System.Security.FrameSecurityDescriptor.CheckDemand2 C# (CSharp) Method

        internal bool CheckDemand2(CodeAccessPermission demand, PermissionToken permToken, RuntimeMethodHandle rmh, bool fDeclarative)
        {
            PermissionSet permSet;
            
            // If the demand is null, there is no need to continue
            BCLDebug.Assert(demand != null && !demand.CheckDemand(null), "Empty demands should have been filtered out by this point");

            // decode imperative
            if (GetPermitOnly(fDeclarative) != null)
                GetPermitOnly(fDeclarative).CheckDecoded(demand, permToken);
    
            if (GetDenials(fDeclarative) != null)
                GetDenials(fDeclarative).CheckDecoded(demand, permToken);
    
            if (GetAssertions(fDeclarative) != null)
                GetAssertions(fDeclarative).CheckDecoded(demand, permToken);
            
            // NOTE: See notes about exceptions and exception handling in FrameDescSetHelper 
    
            bool bThreadSecurity = SecurityManager._SetThreadSecurity(false);
    
            // Check Reduction
            
            try
            {
                permSet = GetPermitOnly(fDeclarative);
                if (permSet != null)
                {
                    CodeAccessPermission perm = (CodeAccessPermission)permSet.GetPermission(demand);
            
                    // If the permit only set does not contain the demanded permission, throw a security exception
                    if (perm == null)
                    {
                        if(!(permSet.IsUnrestricted() && demand.CanUnrestrictedOverride()))
                            throw new SecurityException(String.Format(CultureInfo.InvariantCulture, Environment.GetResourceString("Security_Generic"), demand.GetType().AssemblyQualifiedName), null, permSet, SecurityRuntime.GetMethodInfo(rmh), demand, demand);
                    }
                    else
                    {
                        bool bNeedToThrow = true;
    
                        try
                        {
                            bNeedToThrow = !demand.CheckPermitOnly(perm);
                        }
                        catch (ArgumentException)
                        {
                        }
    
                        if (bNeedToThrow)
                            throw new SecurityException(String.Format(CultureInfo.InvariantCulture, Environment.GetResourceString("Security_Generic"), demand.GetType().AssemblyQualifiedName), null, permSet, SecurityRuntime.GetMethodInfo(rmh), demand, demand);
                    }
                }
            
                // Check Denials
            
                permSet = GetDenials(fDeclarative);
                if (permSet != null)
                {
                    CodeAccessPermission perm = (CodeAccessPermission)permSet.GetPermission(demand);
                    
                    // If an unrestricted set was denied and the demand implements IUnrestricted
                    if (permSet.IsUnrestricted() && demand.CanUnrestrictedOverride())
                        throw new SecurityException(String.Format(CultureInfo.InvariantCulture, Environment.GetResourceString("Security_Generic"), demand.GetType().AssemblyQualifiedName), permSet, null, SecurityRuntime.GetMethodInfo(rmh), demand, demand);
    
                    // If the deny set does contain the demanded permission, throw a security exception
                    bool bNeedToThrow = true;
                    try
                    {
                        bNeedToThrow = !demand.CheckDeny(perm);
                    }
                    catch (ArgumentException)
                    {
                    }
                    if (bNeedToThrow)
                        throw new SecurityException(String.Format(CultureInfo.InvariantCulture, Environment.GetResourceString("Security_Generic"), demand.GetType().AssemblyQualifiedName), permSet, null, SecurityRuntime.GetMethodInfo(rmh), demand, demand);
                }
    
                if (GetAssertAllPossible())
                {
                    return SecurityRuntime.StackHalt;
                }        
    
                permSet = GetAssertions(fDeclarative);
                // Check Assertions
                if (permSet != null)
                {
            
                    CodeAccessPermission perm = (CodeAccessPermission)permSet.GetPermission(demand);
                
                    // If the assert set does contain the demanded permission, halt the stackwalk
            
                    try
                    {
                        if ((permSet.IsUnrestricted() && demand.CanUnrestrictedOverride()) || (demand.CheckAssert(perm)))
                        {
                            return SecurityRuntime.StackHalt;
                        }
                    }
                    catch (ArgumentException)
                    {
                    }
                }
                
            }
            finally
            {
                if (bThreadSecurity)
                    SecurityManager._SetThreadSecurity(true);
            }
            
            return SecurityRuntime.StackContinue;
        }