public static byte[] RsaPkcs15Sha1_Encrypt(ArraySegment <byte> data, X509Certificate2 cert, SecurityPolicy policy)
{
bool useOaep = policy == SecurityPolicy.Basic256;
var padMethod = UASecurity.PaddingMethodForSecurityPolicy(policy);
int padSize = UASecurity.PaddingSizeForMethod(padMethod);
var rsa = cert.PublicKey.Key as RSACryptoServiceProvider;
int inputBlockSize = GetPlainBlockSize(cert, useOaep);
int outputBlockSize = rsa.KeySize / 8;
if (data.Count % inputBlockSize != 0)
{
throw new Exception(string.Format("Input data is not a multiple of block size, {0}/{1}", data.Count, inputBlockSize));
}
var input = new byte[inputBlockSize];
var ms = new MemoryStream();
for (int i = 0; i < data.Count; i += inputBlockSize)
{
Array.Copy(data.Array, data.Offset + i, input, 0, input.Length);
var encoded = rsa.Encrypt(input, useOaep);
ms.Write(encoded, 0, encoded.Length);
}
ms.Close();
return(ms.ToArray());
}
public static int CalculateEncryptedSize(
X509Certificate2 cert,
int messageSize,
UASecurity.PaddingAlgorithm paddingAlgorithm)
{
if (!(cert.PublicKey.Key is RSA))
{
throw new Exception("Could not create RSA");
}
int num1 = UASecurity.PaddingSizeForMethod(paddingAlgorithm);
int num2 = UASecurity.CalculatePublicKeyLength(cert) / 8;
if (num2 < num1)
{
throw new Exception();
}
int num3 = num2 - num1;
return((messageSize + num3 - 1) / num3 * num2);
}
