Missing client certificate

Question

I am using GetHttp2ClientCertificateAsync() to get the client certificate for authentication.When there are a lot of requests, the client certificates is seen to be missing.It is verified that the client does add the certificate for sure.What could be the possible reason here.

Answer 1

Hi @Bevan Thomas , Welcome to Microsoft Q&A,

The most common cause is that the TLS handshake only occurs once due to HTTP/2 connection reuse, and if the client certificate is not negotiated in that handshake, all subsequent requests that reuse the connection will not have a certificate.

Make sure the server requests and negotiates the client certificate during the TLS handshake phase, and confirm that the ClientCertificateMode setting is as expected.

Verify that the client actually sends a certificate during the TLS handshake. See if the certificate can be obtained stably on a single connection to confirm whether the problem is caused by connection reuse.

Locate whether the problem is caused by the client not sending a certificate, the server not correctly requesting a certificate, or the middle layer (such as a load balancer) forwarding improperly.

Best Regards,

Jiale

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