );
// If there is a ternary skip over the part before the ?. However, if
// the ternary is within parentheses, it will be handled in the loop.
if ( false !== $ternary && empty( $this->tokens[ $ternary ]['nested_parenthesis'] ) ) {
$stackPtr = $ternary;
}
}
}
// Ignore the function itself.
$stackPtr++;
$in_cast = false;
// Looping through echo'd components.
$watch = true;
for ( $i = $stackPtr; $i < $end_of_statement; $i++ ) {
// Ignore whitespaces and comments.
if ( isset( Tokens::$emptyTokens[ $this->tokens[ $i ]['code'] ] ) ) {
continue;
}
// Ignore namespace separators.
if ( \T_NS_SEPARATOR === $this->tokens[ $i ]['code'] ) {
continue;
}
if ( \T_OPEN_PARENTHESIS === $this->tokens[ $i ]['code'] ) {
if ( ! isset( $this->tokens[ $i ]['parenthesis_closer'] ) ) {
// Live coding or parse error.
break;
}
if ( $in_cast ) {
// Skip to the end of a function call if it has been casted to a safe value.
$i = $this->tokens[ $i ]['parenthesis_closer'];
$in_cast = false;
} else {
// Skip over the condition part of a ternary (i.e., to after the ?).
$ternary = $this->phpcsFile->findNext( \T_INLINE_THEN, $i, $this->tokens[ $i ]['parenthesis_closer'] );
if ( false !== $ternary ) {
$next_paren = $this->phpcsFile->findNext( \T_OPEN_PARENTHESIS, ( $i + 1 ), $this->tokens[ $i ]['parenthesis_closer'] );
// We only do it if the ternary isn't within a subset of parentheses.
if ( false === $next_paren || ( isset( $this->tokens[ $next_paren ]['parenthesis_closer'] ) && $ternary > $this->tokens[ $next_paren ]['parenthesis_closer'] ) ) {
$i = $ternary;
}
}
}
continue;
}
// Handle arrays for those functions that accept them.
if ( \T_ARRAY === $this->tokens[ $i ]['code'] ) {
$i++; // Skip the opening parenthesis.
continue;
}
if ( \T_OPEN_SHORT_ARRAY === $this->tokens[ $i ]['code']
|| \T_CLOSE_SHORT_ARRAY === $this->tokens[ $i ]['code']
) {
continue;
}
if ( \in_array( $this->tokens[ $i ]['code'], array( \T_DOUBLE_ARROW, \T_CLOSE_PARENTHESIS ), true ) ) {
continue;
}
// Handle magic constants for debug functions.
if ( isset( $this->magic_constant_tokens[ $this->tokens[ $i ]['type'] ] ) ) {
continue;
}
// Handle safe PHP native constants.
if ( \T_STRING === $this->tokens[ $i ]['code']
&& isset( $this->safe_php_constants[ $this->tokens[ $i ]['content'] ] )
&& $this->is_use_of_global_constant( $i )
) {
continue;
}
// Wake up on concatenation characters, another part to check.
if ( \T_STRING_CONCAT === $this->tokens[ $i ]['code'] ) {
$watch = true;
continue;
}
// Wake up after a ternary else (:).
if ( false !== $ternary && \T_INLINE_ELSE === $this->tokens[ $i ]['code'] ) {
$watch = true;
continue;
}
// Wake up for commas.
if ( \T_COMMA === $this->tokens[ $i ]['code'] ) {
$in_cast = false;
$watch = true;
continue;
}
if ( false === $watch ) {
continue;
}
// Allow T_CONSTANT_ENCAPSED_STRING eg: echo 'Some String';
// Also T_LNUMBER, e.g.: echo 45; exit -1; and booleans.
if ( isset( $this->safe_components[ $this->tokens[ $i ]['type'] ] ) ) {
continue;
}
$watch = false;
// Allow int/double/bool casted variables.
if ( isset( $this->safe_casts[ $this->tokens[ $i ]['code'] ] ) ) {
$in_cast = true;
continue;
}
// Now check that next token is a function call.
if ( \T_STRING === $this->tokens[ $i ]['code'] ) {
$ptr = $i;
$functionName = $this->tokens[ $i ]['content'];
$function_opener = $this->phpcsFile->findNext( \T_OPEN_PARENTHESIS, ( $i + 1 ), null, false, null, true );
$is_formatting_function = isset( $this->formattingFunctions[ $functionName ] );
if ( false !== $function_opener ) {
if ( isset( $this->arrayWalkingFunctions[ $functionName ] ) ) {
// Get the callback parameter.
$callback = $this->get_function_call_parameter(
$ptr,
$this->arrayWalkingFunctions[ $functionName ]
);
if ( ! empty( $callback ) ) {
/*
* If this is a function callback (not a method callback array) and we're able
* to resolve the function name, do so.
*/
$mapped_function = $this->phpcsFile->findNext(
Tokens::$emptyTokens,
$callback['start'],
( $callback['end'] + 1 ),
true
);
if ( false !== $mapped_function
&& \T_CONSTANT_ENCAPSED_STRING === $this->tokens[ $mapped_function ]['code']
) {
$functionName = $this->strip_quotes( $this->tokens[ $mapped_function ]['content'] );
$ptr = $mapped_function;
}
}
}
// Skip pointer to after the function.
// If this is a formatting function we just skip over the opening
// parenthesis. Otherwise we skip all the way to the closing.
if ( $is_formatting_function ) {
$i = ( $function_opener + 1 );
$watch = true;
} else {
if ( isset( $this->tokens[ $function_opener ]['parenthesis_closer'] ) ) {
$i = $this->tokens[ $function_opener ]['parenthesis_closer'];
} else {
// Live coding or parse error.
break;
}
}
}
// If this is a safe function, we don't flag it.
if (
$is_formatting_function
|| isset( $this->autoEscapedFunctions[ $functionName ] )
|| isset( $this->escapingFunctions[ $functionName ] )
) {
continue;
}
$content = $functionName;
} else {
$content = $this->tokens[ $i ]['content'];
$ptr = $i;
}
// Make the error message a little more informative for array access variables.
if ( \T_VARIABLE === $this->tokens[ $ptr ]['code'] ) {
$array_keys = $this->get_array_access_keys( $ptr );
if ( ! empty( $array_keys ) ) {
$content .= '[' . implode( '][', $array_keys ) . ']';
}
}
$this->phpcsFile->addError(
"All output should be run through an escaping function (see the Security sections in the WordPress Developer Handbooks), found '%s'.",
$ptr,
'OutputNotEscaped',
array( $content )
);
}
return $end_of_statement;
}
/**
* Merge custom functions provided via a custom ruleset with the defaults, if we haven't already.
*
* @since 0.11.0 Split out from the `process()` method.
*
* @return void
*/
protected function mergeFunctionLists() {
if ( $this->customEscapingFunctions !== $this->addedCustomFunctions['escape'] ) {
$customEscapeFunctions = $this->merge_custom_array( $this->customEscapingFunctions, array(), false );
$this->escapingFunctions = $this->merge_custom_array(
$customEscapeFunctions,
$this->escapingFunctions
);
$this->addedCustomFunctions['escape'] = $this->customEscapingFunctions;
}
if ( $this->customAutoEscapedFunctions !== $this->addedCustomFunctions['autoescape'] ) {
$this->autoEscapedFunctions = $this->merge_custom_array(
$this->customAutoEscapedFunctions,
$this->autoEscapedFunctions
);
$this->addedCustomFunctions['autoescape'] = $this->customAutoEscapedFunctions;
}
if ( $this->customPrintingFunctions !== $this->addedCustomFunctions['print'] ) {
$this->printingFunctions = $this->merge_custom_array(
$this->customPrintingFunctions,
$this->printingFunctions
);
$this->addedCustomFunctions['print'] = $this->customPrintingFunctions;
}
}
}