func()

in oauthproxy.go [610:707]
87 lines of code
33 McCabe index (conditional complexity)

func (p *OAuthProxy) Authenticate(rw http.ResponseWriter, req *http.Request) int {
	var saveSession, clearSession, revalidated bool
	remoteAddr := getRemoteAddr(req)

	session, sessionAge, err := p.LoadCookiedSession(req)
	if err != nil {
		log.Printf("%s %s", remoteAddr, err)
	}
	if session != nil && sessionAge > p.CookieRefresh && p.CookieRefresh != time.Duration(0) {
		log.Printf("%s refreshing %s old session cookie for %s (refresh after %s)", remoteAddr, sessionAge, session, p.CookieRefresh)
		saveSession = true
	}

	if ok, err := p.provider.RefreshSessionIfNeeded(session); err != nil {
		log.Printf("%s removing session. error refreshing access token %s %s", remoteAddr, err, session)
		clearSession = true
		session = nil
	} else if ok {
		saveSession = true
		revalidated = true
	}

	if session != nil && session.IsExpired() {
		log.Printf("%s removing session. token expired %s", remoteAddr, session)
		session = nil
		saveSession = false
		clearSession = true
	}

	if saveSession && !revalidated && session != nil && session.AccessToken != "" {
		if !p.provider.ValidateSessionState(session) {
			log.Printf("%s removing session. error validating %s", remoteAddr, session)
			saveSession = false
			session = nil
			clearSession = true
		}
	}

	if session != nil && session.Email != "" && !p.Validator(session.Email) {
		log.Printf("%s Permission Denied: removing session %s", remoteAddr, session)
		session = nil
		saveSession = false
		clearSession = true
	}

	if saveSession && session != nil {
		err := p.SaveSession(rw, req, session)
		if err != nil {
			log.Printf("%s %s", remoteAddr, err)
			return http.StatusInternalServerError
		}
	}

	if clearSession {
		p.ClearSessionCookie(rw, req)
	}

	if session == nil {
		session, err = p.CheckBasicAuth(req)
		if err != nil {
			log.Printf("%s %s", remoteAddr, err)
		}
	}

	if session == nil {
		return http.StatusForbidden
	}

	// At this point, the user is authenticated. proxy normally
	if p.PassBasicAuth {
		req.SetBasicAuth(session.User, p.BasicAuthPassword)
		req.Header["X-Forwarded-User"] = []string{session.User}
		if session.Email != "" {
			req.Header["X-Forwarded-Email"] = []string{session.Email}
		}
	}
	if p.PassUserHeaders {
		req.Header["X-Forwarded-User"] = []string{session.User}
		if session.Email != "" {
			req.Header["X-Forwarded-Email"] = []string{session.Email}
		}
	}
	if p.SetXAuthRequest {
		rw.Header().Set("X-Auth-Request-User", session.User)
		if session.Email != "" {
			rw.Header().Set("X-Auth-Request-Email", session.Email)
		}
	}
	if p.PassAccessToken && session.AccessToken != "" {
		req.Header["X-Forwarded-Access-Token"] = []string{session.AccessToken}
	}
	if session.Email == "" {
		rw.Header().Set("GAP-Auth", session.User)
	} else {
		rw.Header().Set("GAP-Auth", session.Email)
	}
	return http.StatusAccepted
}