How to extract and verify token sent from frontend

Question

I am using "github.com/dgrijalva/jwt-go", and able to send a token to my frontend, and what I would like to know how I could retrieve the token sent from the frontend so that I can verify if the token that was sent is valid and if so the secured resource will be delivered.

Here is the token sent from frontend JavaScript:

headers: {
       'Authorization':'Bearer' + localStorage.getItem('id_token')
     }

Here is the code to send token

    token := jwt.New(jwt.GetSigningMethod("HS256"))
    claims := make(jwt.MapClaims)
    claims["userName"] = loginRequest.UserName
    claims["exp"] = time.Now().Add(time.Minute * 60).Unix()
    token.Claims = claims
    tokenString, err := token.SignedString([]byte(SecretKey))
    tokenByte, err := json.Marshal(data)
    w.WriteHeader(201)
    w.Write(tokenByte)

Here is the code to verify the token

    func VerifyToken(r *http.Request) bool {

    reqToken := r.Header.Get("Authorization")
    token, err := jwt.Parse(reqToken, func(t *jwt.Token) (interface{}, error) {
        return []byte(SecretKey), nil
    })
    if err == nil && token.Valid {
        fmt.Println("valid token")
        return true
    } else {
        fmt.Println("invalid token")
        return false
    }

}

Am getting nil token as a return, my guess is I have sent bearer and I think it might need parsing if so how?

Answer 1

The server requires a token string without added strings in my case I have added Bearer string to the token string in the header when sending request to the web server i.e.

'Authorization':'Bearer ' + localStorage.getItem('id_token')

At the web server we need to split only the valid token without the Bearer string

reqToken := r.Header.Get("Authorization")
splitToken := strings.Split(reqToken, "Bearer ")
reqToken = splitToken[1]

As a result it becomes valid token without nil.