I'm having difficulty authenticating using Google OAuth2.
I've obtainedd client ID and secret from google developer console, and I came up with this code :
package main
import (
"fmt"
"golang.org/x/oauth2"
"golang.org/x/oauth2/google"
"io/ioutil"
"net/http"
"os"
)
const htmlIndex = `<html><body>
<a href="/GoogleLogin">Log in with Google</a>
</body></html>
`
func init() {
// Setup Google's example test keys
os.Setenv("CLIENT_ID", "somrestring-otherstring.apps.googleusercontent.com")
os.Setenv("SECRET_KEY", "alongcharachterjumble")
}
var (
googleOauthConfig = &oauth2.Config{
RedirectURL: "http://127.0.0.1:8080/auth", //defined in Google console
ClientID: os.Getenv("CLIENT_ID"),
ClientSecret: os.Getenv("SECRET_KEY"),
Scopes: []string{"https://www.googleapis.com/auth/userinfo.profile",
"https://www.googleapis.com/auth/userinfo.email"},
Endpoint: google.Endpoint,
}
// Some random string, random for each request
oauthStateString = "random"
)
func main() {
http.HandleFunc("/", handleMain)
http.HandleFunc("/GoogleLogin", handleGoogleLogin)
http.HandleFunc("/GoogleCallback", handleGoogleCallback)
fmt.Println(http.ListenAndServe(":8080", nil))
}
func handleMain(w http.ResponseWriter, r *http.Request) {
fmt.Fprintf(w, htmlIndex)
fmt.Println("another request made")
}
func handleGoogleLogin(w http.ResponseWriter, r *http.Request) {
url := googleOauthConfig.AuthCodeURL(oauthStateString)
http.Redirect(w, r, url, http.StatusTemporaryRedirect)
}
func handleGoogleCallback(w http.ResponseWriter, r *http.Request) {
state := r.FormValue("state")
if state != oauthStateString {
fmt.Printf("invalid oauth state, expected '%s', got '%s'
", oauthStateString, state)
http.Redirect(w, r, "/", http.StatusTemporaryRedirect)
return
}
code := r.FormValue("code")
token, err := googleOauthConfig.Exchange(oauth2.NoContext, code)
if err != nil {
fmt.Println("Code exchange failed with '%s'
", err)
http.Redirect(w, r, "/", http.StatusTemporaryRedirect)
return
}
response, err := http.Get("https://www.googleapis.com/oauth2/v2/userinfo?access_token=" + token.AccessToken)
defer response.Body.Close()
contents, err := ioutil.ReadAll(response.Body)
fmt.Fprintf(w, "Content: %s
", contents)
}
But I get this error from google:
- That’s an error.
Error: invalid_request
Missing required parameter: client_id
Learn more
Request Details client_id= redirect_uri=http://127.0.0.1:8080/auth response_type=code scope=https://www.googleapis.com/auth/userinfo.profile https://www.googleapis.com/auth/userinfo.email state=random
What's wrong here? How can I fix it?