<?php
namespace PhpXmlRpc\Helper;
use PhpXmlRpc\Exception\ValueErrorException;
use PhpXmlRpc\PhpXmlRpc;
use PhpXmlRpc\Traits\DeprecationLogger;
/**
* @todo implement an interface
*/
class Charset
{
use DeprecationLogger;
// tables used for transcoding different charsets into us-ascii xml
protected $xml_iso88591_Entities = array("in" => array(), "out" => array());
//protected $xml_cp1252_Entities = array('in' => array(), out' => array());
protected $charset_supersets = array(
'US-ASCII' => array('ISO-8859-1', 'ISO-8859-2', 'ISO-8859-3', 'ISO-8859-4',
'ISO-8859-5', 'ISO-8859-6', 'ISO-8859-7', 'ISO-8859-8',
'ISO-8859-9', 'ISO-8859-10', 'ISO-8859-11', 'ISO-8859-12',
'ISO-8859-13', 'ISO-8859-14', 'ISO-8859-15', 'UTF-8',
'EUC-JP', 'EUC-', 'EUC-KR', 'EUC-CN',),
);
/** @var Charset $instance */
protected static $instance = null;
/**
* This class is singleton for performance reasons.
*
* @return Charset
*
* @todo should we just make $xml_iso88591_Entities a static variable instead ?
*/
public static function instance()
{
if (self::$instance === null) {
self::$instance = new static();
}
return self::$instance;
}
/**
* Force usage as singleton.
*/
protected function __construct()
{
}
/**
* @param string $tableName
* @return void
*
* @throws ValueErrorException for unsupported $tableName
*
* @todo add support for cp1252 as well as latin-2 .. latin-10
* Optimization creep: instead of building all those tables on load, keep them ready-made php files
* which are not even included until needed
* @todo should we add to the latin-1 table the characters from cp_1252 range, i.e. 128 to 159 ?
* Those will NOT be present in true ISO-8859-1, but will save the unwary windows user from sending junk
* (though no luck when receiving them...)
* Note also that, apparently, while 'ISO/IEC 8859-1' has no characters defined for bytes 128 to 159,
* IANA ISO-8859-1 does have well-defined 'C1' control codes for those - wikipedia's page on latin-1 says:
* "ISO-8859-1 is the IANA preferred name for this standard when supplemented with the C0 and C1 control codes
* from ISO/IEC 6429." Check what mbstring/iconv do by default with those?
*/
protected function buildConversionTable($tableName)
{
switch ($tableName) {
case 'xml_iso88591_Entities':
if (count($this->xml_iso88591_Entities['in'])) {
return;
}
for ($i = 0; $i < 32; $i++) {
$this->xml_iso88591_Entities["in"][] = chr($i);
$this->xml_iso88591_Entities["out"][] = "&#{$i};";
}
/// @todo to be 'print safe', should we encode as well character 127 (DEL) ?
for ($i = 160; $i < 256; $i++) {
$this->xml_iso88591_Entities["in"][] = chr($i);
$this->xml_iso88591_Entities["out"][] = "&#{$i};";
}
break;
/*case 'xml_cp1252_Entities':
if (count($this->xml_cp1252_Entities['in'])) {
return;
}
for ($i = 128; $i < 160; $i++)
{
$this->xml_cp1252_Entities['in'][] = chr($i);
}
$this->xml_cp1252_Entities['out'] = array(
'€', '?', '‚', 'ƒ',
'„', '…', '†', '‡',
'ˆ', '‰', 'Š', '‹',
'Œ', '?', 'Ž', '?',
'?', '‘', '’', '“',
'”', '•', '–', '—',
'˜', '™', 'š', '›',
'œ', '?', 'ž', 'Ÿ'
);
$this->buildConversionTable('xml_iso88591_Entities');
break;*/
default:
throw new ValueErrorException('Unsupported table: ' . $tableName);
}
}
/**
* Convert a string to the correct XML representation in a target charset.
* This involves:
* - character transformation for all characters which have a different representation in source and dest charsets
* - using 'charset entity' representation for all characters which are outside the target charset
*
* To help correct communication of non-ascii chars inside strings, regardless of the charset used when sending
* requests, parsing them, sending responses and parsing responses, an option is to convert all non-ascii chars
* present in the message into their equivalent 'charset entity'. Charset entities enumerated this way are
* independent of the charset encoding used to transmit them, and all XML parsers are bound to understand them.
*
* Note that when not sending a charset encoding mime type along with http headers, we are bound by RFC 3023 to emit
* strict us-ascii for 'text/xml' payloads (but we should review RFC 7303, which seems to have changed the rules...)
*
* @param string $data
* @param string $srcEncoding
* @param string $destEncoding
* @return string
*
* @todo do a bit of basic benchmarking: strtr vs. str_replace, str_replace vs htmlspecialchars, hand-coded conversion
* vs mbstring when that is enabled
* @todo make use of iconv when it is available and mbstring is not
* @todo support aliases for charset names, eg ASCII, LATIN1, ISO-88591 (see f.e. polyfill-iconv for a list),
* but then take those into account as well in other methods, ie. isValidCharset)
* @todo when converting to ASCII, allow to choose whether to escape the range 0-31,127 (non-print chars) or not
* @todo allow picking different strategies to deal w. invalid chars? eg. source in latin-1 and chars 128-159
* @todo add support for escaping using CDATA sections? (add cdata start and end tokens, replace only ']]>' with ']]]]><![CDATA[>')
*/
public function encodeEntities($data, $srcEncoding = '', $destEncoding = '')
{
if ($srcEncoding == '') {
// lame, but we know no better...
$srcEncoding = PhpXmlRpc::$xmlrpc_internalencoding;
}
if ($destEncoding == '') {
$destEncoding = 'US-ASCII';
}
// in case there is transcoding going on, let's upscale to UTF8
/// @todo we should do this as well when $srcEncoding == $destEncoding and the encoding is not supported by
/// htmlspecialchars
if (!in_array($srcEncoding, array('UTF-8', 'ISO-8859-1', 'US-ASCII')) && $srcEncoding != $destEncoding &&
function_exists('mb_convert_encoding')) {
$data = mb_convert_encoding($data, 'UTF-8', str_replace('US-ASCII', 'ASCII', $srcEncoding));
$srcEncoding = 'UTF-8';
}
$conversion = strtoupper($srcEncoding . '_' . $destEncoding);
// list ordered with (expected) most common scenarios first
switch ($conversion) {
case 'UTF-8_UTF-8':
case 'ISO-8859-1_ISO-8859-1':
case 'US-ASCII_UTF-8':
case 'US-ASCII_US-ASCII':
case 'US-ASCII_ISO-8859-1':
//case 'CP1252_CP1252':
$escapedData = str_replace(array('&', '"', "'", '<', '>'), array('&', '"', ''', '<', '>'), $data);
break;
case 'UTF-8_US-ASCII':
case 'UTF-8_ISO-8859-1':
// NB: this will choke on invalid UTF-8, going most likely beyond EOF
$escapedData = '';
// be kind to users creating string xml-rpc values out of different php types
$data = (string)$data;
$ns = strlen($data);
for ($nn = 0; $nn < $ns; $nn++) {
$ch = $data[$nn];
$ii = ord($ch);
// 7 bits in 1 byte: 0bbbbbbb (127)
if ($ii < 32) {
if ($conversion == 'UTF-8_US-ASCII') {
$escapedData .= sprintf('&#%d;', $ii);
} else {
$escapedData .= $ch;
}
}
else if ($ii < 128) {
/// @todo shall we replace this with a (supposedly) faster str_replace?
/// @todo to be 'print safe', should we encode as well character 127 (DEL) ?
switch ($ii) {
case 34:
$escapedData .= '"';
break;
case 38:
$escapedData .= '&';
break;
case 39:
$escapedData .= ''';
break;
case 60:
$escapedData .= '<';
break;
case 62:
$escapedData .= '>';
break;
default:
$escapedData .= $ch;
} // switch
} // 11 bits in 2 bytes: 110bbbbb 10bbbbbb (2047)
elseif ($ii >> 5 == 6) {
$b1 = ($ii & 31);
$b2 = (ord($data[$nn + 1]) & 63);
$ii = ($b1 * 64) + $b2;
$escapedData .= sprintf('&#%d;', $ii);
$nn += 1;
} // 16 bits in 3 bytes: 1110bbbb 10bbbbbb 10bbbbbb
elseif ($ii >> 4 == 14) {
$b1 = ($ii & 15);
$b2 = (ord($data[$nn + 1]) & 63);
$b3 = (ord($data[$nn + 2]) & 63);
$ii = ((($b1 * 64) + $b2) * 64) + $b3;
$escapedData .= sprintf('&#%d;', $ii);
$nn += 2;
} // 21 bits in 4 bytes: 11110bbb 10bbbbbb 10bbbbbb 10bbbbbb
elseif ($ii >> 3 == 30) {
$b1 = ($ii & 7);
$b2 = (ord($data[$nn + 1]) & 63);
$b3 = (ord($data[$nn + 2]) & 63);
$b4 = (ord($data[$nn + 3]) & 63);
$ii = ((((($b1 * 64) + $b2) * 64) + $b3) * 64) + $b4;
$escapedData .= sprintf('&#%d;', $ii);
$nn += 3;
}
}
// when converting to latin-1, do not be so eager with using entities for characters 160-255
if ($conversion == 'UTF-8_ISO-8859-1') {
$this->buildConversionTable('xml_iso88591_Entities');
$escapedData = str_replace(array_slice($this->xml_iso88591_Entities['out'], 32), array_slice($this->xml_iso88591_Entities['in'], 32), $escapedData);
}
break;
case 'ISO-8859-1_UTF-8':
$escapedData = str_replace(array('&', '"', "'", '<', '>'), array('&', '"', ''', '<', '>'), $data);
/// @todo if on php >= 8.2, prefer using mbstring or iconv. Also: suppress the warning!
if (function_exists('mb_convert_encoding')) {
$escapedData = mb_convert_encoding($escapedData, 'UTF-8', 'ISO-8859-1');
} else {
$escapedData = utf8_encode($escapedData);
}
break;
case 'ISO-8859-1_US-ASCII':
$this->buildConversionTable('xml_iso88591_Entities');
$escapedData = str_replace(array('&', '"', "'", '<', '>'), array('&', '"', ''', '<', '>'), $data);
$escapedData = str_replace($this->xml_iso88591_Entities['in'], $this->xml_iso88591_Entities['out'], $escapedData);
break;
/*
case 'CP1252_US-ASCII':
$this->buildConversionTable('xml_cp1252_Entities');
$escapedData = str_replace(array('&', '"', "'", '<', '>'), array('&', '"', ''', '<', '>'), $data);
$escapedData = str_replace($this->xml_iso88591_Entities']['in'], $this->xml_iso88591_Entities['out'], $escapedData);
$escapedData = str_replace($this->xml_cp1252_Entities['in'], $this->xml_cp1252_Entities['out'], $escapedData);
break;
case 'CP1252_UTF-8':
$this->buildConversionTable('xml_cp1252_Entities');
$escapedData = str_replace(array('&', '"', "'", '<', '>'), array('&', '"', ''', '<', '>'), $data);
/// @todo we could use real UTF8 chars here instead of xml entities... (note that utf_8 encode all alone will NOT convert them)
$escapedData = str_replace($this->xml_cp1252_Entities['in'], $this->xml_cp1252_Entities['out'], $escapedData);
$escapedData = utf8_encode($escapedData);
break;
case 'CP1252_ISO-8859-1':
$this->buildConversionTable('xml_cp1252_Entities');
$escapedData = str_replace(array('&', '"', "'", '<', '>'), array('&', '"', ''', '<', '>'), $data);
// we might as well replace all funky chars with a '?' here, but we are kind and leave it to the receiving application layer to decide what to do with these weird entities...
$escapedData = str_replace($this->xml_cp1252_Entities['in'], $this->xml_cp1252_Entities['out'], $escapedData);
break;
*/
default:
if (function_exists('mb_convert_encoding')) {
// If reaching where, there are only 2 cases possible: UTF8->XXX or XXX->XXX
// If src is UTF8, we run htmlspecialchars before converting to the target charset, as
// htmlspecialchars has limited charset support, but it groks utf8
if ($srcEncoding === 'UTF-8') {
$data = htmlspecialchars($data, defined('ENT_XML1') ? ENT_XML1 | ENT_QUOTES : ENT_QUOTES, 'UTF-8');
}
if ($srcEncoding !== $destEncoding) {
try {
// php 7.4 and lower: a warning is generated. php 8.0 and up: an Error is thrown. So much for BC...
$data = @mb_convert_encoding($data, str_replace('US-ASCII', 'ASCII', $destEncoding), str_replace('US-ASCII', 'ASCII', $srcEncoding));
} catch (\ValueError $e) {
$data = false;
}
}
if ($data === false) {
$escapedData = '';
$this->getLogger()->error('XML-RPC: ' . __METHOD__ . ": Converting from $srcEncoding to $destEncoding via mbstring: failed...");
} else {
if ($srcEncoding === 'UTF-8') {
$escapedData = $data;
} else {
$escapedData = htmlspecialchars($data, defined('ENT_XML1') ? ENT_XML1 | ENT_QUOTES : ENT_QUOTES, $destEncoding);
}
}
} else {
$escapedData = '';
$this->getLogger()->error('XML-RPC: ' . __METHOD__ . ": Converting from $srcEncoding to $destEncoding: not supported...");
}
}
return $escapedData;
}
/**
* @return string[]
*/
public function knownCharsets()
{
$knownCharsets = array('UTF-8', 'ISO-8859-1', 'US-ASCII');
// Add all charsets which mbstring can handle, but remove junk not found in IANA registry at
// http://www.iana.org/assignments/character-sets/character-sets.xhtml
if (function_exists('mb_list_encodings')) {
$knownCharsets = array_unique(array_merge($knownCharsets, array_diff(mb_list_encodings(), array(
'pass', 'auto', 'wchar', 'BASE64', 'UUENCODE', 'ASCII', 'HTML-ENTITIES', 'Quoted-Printable',
'7bit','8bit', 'byte2be', 'byte2le', 'byte4be', 'byte4le'
))));
}
return $knownCharsets;
}
// *** BC layer ***
/**
* Checks if a given charset encoding is present in a list of encodings or if it is a valid subset of any encoding
* in the list.
* @deprecated kept around for BC, as it is not in use by the lib
*
* @param string $encoding charset to be tested
* @param string|array $validList comma separated list of valid charsets (or array of charsets)
* @return bool
*/
public function isValidCharset($encoding, $validList)
{
$this->logDeprecation('Method ' . __METHOD__ . ' is deprecated');
if (is_string($validList)) {
$validList = explode(',', $validList);
}
if (in_array(strtoupper($encoding), $validList)) {
return true;
} else {
if (array_key_exists($encoding, $this->charset_supersets)) {
foreach ($validList as $allowed) {
if (in_array($allowed, $this->charset_supersets[$encoding])) {
return true;
}
}
}
return false;
}
}
/**
* Used only for backwards compatibility (the .inc shims).
* @deprecated
*
* @param string $charset
* @return array
* @throws ValueErrorException for unknown/unsupported charsets
*/
public function getEntities($charset)
{
$this->logDeprecation('Method ' . __METHOD__ . ' is deprecated');
switch ($charset)
{
case 'iso88591':
return $this->xml_iso88591_Entities;
default:
throw new ValueErrorException('Unsupported charset: ' . $charset);
}
}
}