mjg59@dreamwidth.org posted:
Sep. 20th, 2011 02:01 pm
Since there are probably going to be some questions about this in the near future:
The UEFI secure boot protocol is part of recent UEFI specification releases. It permits one or more signing keys to be installed into a system firmware. Once enabled, secure boot prevents executables or drivers from being loaded unless they're signed by one of these keys. Another set of keys (Pkek) permits communication between an OS and the firmware. An OS with a Pkek matching that installed in the firmware may add additional keys to the whitelist. Alternatively, it may add keys to a blacklist. Binaries signed with a blacklisted key will not load.
There is no centralised signing authority for these UEFI keys. If a vendor key is installed on a machine, the only way to get code signed with that key is to get the vendor to perform the signing. A machine may have several keys installed, but if you are unable to get any of them to sign your binary then it won't be installable.
This impacts both software and hardware vendors. An OS vendor cannot boot their software on a system unless it's signed with a key that's included in the system firmware. A hardware vendor cannot run their hardware inside the EFI environment unless their drivers are signed with a key that's included in the system firmware. If you install a new graphics card that either has unsigned drivers, or drivers that are signed with a key that's not in your system firmware, you'll get no graphics support in the firmware.
Sep. 20th, 2011 02:01 pm
Since there are probably going to be some questions about this in the near future:
The UEFI secure boot protocol is part of recent UEFI specification releases. It permits one or more signing keys to be installed into a system firmware. Once enabled, secure boot prevents executables or drivers from being loaded unless they're signed by one of these keys. Another set of keys (Pkek) permits communication between an OS and the firmware. An OS with a Pkek matching that installed in the firmware may add additional keys to the whitelist. Alternatively, it may add keys to a blacklist. Binaries signed with a blacklisted key will not load.
There is no centralised signing authority for these UEFI keys. If a vendor key is installed on a machine, the only way to get code signed with that key is to get the vendor to perform the signing. A machine may have several keys installed, but if you are unable to get any of them to sign your binary then it won't be installable.
This impacts both software and hardware vendors. An OS vendor cannot boot their software on a system unless it's signed with a key that's included in the system firmware. A hardware vendor cannot run their hardware inside the EFI environment unless their drivers are signed with a key that's included in the system firmware. If you install a new graphics card that either has unsigned drivers, or drivers that are signed with a key that's not in your system firmware, you'll get no graphics support in the firmware.
Report continues and includes forum commentary.
