Cannot import x.509 PKCS 12 client certificate on iOS9

Hi everybody,

our company provides a web site that requires SSL client authentication by the browser.

Since October 2015, all our customers who use ipad/iphone (iOS9) cannot import any certificate anymore (by email or http download).

The previous version of iOS allowed to import succesfully our certificate as described by this paper https://www.apple.com/hk/en/ipad/business/docs/iOS_6_Certificates_Sep12.pdf

It's a self-signed PKCS 12 certificate (.p12) and we also tried to import our self-signed Certification Authority .der file with no luck.

Apple Mail can't even open .p12, .cer. der, .pem files!!!

We can'r even find te Profile Settings within the Configuration Menu.

How can I install a self-signed certificate on iOS9 to be used by the browser (https client certificate required)?