<?php
declare(strict_types=1);
if (class_exists('ParagonIE_Sodium_Core_ChaCha20', false)) {
return;
}
/**
* Class ParagonIE_Sodium_Core_ChaCha20
*/
class ParagonIE_Sodium_Core_ChaCha20 extends ParagonIE_Sodium_Core_Util
{
/**
* Bitwise left rotation
*
* @internal You should not use this directly from another application
*
* @param int $v
* @param int $n
* @return int
*/
public static function rotate(int $v, int $n): int
{
$v &= 0xffffffff;
$n &= 31;
return (
0xffffffff & (
($v << $n)
|
($v >> (32 - $n))
)
);
}
/**
* The ChaCha20 quarter round function. Works on four 32-bit integers.
*
* @internal You should not use this directly from another application
*
* @param int $a
* @param int $b
* @param int $c
* @param int $d
* @return array<int, int>
*/
protected static function quarterRound(int $a, int $b, int $c, int $d): array
{
# a = PLUS(a,b); d = ROTATE(XOR(d,a),16);
/** @var int $a */
$a = ($a + $b) & 0xffffffff;
$d = self::rotate($d ^ $a, 16);
# c = PLUS(c,d); b = ROTATE(XOR(b,c),12);
/** @var int $c */
$c = ($c + $d) & 0xffffffff;
$b = self::rotate($b ^ $c, 12);
# a = PLUS(a,b); d = ROTATE(XOR(d,a), 8);
/** @var int $a */
$a = ($a + $b) & 0xffffffff;
$d = self::rotate($d ^ $a, 8);
# c = PLUS(c,d); b = ROTATE(XOR(b,c), 7);
/** @var int $c */
$c = ($c + $d) & 0xffffffff;
$b = self::rotate($b ^ $c, 7);
return array($a, $b, $c, $d);
}
/**
* @internal You should not use this directly from another application
*
* @param ParagonIE_Sodium_Core_ChaCha20_Ctx $ctx
* @param string $message
*
* @return string
* @throws TypeError
* @throws SodiumException
*/
public static function encryptBytes(
ParagonIE_Sodium_Core_ChaCha20_Ctx $ctx,
#[SensitiveParameter]
string $message = ''
): string {
$bytes = self::strlen($message);
$j0 = (int) $ctx[0];
$j1 = (int) $ctx[1];
$j2 = (int) $ctx[2];
$j3 = (int) $ctx[3];
$j4 = (int) $ctx[4];
$j5 = (int) $ctx[5];
$j6 = (int) $ctx[6];
$j7 = (int) $ctx[7];
$j8 = (int) $ctx[8];
$j9 = (int) $ctx[9];
$j10 = (int) $ctx[10];
$j11 = (int) $ctx[11];
$j12 = (int) $ctx[12];
$j13 = (int) $ctx[13];
$j14 = (int) $ctx[14];
$j15 = (int) $ctx[15];
$c = '';
for (;;) {
if ($bytes < 64) {
$message .= str_repeat("\x00", 64 - $bytes);
}
$x0 = $j0;
$x1 = $j1;
$x2 = $j2;
$x3 = $j3;
$x4 = $j4;
$x5 = $j5;
$x6 = $j6;
$x7 = $j7;
$x8 = $j8;
$x9 = $j9;
$x10 = $j10;
$x11 = $j11;
$x12 = $j12;
$x13 = $j13;
$x14 = $j14;
$x15 = $j15;
# for (i = 20; i > 0; i -= 2) {
for ($i = 20; $i > 0; $i -= 2) {
[$x0, $x4, $x8, $x12] = self::quarterRound($x0, $x4, $x8, $x12);
[$x1, $x5, $x9, $x13] = self::quarterRound($x1, $x5, $x9, $x13);
[$x2, $x6, $x10, $x14] = self::quarterRound($x2, $x6, $x10, $x14);
[$x3, $x7, $x11, $x15] = self::quarterRound($x3, $x7, $x11, $x15);
[$x0, $x5, $x10, $x15] = self::quarterRound($x0, $x5, $x10, $x15);
[$x1, $x6, $x11, $x12] = self::quarterRound($x1, $x6, $x11, $x12);
[$x2, $x7, $x8, $x13] = self::quarterRound($x2, $x7, $x8, $x13);
[$x3, $x4, $x9, $x14] = self::quarterRound($x3, $x4, $x9, $x14);
}
$x0 = ($x0 & 0xffffffff) + $j0;
$x1 = ($x1 & 0xffffffff) + $j1;
$x2 = ($x2 & 0xffffffff) + $j2;
$x3 = ($x3 & 0xffffffff) + $j3;
$x4 = ($x4 & 0xffffffff) + $j4;
$x5 = ($x5 & 0xffffffff) + $j5;
$x6 = ($x6 & 0xffffffff) + $j6;
$x7 = ($x7 & 0xffffffff) + $j7;
$x8 = ($x8 & 0xffffffff) + $j8;
$x9 = ($x9 & 0xffffffff) + $j9;
$x10 = ($x10 & 0xffffffff) + $j10;
$x11 = ($x11 & 0xffffffff) + $j11;
$x12 = ($x12 & 0xffffffff) + $j12;
$x13 = ($x13 & 0xffffffff) + $j13;
$x14 = ($x14 & 0xffffffff) + $j14;
$x15 = ($x15 & 0xffffffff) + $j15;
$x0 ^= self::load_4(self::substr($message, 0, 4));
$x1 ^= self::load_4(self::substr($message, 4, 4));
$x2 ^= self::load_4(self::substr($message, 8, 4));
$x3 ^= self::load_4(self::substr($message, 12, 4));
$x4 ^= self::load_4(self::substr($message, 16, 4));
$x5 ^= self::load_4(self::substr($message, 20, 4));
$x6 ^= self::load_4(self::substr($message, 24, 4));
$x7 ^= self::load_4(self::substr($message, 28, 4));
$x8 ^= self::load_4(self::substr($message, 32, 4));
$x9 ^= self::load_4(self::substr($message, 36, 4));
$x10 ^= self::load_4(self::substr($message, 40, 4));
$x11 ^= self::load_4(self::substr($message, 44, 4));
$x12 ^= self::load_4(self::substr($message, 48, 4));
$x13 ^= self::load_4(self::substr($message, 52, 4));
$x14 ^= self::load_4(self::substr($message, 56, 4));
$x15 ^= self::load_4(self::substr($message, 60, 4));
++$j12;
if ($j12 & 0xf0000000) {
throw new SodiumException('Overflow');
}
$block = self::store32_le(($x0 & 0xffffffff)) .
self::store32_le(($x1 & 0xffffffff)) .
self::store32_le(($x2 & 0xffffffff)) .
self::store32_le(($x3 & 0xffffffff)) .
self::store32_le(($x4 & 0xffffffff)) .
self::store32_le(($x5 & 0xffffffff)) .
self::store32_le(($x6 & 0xffffffff)) .
self::store32_le(($x7 & 0xffffffff)) .
self::store32_le(($x8 & 0xffffffff)) .
self::store32_le(($x9 & 0xffffffff)) .
self::store32_le(($x10 & 0xffffffff)) .
self::store32_le(($x11 & 0xffffffff)) .
self::store32_le(($x12 & 0xffffffff)) .
self::store32_le(($x13 & 0xffffffff)) .
self::store32_le(($x14 & 0xffffffff)) .
self::store32_le(($x15 & 0xffffffff));
/* Partial block */
if ($bytes < 64) {
$c .= self::substr($block, 0, $bytes);
break;
}
/* Full block */
$c .= $block;
$bytes -= 64;
if ($bytes <= 0) {
break;
}
$message = self::substr($message, 64);
}
/* end for(;;) loop */
$ctx[12] = $j12;
$ctx[13] = $j13;
return $c;
}
/**
* @internal You should not use this directly from another application
*
* @param int $len
* @param string $nonce
* @param string $key
* @return string
* @throws SodiumException
* @throws TypeError
*/
public static function stream(
int $len = 64,
string $nonce = '',
#[SensitiveParameter]
string $key = ''
): string {
return self::encryptBytes(
new ParagonIE_Sodium_Core_ChaCha20_Ctx($key, $nonce),
str_repeat("\x00", $len)
);
}
/**
* @internal You should not use this directly from another application
*
* @param int $len
* @param string $nonce
* @param string $key
* @return string
* @throws SodiumException
* @throws TypeError
*/
public static function ietfStream(
int $len,
string $nonce = '',
#[SensitiveParameter]
string $key = ''
): string {
return self::encryptBytes(
new ParagonIE_Sodium_Core_ChaCha20_IetfCtx($key, $nonce),
str_repeat("\x00", $len)
);
}
/**
* @internal You should not use this directly from another application
*
* @param string $message
* @param string $nonce
* @param string $key
* @param string $ic
* @return string
* @throws SodiumException
* @throws TypeError
*/
public static function ietfStreamXorIc(
#[SensitiveParameter]
string $message,
string $nonce = '',
#[SensitiveParameter]
string $key = '',
string $ic = ''
): string {
return self::encryptBytes(
new ParagonIE_Sodium_Core_ChaCha20_IetfCtx($key, $nonce, $ic),
$message
);
}
/**
* @internal You should not use this directly from another application
*
* @param string $message
* @param string $nonce
* @param string $key
* @param string $ic
* @return string
* @throws SodiumException
* @throws TypeError
*/
public static function streamXorIc(
#[SensitiveParameter]
string $message,
string $nonce = '',
#[SensitiveParameter]
string $key = '',
string $ic = ''
): string {
return self::encryptBytes(
new ParagonIE_Sodium_Core_ChaCha20_Ctx($key, $nonce, $ic),
$message
);
}
}
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