docs: missing kwargs for Jwk.generate_for_kty method

[vinicius-oa]

I followed the usage.md and got a ValueError because crv and alg kwargs cannot be both None.

[guillp]

Thanks for the PR! Once again, I suck at documentation ^^

Actually, I would consider Jwk.generate_for_kty() as deprecated.
Instead of generating keys based on their key type, you should generate them based on their intended algorithm. So use Jwk.generate(alg="<alg_of_your_choice>") so that jwskate can automatically determine the key type and some extra parameters based on the intended alg_of_your_choice. The extra benefit is that you don't need to specify the alg everytime you use the key.

One of the only alg for which the curve cannot be guessed automatically is ECDH-ES+A128KW since it can be used with keys on any curve. But if you run Jwk.generate(alg="ECDH-ES+A128KW") you will get a UserWarning like this:

UserWarning: No Curve identifier (crv) specified when generating an Elliptic Curve Jwk for Key Management. Curve 'P-256' is used by default. You should explicitly pass a 'crv' parameter to select the appropriate Curve and avoid this warning.

private_jwk = Jwk.generate(alg="ECDH-ES+A128KW", crv="P-256")
public_jwk = private_jwk.public_jwk()

jwe = JweCompact.encrypt(plaintext, public_jwk, enc="A128GCM")

Feel free to edit your PR, or I can update the doc myself otherwise :)
If you spot other things to improve in the docs, feel free to open other PRs or issues.

[vinicius-oa]

Thanks for the PR! Once again, I suck at documentation ^^

Actually, I would consider Jwk.generate_for_kty() as deprecated. Instead of generating keys based on their key type, you should generate them based on their intended algorithm. So use Jwk.generate(alg="<alg_of_your_choice>") so that jwskate can automatically determine the key type and some extra parameters based on the intended alg_of_your_choice. The extra benefit is that you don't need to specify the alg everytime you use the key.

One of the only alg for which the curve cannot be guessed automatically is ECDH-ES+A128KW since it can be used with keys on any curve. But if you run Jwk.generate(alg="ECDH-ES+A128KW") you will get a UserWarning like this:

UserWarning: No Curve identifier (crv) specified when generating an Elliptic Curve Jwk for Key Management. Curve 'P-256' is used by default. You should explicitly pass a 'crv' parameter to select the appropriate Curve and avoid this warning.

private_jwk = Jwk.generate(alg="ECDH-ES+A128KW", crv="P-256")
public_jwk = private_jwk.public_jwk()

jwe = JweCompact.encrypt(plaintext, public_jwk, enc="A128GCM")

Feel free to edit your PR, or I can update the doc myself otherwise :) If you spot other things to improve in the docs, feel free to open other PRs or issues.

usage.md updated along others examples using the deprecated generate_for_kty. I've also put a DeprecationWarning linking to your comment in this PR.

[guillp]

Excellent, thank you!