Self-Signed CA not trusted in iOS 13 anymore

Question

I created a Self-Signed CA and trust this certificate in Settings and it's working well in iOS 12. But after I upgrade the iOS version to 13, even the certificate trusted in Setting but still can't get it to working. So how do I fix this?

Answer 1

Nothing is known about your certificate but it might be that it is not meeting the new requirements introduced in iOS 13. Requirements for trusted certificates in iOS 13 and macOS 10.15 describes these and these include that RSA keys must be at least 2048 bits and it is no longer possible to use SHA-1 as signature algorithm.

Answer 2

I Happen to try something and it actually worked, Send the self signed.cer to the iphone with another configured email. The cert will be added to the iphone cert store. And Go to general setting then find Profil. Within the option you will see the name of the cert you just added and the option to configure it. Just do that in first place. Once done. Add the Exchange email account just like any other, it will prompt with certificate error but you will the option to continue and the account will be added correctly. I tried on Iphone 11 in the Mail App with Latest IOS.