CA2123：重写的链接请求应与基相同
类型名 |
OverrideLinkDemandsShouldBeIdenticalToBase |
CheckId |
CA2123 |
类别 |
Microsoft.Security |
是否重大更改 |
是 |
原因
公共类型中的公共或受保护方法重写方法或实现接口，且没有与该接口或虚方法相同的 链接需求。
规则说明
该规则将一个方法与其基方法（该基方法为另一个类型中的接口或虚方法）相匹配，然后比较两者的链接请求。如果该方法和该基方法中的任何一个具有链接请求，而另一个不具有链接请求，则会报告冲突。
如果与该规则冲突，则恶意调用方只需调用不安全的方法，即可跳过该链接请求。
如何解决冲突
若要修复此规则的冲突，请将同一链接请求应用到重写方法或实现。如果不可能，则使用完全请求标记该方法或完全移除特性。
何时禁止显示警告
不要禁止显示此规则发出的警告。
示例
下面的示例演示与该规则冲突的各种情况。
using System.Security;
using System.Security.Permissions;
using System;
namespace SecurityRulesLibrary
{
public interface ITestOverrides
{
[EnvironmentPermissionAttribute(SecurityAction.LinkDemand, Unrestricted=true)]
Object GetFormat(Type formatType);
}
public class OverridesAndSecurity : ITestOverrides
{
// Rule violation: The interface has security, and this implementation does not.
object ITestOverrides.GetFormat(Type formatType)
{
return (formatType == typeof(OverridesAndSecurity) ? this : null);
}
// These two methods are overridden by DerivedClass and DoublyDerivedClass.
[EnvironmentPermissionAttribute(SecurityAction.LinkDemand, Unrestricted=true)]
public virtual void DoSomething()
{
Console.WriteLine("Doing something.");
}
public virtual void DoSomethingElse()
{
Console.WriteLine("Doing some other thing.");
}
}
public class DerivedClass : OverridesAndSecurity, ITestOverrides
{
// Rule violation: The interface has security, and this implementation does not.
public object GetFormat(Type formatType)
{
return (formatType == typeof(OverridesAndSecurity) ? this : null);
}
// Rule violation: This does not have security, but the base class version does.
public override void DoSomething()
{
Console.WriteLine("Doing some derived thing.");
}
// Rule violation: This has security, but the base class version does not.
[EnvironmentPermissionAttribute(SecurityAction.LinkDemand, Unrestricted=true)]
public override void DoSomethingElse()
{
Console.WriteLine("Doing some other derived thing.");
}
}
public class DoublyDerivedClass : DerivedClass
{
// The OverridesAndSecurity version of this method does not have security.
// Base class DerivedClass's version does.
// The DoublyDerivedClass version does not violate the rule, but the
// DerivedClass version does violate the rule.
public override void DoSomethingElse()
{
Console.WriteLine("Doing some other derived thing.");
}
}
}