<?php
namespace Aws\Crypto;
use Aws\Crypto\Polyfill\AesGcm;
use Aws\Crypto\Polyfill\Key;
use GuzzleHttp\Psr7;
use GuzzleHttp\Psr7\StreamDecoratorTrait;
use Psr\Http\Message\StreamInterface;
use \RuntimeException;
/**
* @internal Represents a stream of data to be gcm encrypted.
*/
class AesGcmEncryptingStream implements AesStreamInterface, AesStreamInterfaceV2
{
use StreamDecoratorTrait;
private $aad;
private $initializationVector;
private $key;
private $keySize;
private $plaintext;
private $tag = '';
private $tagLength;
/**
* Same as non-static 'getAesName' method, allowing calls in a static
* context.
*
* @return string
*/
public static function getStaticAesName()
{
return 'AES/GCM/NoPadding';
}
/**
* @param StreamInterface $plaintext
* @param string $key
* @param string $initializationVector
* @param string $aad
* @param int $tagLength
* @param int $keySize
*/
public function __construct(
StreamInterface $plaintext,
$key,
$initializationVector,
$aad = '',
$tagLength = 16,
$keySize = 256
) {
$this->plaintext = $plaintext;
$this->key = $key;
$this->initializationVector = $initializationVector;
$this->aad = $aad;
$this->tagLength = $tagLength;
$this->keySize = $keySize;
}
public function getOpenSslName()
{
return "aes-{$this->keySize}-gcm";
}
/**
* Same as static method and retained for backwards compatibility
*
* @return string
*/
public function getAesName()
{
return self::getStaticAesName();
}
public function getCurrentIv()
{
return $this->initializationVector;
}
public function createStream()
{
if (version_compare(PHP_VERSION, '7.1', '<')) {
return Psr7\Utils::streamFor(AesGcm::encrypt(
(string) $this->plaintext,
$this->initializationVector,
new Key($this->key),
$this->aad,
$this->tag,
$this->keySize
));
} else {
return Psr7\Utils::streamFor(\openssl_encrypt(
(string)$this->plaintext,
$this->getOpenSslName(),
$this->key,
OPENSSL_RAW_DATA,
$this->initializationVector,
$this->tag,
$this->aad,
$this->tagLength
));
}
}
/**
* @return string
*/
public function getTag()
{
return $this->tag;
}
public function isWritable()
{
return false;
}
}