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Summery Summery
ParagonIE_Sodium_Core_ChaCha20_Ctx constructor.
Syntax Syntax
Parameters Parameters
- $key
-
(Optional) ChaCha20 key.
Default value: ''
- $iv
-
(Optional) Initialization Vector (a.k.a. nonce).
Default value: ''
- $counter
-
(Optional) The initial counter value. Defaults to 8 0x00 bytes.
Default value: ''
Source Source
File: wp-includes/sodium_compat/src/Core32/ChaCha20/Ctx.php
public function __construct($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] = new ParagonIE_Sodium_Core32_Int32(array(0x6170, 0x7865));
$this->container[1] = new ParagonIE_Sodium_Core32_Int32(array(0x3320, 0x646e));
$this->container[2] = new ParagonIE_Sodium_Core32_Int32(array(0x7962, 0x2d32));
$this->container[3] = new ParagonIE_Sodium_Core32_Int32(array(0x6b20, 0x6574));
$this->container[4] = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($key, 0, 4));
$this->container[5] = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($key, 4, 4));
$this->container[6] = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($key, 8, 4));
$this->container[7] = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($key, 12, 4));
$this->container[8] = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($key, 16, 4));
$this->container[9] = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($key, 20, 4));
$this->container[10] = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($key, 24, 4));
$this->container[11] = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($key, 28, 4));
if (empty($counter)) {
$this->container[12] = new ParagonIE_Sodium_Core32_Int32();
$this->container[13] = new ParagonIE_Sodium_Core32_Int32();
} else {
$this->container[12] = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($counter, 0, 4));
$this->container[13] = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($counter, 4, 4));
}
$this->container[14] = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($iv, 0, 4));
$this->container[15] = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($iv, 4, 4));
}