alt Hacker NewsIt's not made easier by the fact that a lot of cryptography is either very old and arcane or it's one hell of a mess of code that doesn't make sense without reading standards.
I had the misfortune of having to dig deep into constructing ASN.1 payloads by hand [1] because that's the only thing Java speaks, and oh holy hell is this A MESS because OF COURSE there's two ways to encode a bunch of bytes (BIT STRING vs OCTET STRING) and encoding ed25519 keys uses BOTH [2].
And ed25519 is a mess in itself. The more-or-less standard implementation by orlp [3] is almost completely lacking any comments explaining what is going on where and reading the relevant RFCs alone doesn't help, it's probably only understandable by reading a 500 pages math paper.
It's almost as if cryptographers have zero interest in interested random people to join the field.
End of rant.
[1] https://github.com/msmuenchen/meshcore-packets-java/blob/mai...
[2] https://datatracker.ietf.org/doc/html/rfc8410#appendix-A
Replies
The typical vector for entering cryptography as a professional is called "grad school".
X.509 is a deep legacy, but at least at this point it's well tested.
> because that's the only thing Java speaks
No, it most definitely is not. You can just construct a private key directly in BouncyCastle: https://downloads.bouncycastle.org/java/docs/bcprov-jdk18on-...
I'm 100% certain that you also can do that with raw java.security. I did that about 15 years ago with raw RSA/EC keys. You can just directly specify the private exponent for RSA (as a bigint!) or the curve point for EC.
Ditto for ed25519, you can just take the canonical implementation from DJB. And you really really shouldn't do that anyway, please just use OpenSSL or another similar major crypto library.
The trick to asn.1 is to generate both parser and serializer from the spec. Elliptic curve math on the other hand is ... yeah, you need to know the math and also know the tricks to code that implements it. Both of those have steep learning curve, but it's hardly because it's a mess or it's old.