This commit replaces the 2nd stage loader path with the first
argument in the Load Options and moves the rest arguments (if any)
to the Load Options for the 2nd stage loader.
For example, to make shim to load elilo.efi, just create a new
boot entry with efibootmgr:
# efibootmgr -c -L "shim elilo" -l "efi\\shim.efi" -u "elilo.efi"
shim needs to verify that MokManager hasn't been modified, but we want to
be able to support configurations where shim is shipped without a vendor
certificate. This patch adds support for generating a certificate at build
time, incorporating the public half into shim and signing MokManager with
the private half. It uses pesign and nss, but still requires openssl for
key generation. Anyone using sbsign will need to figure this out for
themselves.
Cert needs to be modified inside the Index loop, not outside it. This is unlikely to
ever trigger since there will typically only be one X509 certificate per
EFI_SIGNATURE_LIST, but fix it anyway.
read_header would fail if the binary was unsigned, even if we weren't then
going to verify the signature. Move that check to the verify function
instead.
In some rare corner cases, it's useful to add a blacklist of things that
were allowed by a copy of shim that was never signed by the UEFI signing
service. In these cases it's okay for them to go into a local dbx,
rather than taking up precious flash.
Signed-off-by: Peter Jones <pjones@redhat.com>
Add support for setting an MOK password. The OS passes down a password hash.
MokManager then presents an option for setting a password. Selecting it
prompts the user for the same password again. If they match, the hash is
enrolled into a boot services variable and MokManager will prompt for the
password whenever it's started.
Provide a mechanism for a physically present end user to disable signature
verification. This is handled by the OS passing down a variable that
contains a UINT32 and a SHA256 hash. If this variable is present, MokManager
prompts the user to choose whether to enable or disable signature validation
(depending on the value of the UINT32). They are then asked to type the
passphrase that matches the hash. This then saves a boot services variable
which is checked by shim, and if set will skip verification of signatures.
Some systems will show an error dialog if LoadImage() returned
EFI_ACCESS_DENIED, which then requires physical user interaction to skip.
Let's just remove the LoadImage/StartImage code, since the built-in code
is theoretically equivalent.
Using the same format as the UEFI key databases makes it easier for the
kernel to parse and extract keys from MOK, and also permits MOK to contain
multiple key or hash types. Additionally, add support for enrolling hashes.
If we can't verify grub, fall back to MokManager. This permits shipping a
copy of shim and MokManager without distributing a key, letting
distributions provide their own for user installation.
The break in check_db_cert is at the wrong level due to a typo in
indentation, and as a result only the last cert in the list can
correctly match. Rectify that.
Signed-off-by: Peter Jones <pjones@redhat.com>
