internal static SecurityToken ComputeProofKey(RequestSecurityToken rst, RequestSecurityTokenResponse rstr)
{
if (rstr.Entropy == null)
{
throw new NotSupportedException("RSTR entropy is null");
}
if (rst.Entropy == null)
{
throw new NotSupportedException("RST entropy is null");
}
int?keySizeInBits = rst.KeySizeInBits;
int num = keySizeInBits.HasValue ? keySizeInBits.GetValueOrDefault() : 0x400;
if (rstr.KeySizeInBits.HasValue)
{
num = rstr.KeySizeInBits.Value;
}
return(new BinarySecretSecurityToken(
KeyGenerator.ComputeCombinedKey(
rst.Entropy.GetKeyBytes(),
rstr.Entropy.GetKeyBytes(),
num)));
}