ci: verify the InRelease signature before trusting its freshness#27
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The health check read the Date field straight from the downloaded InRelease body, so an attacker or a poisoned cache could serve an unsigned response with a fresh Date and the staleness alert would pass. I now import the committed archive public key and gpg --decrypt the InRelease before reading anything from it, so the Date comes from the cryptographically verified body — the same trust anchor apt clients use. A missing or untrusted signature now fails the check loudly. Signed-off-by: Jaro-c <75870284+Jaro-c@users.noreply.github.com>
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What
The scheduled health check now verifies the
InReleaseGPG signature against the committed archive public key (keyring/glyndor-apt-key.asc) before reading theDatefield, and reads that field from the cryptographically verified body rather than the raw download.Why
The check read
Date:straight from the downloadedInRelease. An attacker able to serve a response, or a poisoned cache, could present an unsigned body with a freshDateand the staleness alert would pass — the freshness signal was spoofable. This does not weaken what apt clients trust (they verify the index themselves), but the monitor that guards against a silent stale archive must gate on the same anchor. A missing or untrusted signature now fails the check loudly.Notes
checkoutstep so the workflow can reach the committed public key.GNUPGHOME, cleaned up on exit.