CreateRSAKeyPair creates a new RSA key pair and returns the private key and public key in PEM format.

Issue issues a JWT token with the given claims, private key and ttl.

NewClaims creates a new Claims.

ParseWithPrivateKey parses a JWT token with the given claims and private key.

ParseWithPublicKey parses a JWT token with the given claims and public key.

Claims is designed for microservice ecosystem.