TypeBuilder.IsSecurityCritical Property

Definition

Namespace:

System.Reflection.Emit

Assembly:

System.Reflection.Emit.dll

Gets a value that indicates whether the current type is security-critical or security-safe-critical, and therefore can perform critical operations.

public:
 virtual property bool IsSecurityCritical { bool get(); };

public override bool IsSecurityCritical { get; }

member this.IsSecurityCritical : bool

Public Overrides ReadOnly Property IsSecurityCritical As Boolean

Property Value

Boolean

true if the current type is security-critical or security-safe-critical; false if it is transparent.

Exceptions

NotSupportedException

The current dynamic type has not been created by calling the CreateType() method.

Remarks

The IsSecurityCritical, IsSecuritySafeCritical, and IsSecurityTransparent properties report the transparency level of the type, as determined by the common language runtime (CLR). The combinations of these properties are shown in the following table:

Security level	IsSecurityCritical	IsSecuritySafeCritical	IsSecurityTransparent
Critical	true	false	false
Safe-critical	true	true	false
Transparent	false	false	true

Using these properties is much simpler than examining the security annotations of an assembly and its types, checking the current trust level, and attempting to duplicate the runtime's rules.

The runtime begins evaluating transparency levels at the assembly. For example, if the dynamic assembly is security-critical, annotations on types are ignored, and all types are security-critical.

By default, a dynamic assembly inherits the transparency of the assembly that emits it. You can override this default by using the AppDomain.DefineDynamicAssembly(AssemblyName, AssemblyBuilderAccess, IEnumerable<CustomAttributeBuilder>), AppDomain.DefineDynamicAssembly(AssemblyName, AssemblyBuilderAccess, String, Boolean, IEnumerable<CustomAttributeBuilder>), or AppDomain.DefineDynamicAssembly(AssemblyName, AssemblyBuilderAccess, String, Evidence, PermissionSet, PermissionSet, PermissionSet, Boolean, IEnumerable<CustomAttributeBuilder>) method overload and specifying security attributes. You cannot elevate security levels by doing this; that is, transparent code cannot emit security-critical or security-safe-critical code. Attributes must be specified when the dynamic assembly is created, or they do not take effect until the assembly has been saved to disk and reloaded.

Note

Default inheritance is limited to the runtime's evaluation of transparency. No attributes are applied to the dynamic assembly. If you want to add security attributes, you must apply them yourself.

For more information about reflection emit and transparency, see Security Issues in Reflection Emit. For information about transparency, see Security Changes.

See also

• IsSecuritySafeCritical
• IsSecurityTransparent
• Security Issues in Reflection Emit
• Security Considerations for Reflection
• Security Changes in the .NET Framework Version 4.0
• Security-Transparent Code, Level 1
• Security-Transparent Code, Level 2