Support x5c chains terminating with an EC key

[Zicchio]

Current strategy for "self contained" key extraction from jwt header does not support x5c chain that represent an EC key. Only RSA is supproted.

eudi-wallet-it-python/pyeudiw/jwk/parse.py

Lines 21 to 29 in 486aa59

	def parse_key_from_x5c(x5c: list[str]) -> JWK:
	"""Parse a key from an x509 chain. This function currently
	support only the parsing of public RSA key from such a chain.
	The first element of the chain will contain the verifying key.
	See RFC7517 https://datatracker.ietf.org/doc/html/rfc7517#section-4.7
	"""
	public_key = import_rsa_key(x5c[0])
	key_dict = RSAKey(pub_key=public_key).to_dict()
	return JWK(key_dict)

This would be the fixing code (that should be tested)

def parse_key_from_x5c(x5c: list[str]) -> JWK:
    """Parse a key from an x509 chain. This function currently
    support only the parsing of public RSA and EC key from such a chain.
    The first element of the chain will contain the verifying key.
    See RFC7517 https://datatracker.ietf.org/doc/html/rfc7517#section-4.7
    """
    try:
        # maybe RSA?
        public_key = import_rsa_key(x5c[0])
        key_dict = RSAKey(pub_key=public_key).to_dict()
        return JWK(key_dict)
    except Exception:
        # maybe EC?
        public_key = import_ec_key(x5c[0])
        key_dict = ECKey(pub_key=public_key).to_dict()
        return JWK(key_dict)
    except Exception:
        # neither RSA nor EC
        raise InvalidJwk(f"unable to parse key from x5c: {x5c}")