dhowett / framework-secure-boot

Secure Boot certificates from the Framework Laptop

Framework Laptop UEFI Secure Boot Certificates

Source: Extracted from live machines.

Date: 2021-10-21 (TGL), 2022-08-02 (ADL)

Certificates marked with ADL are for the 12th generation Intel Framework Laptop.

With thanks to @ngxson and Morpheus636 for providing the certificates from their 12th generation laptops.

KEK (Key Exchange Key)

This certificate allows Framework to add additional certificates to the DB.

Current thumbprints:

• frame.work-LaptopKEK.der: a1c36bd73e143c77954be234f71337370136074f
• frame.work-LaptopADLKEK.der: 55d6ef7949b5b18c5bb7895605c1c4de18943e94

DB (Database)

This certificate allows for the automatic trust of any Framework-signed EFI binaries (such as the BIOS updater.)

Current thumbprints:

• frame.work-LaptopDB.der: 732bcb5921f51141a8cd6ff213e4aad43cbb6adc
• frame.work-LaptopADLDB.der: a6519d24d7f31c548f5f42c2e736a41be7ce622f

Notes

The Framework certificates, when in EFI signature list format, have an owner GUID of 55555555-5555-5555-5555-555555555555. The .esl files in this repository bear the same owner GUID.

Verification

Note If you are on a 12th generation Intel Framework Laptop, substitute ADLDB and ADLKEK in the following commands.

You have no reason to trust me, a stranger on the internet, to provide certificates that can verify boot applications on your machine.

What you can trust, however, is the default key set on your own laptop. Use the following commands to extract the default PK (Platform Key) and validate the KEK.

Assuming efivarfs is mounted at /sys/firmware/efi/efivars

# Read PKDefault (skip the 4-byte EFI variable flags)
dd if=/sys/firmware/efi/efivars/PKDefault-8be4df61-93ca-11d2-aa0d-00e098032b8c of=pk.bin skip=4 iflag=skip_bytes

# Convert EFI signature list to certificates (package efitools on Debian, Ubuntu)
sig-list-to-certs pk.bin pk

# Convert the PK certificate pk-0.der to PEM; do the same for the included KEK
openssl x509 -inform der -outform pem -in pk-0.der -out pk-0.crt
openssl x509 -inform der -outform pem -in frame.work-LaptopKEK.der -out frame.work-LaptopKEK.crt

# Validate KEK was issued by the PK you just extracted
openssl verify -trusted ./pk-0.crt ./frame.work-LaptopKEK.crt

You should hope to see ./frame.work-LaptopKEK.crt: OK.

Once you have established suitable trust in the KEK, you can use it to validate the DB.

NOTE: This is complicated by the fact that the DB certificate was issued by the KEK, but the KEK does not permit certificate signing. OpenSSL will complain about this and fail to validate the chain.

Therefore, a small Go program is provided in verify.go to verify that one certificate was issued by another without validating that the issuing certificate is, in fact, a CA. It's only around 20 lines, and if you're going to use it to trust these certificates you may want to look at the code.

go run verify.go frame.work-LaptopDB.der frame.work-LaptopKEK.der

Once again, look for frame.work-LaptopDB.der: OK.