token.go

package main

import (
	"encoding/json"
	"fmt"
	"io/ioutil"
	"net/http"
	"net/url"
	"strings"
	"time"

	jose "github.com/dvsekhvalnov/jose2go"
	"github.com/dvsekhvalnov/jose2go/keys/rsa"
	uuid "github.com/satori/go.uuid"
	"github.com/spacemonkeygo/openssl"
)

const aud = "https://api.box.com/oauth2/token"

func check(e error) {
	if e != nil {
		panic(e)
	}

}
func main() {
	dat, err := ioutil.ReadFile("./config.json")
	check(err)
	var f interface{}
	errJson := json.Unmarshal(dat, &f)
	check(errJson)
	m := f.(map[string]interface{})

	bap := m["boxAppSettings"].(map[string]interface{})
	bapap := bap["appAuth"].(map[string]interface{})

	privateKey := []byte(bapap["privateKey"].(string))
	passphrase := bapap["passphrase"].(string)

	prive, err := openssl.LoadPrivateKeyFromPEMWithPassword(privateKey, passphrase)
	check(err)

	newKey, err := prive.MarshalPKCS1PrivateKeyPEM()
	check(err)

	newPrivateKey, e := Rsa.ReadPrivate(newKey)
	check(e)

	kid := bapap["publicKeyID"]
	clientId := bap["clientID"]
	clientSecret := bap["clientSecret"]
	enterpriseId := m["enterpriseID"]
	jti := uuid.Must(uuid.NewV4()).String()

	expires := time.Now().Add(time.Duration(50) * time.Second).Unix()
	payload := fmt.Sprintf(`{"iss": "%s","sub": "%s","box_sub_type": "enterprise","aud": "%s","jti": "%s","exp": %d}`, clientId, enterpriseId, aud, jti, expires)
	fmt.Println(payload)
	token, err := jose.Sign(payload, jose.RS256, newPrivateKey, jose.Headers(map[string]interface{}{"alg": "RS256", "kid": kid, "typ": "JWT"}))
	check(err)
	fmt.Println(token)

	data := url.Values{}
	data.Add("grant_type", "urn:ietf:params:oauth:grant-type:jwt-bearer")
	data.Add("client_id", clientId.(string))
	data.Add("client_secret", clientSecret.(string))
	data.Add("assertion", token)
	body := data.Encode()
	resp, err := http.Post(aud, "application/x-www-form-urlencoded", strings.NewReader(body))
	check(err)
	defer resp.Body.Close()
	fmt.Println(resp.Status)
	bodyBytes, err := ioutil.ReadAll(resp.Body)
	check(err)

	bodyString := string(bodyBytes)
	fmt.Println(bodyString)
}