<?php
if (class_exists('ParagonIE_Sodium_Core_Salsa20', false)) {
return;
}
/**
* Class ParagonIE_Sodium_Core_Salsa20
*/
abstract class ParagonIE_Sodium_Core_Salsa20 extends ParagonIE_Sodium_Core_Util
{
const ROUNDS = 20;
/**
* Calculate an salsa20 hash of a single block
*
* @internal You should not use this directly from another application
*
* @param string $in
* @param string $k
* @param string|null $c
* @return string
* @throws TypeError
*/
public static function core_salsa20($in, $k, $c = null)
{
if (self::strlen($k) < 32) {
throw new RangeException('Key must be 32 bytes long');
}
if ($c === null) {
$j0 = $x0 = 0x61707865;
$j5 = $x5 = 0x3320646e;
$j10 = $x10 = 0x79622d32;
$j15 = $x15 = 0x6b206574;
} else {
$j0 = $x0 = self::load_4(self::substr($c, 0, 4));
$j5 = $x5 = self::load_4(self::substr($c, 4, 4));
$j10 = $x10 = self::load_4(self::substr($c, 8, 4));
$j15 = $x15 = self::load_4(self::substr($c, 12, 4));
}
$j1 = $x1 = self::load_4(self::substr($k, 0, 4));
$j2 = $x2 = self::load_4(self::substr($k, 4, 4));
$j3 = $x3 = self::load_4(self::substr($k, 8, 4));
$j4 = $x4 = self::load_4(self::substr($k, 12, 4));
$j6 = $x6 = self::load_4(self::substr($in, 0, 4));
$j7 = $x7 = self::load_4(self::substr($in, 4, 4));
$j8 = $x8 = self::load_4(self::substr($in, 8, 4));
$j9 = $x9 = self::load_4(self::substr($in, 12, 4));
$j11 = $x11 = self::load_4(self::substr($k, 16, 4));
$j12 = $x12 = self::load_4(self::substr($k, 20, 4));
$j13 = $x13 = self::load_4(self::substr($k, 24, 4));
$j14 = $x14 = self::load_4(self::substr($k, 28, 4));
for ($i = self::ROUNDS; $i > 0; $i -= 2) {
$x4 ^= self::rotate($x0 + $x12, 7);
$x8 ^= self::rotate($x4 + $x0, 9);
$x12 ^= self::rotate($x8 + $x4, 13);
$x0 ^= self::rotate($x12 + $x8, 18);
$x9 ^= self::rotate($x5 + $x1, 7);
$x13 ^= self::rotate($x9 + $x5, 9);
$x1 ^= self::rotate($x13 + $x9, 13);
$x5 ^= self::rotate($x1 + $x13, 18);
$x14 ^= self::rotate($x10 + $x6, 7);
$x2 ^= self::rotate($x14 + $x10, 9);
$x6 ^= self::rotate($x2 + $x14, 13);
$x10 ^= self::rotate($x6 + $x2, 18);
$x3 ^= self::rotate($x15 + $x11, 7);
$x7 ^= self::rotate($x3 + $x15, 9);
$x11 ^= self::rotate($x7 + $x3, 13);
$x15 ^= self::rotate($x11 + $x7, 18);
$x1 ^= self::rotate($x0 + $x3, 7);
$x2 ^= self::rotate($x1 + $x0, 9);
$x3 ^= self::rotate($x2 + $x1, 13);
$x0 ^= self::rotate($x3 + $x2, 18);
$x6 ^= self::rotate($x5 + $x4, 7);
$x7 ^= self::rotate($x6 + $x5, 9);
$x4 ^= self::rotate($x7 + $x6, 13);
$x5 ^= self::rotate($x4 + $x7, 18);
$x11 ^= self::rotate($x10 + $x9, 7);
$x8 ^= self::rotate($x11 + $x10, 9);
$x9 ^= self::rotate($x8 + $x11, 13);
$x10 ^= self::rotate($x9 + $x8, 18);
$x12 ^= self::rotate($x15 + $x14, 7);
$x13 ^= self::rotate($x12 + $x15, 9);
$x14 ^= self::rotate($x13 + $x12, 13);
$x15 ^= self::rotate($x14 + $x13, 18);
}
$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 += $j15;
return self::store32_le($x0) .
self::store32_le($x1) .
self::store32_le($x2) .
self::store32_le($x3) .
self::store32_le($x4) .
self::store32_le($x5) .
self::store32_le($x6) .
self::store32_le($x7) .
self::store32_le($x8) .
self::store32_le($x9) .
self::store32_le($x10) .
self::store32_le($x11) .
self::store32_le($x12) .
self::store32_le($x13) .
self::store32_le($x14) .
self::store32_le($x15);
}
/**
* @internal You should not use this directly from another application
*
* @param int $len
* @param string $nonce
* @param string $key
* @return string
* @throws SodiumException
* @throws TypeError
*/
public static function salsa20($len, $nonce, $key)
{
if (self::strlen($key) !== 32) {
throw new RangeException('Key must be 32 bytes long');
}
$kcopy = '' . $key;
$in = self::substr($nonce, 0, 8) . str_repeat("\0", 8);
$c = '';
while ($len >= 64) {
$c .= self::core_salsa20($in, $kcopy, null);
$u = 1;
// Internal counter.
for ($i = 8; $i < 16; ++$i) {
$u += self::chrToInt($in[$i]);
$in[$i] = self::intToChr($u & 0xff);
$u >>= 8;
}
$len -= 64;
}
if ($len > 0) {
$c .= self::substr(
self::core_salsa20($in, $kcopy, null),
0,
$len
);
}
try {
ParagonIE_Sodium_Compat::memzero($kcopy);
} catch (SodiumException $ex) {
$kcopy = null;
}
return $c;
}
/**
* @internal You should not use this directly from another application
*
* @param string $m
* @param string $n
* @param int $ic
* @param string $k
* @return string
* @throws SodiumException
* @throws TypeError
*/
public static function salsa20_xor_ic($m, $n, $ic, $k)
{
$mlen = self::strlen($m);
if ($mlen < 1) {
return '';
}
$kcopy = self::substr($k, 0, 32);
$in = self::substr($n, 0, 8);
// Initialize the counter
$in .= ParagonIE_Sodium_Core_Util::store64_le($ic);
$c = '';
while ($mlen >= 64) {
$block = self::core_salsa20($in, $kcopy, null);
$c .= self::xorStrings(
self::substr($m, 0, 64),
self::substr($block, 0, 64)
);
$u = 1;
for ($i = 8; $i < 16; ++$i) {
$u += self::chrToInt($in[$i]);
$in[$i] = self::intToChr($u & 0xff);
$u >>= 8;
}
$mlen -= 64;
$m = self::substr($m, 64);
}
if ($mlen) {
$block = self::core_salsa20($in, $kcopy, null);
$c .= self::xorStrings(
self::substr($m, 0, $mlen),
self::substr($block, 0, $mlen)
);
}
try {
ParagonIE_Sodium_Compat::memzero($block);
ParagonIE_Sodium_Compat::memzero($kcopy);
} catch (SodiumException $ex) {
$block = null;
$kcopy = null;
}
return $c;
}
/**
* @internal You should not use this directly from another application
*
* @param string $message
* @param string $nonce
* @param string $key
* @return string
* @throws SodiumException
* @throws TypeError
*/
public static function salsa20_xor($message, $nonce, $key)
{
return self::xorStrings(
$message,
self::salsa20(
self::strlen($message),
$nonce,
$key
)
);
}
/**
* @internal You should not use this directly from another application
*
* @param int $u
* @param int $c
* @return int
*/
public static function rotate($u, $c)
{
$u &= 0xffffffff;
$c %= 32;
return (int) (0xffffffff & (
($u << $c)
|
($u >> (32 - $c))
)
);
}
}
ما بقاش الذكاء الاصطناعي مجرد خيال علمي أو تطور مستنيينه في المستقبل… لأ، ده بقى واقع عايشينه كل يوم، وبيأثر بشكل مباشر على شغلنا، ومهاراتنا، وحتى على الوظايف نفسها. في الفيديو ده، هنتكلم عن إزاي الذكاء الاصطناعي قلب موازين سوق العمل، إيه المهن اللي بدأت تختفي، وإيه اللي طلع جديد، وإزاي نجهز نفسنا للمستقبل اللي بدأ خلاص.