CA2130: Security critical constants should be transparent

TypeName	ConstantsShouldBeTransparent
CheckId	CA2130
Category	Microsoft.Security
Breaking Change	Breaking

Cause

A constant field or an enumeration member is marked with the SecurityCriticalAttribute.

Rule Description

Transparency enforcement is not enforced for constant values because compilers inline constant values so that no lookup is required at run time. Constant fields should be security transparent so that code reviewers do not assume that transparent code cannot access the constant.

How to Fix Violations

To fix a violation of this rule, remove the SecurityCritical attribute from the field or value.

When to Suppress Warnings

Do not suppress a warning from this rule.

Example

In the following examples, the enum value EnumWithCriticalValues.CriticalEnumValue and the constant CriticalConstant raise this warning. To fix the issues, remove the [SecurityCritical] attribute to make them security transparent.

using System;
using System.Security;

//[assembly: SecurityRules(SecurityRuleSet.Level2)] 
//[assembly: AllowPartiallyTrustedCallers] 

namespace TransparencyWarningsDemo
{

    public enum EnumWithCriticalValues
    {
        TransparentEnumValue,

        // CA2130 violation
        [SecurityCritical]
        CriticalEnumValue
    }

    public class ClassWithCriticalConstant
    {
        // CA2130 violation
        [SecurityCritical]
        public const int CriticalConstant = 21;
    }
}