JwtDecoder constructor using Public Key

[antmordel]

Summary

As in the class NimbusReactiveJwtDecoder, it'd be nice to have a constructor in NimbusJwtDecoderJwkSupport to create the JwtDecoder using only the PublicKey to used to verify the signature.

Version

Spring Security 5.1

Sample

public NimbusJwtDecoderJwkSupport(RSAPublicKey publicKey) throws InvalidKeySpecException, NoSuchAlgorithmException {
        RSAKey rsaKey = new RSAKey.Builder(publicKey).build();
        JWKSet jwkSet = new JWKSet(rsaKey);
        JWKSource jwkSource = new ImmutableJWKSet<>(jwkSet);
        JWSKeySelector<SecurityContext> jwsKeySelector =
                new JWSVerificationKeySelector<>(JWSAlgorithm.parse(JwsAlgorithms.RS256), jwkSource);
        DefaultJWTProcessor jwtProcessor = new DefaultJWTProcessor<>();
        jwtProcessor.setJWSKeySelector(jwsKeySelector);
        this.jwtProcessor = new DefaultJWTProcessor<>();
        this.jwtProcessor.setJWSKeySelector(jwsKeySelector);

        // Spring Security validates the claim set independent from Nimbus
        this.jwtProcessor.setJWTClaimsSetVerifier((claims, context) -> {});
    }

[jzheaux]

@antmordel thanks for the suggestion!

I'm going to link this to the original task that we already have for this: #5131

That way, you can follow progress there.