/// <summary>
/// Checks if the given public key is valid.
/// </summary>
/// <param name="bytes">The array of bytes that will be crypted/decrypted as a checker.</param>
/// <param name="publicKey">The public key that will be checked.</param>
public static bool CheckPublicKey(byte[] bytes, Key publicKey, bool silent = false)
{
if (publicKey.IsPrivate)
{
return(false);
}
switch (publicKey.Version)
{
case Version.LEA4:
return(bytes.IsEqual(
LEA4.Obfuscate(
LEA4.Obfuscate(bytes, publicKey),
LEA4.GetPrivateKey(publicKey, silent)
)
));
case Version.LEA9:
return(bytes.IsEqual(
LEA9.Obfuscate(
LEA9.Obfuscate(bytes, publicKey),
LEA9.GetPrivateKey(publicKey, silent)
)
));
default:
throw new UnsupportedVersionException((int)publicKey.Version);
}
}
/// <summary>
/// Encrypts a file with the given private key.
/// </summary>
/// <param name="privateKey">Private key used to encrypt the file.</param>
/// <returns>A boolean value indicating that the output file has been written.</returns>
public static bool Decrypt(FileInfo file, FileInfo output, Key key)
{
if (!key.IsPrivate)
{
throw new InvalidKeyException(key);
}
if (key.Version != LEA.Version.LEA4)
{
throw new WrongKeyVersionException(key.Version, LEA.Version.LEA4);
}
if (!file.Exists)
{
throw new FileNotFoundException($"The file '{file.FullName}' has not been found.", file.Name);
}
try
{
File.WriteAllBytes(output.FullName, LEA4.Obfuscate(File.ReadAllBytes(file.FullName), key));
return(File.Exists(output.FullName));
}
catch (Exception innerException)
{
throw new EncryptionException(key, file, innerException);
}
}