X509Certificate2.SubjectName Property

Definition

Gets the subject distinguished name from a certificate.

C#
public System.Security.Cryptography.X509Certificates.X500DistinguishedName SubjectName { get; }

Property Value

An X500DistinguishedName object that represents the name of the certificate subject.

Exceptions

The certificate context is invalid.

Examples

The following code example creates a command-line executable that takes a certificate file as an argument and prints various certificate properties to the console.

C#
using System;
using System.Security.Cryptography;
using System.Security.Permissions;
using System.IO;
using System.Security.Cryptography.X509Certificates;

class CertInfo
{
    //Reads a file.
    internal static byte[] ReadFile (string fileName)
    {
        FileStream f = new FileStream(fileName, FileMode.Open, FileAccess.Read);
        int size = (int)f.Length;
        byte[] data = new byte[size];
        size = f.Read(data, 0, size);
        f.Close();
        return data;
    }
    //Main method begins here.
    static void Main(string[] args)
    {
        //Test for correct number of arguments.
        if (args.Length < 1)
        {
            Console.WriteLine("Usage: CertInfo <filename>");
            return;
        }
        try
        {
            byte[] rawData = ReadFile(args[0]);
            //Create X509Certificate2 object from .cer file.
            X509Certificate2 x509 = new X509Certificate2(rawData);

            //Print to console information contained in the certificate.
            Console.WriteLine("{0}Subject: {1}{0}", Environment.NewLine, x509.Subject);
            Console.WriteLine("{0}Issuer: {1}{0}", Environment.NewLine, x509.Issuer);
            Console.WriteLine("{0}Version: {1}{0}", Environment.NewLine, x509.Version);
            Console.WriteLine("{0}Valid Date: {1}{0}", Environment.NewLine, x509.NotBefore);
            Console.WriteLine("{0}Expiry Date: {1}{0}", Environment.NewLine, x509.NotAfter);
            Console.WriteLine("{0}Thumbprint: {1}{0}", Environment.NewLine, x509.Thumbprint);
            Console.WriteLine("{0}Serial Number: {1}{0}", Environment.NewLine, x509.SerialNumber);
            Console.WriteLine("{0}Friendly Name: {1}{0}", Environment.NewLine, x509.PublicKey.Oid.FriendlyName);
            Console.WriteLine("{0}Public Key Format: {1}{0}", Environment.NewLine, x509.PublicKey.EncodedKeyValue.Format(true));
            Console.WriteLine("{0}Raw Data Length: {1}{0}", Environment.NewLine, x509.RawData.Length);
            Console.WriteLine("{0}Certificate to string: {1}{0}", Environment.NewLine, x509.ToString(true));
            Console.WriteLine("{0}Certificate to XML String: {1}{0}", Environment.NewLine, x509.PublicKey.Key.ToXmlString(false));

            //Add the certificate to a X509Store.
            X509Store store = new X509Store();
            store.Open(OpenFlags.MaxAllowed);
            store.Add(x509);
            store.Close();
        }
        catch (DirectoryNotFoundException)
        {
               Console.WriteLine("Error: The directory specified could not be found.");
        }
        catch (IOException)
        {
            Console.WriteLine("Error: A file in the directory could not be accessed.");
        }
        catch (NullReferenceException)
        {
            Console.WriteLine("File must be a .cer file. Program does not have access to that type of file.");
        }
    }
}

Remarks

The subject distinguished name is the name of the user of the certificate. The distinguished name for the certificate is a textual representation of the subject or issuer of the certificate. This representation consists of name attributes, for example, "CN=MyName, OU=MyOrgUnit, C=US".

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, 10
.NET Framework 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