namespace System.IdentityModel.Tokens { public abstract class SymmetricSecurityKey : SecurityKey { public abstract byte[] GenerateDerivedKey(string algorithm, byte[] label, byte[] nonce, int derivedKeyLength, int offset); public abstract ICryptoTransform GetDecryptionTransform(string algorithm, byte[] iv); public abstract ICryptoTransform GetEncryptionTransform(string algorithm, byte[] iv); public abstract int GetIVSize(string algorithm); public abstract KeyedHashAlgorithm GetKeyedHashAlgorithm(string algorithm); public abstract SymmetricAlgorithm GetSymmetricAlgorithm(string algorithm); public abstract byte[] GetSymmetricKey(); protected SymmetricSecurityKey(); } }