X509Certificate.GetPublicKey Method

Definition

Returns the public key for the X.509v3 certificate as an array of bytes.

C#
public virtual byte[] GetPublicKey();

Returns

Byte[]

The public key for the X.509 certificate as an array of bytes.

Exceptions

The certificate context is invalid.

Examples

The following example uses the GetPublicKey method to return a certificate's public key as an array of bytes and displays it to the console.

C#

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

public class X509
{

    public static void Main()
    {

        // The path to the certificate.
        string Certificate =  "Certificate.cer";

        // Load the certificate into an X509Certificate object.
        X509Certificate cert = X509Certificate.CreateFromCertFile(Certificate);

        // Get the value.
        byte[] results = cert.GetPublicKey();

        // Display the value to the console.
        foreach(byte b in results)
        {
            Console.Write(b);
        }
    }
}

Remarks

This value corresponds to the contents of the subjectPublicKey field of the SubjectPublicKeyInfo data within the certificate.

Applies to

Product Versions
.NET Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Framework 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard 1.3, 1.4, 1.6, 2.0, 2.1