WindowsUserNameCachingSecurityTokenAuthenticator.cs source code in C# .NET

                        Code:
                         / WCF / WCF / 3.5.30729.1 / untmp / Orcas / SP / ndp / cdf / src / WCF / ServiceModel / System / ServiceModel / Security / Tokens / WindowsUserNameCachingSecurityTokenAuthenticator.cs / 1 / WindowsUserNameCachingSecurityTokenAuthenticator.cs
                        
                        
                            //------------------------------------------------------------------------------ 
// Copyright (c) Microsoft Corporation.  All rights reserved.
//-----------------------------------------------------------------------------

namespace System.ServiceModel.Security.Tokens 
{
    using System.Collections; 
    using System.Collections.Generic; 
    using System.Collections.ObjectModel;
    using System.IdentityModel.Policy; 
    using System.IdentityModel.Selectors;
    using System.IdentityModel.Tokens;
    using System.Security.Cryptography;
    using System.Text; 

    public interface ILogonTokenCacheManager 
    { 
        bool RemoveCachedLogonToken(string username);
        void FlushLogonTokenCache(); 
    }

    class LogonTokenCache : TimeBoundedCache
    { 
        const int lowWaterMarkFactor = 75;
        const int saltSize = 4; 
 
        TimeSpan cachedLogonTokenLifetime;
        RNGCryptoServiceProvider random; 

        public LogonTokenCache(int maxCachedLogonTokens, TimeSpan cachedLogonTokenLifetime)
            : base((maxCachedLogonTokens * lowWaterMarkFactor) / 100, maxCachedLogonTokens, StringComparer.OrdinalIgnoreCase, PurgingMode.TimerBasedPurge, TimeSpan.FromTicks(cachedLogonTokenLifetime.Ticks >> 2), true)
        { 
            this.cachedLogonTokenLifetime = cachedLogonTokenLifetime;
            this.random = new RNGCryptoServiceProvider(); 
        } 

        public bool TryGetTokenCache(string userName, out LogonToken token) 
        {
            token = (LogonToken)GetItem(userName);
            return token != null;
        } 

        public bool TryAddTokenCache(string userName, string password, ReadOnlyCollection authorizationPolicies) 
        { 
            byte[] salt = new byte[saltSize];
            this.random.GetBytes(salt); 
            LogonToken token = new LogonToken(userName, password, salt, authorizationPolicies);
            DateTime expirationTime = DateTime.UtcNow.Add(this.cachedLogonTokenLifetime);
            return TryAddItem(userName, token, expirationTime, true);
        } 

        // Remove those about to expire 
        protected override ArrayList OnQuotaReached(Hashtable cacheTable) 
        {
            List items = new List(cacheTable.Count); 
            foreach (IExpirableItem value in cacheTable.Values)
            {
                items.Add(value);
            } 
            // Those expired soon in front
            items.Sort(ExpirableItemComparer.Default); 
            int pruningAmount = (items.Count * (100 - lowWaterMarkFactor)) / 100; 
            // edge case
            pruningAmount = pruningAmount <= 0 ? items.Count : pruningAmount; 
            ArrayList keys = new ArrayList(pruningAmount);
            for (int i = 0; i < pruningAmount; ++i)
            {
                LogonToken token = (LogonToken)ExtractItem(items[i]); 
                keys.Add(token.UserName);
                OnRemove(token); 
            } 
            return keys;
        } 

        public bool TryRemoveTokenCache(string userName)
        {
            return this.TryRemoveItem(userName); 
        }
 
        public void Flush() 
        {
            this.ClearItems(); 
        }

        protected override void OnRemove(object item)
        { 
            ((LogonToken)item).Dispose();
            base.OnRemove(item); 
        } 
    }
 
    class LogonToken : IDisposable
    {
        string userName;
        byte[] passwordHash; 
        byte[] salt;
        ReadOnlyCollection authorizationPolicies; 
 
        public LogonToken(string userName, string password, byte[] salt, ReadOnlyCollection authorizationPolicies)
        { 
            this.userName = userName;
            this.passwordHash = ComputeHash(password, salt);
            this.salt = salt;
            this.authorizationPolicies = System.IdentityModel.SecurityUtils.CloneAuthorizationPoliciesIfNecessary(authorizationPolicies); 
        }
 
        public bool PasswordEquals(string password) 
        {
            byte[] passwordHash = ComputeHash(password, this.salt); 
            return CryptoHelper.IsEqual(this.passwordHash, passwordHash);
        }

        public string UserName 
        {
            get { return this.userName; } 
        } 

        public ReadOnlyCollection GetAuthorizationPolicies() 
        {
            return System.IdentityModel.SecurityUtils.CloneAuthorizationPoliciesIfNecessary(this.authorizationPolicies);
        }
 
        public void Dispose()
        { 
            System.IdentityModel.SecurityUtils.DisposeAuthorizationPoliciesIfNecessary(this.authorizationPolicies); 
        }
 
        static byte[] ComputeHash(string password, byte[] salt)
        {
            if (String.IsNullOrEmpty(password))
            { 
                return salt;
            } 
            byte[] bytes = Encoding.Unicode.GetBytes(password); 
            int saltSize = salt.Length;
            for (int i = 0; i < bytes.Length; ++i) 
            {
                bytes[i] ^= salt[i % saltSize];
            }
            using (SHA1 sha1 = CryptoHelper.NewSha1HashAlgorithm()) 
            {
                return sha1.ComputeHash(bytes); 
            } 
        }
    } 

    class WindowsUserNameCachingSecurityTokenAuthenticator : WindowsUserNameSecurityTokenAuthenticator, ILogonTokenCacheManager, IDisposable
    {
        LogonTokenCache logonTokenCache; 

        public WindowsUserNameCachingSecurityTokenAuthenticator(bool includeWindowsGroups, int maxCachedLogonTokens, TimeSpan cachedLogonTokenLifetime) 
            : base(includeWindowsGroups) 
        {
            this.logonTokenCache = new LogonTokenCache(maxCachedLogonTokens, cachedLogonTokenLifetime); 
        }

        public void Dispose()
        { 
            FlushLogonTokenCache();
        } 
 
        protected override ReadOnlyCollection ValidateUserNamePasswordCore(string userName, string password)
        { 
            LogonToken token;
            if (this.logonTokenCache.TryGetTokenCache(userName, out token))
            {
                if (token.PasswordEquals(password)) 
                {
                    return token.GetAuthorizationPolicies(); 
                } 
                else
                { 
                    // this prevents logon with old password.
                    this.logonTokenCache.TryRemoveTokenCache(userName);
                }
            } 

            ReadOnlyCollection authorizationPolicies = base.ValidateUserNamePasswordCore(userName, password); 
            this.logonTokenCache.TryAddTokenCache(userName, password, authorizationPolicies); 
            return authorizationPolicies;
        } 

        public bool RemoveCachedLogonToken(string username)
        {
            if (this.logonTokenCache == null) 
                return false;
 
            return this.logonTokenCache.TryRemoveTokenCache(username); 
        }
 
        public void FlushLogonTokenCache()
        {
            if (this.logonTokenCache != null)
                this.logonTokenCache.Flush(); 
        }
    } 
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
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WindowsUserNameCachingSecurityTokenAuthenticator.cs source code in C# .NET

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