<?php
if (class_exists('ParagonIE_Sodium_Core_ChaCha20_Ctx', false)) {
return;
}
/**
* Class ParagonIE_Sodium_Core_ChaCha20_Ctx
*/
class ParagonIE_Sodium_Core_ChaCha20_Ctx extends ParagonIE_Sodium_Core_Util implements ArrayAccess
{
/**
* @var SplFixedArray internally, <int, int>
*/
protected $container;
/**
* ParagonIE_Sodium_Core_ChaCha20_Ctx constructor.
*
* @internal You should not use this directly from another application
*
* @param string $key ChaCha20 key.
* @param string $iv Initialization Vector (a.k.a. nonce).
* @param string $counter The initial counter value.
* Defaults to 8 0x00 bytes.
* @throws InvalidArgumentException
* @throws TypeError
*/
public function __construct($key = '', $iv = '', $counter = '')
{
if (self::strlen($key) !== 32) {
throw new InvalidArgumentException('ChaCha20 expects a 256-bit key.');
}
if (self::strlen($iv) !== 8) {
throw new InvalidArgumentException('ChaCha20 expects a 64-bit nonce.');
}
$this->container = new SplFixedArray(16);
/* "expand 32-byte k" as per ChaCha20 spec */
$this->container[0] = 0x61707865;
$this->container[1] = 0x3320646e;
$this->container[2] = 0x79622d32;
$this->container[3] = 0x6b206574;
$this->container[4] = self::load_4(self::substr($key, 0, 4));
$this->container[5] = self::load_4(self::substr($key, 4, 4));
$this->container[6] = self::load_4(self::substr($key, 8, 4));
$this->container[7] = self::load_4(self::substr($key, 12, 4));
$this->container[8] = self::load_4(self::substr($key, 16, 4));
$this->container[9] = self::load_4(self::substr($key, 20, 4));
$this->container[10] = self::load_4(self::substr($key, 24, 4));
$this->container[11] = self::load_4(self::substr($key, 28, 4));
if (empty($counter)) {
$this->container[12] = 0;
$this->container[13] = 0;
} else {
$this->container[12] = self::load_4(self::substr($counter, 0, 4));
$this->container[13] = self::load_4(self::substr($counter, 4, 4));
}
$this->container[14] = self::load_4(self::substr($iv, 0, 4));
$this->container[15] = self::load_4(self::substr($iv, 4, 4));
}
/**
* @internal You should not use this directly from another application
*
* @param int $offset
* @param int $value
* @return void
* @psalm-suppress MixedArrayOffset
*/
#[ReturnTypeWillChange]
public function offsetSet($offset, $value)
{
if (!is_int($offset)) {
throw new InvalidArgumentException('Expected an integer');
}
if (!is_int($value)) {
throw new InvalidArgumentException('Expected an integer');
}
$this->container[$offset] = $value;
}
/**
* @internal You should not use this directly from another application
*
* @param int $offset
* @return bool
*/
#[ReturnTypeWillChange]
public function offsetExists($offset)
{
return isset($this->container[$offset]);
}
/**
* @internal You should not use this directly from another application
*
* @param int $offset
* @return void
* @psalm-suppress MixedArrayOffset
*/
#[ReturnTypeWillChange]
public function offsetUnset($offset)
{
unset($this->container[$offset]);
}
/**
* @internal You should not use this directly from another application
*
* @param int $offset
* @return mixed|null
* @psalm-suppress MixedArrayOffset
*/
#[ReturnTypeWillChange]
public function offsetGet($offset)
{
return isset($this->container[$offset])
? $this->container[$offset]
: null;
}
}
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.