SecurityPermission.cs source code in C# .NET

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                         / DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / clr / src / BCL / System / Security / Permissions / SecurityPermission.cs / 1 / SecurityPermission.cs
                        

                        
                            // ==++== 
//
//   Copyright (c) Microsoft Corporation.  All rights reserved.
//
// ==--== 
// SecurityPermission.cs
// 
 
namespace System.Security.Permissions
{ 
    using System;
    using System.IO;
    using System.Security.Util;
    using System.Text; 
    using System.Threading;
    using System.Runtime.Remoting; 
    using System.Security; 
    using System.Runtime.Serialization;
    using System.Reflection; 
    using System.Globalization;

    [Flags, Serializable]
[System.Runtime.InteropServices.ComVisible(true)] 
    public enum SecurityPermissionFlag
    { 
        NoFlags = 0x00, 
        /* The following enum value is used in the EE (ASSERT_PERMISSION in security.cpp)
         * Should this value change, make corresponding changes there 
         */
        Assertion = 0x01,
        UnmanagedCode = 0x02,       // Update vm\Security.h if you change this !
        SkipVerification = 0x04,    // Update vm\Security.h if you change this ! 
        Execution = 0x08,
        ControlThread = 0x10, 
        ControlEvidence = 0x20, 
        ControlPolicy = 0x40,
        SerializationFormatter = 0x80, 
        ControlDomainPolicy = 0x100,
        ControlPrincipal = 0x200,
        ControlAppDomain = 0x400,
        RemotingConfiguration = 0x800, 
        Infrastructure = 0x1000,
        BindingRedirects = 0x2000, 
        AllFlags = 0x3fff, 
    }
 
[System.Runtime.InteropServices.ComVisible(true)]
    [Serializable()] sealed public class SecurityPermission
           : CodeAccessPermission, IUnrestrictedPermission, IBuiltInPermission
    { 
        private SecurityPermissionFlag m_flags;
 
        // 
        // Public Constructors
        // 

        public SecurityPermission(PermissionState state)
        {
            if (state == PermissionState.Unrestricted) 
            {
                SetUnrestricted( true ); 
            } 
            else if (state == PermissionState.None)
            { 
                SetUnrestricted( false );
                Reset();
            }
            else 
            {
                throw new ArgumentException(Environment.GetResourceString("Argument_InvalidPermissionState")); 
            } 
        }
 

        // SecurityPermission
        //
        public SecurityPermission(SecurityPermissionFlag flag) 
        {
            VerifyAccess(flag); 
 
            SetUnrestricted(false);
            m_flags = flag; 
        }


        //------------------------------------------------------ 
        //
        // PRIVATE AND PROTECTED MODIFIERS 
        // 
        //-----------------------------------------------------
 

        private void SetUnrestricted(bool unrestricted)
        {
            if (unrestricted) 
            {
                m_flags = SecurityPermissionFlag.AllFlags; 
            } 
        }
 
        private void Reset()
        {
            m_flags = SecurityPermissionFlag.NoFlags;
        } 

 
        public SecurityPermissionFlag Flags 
        {
            set 
            {
                VerifyAccess(value);

                m_flags = value; 
            }
 
            get 
            {
                return m_flags; 
            }
        }

        // 
        // CodeAccessPermission methods
        // 
 
       /*
         * IPermission interface implementation 
         */

        public override bool IsSubsetOf(IPermission target)
        { 
            if (target == null)
            { 
                return m_flags == 0; 
            }
 
            SecurityPermission operand = target as SecurityPermission;
            if (operand != null)
            {
                return (((int)this.m_flags) & ~((int)operand.m_flags)) == 0; 
            }
            else 
            { 
                throw new
                    ArgumentException( 
                                    String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("Argument_WrongType"), this.GetType().FullName)
                                     );
            }
 
        }
 
        public override IPermission Union(IPermission target) { 
            if (target == null) return(this.Copy());
            if (!VerifyType(target)) { 
                throw new
                    ArgumentException(
                                    String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("Argument_WrongType"), this.GetType().FullName)
                                     ); 
            }
            SecurityPermission sp_target = (SecurityPermission) target; 
            if (sp_target.IsUnrestricted() || IsUnrestricted()) { 
                return(new SecurityPermission(PermissionState.Unrestricted));
            } 
            SecurityPermissionFlag flag_union = (SecurityPermissionFlag)(m_flags | sp_target.m_flags);
            return(new SecurityPermission(flag_union));
        }
 
        public override IPermission Intersect(IPermission target)
        { 
            if (target == null) 
                return null;
            else if (!VerifyType(target)) 
            {
                throw new
                    ArgumentException(
                                    String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("Argument_WrongType"), this.GetType().FullName) 
                                     );
            } 
 
            SecurityPermission operand = (SecurityPermission)target;
            SecurityPermissionFlag isectFlags = SecurityPermissionFlag.NoFlags; 

            if (operand.IsUnrestricted())
            {
                if (this.IsUnrestricted()) 
                    return new SecurityPermission(PermissionState.Unrestricted);
                else 
                    isectFlags = (SecurityPermissionFlag)this.m_flags; 
            }
            else if (this.IsUnrestricted()) 
            {
                isectFlags = (SecurityPermissionFlag)operand.m_flags;
            }
            else 
            {
                isectFlags = (SecurityPermissionFlag)m_flags & (SecurityPermissionFlag)operand.m_flags; 
            } 

            if (isectFlags == 0) 
                return null;
            else
                return new SecurityPermission(isectFlags);
        } 

        public override IPermission Copy() 
        { 
            if (IsUnrestricted())
                return new SecurityPermission(PermissionState.Unrestricted); 
            else
                return new SecurityPermission((SecurityPermissionFlag)m_flags);
        }
 
        public bool IsUnrestricted()
        { 
            return m_flags == SecurityPermissionFlag.AllFlags; 
        }
 
        private
        void VerifyAccess(SecurityPermissionFlag type)
        {
            if ((type & ~SecurityPermissionFlag.AllFlags) != 0) 
                throw new ArgumentException(String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("Arg_EnumIllegalVal"), (int)type));
        } 
 

        //----------------------------------------------------- 
        //
        // PUBLIC ENCODING METHODS
        //
        //----------------------------------------------------- 

        private const String _strHeaderAssertion  = "Assertion"; 
        private const String _strHeaderUnmanagedCode = "UnmanagedCode"; 
        private const String _strHeaderExecution = "Execution";
        private const String _strHeaderSkipVerification = "SkipVerification"; 
        private const String _strHeaderControlThread = "ControlThread";
        private const String _strHeaderControlEvidence = "ControlEvidence";
        private const String _strHeaderControlPolicy = "ControlPolicy";
        private const String _strHeaderSerializationFormatter = "SerializationFormatter"; 
        private const String _strHeaderControlDomainPolicy = "ControlDomainPolicy";
        private const String _strHeaderControlPrincipal = "ControlPrincipal"; 
        private const String _strHeaderControlAppDomain = "ControlAppDomain"; 

        public override SecurityElement ToXml() 
        {
            SecurityElement esd = CodeAccessPermission.CreatePermissionElement( this, "System.Security.Permissions.SecurityPermission" );
            if (!IsUnrestricted())
            { 
                esd.AddAttribute( "Flags", XMLUtil.BitFieldEnumToString( typeof( SecurityPermissionFlag ), m_flags ) );
            } 
            else 
            {
                esd.AddAttribute( "Unrestricted", "true" ); 
            }
            return esd;
        }
 
        public override void FromXml(SecurityElement esd)
        { 
            CodeAccessPermission.ValidateElement( esd, this ); 
            if (XMLUtil.IsUnrestricted( esd ))
            { 
                m_flags = SecurityPermissionFlag.AllFlags;
                return;
            }
 
            Reset () ;
            SetUnrestricted (false) ; 
 
            String flags = esd.Attribute( "Flags" );
 
            if (flags != null)
                m_flags = (SecurityPermissionFlag)Enum.Parse( typeof( SecurityPermissionFlag ), flags );
        }
 
        //
        // Object Overrides 
        // 

    #if ZERO   // Do not remove this code, usefull for debugging 
        public override String ToString()
        {
            StringBuilder sb = new StringBuilder();
            sb.Append("SecurityPermission("); 
            if (IsUnrestricted())
            { 
                sb.Append("Unrestricted"); 
            }
            else 
            {
                if (GetFlag(SecurityPermissionFlag.Assertion))
                    sb.Append("Assertion; ");
                if (GetFlag(SecurityPermissionFlag.UnmanagedCode)) 
                    sb.Append("UnmangedCode; ");
                if (GetFlag(SecurityPermissionFlag.SkipVerification)) 
                    sb.Append("SkipVerification; "); 
                if (GetFlag(SecurityPermissionFlag.Execution))
                    sb.Append("Execution; "); 
                if (GetFlag(SecurityPermissionFlag.ControlThread))
                    sb.Append("ControlThread; ");
                if (GetFlag(SecurityPermissionFlag.ControlEvidence))
                    sb.Append("ControlEvidence; "); 
                if (GetFlag(SecurityPermissionFlag.ControlPolicy))
                    sb.Append("ControlPolicy; "); 
                if (GetFlag(SecurityPermissionFlag.SerializationFormatter)) 
                    sb.Append("SerializationFormatter; ");
                if (GetFlag(SecurityPermissionFlag.ControlDomainPolicy)) 
                    sb.Append("ControlDomainPolicy; ");
                if (GetFlag(SecurityPermissionFlag.ControlPrincipal))
                    sb.Append("ControlPrincipal; ");
            } 

            sb.Append(")"); 
            return sb.ToString(); 
        }
    #endif 

        /// 
        int IBuiltInPermission.GetTokenIndex()
        { 
            return SecurityPermission.GetTokenIndex();
        } 
 
        internal static int GetTokenIndex()
        { 
            return BuiltInPermissionIndex.SecurityPermissionIndex;
        }

        // This can be used as a place-holder for SkipVerification permission 
        [SecurityPermission(SecurityAction.LinkDemand, SkipVerification = true)]
        static internal void MethodWithSkipVerificationLinkDemand() {} 
    } 

 
}

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