Added new preference SSL Settings->Client Certificate. It invokes the android certificate selection dialog, not an app-specific one. This is necessary to authorize the app to use a cert from the central store. The dialog may vary by device, but you should be able to add certs from either there or in the device settings (typically you need to store a .p12 file in the phone / directory).
I've tested that Apache can be configured to require this cert, and that ttrss can then be configured to use the cert as login.
Added new preference SSL Settings->Client Certificate. It invokes the android certificate selection dialog, not an app-specific one. This is necessary to authorize the app to use a cert from the central store. The dialog may vary by device, but you should be able to add certs from either there or in the device settings (typically you need to store a .p12 file in the phone / directory).
I've tested that Apache can be configured to require this cert, and that ttrss can then be configured to use the cert as login.