Software updates and TUF
The Release Role
The release role is used to sign the metadata within the update system to ensure clients see a consistent state. This basically links up the signatures, the root keys, and the signed files into a cohesive package. Otherwise, an attacker could modify the metadata to cause you to download an older version, for example.
The Timestamp Role
The final role is the timestamp role, which is used to provide information on the availability of updates. Basically, you modify the timestamp file when a new update is ready and sign it to let clients know a new update is available. However, when an update is not available, how do clients know they aren't simply being fed an old version of the file? By re-signing the file frequently, the client will know that even though the file has not changed, it is still valid.
Typically, you want to re-sign the timestamp file daily – ideally, every few hours – so this activity should be automated. Again, if possible, this should be done on a server that is separate from the server on which files are then uploaded to become publicly available.
Why Metadata Matters
You might wonder why you should you be concerned about signing multiple files and metadata within the update system. Why not just create a new version of the software then sign and upload it? By supporting the signing of multiple separate files and using metadata to define updates, you can avoid situations in which your version of an application and a library cause a security vulnerability or simply don't work together. You can also prevent clients from updating a library, which then breaks the system. Additionally, this approach allows you to update separate components individually. Thus, for a large application that includes optional plugins, you can separate everything.
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.
![Learn More](https://www.linux-magazine.com/var/linux_magazin/storage/images/media/linux-magazine-eng-us/images/misc/learn-more/834592-1-eng-US/Learn-More_medium.png)
News
-
NVIDIA Released Driver for Upcoming NVIDIA 560 GPU for Linux
Not only has NVIDIA released the driver for its upcoming CPU series, it's the first release that defaults to using open-source GPU kernel modules.
-
OpenMandriva Lx 24.07 Released
If you’re into rolling release Linux distributions, OpenMandriva ROME has a new snapshot with a new kernel.
-
Kernel 6.10 Available for General Usage
Linus Torvalds has released the 6.10 kernel and it includes significant performance increases for Intel Core hybrid systems and more.
-
TUXEDO Computers Releases InfinityBook Pro 14 Gen9 Laptop
Sporting either AMD or Intel CPUs, the TUXEDO InfinityBook Pro 14 is an extremely compact, lightweight, sturdy powerhouse.
-
Google Extends Support for Linux Kernels Used for Android
Because the LTS Linux kernel releases are so important to Android, Google has decided to extend the support period beyond that offered by the kernel development team.
-
Linux Mint 22 Stable Delayed
If you're anxious about getting your hands on the stable release of Linux Mint 22, it looks as if you're going to have to wait a bit longer.
-
Nitrux 3.5.1 Available for Install
The latest version of the immutable, systemd-free distribution includes an updated kernel and NVIDIA driver.
-
Debian 12.6 Released with Plenty of Bug Fixes and Updates
The sixth update to Debian "Bookworm" is all about security mitigations and making adjustments for some "serious problems."
-
Canonical Offers 12-Year LTS for Open Source Docker Images
Canonical is expanding its LTS offering to reach beyond the DEB packages with a new distro-less Docker image.
-
Plasma Desktop 6.1 Released with Several Enhancements
If you're a fan of Plasma Desktop, you should be excited about this new point release.