Implement refreshing within OIDC provider

providers/oidc.go

@@ -38,7 +38,61 @@ func (p *OIDCProvider) Redeem(redirectURL, code string) (s *SessionState, err er
 	if err != nil {
 		return nil, fmt.Errorf("token exchange: %v", err)
 	}
+	s, err = p.createSessionState(ctx, token)
+	if err != nil {
+		return nil, fmt.Errorf("unable to update session: %v", err)
+	}
+	return
+}
 
+// RefreshSessionIfNeeded checks if the session has expired and uses the
+// RefreshToken to fetch a new ID token if required
+func (p *OIDCProvider) RefreshSessionIfNeeded(s *SessionState) (bool, error) {
+	if s == nil || s.ExpiresOn.After(time.Now()) || s.RefreshToken == "" {
+		return false, nil
+	}
+
+	origExpiration := s.ExpiresOn
+
+	err := p.redeemRefreshToken(s)
+	if err != nil {
+		return false, fmt.Errorf("unable to redeem refresh token: %v", err)
+	}
+
+	fmt.Printf("refreshed id token %s (expired on %s)\n", s, origExpiration)
+	return true, nil
+}
+
+func (p *OIDCProvider) redeemRefreshToken(s *SessionState) (err error) {
+	c := oauth2.Config{
+		ClientID:     p.ClientID,
+		ClientSecret: p.ClientSecret,
+		Endpoint: oauth2.Endpoint{
+			TokenURL: p.RedeemURL.String(),
+		},
+	}
+	ctx := context.Background()
+	t := &oauth2.Token{
+		RefreshToken: s.RefreshToken,
+		Expiry:       time.Now().Add(-time.Hour),
+	}
+	token, err := c.TokenSource(ctx, t).Token()
+	if err != nil {
+		return fmt.Errorf("failed to get token: %v", err)
+	}
+	newSession, err := p.createSessionState(ctx, token)
+	if err != nil {
+		return fmt.Errorf("unable to update session: %v", err)
+	}
+	s.AccessToken = newSession.AccessToken
+	s.IDToken = newSession.IDToken
+	s.RefreshToken = newSession.RefreshToken
+	s.ExpiresOn = newSession.ExpiresOn
+	s.Email = newSession.Email
+	return
+}
+
+func (p *OIDCProvider) createSessionState(ctx context.Context, token *oauth2.Token) (*SessionState, error) {
 	rawIDToken, ok := token.Extra("id_token").(string)
 	if !ok {
 		return nil, fmt.Errorf("token response did not contain an id_token")
@@ -66,29 +120,11 @@ func (p *OIDCProvider) Redeem(redirectURL, code string) (s *SessionState, err er
 		return nil, fmt.Errorf("email in id_token (%s) isn't verified", claims.Email)
 	}
 
-	s = &SessionState{
+	return &SessionState{
 		AccessToken:  token.AccessToken,
 		IDToken:      rawIDToken,
 		RefreshToken: token.RefreshToken,
 		ExpiresOn:    token.Expiry,
 		Email:        claims.Email,
-	}
-
-	return
-}
-
-// RefreshSessionIfNeeded checks if the session has expired and uses the
-// RefreshToken to fetch a new ID token if required
-//
-// WARNGING: This implementation is broken and does not check with the upstream
-// OIDC provider before refreshing the session
-func (p *OIDCProvider) RefreshSessionIfNeeded(s *SessionState) (bool, error) {
-	if s == nil || s.ExpiresOn.After(time.Now()) || s.RefreshToken == "" {
-		return false, nil
-	}
-
-	origExpiration := s.ExpiresOn
-	s.ExpiresOn = time.Now().Add(time.Second).Truncate(time.Second)
-	fmt.Printf("refreshed access token %s (expired on %s)\n", s, origExpiration)
-	return false, nil
+	}, nil
 }