X509Certificate2.Verify Method

Definition

Namespace:

System.Security.Cryptography.X509Certificates

Assemblies:

netstandard.dll, System.Security.Cryptography.dll

Source:

X509Certificate2.cs

Performs a X.509 chain validation using basic validation policy.

C#

public bool Verify();

Returns

Boolean

true if the validation succeeds; false if the validation fails.

Exceptions

CryptographicException

The certificate is unreadable.

Examples

The following code example opens the current user certificate store, selects only active certificates, then allows the user to select one or more certificates. The example then writes certificate information to the console.

C#

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

class CertSelect
{
    static void Main()
    {
        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);
        X509Certificate2Collection scollection = X509Certificate2UI.SelectFromCollection(fcollection, "Test Certificate Select","Select a certificate from the following list to get information on that certificate",X509SelectionFlag.MultiSelection);
        Console.WriteLine("Number of certificates: {0}{1}",scollection.Count,Environment.NewLine);

        foreach (X509Certificate2 x509 in scollection)
        {
            try
            {
                byte[] rawdata = x509.RawData;
                Console.WriteLine("Content Type: {0}{1}",X509Certificate2.GetCertContentType(rawdata),Environment.NewLine);
                Console.WriteLine("Friendly Name: {0}{1}",x509.FriendlyName,Environment.NewLine);
                Console.WriteLine("Certificate Verified?: {0}{1}",x509.Verify(),Environment.NewLine);
                Console.WriteLine("Simple Name: {0}{1}",x509.GetNameInfo(X509NameType.SimpleName,true),Environment.NewLine);
                Console.WriteLine("Signature Algorithm: {0}{1}",x509.SignatureAlgorithm.FriendlyName,Environment.NewLine);
                Console.WriteLine("Public Key: {0}{1}",x509.PublicKey.Key.ToXmlString(false),Environment.NewLine);
                Console.WriteLine("Certificate Archived?: {0}{1}",x509.Archived,Environment.NewLine);
                Console.WriteLine("Length of Raw Data: {0}{1}",x509.RawData.Length,Environment.NewLine);
                X509Certificate2UI.DisplayCertificate(x509);
                x509.Reset();
            }
            catch (CryptographicException)
            {
                Console.WriteLine("Information could not be written out for this certificate.");
            }
        }
        store.Close();
    }
}

Remarks

This method builds a simple chain for the certificate and applies the base policy to that chain. If you need more information about a failure, validate the certificate directly using the X509Chain object.

Note that the default chaining engine can be overridden using the CryptoConfig class. On Microsoft Windows Server 2003, the default engine conforms to the specification described in RFC3280, "Certificate and Certificate Revocation List (CRL) Profile."

Applies to