Proyectos de Subversion Moodle

<?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('&amp;', '&quot;', '&apos;', '&lt;', '&gt;'), $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('&amp;', '&quot;', '&apos;', '&lt;', '&gt;'), $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('&amp;', '&quot;', '&apos;', '&lt;', '&gt;'), $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('&amp;', '&quot;', '&apos;', '&lt;', '&gt;'), $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('&amp;', '&quot;', '&apos;', '&lt;', '&gt;'), $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('&amp;', '&quot;', '&apos;', '&lt;', '&gt;'), $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);

        }

    }

}