// ==++==
// 
//   Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// ==--==
// <OWNER>Microsoft</OWNER>
// 
 
//
//  Publisher.cs
//
//  Publisher is an IIdentity representing internet sites.
//
 
namespace System.Security.Policy {
    using System.Runtime.Remoting;
    using System;
    using System.IO;
    using System.Security.Util;
    using System.Collections;
    using PublisherIdentityPermission = System.Security.Permissions.PublisherIdentityPermission;
    using System.Security.Cryptography.X509Certificates;
    using System.Diagnostics.Contracts;
 
    [Serializable]
    [System.Runtime.InteropServices.ComVisible(true)]
    sealed public class Publisher : EvidenceBase, IIdentityPermissionFactory
    {
        private X509Certificate m_cert;
 
        public Publisher(X509Certificate cert)
        {
            if (cert == null)
                throw new ArgumentNullException("cert");
            Contract.EndContractBlock();
 
            m_cert = cert;
        }
 
        public IPermission CreateIdentityPermission( Evidence evidence )
        {
            return new PublisherIdentityPermission( m_cert );
        }
 
        // Two Publisher objects are equal if the public keys contained within their certificates
        // are equal.  The certs themselves may be different...
 
        public override bool Equals(Object o)
        {
            Publisher that = (o as Publisher);
 
            return (that != null && PublicKeyEquals( this.m_cert, that.m_cert ));
        }
 
        // Checks if two certificates have the same public key, keyalg, and keyparam.
        internal static bool PublicKeyEquals( X509Certificate cert1, X509Certificate cert2 )
        {
            if (cert1 == null)
            {
                return (cert2 == null);
            }
            else if (cert2 == null)
            {
                return false;
            }
 
            byte[] publicKey1 = cert1.GetPublicKey();
            String keyAlg1 = cert1.GetKeyAlgorithm();
            byte[] keyAlgParam1 = cert1.GetKeyAlgorithmParameters();
            byte[] publicKey2 = cert2.GetPublicKey();
            String keyAlg2 = cert2.GetKeyAlgorithm();
            byte[] keyAlgParam2 = cert2.GetKeyAlgorithmParameters();
 
            // Keys are most likely to be different of the three components,
            // so check them first
 
            int len = publicKey1.Length;
            if (len != publicKey2.Length) return(false);
            for (int i = 0; i < len; i++) {
                if (publicKey1[i] != publicKey2[i]) return(false);
            }
            if (!(keyAlg1.Equals(keyAlg2))) return(false);
            len = keyAlgParam1.Length;
            if (keyAlgParam2.Length != len) return(false);
            for (int i = 0; i < len; i++) {
                if (keyAlgParam1[i] != keyAlgParam2[i]) return(false);
            }
 
            return true;
        }
 
        public override int GetHashCode()
        {
            return m_cert.GetHashCode();
        }
 
        public X509Certificate Certificate
        {
            get { return new X509Certificate(m_cert); }
        }
 
        public override EvidenceBase Clone()
        {
            return new Publisher(m_cert);
        }
 
        public object Copy()
        {
            return Clone();
        }
 
        internal SecurityElement ToXml()
        {
            SecurityElement elem = new SecurityElement( "System.Security.Policy.Publisher" );
            // If you hit this assert then most likely you are trying to change the name of this class. 
            // This is ok as long as you change the hard coded string above and change the assert below.
            Contract.Assert( this.GetType().FullName.Equals( "System.Security.Policy.Publisher" ), "Class name changed!" );
 
            elem.AddAttribute( "version", "1" );
            elem.AddChild( new SecurityElement( "X509v3Certificate", m_cert != null ? m_cert.GetRawCertDataString() : "" ) );
            return elem;
        }
 
        public override String ToString()
        {
            return ToXml().ToString();
        }
 
        // INormalizeForIsolatedStorage is not implemented for startup perf
        // equivalent to INormalizeForIsolatedStorage.Normalize()
        internal Object Normalize()
        {
            MemoryStream ms = new MemoryStream(m_cert.GetRawCertData());
            ms.Position = 0;
            return ms;
        }
    }
}