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Diffstat (limited to 'wp-includes/compat.php')
| -rw-r--r-- | wp-includes/compat.php | 499 |
1 files changed, 499 insertions, 0 deletions
diff --git a/wp-includes/compat.php b/wp-includes/compat.php new file mode 100644 index 0000000..5bfdbc2 --- /dev/null +++ b/wp-includes/compat.php @@ -0,0 +1,499 @@ +<?php +/** + * WordPress implementation for PHP functions either missing from older PHP versions or not included by default. + * + * @package PHP + * @access private + */ + +// If gettext isn't available. +if ( ! function_exists( '_' ) ) { + function _( $message ) { + return $message; + } +} + +/** + * Returns whether PCRE/u (PCRE_UTF8 modifier) is available for use. + * + * @ignore + * @since 4.2.2 + * @access private + * + * @param bool $set - Used for testing only + * null : default - get PCRE/u capability + * false : Used for testing - return false for future calls to this function + * 'reset': Used for testing - restore default behavior of this function + */ +function _wp_can_use_pcre_u( $set = null ) { + static $utf8_pcre = 'reset'; + + if ( null !== $set ) { + $utf8_pcre = $set; + } + + if ( 'reset' === $utf8_pcre ) { + // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- intentional error generated to detect PCRE/u support. + $utf8_pcre = @preg_match( '/^./u', 'a' ); + } + + return $utf8_pcre; +} + +if ( ! function_exists( 'mb_substr' ) ) : + /** + * Compat function to mimic mb_substr(). + * + * @ignore + * @since 3.2.0 + * + * @see _mb_substr() + * + * @param string $string The string to extract the substring from. + * @param int $start Position to being extraction from in `$string`. + * @param int|null $length Optional. Maximum number of characters to extract from `$string`. + * Default null. + * @param string|null $encoding Optional. Character encoding to use. Default null. + * @return string Extracted substring. + */ + function mb_substr( $string, $start, $length = null, $encoding = null ) { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.stringFound + return _mb_substr( $string, $start, $length, $encoding ); + } +endif; + +/** + * Internal compat function to mimic mb_substr(). + * + * Only understands UTF-8 and 8bit. All other character sets will be treated as 8bit. + * For `$encoding === UTF-8`, the `$str` input is expected to be a valid UTF-8 byte + * sequence. The behavior of this function for invalid inputs is undefined. + * + * @ignore + * @since 3.2.0 + * + * @param string $str The string to extract the substring from. + * @param int $start Position to being extraction from in `$str`. + * @param int|null $length Optional. Maximum number of characters to extract from `$str`. + * Default null. + * @param string|null $encoding Optional. Character encoding to use. Default null. + * @return string Extracted substring. + */ +function _mb_substr( $str, $start, $length = null, $encoding = null ) { + if ( null === $str ) { + return ''; + } + + if ( null === $encoding ) { + $encoding = get_option( 'blog_charset' ); + } + + /* + * The solution below works only for UTF-8, so in case of a different + * charset just use built-in substr(). + */ + if ( ! in_array( $encoding, array( 'utf8', 'utf-8', 'UTF8', 'UTF-8' ), true ) ) { + return is_null( $length ) ? substr( $str, $start ) : substr( $str, $start, $length ); + } + + if ( _wp_can_use_pcre_u() ) { + // Use the regex unicode support to separate the UTF-8 characters into an array. + preg_match_all( '/./us', $str, $match ); + $chars = is_null( $length ) ? array_slice( $match[0], $start ) : array_slice( $match[0], $start, $length ); + return implode( '', $chars ); + } + + $regex = '/( + [\x00-\x7F] # single-byte sequences 0xxxxxxx + | [\xC2-\xDF][\x80-\xBF] # double-byte sequences 110xxxxx 10xxxxxx + | \xE0[\xA0-\xBF][\x80-\xBF] # triple-byte sequences 1110xxxx 10xxxxxx * 2 + | [\xE1-\xEC][\x80-\xBF]{2} + | \xED[\x80-\x9F][\x80-\xBF] + | [\xEE-\xEF][\x80-\xBF]{2} + | \xF0[\x90-\xBF][\x80-\xBF]{2} # four-byte sequences 11110xxx 10xxxxxx * 3 + | [\xF1-\xF3][\x80-\xBF]{3} + | \xF4[\x80-\x8F][\x80-\xBF]{2} + )/x'; + + // Start with 1 element instead of 0 since the first thing we do is pop. + $chars = array( '' ); + + do { + // We had some string left over from the last round, but we counted it in that last round. + array_pop( $chars ); + + /* + * Split by UTF-8 character, limit to 1000 characters (last array element will contain + * the rest of the string). + */ + $pieces = preg_split( $regex, $str, 1000, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY ); + + $chars = array_merge( $chars, $pieces ); + + // If there's anything left over, repeat the loop. + } while ( count( $pieces ) > 1 && $str = array_pop( $pieces ) ); + + return implode( '', array_slice( $chars, $start, $length ) ); +} + +if ( ! function_exists( 'mb_strlen' ) ) : + /** + * Compat function to mimic mb_strlen(). + * + * @ignore + * @since 4.2.0 + * + * @see _mb_strlen() + * + * @param string $string The string to retrieve the character length from. + * @param string|null $encoding Optional. Character encoding to use. Default null. + * @return int String length of `$string`. + */ + function mb_strlen( $string, $encoding = null ) { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.stringFound + return _mb_strlen( $string, $encoding ); + } +endif; + +/** + * Internal compat function to mimic mb_strlen(). + * + * Only understands UTF-8 and 8bit. All other character sets will be treated as 8bit. + * For `$encoding === UTF-8`, the `$str` input is expected to be a valid UTF-8 byte + * sequence. The behavior of this function for invalid inputs is undefined. + * + * @ignore + * @since 4.2.0 + * + * @param string $str The string to retrieve the character length from. + * @param string|null $encoding Optional. Character encoding to use. Default null. + * @return int String length of `$str`. + */ +function _mb_strlen( $str, $encoding = null ) { + if ( null === $encoding ) { + $encoding = get_option( 'blog_charset' ); + } + + /* + * The solution below works only for UTF-8, so in case of a different charset + * just use built-in strlen(). + */ + if ( ! in_array( $encoding, array( 'utf8', 'utf-8', 'UTF8', 'UTF-8' ), true ) ) { + return strlen( $str ); + } + + if ( _wp_can_use_pcre_u() ) { + // Use the regex unicode support to separate the UTF-8 characters into an array. + preg_match_all( '/./us', $str, $match ); + return count( $match[0] ); + } + + $regex = '/(?: + [\x00-\x7F] # single-byte sequences 0xxxxxxx + | [\xC2-\xDF][\x80-\xBF] # double-byte sequences 110xxxxx 10xxxxxx + | \xE0[\xA0-\xBF][\x80-\xBF] # triple-byte sequences 1110xxxx 10xxxxxx * 2 + | [\xE1-\xEC][\x80-\xBF]{2} + | \xED[\x80-\x9F][\x80-\xBF] + | [\xEE-\xEF][\x80-\xBF]{2} + | \xF0[\x90-\xBF][\x80-\xBF]{2} # four-byte sequences 11110xxx 10xxxxxx * 3 + | [\xF1-\xF3][\x80-\xBF]{3} + | \xF4[\x80-\x8F][\x80-\xBF]{2} + )/x'; + + // Start at 1 instead of 0 since the first thing we do is decrement. + $count = 1; + + do { + // We had some string left over from the last round, but we counted it in that last round. + --$count; + + /* + * Split by UTF-8 character, limit to 1000 characters (last array element will contain + * the rest of the string). + */ + $pieces = preg_split( $regex, $str, 1000 ); + + // Increment. + $count += count( $pieces ); + + // If there's anything left over, repeat the loop. + } while ( $str = array_pop( $pieces ) ); + + // Fencepost: preg_split() always returns one extra item in the array. + return --$count; +} + +if ( ! function_exists( 'hash_hmac' ) ) : + /** + * Compat function to mimic hash_hmac(). + * + * The Hash extension is bundled with PHP by default since PHP 5.1.2. + * However, the extension may be explicitly disabled on select servers. + * As of PHP 7.4.0, the Hash extension is a core PHP extension and can no + * longer be disabled. + * I.e. when PHP 7.4.0 becomes the minimum requirement, this polyfill + * and the associated `_hash_hmac()` function can be safely removed. + * + * @ignore + * @since 3.2.0 + * + * @see _hash_hmac() + * + * @param string $algo Hash algorithm. Accepts 'md5' or 'sha1'. + * @param string $data Data to be hashed. + * @param string $key Secret key to use for generating the hash. + * @param bool $binary Optional. Whether to output raw binary data (true), + * or lowercase hexits (false). Default false. + * @return string|false The hash in output determined by `$binary`. + * False if `$algo` is unknown or invalid. + */ + function hash_hmac( $algo, $data, $key, $binary = false ) { + return _hash_hmac( $algo, $data, $key, $binary ); + } +endif; + +/** + * Internal compat function to mimic hash_hmac(). + * + * @ignore + * @since 3.2.0 + * + * @param string $algo Hash algorithm. Accepts 'md5' or 'sha1'. + * @param string $data Data to be hashed. + * @param string $key Secret key to use for generating the hash. + * @param bool $binary Optional. Whether to output raw binary data (true), + * or lowercase hexits (false). Default false. + * @return string|false The hash in output determined by `$binary`. + * False if `$algo` is unknown or invalid. + */ +function _hash_hmac( $algo, $data, $key, $binary = false ) { + $packs = array( + 'md5' => 'H32', + 'sha1' => 'H40', + ); + + if ( ! isset( $packs[ $algo ] ) ) { + return false; + } + + $pack = $packs[ $algo ]; + + if ( strlen( $key ) > 64 ) { + $key = pack( $pack, $algo( $key ) ); + } + + $key = str_pad( $key, 64, chr( 0 ) ); + + $ipad = ( substr( $key, 0, 64 ) ^ str_repeat( chr( 0x36 ), 64 ) ); + $opad = ( substr( $key, 0, 64 ) ^ str_repeat( chr( 0x5C ), 64 ) ); + + $hmac = $algo( $opad . pack( $pack, $algo( $ipad . $data ) ) ); + + if ( $binary ) { + return pack( $pack, $hmac ); + } + + return $hmac; +} + +if ( ! function_exists( 'hash_equals' ) ) : + /** + * Timing attack safe string comparison. + * + * Compares two strings using the same time whether they're equal or not. + * + * Note: It can leak the length of a string when arguments of differing length are supplied. + * + * This function was added in PHP 5.6. + * However, the Hash extension may be explicitly disabled on select servers. + * As of PHP 7.4.0, the Hash extension is a core PHP extension and can no + * longer be disabled. + * I.e. when PHP 7.4.0 becomes the minimum requirement, this polyfill + * can be safely removed. + * + * @since 3.9.2 + * + * @param string $known_string Expected string. + * @param string $user_string Actual, user supplied, string. + * @return bool Whether strings are equal. + */ + function hash_equals( $known_string, $user_string ) { + $known_string_length = strlen( $known_string ); + + if ( strlen( $user_string ) !== $known_string_length ) { + return false; + } + + $result = 0; + + // Do not attempt to "optimize" this. + for ( $i = 0; $i < $known_string_length; $i++ ) { + $result |= ord( $known_string[ $i ] ) ^ ord( $user_string[ $i ] ); + } + + return 0 === $result; + } +endif; + +// sodium_crypto_box() was introduced in PHP 7.2. +if ( ! function_exists( 'sodium_crypto_box' ) ) { + require ABSPATH . WPINC . '/sodium_compat/autoload.php'; +} + +if ( ! function_exists( 'is_countable' ) ) { + /** + * Polyfill for is_countable() function added in PHP 7.3. + * + * Verify that the content of a variable is an array or an object + * implementing the Countable interface. + * + * @since 4.9.6 + * + * @param mixed $value The value to check. + * @return bool True if `$value` is countable, false otherwise. + */ + function is_countable( $value ) { + return ( is_array( $value ) + || $value instanceof Countable + || $value instanceof SimpleXMLElement + || $value instanceof ResourceBundle + ); + } +} + +if ( ! function_exists( 'is_iterable' ) ) { + /** + * Polyfill for is_iterable() function added in PHP 7.1. + * + * Verify that the content of a variable is an array or an object + * implementing the Traversable interface. + * + * @since 4.9.6 + * + * @param mixed $value The value to check. + * @return bool True if `$value` is iterable, false otherwise. + */ + function is_iterable( $value ) { + return ( is_array( $value ) || $value instanceof Traversable ); + } +} + +if ( ! function_exists( 'array_key_first' ) ) { + /** + * Polyfill for array_key_first() function added in PHP 7.3. + * + * Get the first key of the given array without affecting + * the internal array pointer. + * + * @since 5.9.0 + * + * @param array $array An array. + * @return string|int|null The first key of array if the array + * is not empty; `null` otherwise. + */ + function array_key_first( array $array ) { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.arrayFound + foreach ( $array as $key => $value ) { + return $key; + } + } +} + +if ( ! function_exists( 'array_key_last' ) ) { + /** + * Polyfill for `array_key_last()` function added in PHP 7.3. + * + * Get the last key of the given array without affecting the + * internal array pointer. + * + * @since 5.9.0 + * + * @param array $array An array. + * @return string|int|null The last key of array if the array + *. is not empty; `null` otherwise. + */ + function array_key_last( array $array ) { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.arrayFound + if ( empty( $array ) ) { + return null; + } + + end( $array ); + + return key( $array ); + } +} + +if ( ! function_exists( 'str_contains' ) ) { + /** + * Polyfill for `str_contains()` function added in PHP 8.0. + * + * Performs a case-sensitive check indicating if needle is + * contained in haystack. + * + * @since 5.9.0 + * + * @param string $haystack The string to search in. + * @param string $needle The substring to search for in the `$haystack`. + * @return bool True if `$needle` is in `$haystack`, otherwise false. + */ + function str_contains( $haystack, $needle ) { + if ( '' === $needle ) { + return true; + } + + return false !== strpos( $haystack, $needle ); + } +} + +if ( ! function_exists( 'str_starts_with' ) ) { + /** + * Polyfill for `str_starts_with()` function added in PHP 8.0. + * + * Performs a case-sensitive check indicating if + * the haystack begins with needle. + * + * @since 5.9.0 + * + * @param string $haystack The string to search in. + * @param string $needle The substring to search for in the `$haystack`. + * @return bool True if `$haystack` starts with `$needle`, otherwise false. + */ + function str_starts_with( $haystack, $needle ) { + if ( '' === $needle ) { + return true; + } + + return 0 === strpos( $haystack, $needle ); + } +} + +if ( ! function_exists( 'str_ends_with' ) ) { + /** + * Polyfill for `str_ends_with()` function added in PHP 8.0. + * + * Performs a case-sensitive check indicating if + * the haystack ends with needle. + * + * @since 5.9.0 + * + * @param string $haystack The string to search in. + * @param string $needle The substring to search for in the `$haystack`. + * @return bool True if `$haystack` ends with `$needle`, otherwise false. + */ + function str_ends_with( $haystack, $needle ) { + if ( '' === $haystack ) { + return '' === $needle; + } + + $len = strlen( $needle ); + + return substr( $haystack, -$len, $len ) === $needle; + } +} + +// IMAGETYPE_WEBP constant is only defined in PHP 7.1 or later. +if ( ! defined( 'IMAGETYPE_WEBP' ) ) { + define( 'IMAGETYPE_WEBP', 18 ); +} + +// IMG_WEBP constant is only defined in PHP 7.0.10 or later. +if ( ! defined( 'IMG_WEBP' ) ) { + define( 'IMG_WEBP', IMAGETYPE_WEBP ); +} |