Commit Graph

10 Commits

Author SHA1 Message Date
Alois Wohlschlager 3885f114a8
Do not sign the kernel
Malicious boot loader specification entries could be used to make a
signed kernel load arbitrary unprotected initrds. Since we do not want
this, do not sign the kernel. This way, the only things allowed to boot
are our UKI stubs, which do verify the initrd.
2023-01-31 18:25:27 +01:00
Janne Heß 96d52b215c
Make the os-release parser more precise
Closes #77
2023-01-30 11:46:48 +01:00
nikstur ce3b2c27b5 tool: write systemd-boot loader.conf
To minimize the number of arguments passed to `lzbt`, the loader config
is assembled outside `lzbt` and passed as a single argument.

Instead of reimplementing `consoleMode` under the `lanzaboote`
namespace, `config.loader.systemd-boot.consoleMode` is reused as is.
2023-01-29 16:19:14 +01:00
nikstur 5f28ae75ea tool: atomically write to ESP
To minimize the potential for irrecoverable errors, only atomic writes
to the ESP are performed. This is implemented by first copying the file
to the destination with a `.tmp` suffix and then renaming it to the
final desintation. This is atomic because the rename operation is atomic
on POSIX platforms.

Specifically, this means that even if the system crashes during the
operation, the final desintation path will most likely be intact if it
exists at all. There are some nuances to this however. It **cannot** be
actually guaranteed that the operation was performed on the filesystem
level. However, this is the best we can do for now.

For reference:
- POSIX rename(2): https://pubs.opengroup.org/onlinepubs/9699919799/
- Rust fs::rename corresponds to rename(2) on Unix: https://doc.rust-lang.org/std/fs/fn.rename.html
- Rust fs::rename is implemented using libc's rename: https://github.com/rust-lang/rust/blob/master/library/std/src/sys/unix/fs.rs#L1397
- Renaming in libc is atomic: https://www.gnu.org/software/libc/manual/html_node/Renaming-Files.html
2023-01-29 15:31:38 +01:00
nikstur 247afb33a2 tool: make systemd version parsing robust
To make handling systemd versions more robust, they are parsed into a
u32 tuple instead of an f32. Additionally, some unit tests for correct
parsing and comparing of versions are added.
2023-01-26 21:30:44 +01:00
nikstur cc169689f3 tool: smarter systemd-boot install
The process of installing systemd-boot is "smarter" because it now
considers a a few conditions instead of doing nothing if there is a file
at the deistination path. systemd-boot is now forcibly installed (i.e.
overwriting any file at the destination) if (1) there is no file at the
destination, OR (2) a newer version of systemd-boot is available, OR (3)
the signature of the file at the destination could not be verified.
2023-01-25 22:21:14 +01:00
nikstur db75203e31 tool: split esp paths
To access paths on the ESP before or after installing generations, split
EspPaths into general EspPaths that only depend on the path to the ESP
and EspGenerationPaths which additionally depend on generation specific
information (e.g. version number and initrd filename).
2023-01-25 00:24:40 +01:00
nikstur 6e452b50df tool: add SecureTempDirExt
Add an extension to TempDir that allows to create secure tempfiles. This
way, everything related to creating secure tempfiles is bundled in a
single place and can easily be reused.
2023-01-21 16:26:17 +01:00
Julian Stecklina dd499f6642 treewide: fix typos 2023-01-21 10:27:34 +01:00
nikstur 2fce3c0802 treewde: simplify subproject directory names
This commit only moves the directories instead of chaning any names
inside files.
2023-01-17 21:31:14 +01:00