On June 16, 2019 5:57:34 PM GMT+02:00, Eli Schwartz via arch-general email@example.com wrote:
That being said, if you have signed the repository db then as you mentioned the sha256 checksums for the package file are securely signed, so you are guaranteed that use of pacman -S pkgname will securely verify that it is installing the package the repo-add user expected to provide when running repo-add.
What is your threat model? These things will not be protected against:
- people installing the package file directly, as such:
- An attacker with local filesystem access on the signing/hosting
server can retroactively replace *all* packages built at any date, and trick you into signing a new repo DB referencing them.
- In shared packaging situations, like when a team of dozens of people
all upload packages, you want to be able to verify who signed each package, as opposed to only verifying that the last person to update the repository asserted that all other packages are good and backed by his/her good name -- this does not concern you.
An important side note: This will only really help if users of the repo have set the repository SigLevel to Required (which is not the default). When using the default of Optional a MitM attacker can just drop signatures for that database, which obviously is much much much easier to achieve for non https mirrors.