Represents an X509 extension.
Assembly: System (in System.dll)
Thetype exposes the following members.
|X509Extension()||Initializes a new instance of the class.|
|X509Extension(AsnEncodedData, Boolean)||Initializes a new instance of the class.|
|X509Extension(Oid, Byte, Boolean)||Initializes a new instance of the class.|
|X509Extension(String, Byte, Boolean)||Initializes a new instance of the class.|
|Critical||Gets a Boolean value indicating whether the extension is critical.|
|Oid||Gets or sets the Oid value for an AsnEncodedData object. (Inherited from AsnEncodedData.)|
|RawData||Gets or sets the Abstract Syntax Notation One (ASN.1)-encoded data represented in a byte array. (Inherited from AsnEncodedData.)|
|CopyFrom||Copies the extension properties of the specified AsnEncodedData object. (Overrides AsnEncodedData.CopyFrom(AsnEncodedData).)|
|Equals(Object)||Determines whether the specified object is equal to the current object. (Inherited from Object.)|
|Finalize||Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)|
|Format||Returns a formatted version of the Abstract Syntax Notation One (ASN.1)-encoded data as a string. (Inherited from AsnEncodedData.)|
|GetHashCode||Serves as the default hash function. (Inherited from Object.)|
|GetType||Gets the Type of the current instance. (Inherited from Object.)|
|MemberwiseClone||Creates a shallow copy of the current Object. (Inherited from Object.)|
|ToString||Returns a string that represents the current object. (Inherited from Object.)|
X509 extensions are dynamic, extended properties that can be added to an X509 certificate and changed. The class can be used to create extensions that are associated with a certificate but are not part of a certificate as issued by a certification authority (CA).
In its most basic form, an X509 extension has an object identifier (OID), a Boolean value describing whether the extension is considered critical or not, and ASN-encoded data. Custom extensions can be registered in a CryptoConfig file.
The.NET Framework includes implementations of several common X509 extensions:
X509KeyUsageExtension. Describes the key usages of a certificate.
X509BasicConstraintsExtension. Describes the constraints for a certificate.
X509EnhancedKeyUsageExtension. Describes the enhanced key usages of a certificate.
X509SubjectKeyIdentifierExtension. Describes the key identifier. For example, used with XMLDSIG.