JWK to PEM Converter

Move a key between the JSON Web Key form and PEM, both ways. RSA, EC (P-256, P-384, P-521, secp256k1) and OKP (Ed25519, Ed448) are supported; a JWK with a d becomes a PKCS#8 private key, one without becomes a PUBLIC KEY . Paste a whole JWK Set and the first key in it is used.