public static byte[] RsaPkcs15Sha_Decrypt(
ArraySegment <byte> data,
X509Certificate2 cert,
RSA rsaPrivate,
SecurityPolicy policy)
{
int cipherTextBlockSize = UASecurity.GetCipherTextBlockSize(cert);
byte[] buffer1 = new byte[data.Count / cipherTextBlockSize * UASecurity.GetPlainBlockSize(cert, UASecurity.UseOaepForSecurityPolicy(policy))];
int length = rsaPrivate.KeySize / 8;
UASecurity.GetPlainBlockSize(cert, UASecurity.UseOaepForSecurityPolicy(policy));
if ((uint)(data.Count % length) > 0U)
{
throw new Exception(string.Format("Input data is not a multiple of block size, {0}/{1}", data.Count, length));
}
MemoryStream memoryStream = new MemoryStream(buffer1);
byte[] data1 = new byte[length];
for (int offset = data.Offset; offset < data.Offset + data.Count; offset += length)
{
Array.Copy(data.Array, offset, data1, 0, data1.Length);
byte[] buffer2 = rsaPrivate.Decrypt(data1, UASecurity.UseOaepForSecurityPolicy(policy));
memoryStream.Write(buffer2, 0, buffer2.Length);
}
memoryStream.Close();
return(buffer1);
}
