moodle/lib/htmlpurifier/HTMLPurifier/PercentEncoder.php
Daniel Ziegenberg be7f6d4834
MDL-74823 lib: normalize line endings for HTMLPurifier
Prior to this change, all the line endings in the imported HTMLPurifier
library were using CRLF (\r\n aka Windows style), but the HTMLPurifier
source and also the downloadable artefacts use LF (\n aka Linux style)
as line endings. This has been the case since
510d190382003985eafd6f4407190d43509016a5 when with the commit
"MDL-38672 import HTML Purifier 4.5.0" all line endings were changed
from LF to CRLF. There was no comment in the commit on why this change
was done.

As the original source uses LF, this commit partly reverts
510d190382003985eafd6f4407190d43509016a5 and goes back to LF as line
endings.

Signed-off-by: Daniel Ziegenberg <daniel@ziegenberg.at>
2022-11-17 18:26:26 +01:00

112 lines
3.5 KiB
PHP

<?php
/**
* Class that handles operations involving percent-encoding in URIs.
*
* @warning
* Be careful when reusing instances of PercentEncoder. The object
* you use for normalize() SHOULD NOT be used for encode(), or
* vice-versa.
*/
class HTMLPurifier_PercentEncoder
{
/**
* Reserved characters to preserve when using encode().
* @type array
*/
protected $preserve = array();
/**
* String of characters that should be preserved while using encode().
* @param bool $preserve
*/
public function __construct($preserve = false)
{
// unreserved letters, ought to const-ify
for ($i = 48; $i <= 57; $i++) { // digits
$this->preserve[$i] = true;
}
for ($i = 65; $i <= 90; $i++) { // upper-case
$this->preserve[$i] = true;
}
for ($i = 97; $i <= 122; $i++) { // lower-case
$this->preserve[$i] = true;
}
$this->preserve[45] = true; // Dash -
$this->preserve[46] = true; // Period .
$this->preserve[95] = true; // Underscore _
$this->preserve[126]= true; // Tilde ~
// extra letters not to escape
if ($preserve !== false) {
for ($i = 0, $c = strlen($preserve); $i < $c; $i++) {
$this->preserve[ord($preserve[$i])] = true;
}
}
}
/**
* Our replacement for urlencode, it encodes all non-reserved characters,
* as well as any extra characters that were instructed to be preserved.
* @note
* Assumes that the string has already been normalized, making any
* and all percent escape sequences valid. Percents will not be
* re-escaped, regardless of their status in $preserve
* @param string $string String to be encoded
* @return string Encoded string.
*/
public function encode($string)
{
$ret = '';
for ($i = 0, $c = strlen($string); $i < $c; $i++) {
if ($string[$i] !== '%' && !isset($this->preserve[$int = ord($string[$i])])) {
$ret .= '%' . sprintf('%02X', $int);
} else {
$ret .= $string[$i];
}
}
return $ret;
}
/**
* Fix up percent-encoding by decoding unreserved characters and normalizing.
* @warning This function is affected by $preserve, even though the
* usual desired behavior is for this not to preserve those
* characters. Be careful when reusing instances of PercentEncoder!
* @param string $string String to normalize
* @return string
*/
public function normalize($string)
{
if ($string == '') {
return '';
}
$parts = explode('%', $string);
$ret = array_shift($parts);
foreach ($parts as $part) {
$length = strlen($part);
if ($length < 2) {
$ret .= '%25' . $part;
continue;
}
$encoding = substr($part, 0, 2);
$text = substr($part, 2);
if (!ctype_xdigit($encoding)) {
$ret .= '%25' . $part;
continue;
}
$int = hexdec($encoding);
if (isset($this->preserve[$int])) {
$ret .= chr($int) . $text;
continue;
}
$encoding = strtoupper($encoding);
$ret .= '%' . $encoding . $text;
}
return $ret;
}
}
// vim: et sw=4 sts=4