Hi there, since a few days Android 6 (SIX) is having trouble with the lets encrypt certificate.
Runs fine on windows and newer android versions. I tested some changes to the config, but that did not work.
Android error is ERR_CERT_AUTHORITY_INVALID.
I see the the tipsa.defcon.eu cert and the R3 in the browser info.
No. Your ACME Client (KeyHelp?) must select the alternate longer chain. In the past the longer chain was the default.
This longer alternate chain will only be available until Jun6 anyway.
You will have to ask your hosting provider about selecting the alternate chain with KeyHelp to get a few more months of compatibility. Or, using a different CA if you need support for such old devices for the long term.
Or, is it possible for you to install a different ACME Client which supports choosing the alternate chain? Or one which supports a different CA?
I looked at KeyWeb's docs and did not see much info. Which is why you will need to ask them. You could ask them to look at this thread and post their own questions if they choose to proceed.
Please note that using the now alternate chain will only temporarily fix your problem with Android 7.0 or older. Please use the borrowed time for a more permanent fix (upgrade the OS, redistribute the ISRG Root X1 root to all devices et c.)
If you need older devices to access your service my suggestion would be to change certificate authority to one with a trusted root that's available on your target devices. All trusted roots will eventually expire (e.g. some have another 10yrs to go) so devices that can't update their trusted root certificate store will eventually fail to use any publicly trusted certificate.
thanks for all your help guys!
we switched to another CA for the time beeing to get the service up and running again.
maybe its time to get rid of those "legacy" devices in the near future