hackathon/auth/oauth.go

63 lines
1.4 KiB
Go

package auth
import (
"context"
"errors"
"fmt"
"os"
"golang.org/x/oauth2"
"golang.org/x/oauth2/google"
)
type OAuthConfig struct {
*oauth2.Config
}
const (
base = "https://www.googleapis.com"
scopeEmail = base + "/auth/userinfo.email"
scopeProfile = base + "/auth/userinfo.profile"
)
func NewOauthConfig(path string) (OAuthConfig, error) {
key, err := os.ReadFile(path)
if err != nil {
return OAuthConfig{}, fmt.Errorf("could not open file: %w", err)
}
config, err := google.ConfigFromJSON(key, scopeEmail, scopeProfile)
if err != nil {
return OAuthConfig{}, fmt.Errorf("could not load config: %w", err)
}
return OAuthConfig{
Config: config,
}, nil
}
var ErrInvalidState = errors.New("invalid ouath state provided")
type OAuthManager interface {
Create(callback string) (code string)
Validate(code string) (callback string, valid bool)
}
func (cfg OAuthConfig) AuthCodeURL(manager OAuthManager, callback string) string {
state := manager.Create(callback)
fmt.Printf("state: %v\n", state)
return cfg.Config.AuthCodeURL(state, oauth2.AccessTypeOffline)
}
func (cfg OAuthConfig) Exchange(ctx context.Context, manager OAuthManager, state, code string) (string, *oauth2.Token, error) {
var ok bool
var callback string
if callback, ok = manager.Validate(state); !ok {
return "", nil, ErrInvalidState
}
tk, err := cfg.Config.Exchange(ctx, code, oauth2.AccessTypeOffline)
return callback, tk, err
}