disable broken tests on net_4_0

[mcs.git] / class / System.ServiceModel / Mono.Security.Protocol.Tls / ClientSessionCache.cs

//
// ClientSessionCache.cs: Client-side cache for re-using sessions
//
// Author:
//      Sebastien Pouliot  <sebastien@ximian.com>
//
// Copyright (C) 2006 Novell (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

using System;
using System.Collections;

namespace Mono.Security.Protocol.Tls {

        internal class ClientSessionInfo : IDisposable {

                // (by default) we keep this item valid for 3 minutes (if unused)
                private const int DefaultValidityInterval = 3 * 60;
                private static readonly int ValidityInterval;

                private bool disposed;
                private DateTime validuntil;
                private string host;

                // see RFC2246 - Section 7
                private byte[] sid;
                private byte[] masterSecret;

                static ClientSessionInfo ()
                {
                        string user_cache_timeout = Environment.GetEnvironmentVariable ("MONO_TLS_SESSION_CACHE_TIMEOUT");
                        if (user_cache_timeout == null) {
                                ValidityInterval = DefaultValidityInterval;
                        } else {
                                try {
                                        ValidityInterval = Int32.Parse (user_cache_timeout);
                                }
                                catch {
                                        ValidityInterval = DefaultValidityInterval;
                                }
                        }
                }

                public ClientSessionInfo (string hostname, byte[] id)
                {
                        host = hostname;
                        sid = id;
                        KeepAlive ();
                }

                ~ClientSessionInfo ()
                {
                        Dispose (false);
                }


                public string HostName {
                        get { return host; }
                }

                public byte[] Id {
                        get { return sid; }
                }

                public bool Valid {
                        get { return ((masterSecret != null) && (validuntil > DateTime.UtcNow)); }
                }


                public void GetContext (Context context)
                {
                        CheckDisposed ();
                        if (context.MasterSecret != null)
                                masterSecret = (byte[]) context.MasterSecret.Clone ();
                }

                public void SetContext (Context context)
                {
                        CheckDisposed ();
                        if (masterSecret != null)
                                context.MasterSecret = (byte[]) masterSecret.Clone ();
                }

                public void KeepAlive ()
                {
                        CheckDisposed ();
                        validuntil = DateTime.UtcNow.AddSeconds (ValidityInterval);
                }

                public void Dispose ()
                {
                        Dispose (true);
                        GC.SuppressFinalize (this);
                }

                private void Dispose (bool disposing)
                {
                        if (!disposed) {
                                validuntil = DateTime.MinValue;
                                host = null;
                                sid = null;

                                if (masterSecret != null) {
                                        Array.Clear (masterSecret, 0, masterSecret.Length);
                                        masterSecret = null;
                                }
                        }
                        disposed = true;
                }

                private void CheckDisposed ()
                {
                        if (disposed) {
                                string msg = Locale.GetText ("Cache session information were disposed.");
                                throw new ObjectDisposedException (msg);
                        }
                }
        }

        // note: locking is aggressive but isn't used often (and we gain much more :)
        internal class ClientSessionCache {

                static Hashtable cache;
                static object locker;

                static ClientSessionCache ()
                {
                        cache = new Hashtable ();
                        locker = new object ();
                }

                // note: we may have multiple connections with a host, so 
                // possibly multiple entries per host (each with a different 
                // id), so we do not use the host as the hashtable key
                static public void Add (string host, byte[] id)
                {
                        lock (locker) {
                                string uid = BitConverter.ToString (id);
                                ClientSessionInfo si = (ClientSessionInfo) cache[uid];
                                if (si == null) {
                                        cache.Add (uid, new ClientSessionInfo (host, id));
                                } else if (si.HostName == host) {
                                        // we already have this and it's still valid
                                        // on the server, so we'll keep it a little longer
                                        si.KeepAlive ();
                                } else {
                                        // it's very unlikely but the same session id 
                                        // could be used by more than one host. In this
                                        // case we replace the older one with the new one
                                        si.Dispose ();
                                        cache.Remove (uid);
                                        cache.Add (uid, new ClientSessionInfo (host, id));
                                }
                        }
                }

                // return the first session us
                static public byte[] FromHost (string host)
                {
                        lock (locker) {
                                foreach (ClientSessionInfo si in cache.Values) {
                                        if (si.HostName == host) {
                                                if (si.Valid) {
                                                        // ensure it's still valid when we really need it
                                                        si.KeepAlive ();
                                                        return si.Id;
                                                }
                                        }
                                }
                                return null;
                        }
                }

                // only called inside the lock
                static private ClientSessionInfo FromContext (Context context, bool checkValidity)
                {
                        if (context == null)
                                return null;

                        byte[] id = context.SessionId;
                        if ((id == null) || (id.Length == 0))
                                return null;

                        // do we have a session cached for this host ?
                        string uid = BitConverter.ToString (id);

                        ClientSessionInfo si = (ClientSessionInfo) cache[uid];
                        if (si == null)
                                return null;

                        // In the unlikely case of multiple hosts using the same 
                        // session id, we just act like we do not know about it
                        if (context.ClientSettings.TargetHost != si.HostName)
                                return null;

                        // yes, so what's its status ?
                        if (checkValidity && !si.Valid) {
                                si.Dispose ();
                                cache.Remove (uid);
                                return null;
                        }

                        // ok, it make sense
                        return si;
                }

                static public bool SetContextInCache (Context context)
                {
                        lock (locker) {
                                // Don't check the validity because the masterKey of the ClientSessionInfo
                                // can still be null when this is called the first time
                                ClientSessionInfo csi = FromContext (context, false);
                                if (csi == null)
                                        return false;

                                csi.GetContext (context);
                                csi.KeepAlive ();
                                return true;
                        }
                }

                static public bool SetContextFromCache (Context context)
                {
                        lock (locker) {
                                ClientSessionInfo csi = FromContext (context, true);
                                if (csi == null)
                                        return false;

                                csi.SetContext (context);
                                csi.KeepAlive ();
                                return true;
                        }
                }
        }
}