JWK.go

func getJWKKey(token *jwt.Token) (interface{}, error) {

	kid := fmt.Sprintf("%v", token.Header["kid"])

	set, err := jwk.FetchHTTP(jwkKeyURL)
	if err != nil {
		log.Printf("failed to parse JWK: %s", err)
		return nil, err
	}

	keys := set.LookupKeyID(kid)
	var publicKey interface{}
	keys[0].Raw(&publicKey)
	return publicKey, nil
}

func fetchClaim(token string) *EVEClaim {
	claim := &EVEClaim{}
	_, err := jwt.ParseWithClaims(token, claim, getJWKKey)
	if err != nil {
		log.Fatal(err)
	}
	return claim
}