Big exponents are exponents, too

In kbpgp, there is an RSA public key validity check complaining of exponents bigger than 2^16 + 1:

https://github.com/keybase/kbpgp/blob/04ca97eb1b29885c1358cea99135019851379c0c/src/rsa.iced#L198

But those are perfectly legal exponents! (I have one, for instance, in my key 0x9080C092EA80E0B4.) I got mine by using a vanity key generation tool.

I submitted a pull request on kbpgp to remove that check.

Review the RSA public-key validity check at src/rsa.iced#L198 in the referenced kbpgp repository, then compare it with the pull request mentioned in the issue. Done means valid public exponents larger than 2^16 + 1 are no longer rejected.

Written by the indexing model from the issue text.