/// <summary>
/// Asynchronously decrypts the specified <see cref="EncryptionResult"/> that was obtained using <see cref="ISymmetricCryptography.EncryptAsync(byte[])"/>.
/// </summary>
/// <param name="encryptionResult">The <see cref="EncryptionResult"/> that was obtained using <see cref="ISymmetricCryptography.EncryptAsync(byte[])"/>.</param>
/// <returns>Decrypted <c>byte[]</c> or <c>null</c> if decryption failed.</returns>
public async Task <byte[]> DecryptAsync(EncryptionResult encryptionResult)
{
int encryptedBytesLength = encryptionResult?.EncryptedData?.Length ?? 0;
if (encryptedBytesLength == 0)
{
return(Array.Empty <byte>());
}
byte[] result;
await using var output = new MemoryStream(encryptedBytesLength);
await using var input = new MemoryStream(encryptionResult.EncryptedData);
try
{
using var aes = new AesManaged
{
KeySize = 256,
Mode = CipherMode.CBC,
Padding = PaddingMode.PKCS7,
IV = encryptionResult.IV,
Key = encryptionResult.Key
};
using ICryptoTransform decryptor = aes.CreateDecryptor();
await using var cryptoStream = new CryptoStream(input, decryptor, CryptoStreamMode.Read);
await cryptoStream.CopyToAsync(output).ConfigureAwait(false);
await cryptoStream.FlushAsync();
result = output.ToArray();
}
catch
{
result = null;
}
return(result);
}
/// <summary>
/// Decrypts the specified <see cref="EncryptionResult"/> that was obtained using <see cref="ISymmetricCryptography.Encrypt(byte[])"/>.
/// </summary>
/// <param name="encryptionResult">The <see cref="EncryptionResult"/> that was obtained using <see cref="ISymmetricCryptography.Encrypt(byte[])"/>.</param>
/// <returns>Decrypted <c>byte[]</c> array or <c>null</c> if decryption failed.</returns>
public byte[] Decrypt(EncryptionResult encryptionResult)
{
int encryptedBytesLength = encryptionResult?.EncryptedData?.Length ?? 0;
if (encryptedBytesLength == 0)
{
return(Array.Empty <byte>());
}
byte[] result;
AesManaged aes = null;
ICryptoTransform decryptor = null;
try
{
aes = new AesManaged
{
KeySize = 256,
Mode = CipherMode.CBC,
Padding = PaddingMode.PKCS7,
IV = encryptionResult.IV,
Key = encryptionResult.Key
};
decryptor = aes.CreateDecryptor();
result = decryptor.TransformFinalBlock(encryptionResult.EncryptedData, 0, encryptedBytesLength);
}
catch
{
result = null;
}
finally
{
aes?.Dispose();
decryptor?.Dispose();
}
return(result);
}
