// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
using System.ServiceModel;
 
namespace System.IdentityModel.Tokens
{
    // All subclasses are required to be thread-safe and immutable
 
    // Self-resolving clauses such as RSA and X509 raw data should
    // override CanCreateKey and return true, and implement
    // CreateKey()
 
    public abstract class SecurityKeyIdentifierClause
    {
        private readonly string _clauseType;
        private byte[] _derivationNonce;
        private int _derivationLength;
        private string _id = null;
 
        protected SecurityKeyIdentifierClause(string clauseType)
            : this(clauseType, null, 0)
        {
        }
 
        protected SecurityKeyIdentifierClause(string clauseType, byte[] nonce, int length)
        {
            _clauseType = clauseType;
            _derivationNonce = nonce;
            _derivationLength = length;
        }
 
        public virtual bool CanCreateKey
        {
            get { return false; }
        }
 
        public string ClauseType
        {
            get { return _clauseType; }
        }
 
        public string Id
        {
            get { return _id; }
            set { _id = value; }
        }
 
        public virtual SecurityKey CreateKey()
        {
            throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new NotSupportedException(SRServiceModel.KeyIdentifierClauseDoesNotSupportKeyCreation));
        }
 
        public virtual bool Matches(SecurityKeyIdentifierClause keyIdentifierClause)
        {
            return ReferenceEquals(this, keyIdentifierClause);
        }
 
        public byte[] GetDerivationNonce()
        {
            return (_derivationNonce != null) ? (byte[])_derivationNonce.Clone() : null;
        }
 
        public int DerivationLength
        {
            get { return _derivationLength; }
        }
    }
}