I am working on yet another ARC library and am wondering what to do about SHA1 signatures and 512 bit keys. The DCRUP working group has sent a DKIM update to the RFC editor which finally kills SHA1 hashes and RSA keys shorter than 1024 bits. It's in the queue and will be published when they get around to it, probably next month.
On the assumption that ARC signatures track DKIM, what should I do? At the moment I have a "strict" option in the verifier which when set rejects SHA1 hashes and short keys. I suppose it should be on by default, but a couple of the tests in the YANG test suite have SHA1 signatures. There's also a test that 512 bit signatures are rejected, so depending on the setting currently I can either fail the SHA1 signatures or I can fail the short key signature. Suggestions? Signed, Uncertain PS: Coming soon to DKIM, ed25519 signatures, but since the underlying library code isn't in OpenSSL yet, I'm not yet worrying about it. _______________________________________________ dmarc mailing list dmarc@ietf.org https://www.ietf.org/mailman/listinfo/dmarc
