Viewing file:  AesGcmDecryptingStream.php (2.7 KB) -rw-r--r--
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<?php
namespace Aws\Crypto;
use Aws\Exception\CryptoException;
use GuzzleHttp\Psr7;
use GuzzleHttp\Psr7\StreamDecoratorTrait;
use Psr\Http\Message\StreamInterface;
use Aws\Crypto\Polyfill\AesGcm;
use Aws\Crypto\Polyfill\Key;
/**
* @internal Represents a stream of data to be gcm decrypted.
*/
class AesGcmDecryptingStream implements AesStreamInterface
{
use StreamDecoratorTrait;
private $aad;
private $initializationVector;
private $key;
private $keySize;
private $cipherText;
private $tag;
private $tagLength;
/**
* @var StreamInterface
*/
private $stream;
/**
* @param StreamInterface $cipherText
* @param string $key
* @param string $initializationVector
* @param string $tag
* @param string $aad
* @param int $tagLength
* @param int $keySize
*/
public function __construct(
StreamInterface $cipherText,
$key,
$initializationVector,
$tag,
$aad = '',
$tagLength = 128,
$keySize = 256
) {
$this->cipherText = $cipherText;
$this->key = $key;
$this->initializationVector = $initializationVector;
$this->tag = $tag;
$this->aad = $aad;
$this->tagLength = $tagLength;
$this->keySize = $keySize;
// unsetting the property forces the first access to go through
// __get().
unset($this->stream);
}
public function getOpenSslName()
{
return "aes-{$this->keySize}-gcm";
}
public function getAesName()
{
return 'AES/GCM/NoPadding';
}
public function getCurrentIv()
{
return $this->initializationVector;
}
public function createStream()
{
if (version_compare(PHP_VERSION, '7.1', '<')) {
return Psr7\Utils::streamFor(AesGcm::decrypt(
(string) $this->cipherText,
$this->initializationVector,
new Key($this->key),
$this->aad,
$this->tag,
$this->keySize
));
} else {
$result = \openssl_decrypt(
(string)$this->cipherText,
$this->getOpenSslName(),
$this->key,
OPENSSL_RAW_DATA,
$this->initializationVector,
$this->tag,
$this->aad
);
if ($result === false) {
throw new CryptoException('The requested object could not be'
. ' decrypted due to an invalid authentication tag.');
}
return Psr7\Utils::streamFor($result);
}
}
public function isWritable(): bool
{
return false;
}
}
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