sharee.bike-App/LockItShared/Services/BluetoothLock/Crypto/Cipher.cs
Anja Müller-Meißner 0468955d49 Version 3.0.338
2022-09-08 09:55:14 +02:00

88 lines
2.7 KiB
C#

using System;
using System.IO;
using System.Security.Cryptography;
using TINK.Model.Device;
namespace TINK.Services.BluetoothLock.Crypto
{
public class Cipher : ICipher
{
/// <summary> Decrypt data. </summary>
/// <remarks>
/// Further info see:
/// https://docs.microsoft.com/en-us/dotnet/api/system.security.cryptography.aes?view=netcore-3.1 for further info
// https://docs.microsoft.com/en-us/dotnet/standard/security/cryptographic-services
// https://stackoverflow.com/questions/24903575/how-to-return-byte-when-decrypt-using-cryptostream-descryptoserviceprovider/24903689
/// </remarks>
/// <param name="key">Key to decrypt data with.</param>
/// <param name="encrypted">Encrpyted data to decrypt.</param>
/// <returns>Decrypted data.</returns>
public byte[] Decrypt(byte[] key, byte[] encrypted)
{
// Check arguments.
if (encrypted == null || encrypted.Length <= 0)
throw new ArgumentNullException(nameof(encrypted));
if (key == null || key.Length <= 0)
throw new ArgumentNullException(nameof(key));
using (Aes aesAlg = Aes.Create())
{
aesAlg.KeySize = 192;
aesAlg.Mode = CipherMode.ECB;
aesAlg.Padding = PaddingMode.None;
aesAlg.Key = key;
// Create a decryptor to perform the stream transform.
ICryptoTransform decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV);
// Create the streams used for decryption.
using (var msDecrypt = new MemoryStream())
{
using (var csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Write))
{
csDecrypt.Write(encrypted, 0, encrypted.Length);
csDecrypt.FlushFinalBlock();
return msDecrypt.ToArray();
}
}
}
}
public byte[] Encrypt(byte[] key, byte[] clear)
{
// Check arguments.
if (clear == null || clear.Length <= 0)
throw new ArgumentNullException("plainText");
if (key == null || key.Length <= 0)
throw new ArgumentNullException("Key");
// Create an AesCryptoServiceProvider object
// with the specified key and IV.
using (AesCryptoServiceProvider aesAlg = new AesCryptoServiceProvider())
{
aesAlg.KeySize = 192;
aesAlg.Mode = CipherMode.ECB;
aesAlg.Padding = PaddingMode.None;
aesAlg.Key = key;
// Create an encryptor to perform the stream transform.
ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);
// Create the streams used for encryption.
using (var msEncrypt = new MemoryStream())
{
using (var csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
{
csEncrypt.Write(clear, 0, clear.Length);
csEncrypt.FlushFinalBlock();
return msEncrypt.ToArray();
}
}
}
}
}
}