decoding EC point format

[cagney]

In an EC Subject Public Key Info PEM:

-----BEGIN PUBLIC KEY-----
MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEU7FK0bi1qUymF77fmVfsUWQzwsWVacE9huKsKRIj7tku/QG7peRfmrvMOLbezIqpnRADROwTXQEgCx2rUjee/Q==
-----END PUBLIC KEY-----

which is for a 256 bit EC, the 520 bit string:

04 53 B1 4A D1 B8
B5 A9 4C A6 17 BE DF 99  57 EC 51 64 33 C2 C5 95
69 C1 3D 86 E2 AC 29 12  23 EE D9 2E FD 01 BB A5
E4 5F 9A BB CC 38 B6 DE  CC 8A A9 9D 10 03 44 EC
13 5D 01 20 0B 1D AB 52  37 9E FD

is made up of a one byte prefix:
04 == EC_POINT_FORM_UNCOMPRESSED
followed by two raw 256 bit EC points.

It would be nice if that, while not ASN.1, was decoded.

(really helpful tool)

[lapo-luchini]

I agree it would be nice… but it potentially open up a can of worms I'm not sure I have time to maintain (as in: if this very specific decoding is added, how many other should/could be added?).
I'll think about it. 🤔
(thanks!)

[lapo-luchini]

This is similar to not being able to detect types of a PKCS#1 embedded in a PKCS#8 as in #76 but potentially more complex because the content is not even ASN.1.
But in that case at least the PKCS#8 contains an OID that uniquely identifies the content type (and a plugin system could for example theoretically support that) while for this raw value, which is not even ASN.1 itself… I'm not sure there's any sensible way to do it in a generic way, seems kinda out of scope.