FileIOPermissionAttribute Class

Definition

Namespace:

System.Security.Permissions

Assembly:

System.Security.Permissions.dll

Source:

FileIOPermissionAttribute.cs

Caution

Code Access Security is not supported or honored by the runtime.

Allows security actions for FileIOPermission to be applied to code using declarative security. This class cannot be inherited.

public ref class FileIOPermissionAttribute sealed : System::Security::Permissions::CodeAccessSecurityAttribute

[System.AttributeUsage(System.AttributeTargets.Assembly | System.AttributeTargets.Class | System.AttributeTargets.Constructor | System.AttributeTargets.Method | System.AttributeTargets.Struct, AllowMultiple=true, Inherited=false)]
[System.Obsolete("Code Access Security is not supported or honored by the runtime.", DiagnosticId="SYSLIB0003", UrlFormat="https://aka.ms/dotnet-warnings/{0}")]
public sealed class FileIOPermissionAttribute : System.Security.Permissions.CodeAccessSecurityAttribute

[<System.AttributeUsage(System.AttributeTargets.Assembly | System.AttributeTargets.Class | System.AttributeTargets.Constructor | System.AttributeTargets.Method | System.AttributeTargets.Struct, AllowMultiple=true, Inherited=false)>]
[<System.Obsolete("Code Access Security is not supported or honored by the runtime.", DiagnosticId="SYSLIB0003", UrlFormat="https://aka.ms/dotnet-warnings/{0}")>]
type FileIOPermissionAttribute = class
    inherit CodeAccessSecurityAttribute

Public NotInheritable Class FileIOPermissionAttribute
Inherits CodeAccessSecurityAttribute

Inheritance

Object

Attribute

SecurityAttribute

CodeAccessSecurityAttribute

FileIOPermissionAttribute

Attributes

AttributeUsageAttribute ObsoleteAttribute

Examples

The following code example demonstrates how to request FileIOPermission by using the FileIOPermissionAttribute class, indicating the only permission that is to be granted to the code.

[FileIOPermissionAttribute(SecurityAction::PermitOnly,ViewAndModify="C:\\example\\sample.txt")]

[FileIOPermissionAttribute(SecurityAction.PermitOnly, ViewAndModify = "C:\\example\\sample.txt")]

<FileIOPermissionAttribute(SecurityAction.PermitOnly, _
ViewAndModify:="C:\example\sample.txt")> Public Class SampleClass

The following example shows how to demand that the calling code has unrestricted FileIOPermission. You typically make demands in managed libraries (DLLs) to help protect methods or classes from potentially harmful code.

[FileIOPermissionAttribute(SecurityAction::Demand,Unrestricted=true)]

[FileIOPermissionAttribute(SecurityAction.Demand, Unrestricted=true)]

<FileIOPermissionAttribute(SecurityAction.Demand, _
 Unrestricted := True)> Public Class SampleClass

Remarks

Caution

Code Access Security (CAS) has been deprecated across all versions of .NET Framework and .NET. Recent versions of .NET do not honor CAS annotations and produce errors if CAS-related APIs are used. Developers should seek alternative means of accomplishing security tasks.

Files and directories are specified using absolute paths. When accessing files, a security check is performed when the file is created or opened. The security check is not done again unless the file is closed and reopened. Checking permissions when the file is first accessed minimizes the impact of the security check on application performance because opening a file happens only once, while reading and writing can happen multiple times.

The scope of the declaration that is allowed depends on the SecurityAction that is used.

The security information declared by a security attribute is stored in the metadata of the attribute target and is accessed by the system at run time. Security attributes are used only for declarative security. For imperative security, use the corresponding permission class.

Caution

Unrestricted FileIOPermission grants permission for all paths within a file system, including multiple pathnames that can be used to access a single given file. To Deny access to a file, you must Deny all possible paths to the file. For example, if \\server\share is mapped to the network drive X, to Deny access to \\server\share\file, you must Deny \\server\share\file, X:\file and any other path that you can use to access the file.

Constructors

FileIOPermissionAttribute(SecurityAction)

Initializes a new instance of the FileIOPermissionAttribute class with the specified SecurityAction.

Properties

Action	Gets or sets a security action. (Inherited from SecurityAttribute)
All	Obsolete. Gets or sets full access for the file or directory that is specified by the string value.
AllFiles	Gets or sets the permitted access to all files.
AllLocalFiles	Gets or sets the permitted access to all local files.
Append	Gets or sets append access for the file or directory that is specified by the string value.
ChangeAccessControl	Gets or sets the file or directory in which access control information can be changed.
PathDiscovery	Gets or sets the file or directory to which to grant path discovery.
Read	Gets or sets read access for the file or directory specified by the string value.
TypeId	When implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute)
Unrestricted	Gets or sets a value indicating whether full (unrestricted) permission to the resource protected by the attribute is declared. (Inherited from SecurityAttribute)
ViewAccessControl	Gets or sets the file or directory in which access control information can be viewed.
ViewAndModify	Gets or sets the file or directory in which file data can be viewed and modified.
Write	Gets or sets write access for the file or directory specified by the string value.

Methods

CreatePermission()	Creates and returns a new FileIOPermission.
Equals(Object)	Returns a value that indicates whether this instance is equal to a specified object. (Inherited from Attribute)
GetHashCode()	Returns the hash code for this instance. (Inherited from Attribute)
GetType()	Gets the Type of the current instance. (Inherited from Object)
IsDefaultAttribute()	When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class. (Inherited from Attribute)
Match(Object)	When overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
ToString()	Returns a string that represents the current object. (Inherited from Object)

See also

• FileIOPermission
• FileIOPermissionAccess
• Extending Metadata Using Attributes