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AsnEncodedData Class

Represents Abstract Syntax Notation One (ASN.1)-encoded data.

Namespace:  System.Security.Cryptography
Assembly:  System (in System.dll)
public class AsnEncodedData

The AsnEncodedData type exposes the following members.

  NameDescription
Protected methodAsnEncodedData()Initializes a new instance of the AsnEncodedData class.
Public methodAsnEncodedData(AsnEncodedData)Initializes a new instance of the AsnEncodedData class using an instance of the AsnEncodedData class.
Public methodAsnEncodedData(Byte[])Initializes a new instance of the AsnEncodedData class using a byte array.
Public methodAsnEncodedData(Oid, Byte[])Initializes a new instance of the AsnEncodedData class using an Oid object and a byte array.
Public methodAsnEncodedData(String, Byte[])Initializes a new instance of the AsnEncodedData class using a byte array.
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  NameDescription
Public propertyOidGets or sets the Oid value for an AsnEncodedData object.
Public propertyRawDataGets or sets the Abstract Syntax Notation One (ASN.1)-encoded data represented in a byte array.
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  NameDescription
Public methodCopyFromCopies information from an AsnEncodedData object.
Public methodEquals(Object)Determines whether the specified object is equal to the current object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodFormatReturns a formatted version of the Abstract Syntax Notation One (ASN.1)-encoded data as a string.
Public methodGetHashCodeServes as the default hash function. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
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Abstract Syntax Notation One (ASN.1), which is defined in CCITT Recommendation X.208, is a way to specify abstract objects that will be serially transmitted. The set of ASN.1 rules for representing such objects as strings of ones and zeros is called the Distinguished Encoding Rules (DER), and is defined in CCITT Recommendation X.509, Section 8.7. These encoding methods are currently used by the cryptography namespace in the .NET Framework.

Note that if an unknown data type is encountered while accessing an instance of this class, data is returned as a hexadecimal string.

The following code example shows how to use the AsnEncodedData class.

using System;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;

class AsnEncodedDataSample
{
	static void Main()
	{		
		//The following example demonstrates the usage the AsnEncodedData classes. 
		// Asn encoded data is read from the extensions of an X509 certificate. 
		try
		{
			// Open the certificate store.
			X509Store store = new X509Store("MY", StoreLocation.CurrentUser);
			store.Open(OpenFlags.ReadOnly | OpenFlags.OpenExistingOnly);
			X509Certificate2Collection collection = (X509Certificate2Collection)store.Certificates;
			X509Certificate2Collection fcollection = (X509Certificate2Collection)collection.Find(X509FindType.FindByTimeValid, DateTime.Now, false);
			// Select one or more certificates to display extensions information.
			X509Certificate2Collection scollection = X509Certificate2UI.SelectFromCollection(fcollection, "Certificate Select", "Select certificates from the following list to get extension information on that certificate", X509SelectionFlag.MultiSelection);

			// Create a new AsnEncodedDataCollection object.
			AsnEncodedDataCollection asncoll = new AsnEncodedDataCollection();
			for (int i = 0; i < scollection.Count; i++)
			{
				// Display certificate information.
				Console.ForegroundColor = ConsoleColor.Red;
				Console.WriteLine("Certificate name: {0}", scollection[i].GetName());
				Console.ResetColor();
				// Display extensions information. 
				foreach (X509Extension extension in scollection[i].Extensions)
				{
					// Create an AsnEncodedData object using the extensions information.
					AsnEncodedData asndata = new AsnEncodedData(extension.Oid, extension.RawData);
					Console.ForegroundColor = ConsoleColor.Green;
					Console.WriteLine("Extension type: {0}", extension.Oid.FriendlyName);
					Console.WriteLine("Oid value: {0}",asndata.Oid.Value);
					Console.WriteLine("Raw data length: {0} {1}", asndata.RawData.Length, Environment.NewLine);
					Console.ResetColor();
					Console.WriteLine(asndata.Format(true));
					Console.WriteLine(Environment.NewLine);
					// Add the AsnEncodedData object to the AsnEncodedDataCollection object.
					asncoll.Add(asndata);
				}
				Console.WriteLine(Environment.NewLine);
			}
			Console.ForegroundColor = ConsoleColor.Red;
			Console.WriteLine("Number of AsnEncodedData items in the collection: {0} {1}", asncoll.Count, Environment.NewLine);
			Console.ResetColor();

			store.Close();
			//Create an enumerator for moving through the collection.
			AsnEncodedDataEnumerator asne = asncoll.GetEnumerator();
			//You must execute a MoveNext() to get to the first item in the collection.
			asne.MoveNext();
			// Write out AsnEncodedData in the collection.
			Console.ForegroundColor = ConsoleColor.Blue;
			Console.WriteLine("First AsnEncodedData in the collection: {0}", asne.Current.Format(true));
			Console.ResetColor();

			asne.MoveNext();
			Console.ForegroundColor = ConsoleColor.DarkBlue;
			Console.WriteLine("Second AsnEncodedData in the collection: {0}", asne.Current.Format(true));
			Console.ResetColor();
			//Return index in the collection to the beginning.
			asne.Reset();
		}
		catch (CryptographicException)
		{
			Console.WriteLine("Information could not be written out for this certificate.");
		}
	}
}

.NET Framework

Supported in: 4.5.1, 4.5, 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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