/// <summary>
/// Encrypts data
/// </summary>
/// <param name="publicKey">The public key to use to encrypt the data</param>
/// <param name="data">The data to encrypt</param>
/// <returns>The ecrypted data</returns>
/// <exception cref="ArgumentNullException"><paramref name="publicKey"/> is null</exception>
/// <exception cref="ArgumentNullException"><paramref name="data"/> is null</exception>
public static byte[] Encrypt(string publicKey, byte[] data)
{
if (publicKey == null)
{
throw new ArgumentNullException(nameof(publicKey));
}
if (data == null)
{
throw new ArgumentNullException(nameof(data));
}
byte[] result = null;
// If the RSA key size allows us to encrypt the data without AES then... Let us do that
if (Convert.FromBase64String(publicKey).Length - 10 >= data.Length)
{
var d = Rsa.Encrypt(publicKey, data);
result = new byte[d.Length + 1];
Array.Copy(d, 0, result, 0, d.Length);
// The zero in the end of the encrypted data indicates us that
// there is no AES in place
result[result.Length - 1] = 0;
}
else
{
using (var randomPassword = (CryptoUtils.BrewPassword(80) + publicKey + DateTime.Now.ToString()).GetHash(Core.HashAlgorithms.Sha512).ToSecureString())
{
var d = Aes.Encrypt(randomPassword, data);
var k = Rsa.Encrypt(publicKey, randomPassword.GetBytes());
var keyLength = k.Length.ToBytes();
result = new byte[k.Length + d.Length + 4 + 1];
Array.Copy(k, result, k.Length);
Array.Copy(d, 0, result, k.Length, d.Length);
Array.Copy(keyLength, 0, result, k.Length + d.Length, 4);
result[result.Length - 1] = 1;
}
}
return(result);
}
