utils/google_auth_util.go

package utils

import (
	"encoding/json"
	"fmt"
	"io"
	"net/http"
)

type GoogleTokenInfo struct {
	Email         string `json:"email"`
	EmailVerified string `json:"email_verified"`
	Name          string `json:"name"`
	Picture       string `json:"picture"`
	Sub           string `json:"sub"`
}

func VerifyGoogleToken(idToken string) (*GoogleTokenInfo, error) {
	resp, err := http.Get(fmt.Sprintf("https://oauth2.googleapis.com/tokeninfo?id_token=%s", idToken))
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("invalid token")
	}

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, err
	}

	var tokenInfo GoogleTokenInfo
	if err := json.Unmarshal(body, &tokenInfo); err != nil {
		return nil, err
	}

	return &tokenInfo, nil
}