using System;

using System.Text;

using Amazon;

using Amazon.KeyManagementService;

using Amazon.KeyManagementService.Model;

using Amazon.Runtime;

using System.Threading.Tasks;

using System.IO;

using Newtonsoft.Json;

using System.Security.Cryptography;

public class Program

{

    public async static Task Main()

    {

        var aesKey = await DecryptDataEncryptionKeyWithKms("H6+isEXPXRxa5uHYMumUpEXHrw6T8SDxo6YlvFdh9hEQ6I4K3WlAFdMgt1KYR0XHBwIMy2kgjyBe\nXojJfp+Wf0PQghGUpbi8YLYuBOEdhIzL4j7EInc3roVTYa973mhR8Xc0NnpdPaMcAnwK5aU6tNVt\nW1Y0cjEdn4cIl+qrMdPzzokxnYk8WT+CuVWWfgywuxXwc5BgxNasYIjKYt27nxv1XO9jWft6wI+O\n8LqG47MuY4I3l9oBKmi8afrnDBFmrJhye+XuOyxxlkgOIH+DA7Qa1dp+cHRiHpNZyloI/HfWJ1Fg\nnDlJHMqpsra1bwDwNXClKhUtCqhwJVRcZU0/CA==\n");

        var key = Convert.FromBase64String(aesKey.Key);

        var iv = Convert.FromBase64String(aesKey.Iv);

        var encryptedBytes = Convert.FromBase64String("Q6f/BlWR6JBXXFbKuD/J7yt6PwFllvH3pWolQ3j6UFrDBVNgBRlCH4T1+oRgrkTXQBuB5C0s3FEq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\n");

        Console.WriteLine(Decrypt2(encryptedBytes, key, iv));

    }

    public class AESSettings

    {

        public string Key { get; set; }

​

        public string Iv { get; set; }

    }

     public async static Task<AESSettings> DecryptDataEncryptionKeyWithKms(string dataEncryptionKey)

     {

         var decryptResult = await Decrypt(dataEncryptionKey, "220db2d0-84b0-4400-9e18-91c6ad5dc8f0");

​

         return JsonConvert.DeserializeObject<AESSettings>(decryptResult);

     }

    public async static Task<string> Decrypt(string cipherText, string keyId)

    {

        var credentials = new BasicAWSCredentials("AKIAQJT3IMNWUZ4TTWGV", "ViMzmjUmG7gnVqf44uyj6+Vs8AvOUFp2r+rYiCwM");

        var kmsClient = new AmazonKeyManagementServiceClient(credentials, RegionEndpoint.APSoutheast1);

        var ciphertextBlob = new MemoryStream(Convert.FromBase64String(cipherText));

        var decryptRequest = new DecryptRequest

        {

            CiphertextBlob = ciphertextBlob,

            EncryptionAlgorithm = EncryptionAlgorithmSpec.RSAES_OAEP_SHA_256,

            KeyId = keyId

        };

        var decryptResponse = await kmsClient.DecryptAsync(decryptRequest).ConfigureAwait(false);

        return Encoding.UTF8.GetString(decryptResponse.Plaintext.ToArray());

    }

    public static string Decrypt2(byte[] encryptedData, byte[] key, byte[] iv)

    {

        MemoryStream memoryStream = null;

        CryptoStream cryptoStream = null;

        StreamReader reader = null;

        Aes cipher = null;

        string plainText = null;

        try

        {

            cipher = Aes.Create();

            cipher.Key = key;

            cipher.IV = iv;

            var decryptor = cipher.CreateDecryptor(cipher.Key, cipher.IV);

            memoryStream = new MemoryStream(encryptedData);

            cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read);

            using (reader = new StreamReader(cryptoStream))

            {

                plainText = reader.ReadToEnd();

            }

        }

        catch (Exception ex)

        {

            Console.WriteLine(ex);

        }

        finally

        {

            if (reader != null)

            {

                reader.Close();

            }

            if (cryptoStream != null)

            {

                cryptoStream.Close();

            }

            if (memoryStream != null)

            {

                memoryStream.Close();

            }

            if (cipher != null)

            {

                cipher.Clear();

                cipher.Dispose();

            }

        }

        return plainText;

    }

}