The linker embeds a timestamp into our UEFI stub. objdump -p
reports:
Time/Date Mon Nov 13 20:02:35 2023
With /Brepro we get the following instead:
Time/Date d597e888 (This is a reproducible build file hash, not a timestamp)
Fixes#260
We are getting this warning:
warning: some crates are on edition 2021 which defaults to `resolver = "2"`, but virtual workspaces default to `resolver = "1"`
note: to keep the current resolver, specify `workspace.resolver = "1"` in the workspace root's manifest
note: to use the edition 2021 resolver, specify `workspace.resolver = "2"` in the workspace root's manifest
Silence by opting into the new behavior.
`Option<&T>` has the same ABI layout as `*const T`, so we have some room for
improvement where we get more Rust convenience. Further, a bug is fixed where
INVALID_PARAMETER wasn't returned when the BUFFER_SIZE pointer is NULL.
See UEFI 2.10 13.2.2. EFI_LOAD_FILE2_PROTOCOL.LoadFile() for reference.
When booting without Secure Boot active, it is not necessary to defend
against a malicious command line being passed from the loader. So just
use it in this case, to facilitaty some debugging and recovery use
cases.
Fixes: https://github.com/nix-community/lanzaboote/issues/226
When Secure Boot is not available (unsupported or disabled), Lanzaboote
will attempt to boot kernels and initrds even when they fail the hash
verification. Previously, this would happen by falling back to use
LoadImage on the kernel, which fails if Secure Boot is available, as the
kernel is not signed.
The SecureBoot variable offers a more explicit way of checking whether
Secure Boot is available. If the firmware supports Secure Boot, it
initializes this variable to 1 if it is enabled, and to 0 if it is
disabled. Applications are not supposed to modify this variable, and in
particular, since only trusted applications are loaded when Secure Boot
is active, we can assume it is never changed to 0 or deleted if Secure
Boot is active.
Hence, we can be sure of Secure Boot being inactive if this variable is
absent or set to 0, and thus treat all hash verification errors as
non-fatal and proceed to boot arbitrary kernels and initrds (a warning
is still logged in this case). In all other cases, we treat all hash
verification failures as fatal security violations, as it must be done
in the case where Secure Boot is active (it is expected that this does
not lead to any false positives in practice, unless there are bigger
problems anyway).
goblin 0.7.1 introduces certification support for PE files. This seems to be broken, because we get:
Parsing PE failed Malformed entity: Unable to extract certificate. Probably cert_size:1599360838 is malformed!
from goblin when trying to parse our PE file in memory.
See #237 for context.
Atomic write works by first writing a temporary file, then syncing that
temporary file to ensure it is fully on disk before the program can
continue, and in the last step renaming the temporary file to the
target. The middle step was missing, which is likely to lead to a
truncated target file being present after power loss. Add this step.
Furthermore, even with this fix, atomicity is not fully guaranteed,
because FAT32 can become corrupted after power loss due to its design
shortcomings. Even though we cannot really do anything about this case,
adjust the comment to at least acknowledge the situation.
nikstur