kms Crypto AESEncrypter Encrypt

AESEncrypter.cs

public async Task<IEncryptionPackage> Encrypt(string plainText)
{
    byte[] encryptedData;

    GenerateDataKeyRequest dataKeyRequest = new GenerateDataKeyRequest()
    {
        KeyId = _keyId,
        KeySpec = DataKeySpec.AES_256
    };

    GenerateDataKeyResponse dataKeyResponse = await _kmsClient.GenerateDataKeyAsync(dataKeyRequest);
    
    byte[] encryptedDataKey = dataKeyResponse.CiphertextBlob.ToArray();
    byte[] plainTextKey = dataKeyResponse.Plaintext.ToArray();

    using(Aes aes = Aes.Create()){
    
        ICryptoTransform cryptoTransform = aes.CreateEncryptor(plainTextKey, _iv);
        
        using (MemoryStream memoryStream = new MemoryStream())
        {    
            using (CryptoStream cryptoStream = new CryptoStream(memoryStream, cryptoTransform, CryptoStreamMode.Write))
            {
                using (StreamWriter streamWriter = new StreamWriter(cryptoStream))
                {
                    await streamWriter.WriteAsync(plainText);
                }

                encryptedData = memoryStream.ToArray();
            }
        }
    }

    string encryptedString = Convert.ToBase64String(encryptedData);

    IEncryptionPackage encryptionPackage = new EncryptionPackage{ 
            CipherText = encryptedString, 
            EncryptedKey = Convert.ToBase64String(encryptedDataKey) 
        };

    return encryptionPackage;

}