** Description changed: - APT 2.9.x and 2.8.0 revoke any of the non-asserted algorithms, we should - modify the mechanism such that only RSA1024 is raised to an error to - avoid unwanted regressions while still keeping the set of fully - supported algorithms small. + [Impact] + We have received feedback from users that use NIST-P256 keys for their repositories that are upset about receiving a warning. APT 2.8.0 in noble-proposed would bump the warning to an error, breaking them. + + [Solution] + Hence we will restore all elliptic curve keys of 256 or more bit to trusted: + + APT::Key::Assert-Pubkey-Algo + ">=rsa2048,ed25519,ed448,nistp256,nistp384,nistp512,brainpoolP256r1,brainpoolP320r1,brainpoolP384r1,brainpoolP512r1,secp256k1"; + + + At the same time we will also introduce a more nuanced approach to revocations by introducing a 'next' level that issues a warning if the key is not allowed in it and a 'future' level that will issue an audit message with the --audit option. + + For the next level, we will set it to: + + ">=rsa2048,ed25519,ed448,nistp256,nistp384,nistp512" + + This means we restrict warnings to Brainpool curves and the secp256k1 + key, which we have not received any feedback about them being used yet. + + For the future level, we will take a strong approach to best practices + as it is only seen when explictly running with --audit and the intention + is to highlight best practices. It will be set to + + ">=rsa3072,ed25519,ed448"; + + Which corresponds to the NIST recommendations for 2031 (and as little + curves as possible) + + [Test plan] + Tests are included in the library unit tests for parsing the specification strings; we have also included a test for the gpgv method to ensure that it produces the correct outcome for both 'next' and 'future' revoked keys. + + A spot check with a 1024-bit RSA repository and a 4096 RSA repository + would still be nice. + + + [Where problems could occur] + There could of course be bugs in the implementation of the new feature; this could result in verification of files failing. This also happens if you specify an invalid `next` or `future` string. + + There cannot be any false positives: The new levels are only + *additional* checks, anything not in the `Assert-Pubkey-Algo` list is + still revoked.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2073126 Title: More nuanced public key algorithm revocation To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/apt/+bug/2073126/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
