Autenticação Service Provider

package main

import (
	"encoding/json"
	"flag"
	"log"
	"net/http"
	"os"
	"strings"

	"github.com/golang-jwt/jwt"
)

var (
	keyFile       = flag.String("private_key_file", "auth.key", "OAuth private key file")
	publicKeyFile = flag.String("public_key_file", "auth.pem", "OAuth public key file")
)

func verifyToken(token string) (bool, error) {
	bytes, err := os.ReadFile(*publicKeyFile)
	if err != nil {
		log.Panic(err)
	}

	publicKey, err := jwt.ParseRSAPublicKeyFromPEM(bytes)
	if err != nil {
		log.Panic(err)
	}

	parts := strings.Split(token, ".")
	err = jwt.SigningMethodRS256.Verify(strings.Join(parts[0:2], "."), parts[2], publicKey)
	if err != nil {
		return false, nil
	}
	return true, nil

}

func main() {

	http.HandleFunc("/validate", func(w http.ResponseWriter, r *http.Request) {
		tokenString := r.URL.Query().Get("token")
		valid, err := verifyToken(tokenString)
		if err != nil {
			log.Panic(err)
		}

		log.Println(valid)
	})

	http.HandleFunc("/token", func(w http.ResponseWriter, r *http.Request) {
		
		token := jwt.NewWithClaims(jwt.SigningMethodRS256, jwt.MapClaims{
			"aud":   "aud",
			"scope": "scope",
			"iss":   "iss",
			"exp":   "exp",
			"sub":   "sub",
		})

		// Read private key
		bytes, err := os.ReadFile(*keyFile)
		if err != nil {
			log.Panic(err)
		}
		privateKey, err := jwt.ParseRSAPrivateKeyFromPEM(bytes)
		if err != nil {
			log.Panic(err)
		}

		// Sign and get the complete encoded token as a string using the secret
		tokenString, err := token.SignedString(privateKey)
		if err != nil {
			log.Panic(err)
		}

		resp := make(map[string]string)
		resp["access_token"] = tokenString
		jsonResp, err := json.Marshal(resp)
		if err != nil {
			log.Fatalf("Error happened in JSON marshal. Err: %s", err)
		}
		w.WriteHeader(http.StatusOK)
		w.Header().Set("Content-Type", "application/json")
		w.Write(jsonResp)
		return

	})

	log.Fatal(http.ListenAndServe(":9096", nil))
}

-----BEGIN PUBLIC KEY-----
MIGeMA0GCSqGSIb3DQEBAQUAA4GMADCBiAKBgHkNtpy3GB0YTCl2VCCd22i0rJwI
GBSazD4QRKvH6rch0IP4igb+02r7t0X//tuj0VbwtJz3cEICP8OGSqrdTSCGj5Y0
3Oa2gPkx/0c0V8D0eSXS/CUC0qrYHnAGLqko7eW87HW0rh7nnl2bB4Lu+R8fOmQt
5frCJ5eTkzwK5YczAgMBAAE=
-----END PUBLIC KEY-----

response = requests.get(
            f"{AUTH_URL}/token",
            params={
                "grant_type": "client_credentials",
                "intended_audience": "localhost",
                "scope": "utm.constraint_management",
                "apikey": "brutm",
            },
        )