When performing device certificate authentication on iOS18, it takes time to respond.

We are using device certificates for authentication when logging into our web page. After updating an iPhone 12 to iOS 18, the authentication process takes up to two minutes to respond.

Upon investigating IIS, it was found that the certificate is not being presented from the iPhone, resulting in a timeout.

This issue is affecting our operations, and we need a solution urgently. Could you please advise on how to resolve this?

In addition to the investigation of this issue, we found the following from our IIS logs: When the communication timeout occurs, a "timer_sslrenegotiation" error log is output.

By enabling "Negotiation Client Certificate" in the server's SSL settings, the error log is no longer output, and the timeout does not occur.

We suspect that iOS 18 does not support renegotiation or that some other cause is preventing renegotiation, resulting in the timeout.

Thank you for your response. The FB number is FB15619515.

I appreciate your assistance in resolving this issue.

When performing device certificate authentication on iOS18, it takes time to respond.
 
 
Q