HttpWebRequest.ClientCertificates Property

Definition

Gets or sets the collection of security certificates that are associated with this request.

public System.Security.Cryptography.X509Certificates.X509CertificateCollection ClientCertificates { get; set; }
public System.Security.Cryptography.X509Certificates.X509CertificateCollection ClientCertificates { get; }

Property Value

The X509CertificateCollection that contains the security certificates associated with this request.

Exceptions

The value specified for a set operation is null.

Remarks

Caution

WebRequest, HttpWebRequest, ServicePoint, and WebClient are obsolete, and you shouldn't use them for new development. Use HttpClient instead.

An application can add a certificate to a collection, but might not have access rights to it. To use a certificate contained in the collection, the application must have the same access rights as the entity that issued the certificate.

Note

The Framework caches SSL sessions as they are created and attempts to reuse a cached session for a new request, if possible. When attempting to reuse an SSL session, the Framework uses the first element of ClientCertificates (if there is one), or tries to reuse an anonymous sessions if ClientCertificates is empty.

Note

For performance reasons, you shouldn't add a client certificate to a HttpWebRequest unless you know the server will ask for it.

For a code example illustrating how to enumerate the certificates in the client certificate store, see the X509Certificate2Collection class.

Applies to

Product Versions
.NET 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 2.0, 2.1