By the way, I agree with you. My original point was that the "hivemind" somehow has shifted away from the reasonable conclusion.
I haven't so much seen the latter kind of guy, the one saying you need a certified professional to safely output-filter HTML or whatever, but I see "lol block cipher modes whatever" people on HN all the time, on almost every thread about cryptography, dunking on anyone who says "don't roll your own cryptography".
I sort of assume that the latter is a random sampling of software engineers but the former is sampled specifically for idiots who YOLO their crypto.
If you're using minisign or Sigstore or whatever to do something like verify upstream dependencies, sure. But if you're building a system that is about some novel problem domain involving signatures: you should get an expert to verify your system. The trail of dead bodies here is long and bloody.
I think you have a pre-defined notion when I say the word "signature" about what I meant (perhaps something about software signing or SSL certificates). I literally meant "checking that HMAC-SHA-2 of some bytes is what you expect" (using a library for the hash). Incidentally, that's how you authenticate a JWT.
It's not only about the raw operation of checking bytes are equal (hopefully in a constant time manner, if applicable), but also about ensuring the desired security properties are actually present in the application!
- memcmp(actual_sig, expected_sig) == 0
- strcmp(actual_sig_base64, expected_sig_base64) == 0
- strcasecmp(actual_sig_base64, expected_sig_base64) == 0No, not "sure". minisign and Sigstore are completely different things, and one needs to understand how those work and what the corresponding signatures mean: A minisign signature says "the owner of that key signed this". Whoever the owner might be at the moment of signature. Whenever that might have happened.
A sigstore signature says "Google/Github/... says that this OpenID account generated that one key that the sigstore CA attests and that signed that blob at that time". Time/ordering verification is better than in minisign, because it is there, even if through a trusted party. But identity verification relies on a trusted third and fourth party, some of whom do have a history of botching their OpenID auth.
Those are not equivalent, and knowledge is needed to not mix them up. You don't need to be an expert, but you should try to understand as much as you can, identify what you don't understand and where you must trust an expert, implementation, company, recommendation or standard to be correct and trustworthy. And then decide if that is ok with you.