public static void DecryptFile(FileInfo file, byte[] key)
{
if (file == null || !file.Exists)
{
throw new FileNotFoundException();
}
var bytes = File.ReadAllBytes(file.FullName);
var tmpName = file.FullName + ".tmp";
try
{
using (var fileStream =
new FileStream(tmpName, FileMode.Create, FileAccess.Write, FileShare.ReadWrite))
{
var m = WeakSymmetricEncryption.Decrypt(bytes, key, WeakCryptoConfig.SaltSizeBytes);
fileStream.Write(m, 0, m.Length);
}
File.Delete(file.FullName);
File.Move(tmpName, tmpName.Replace(".falsecrypt.tmp", ""));
}
catch (Exception)
{
File.Delete(file.FullName + ".tmp");
throw;
}
}
public static byte[] DecryptMessage(byte[] encryptedMessage, string password)
{
if (encryptedMessage == null || encryptedMessage.Length == 0)
{
throw new ArgumentException("Encrypted Message Required!", nameof(encryptedMessage));
}
var data = WeakPasswordDerivation.DerivePassword(password);
return(WeakSymmetricEncryption.Decrypt(encryptedMessage, data.Key, data.Salt.Length));
}
public static string DecryptMessage(string encryptedMessage, byte[] key, Encoding encoding)
{
if (string.IsNullOrWhiteSpace(encryptedMessage))
{
throw new ArgumentException("Encrypted Message Required!", nameof(encryptedMessage));
}
var cipherText = Convert.FromBase64String(encryptedMessage);
var plainText = WeakSymmetricEncryption.Decrypt(cipherText, key, 0);
return(plainText == null ? null : Encoding.UTF8.GetString(plainText));
}