forked from GNUsocial/gnu-social
126 lines
4.1 KiB
PHP
126 lines
4.1 KiB
PHP
<?php
|
|
namespace ParagonIE\ConstantTime;
|
|
|
|
/**
|
|
* Copyright (c) 2016 Paragon Initiative Enterprises.
|
|
* Copyright (c) 2014 Steve "Sc00bz" Thomas (steve at tobtu dot com)
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
* of this software and associated documentation files (the "Software"), to deal
|
|
* in the Software without restriction, including without limitation the rights
|
|
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
* copies of the Software, and to permit persons to whom the Software is
|
|
* furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in all
|
|
* copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
|
|
* SOFTWARE.
|
|
*/
|
|
|
|
/**
|
|
* Class Hex
|
|
* @package ParagonIE\ConstantTime
|
|
*/
|
|
abstract class Hex implements EncoderInterface
|
|
{
|
|
/**
|
|
* Convert a binary string into a hexadecimal string without cache-timing
|
|
* leaks
|
|
*
|
|
* @param string $bin_string (raw binary)
|
|
* @return string
|
|
*/
|
|
public static function encode($bin_string)
|
|
{
|
|
$hex = '';
|
|
$len = Binary::safeStrlen($bin_string);
|
|
for ($i = 0; $i < $len; ++$i) {
|
|
$chunk = \unpack('C', Binary::safeSubstr($bin_string, $i, 2));
|
|
$c = $chunk[1] & 0xf;
|
|
$b = $chunk[1] >> 4;
|
|
$hex .= pack(
|
|
'CC',
|
|
(87 + $b + ((($b - 10) >> 8) & ~38)),
|
|
(87 + $c + ((($c - 10) >> 8) & ~38))
|
|
);
|
|
}
|
|
return $hex;
|
|
}
|
|
|
|
/**
|
|
* Convert a binary string into a hexadecimal string without cache-timing
|
|
* leaks, returning uppercase letters (as per RFC 4648)
|
|
*
|
|
* @param string $bin_string (raw binary)
|
|
* @return string
|
|
*/
|
|
public static function encodeUpper($bin_string)
|
|
{
|
|
$hex = '';
|
|
$len = Binary::safeStrlen($bin_string);
|
|
for ($i = 0; $i < $len; ++$i) {
|
|
$chunk = \unpack('C', Binary::safeSubstr($bin_string, $i, 2));
|
|
$c = $chunk[1] & 0xf;
|
|
$b = $chunk[1] >> 4;
|
|
$hex .= pack(
|
|
'CC',
|
|
(55 + $b + ((($b - 10) >> 8) & ~6)),
|
|
(55 + $c + ((($c - 10) >> 8) & ~6))
|
|
);
|
|
}
|
|
return $hex;
|
|
}
|
|
|
|
/**
|
|
* Convert a hexadecimal string into a binary string without cache-timing
|
|
* leaks
|
|
*
|
|
* @param string $hex_string
|
|
* @return string (raw binary)
|
|
* @throws \RangeException
|
|
*/
|
|
public static function decode($hex_string)
|
|
{
|
|
$hex_pos = 0;
|
|
$bin = '';
|
|
$c_acc = 0;
|
|
$hex_len = Binary::safeStrlen($hex_string);
|
|
$state = 0;
|
|
if (($hex_len & 1) !== 0) {
|
|
throw new \RangeException(
|
|
'Expected an even number of hexadecimal characters'
|
|
);
|
|
}
|
|
|
|
$chunk = \unpack('C*', $hex_string);
|
|
while ($hex_pos < $hex_len) {
|
|
++$hex_pos;
|
|
$c = $chunk[$hex_pos];
|
|
$c_num = $c ^ 48;
|
|
$c_num0 = ($c_num - 10) >> 8;
|
|
$c_alpha = ($c & ~32) - 55;
|
|
$c_alpha0 = (($c_alpha - 10) ^ ($c_alpha - 16)) >> 8;
|
|
if (($c_num0 | $c_alpha0) === 0) {
|
|
throw new \RangeException(
|
|
'hexEncode() only expects hexadecimal characters'
|
|
);
|
|
}
|
|
$c_val = ($c_num0 & $c_num) | ($c_alpha & $c_alpha0);
|
|
if ($state === 0) {
|
|
$c_acc = $c_val * 16;
|
|
} else {
|
|
$bin .= \pack('C', $c_acc | $c_val);
|
|
}
|
|
$state ^= 1;
|
|
}
|
|
return $bin;
|
|
}
|
|
}
|