kms Crypto AESDecrypter Decrypt Complete

AESDecrypter.cs

public async Task<string> Decrypt(IEncryptionPackage encryptionPackage)
{

    AmazonKeyManagementServiceClient kmsClient = new AmazonKeyManagementServiceClient();

    MemoryStream ciphertextBlob = new MemoryStream(Convert.FromBase64String((encryptionPackage.EncryptedKey)));

    DecryptRequest decryptRequest = new DecryptRequest()
    {
        CiphertextBlob = ciphertextBlob,
        KeyId = _keyId
    };

    DecryptResponse decryptResponse = await kmsClient.DecryptAsync(decryptRequest);

    byte[] key = decryptResponse.Plaintext.ToArray();

    string plainText = String.Empty;

    byte[] byteData = Convert.FromBase64String(encryptionPackage.CipherText);

    using (Aes aes = Aes.Create())
    {
        using (MemoryStream memoryStream = new MemoryStream(byteData))
        {
            using (CryptoStream cryptoStream = new CryptoStream(memoryStream, aes.CreateDecryptor(key, _iv), CryptoStreamMode.Read))
            {
                using (StreamReader streamReader = new StreamReader(cryptoStream))
                {
                    plainText = streamReader.ReadToEnd();
                }
            }
        }

    }

    return plainText;

}