Keygrip calculation

[gaellalire]

Hello,

It would be nice for JGit if BC support keygrip.
Maybe a public abstract String BCPGKey.getKeygrip().

For RSAPublicBCPGKey I put the code of keygrip here https://bugs.eclipse.org/bugs/show_bug.cgi?id=548763#c5

There is some links to specification at
https://bugs.eclipse.org/bugs/show_bug.cgi?id=547536

http://gnupg.10057.n7.nabble.com/GnuPG-2-1-x-and-2-2-x-keyring-formats-td54146.html
https://github.com/riboseinc/rnp/blob/e6c7fef/src/librekey/rnp_key_store.cpp#L952

[tomaswolf]

I'm currently implementing this in JGit directly.

Looks like BC lacks a few OIDs and uses different curve parameters for curve25519 than libgcrypt.

[dghgit]

For what it's worth, there's now a basic KeyGripCalculator for RSA keys in the org.bouncycastle.gpg package. Up on https://www.bouncycastle.org/betas