Prevent silent attestation downgrade on gem push - #9825
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On GitHub Actions the push tests inherited the real variable, took the auto-attestation path, and spawned `gem exec sigstore-cli` subprocesses. Scrubbing it in setup also made the host and engine skip guards decide nothing, so those tests now set it themselves. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
GitHub Actions documents the variable as "true", so any other value, including "false", should not trigger the auto-attestation path. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
The whole attested push was wrapped in rescue StandardError. A failure to read a file given to --attestation printed a warning and published the gem unattested with exit 0, and a network error after the server may have accepted the multipart push retried it unattested, letting an on-path attacker strip attestations by cutting the first connection. Only the opportunistic auto-signing step falls back now. attest! also returned just the tempfile path, so GC could unlink the bundle before it was read, which fell into that same rescue. Each bundle is now validated as a JSON object before it is sent. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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gem pushwrapped the whole attested push inrescue StandardError. A failure to read a file given to--attestationprinted a warning and published the gem unattested with exit 0, contradicting the comment right above that branch. The same rescue covered the HTTP POST, so a read timeout after the server had already accepted the multipart push retried it unattested, which also lets an on-path attacker strip attestations by cutting the first connection.Only the opportunistic auto-signing step falls back now. Errors from an explicit
--attestationabort the push, and the request stays outside the rescue.Three smaller problems from the same review are fixed here too.
attest!returned only the tempfile path, so GC could unlink the bundle before it was read.ENV["GITHUB_ACTIONS"]was tested for truthiness instead of against"true". Attestation bundles were concatenated into a JSON array unvalidated. The test helper also scrubsGITHUB_ACTIONS, which was making CI spawn realgem exec sigstore-clisubprocesses.#9325