handlers.go

// Statping
// Copyright (C) 2018.  Hunter Long and the project contributors
// Written by Hunter Long <info@socialeck.com> and the project contributors
//
// https://github.com/hunterlong/statping
//
// The licenses for most software and other practical works are designed
// to take away your freedom to share and change the works.  By contrast,
// the GNU General Public License is intended to guarantee your freedom to
// share and change all versions of a program--to make sure it remains free
// software for all its users.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package handlers

import (
	"crypto/tls"
	"encoding/json"
	"fmt"
	"github.com/gorilla/sessions"
	"github.com/hunterlong/statping/core"
	"github.com/hunterlong/statping/source"
	"github.com/hunterlong/statping/types"
	"github.com/hunterlong/statping/utils"
	"html/template"
	"net/http"
	"os"
	"reflect"
	"strings"
	"time"
)

const (
	cookieKey = "statping_auth"
	timeout   = time.Second * 60
)

var (
	sessionStore *sessions.CookieStore
	httpServer   *http.Server
	usingSSL     bool
)

// RunHTTPServer will start a HTTP server on a specific IP and port
func RunHTTPServer(ip string, port int) error {
	host := fmt.Sprintf("%v:%v", ip, port)

	key := utils.FileExists(utils.Directory + "/server.key")
	cert := utils.FileExists(utils.Directory + "/server.crt")

	if key && cert {
		utils.Log(1, "server.cert and server.key was found in root directory! Starting in SSL mode.")
		utils.Log(1, fmt.Sprintf("Statping Secure HTTPS Server running on https://%v:%v", ip, 443))
		usingSSL = true
	} else {
		utils.Log(1, "Statping HTTP Server running on http://"+host)
	}

	router = Router()
	resetCookies()

	if usingSSL {
		cfg := &tls.Config{
			MinVersion:               tls.VersionTLS12,
			CurvePreferences:         []tls.CurveID{tls.CurveP521, tls.CurveP384, tls.CurveP256},
			PreferServerCipherSuites: true,
			CipherSuites: []uint16{
				tls.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
				tls.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,
				tls.TLS_RSA_WITH_AES_256_GCM_SHA384,
				tls.TLS_RSA_WITH_AES_256_CBC_SHA,
			},
		}
		srv := &http.Server{
			Addr:         fmt.Sprintf("%v:%v", ip, 443),
			Handler:      router,
			TLSConfig:    cfg,
			TLSNextProto: make(map[string]func(*http.Server, *tls.Conn, http.Handler), 0),
			WriteTimeout: timeout,
			ReadTimeout:  timeout,
			IdleTimeout:  timeout,
		}
		return srv.ListenAndServeTLS(utils.Directory+"/server.crt", utils.Directory+"/server.key")
	} else {
		httpServer = &http.Server{
			Addr:         host,
			WriteTimeout: timeout,
			ReadTimeout:  timeout,
			IdleTimeout:  timeout,
			Handler:      router,
		}
		return httpServer.ListenAndServe()
	}
	return nil
}

// IsReadAuthenticated will allow Read Only authentication for some routes
func IsReadAuthenticated(r *http.Request) bool {
	var token string
	query := r.URL.Query()
	key := query.Get("api")
	if key == core.CoreApp.ApiKey {
		return true
	}
	tokens, ok := r.Header["Authorization"]
	if ok && len(tokens) >= 1 {
		token = tokens[0]
		token = strings.TrimPrefix(token, "Bearer ")
		if token == core.CoreApp.ApiKey {
			return true
		}
	}
	return IsFullAuthenticated(r)
}

// IsFullAuthenticated returns true if the HTTP request is authenticated. You can set the environment variable GO_ENV=test
// to bypass the admin authenticate to the dashboard features.
func IsFullAuthenticated(r *http.Request) bool {
	if os.Getenv("GO_ENV") == "test" {
		return true
	}
	if core.CoreApp == nil {
		return true
	}
	if sessionStore == nil {
		return true
	}
	var token string
	tokens, ok := r.Header["Authorization"]
	if ok && len(tokens) >= 1 {
		token = tokens[0]
		token = strings.TrimPrefix(token, "Bearer ")
		if token == core.CoreApp.ApiSecret {
			return true
		}
	}
	return IsAdmin(r)
}

// IsAdmin returns true if the user session is an administrator
func IsAdmin(r *http.Request) bool {
	session, err := sessionStore.Get(r, cookieKey)
	if err != nil {
		return false
	}
	if session.Values["admin"] == nil {
		return false
	}
	return session.Values["admin"].(bool)
}

// IsUser returns true if the user is registered
func IsUser(r *http.Request) bool {
	if os.Getenv("GO_ENV") == "test" {
		return true
	}
	session, err := sessionStore.Get(r, cookieKey)
	if err != nil {
		return false
	}
	if session.Values["authenticated"] == nil {
		return false
	}
	return session.Values["authenticated"].(bool)
}

var handlerFuncs = func(w http.ResponseWriter, r *http.Request) template.FuncMap {
	return template.FuncMap{
		"js": func(html interface{}) template.JS {
			return template.JS(utils.ToString(html))
		},
		"safe": func(html string) template.HTML {
			return template.HTML(html)
		},
		"safeURL": func(u string) template.URL {
			return template.URL(u)
		},
		"Auth": func() bool {
			return IsFullAuthenticated(r)
		},
		"IsUser": func() bool {
			return IsUser(r)
		},
		"VERSION": func() string {
			return core.VERSION
		},
		"CoreApp": func() *core.Core {
			return core.CoreApp
		},
		"Services": func() []types.ServiceInterface {
			return core.CoreApp.Services
		},
		"Groups": func(includeAll bool) []*core.Group {
			auth := IsUser(r)
			return core.SelectGroups(includeAll, auth)
		},
		"len": func(g interface{}) int {
			val := reflect.ValueOf(g)
			return val.Len()
		},
		"IsNil": func(g interface{}) bool {
			return g == nil
		},
		"USE_CDN": func() bool {
			return core.CoreApp.UseCdn.Bool
		},
		"QrAuth": func() string {
			return fmt.Sprintf("statping://setup?domain=%v&api=%v", core.CoreApp.Domain, core.CoreApp.ApiSecret)
		},
		"Type": func(g interface{}) []string {
			fooType := reflect.TypeOf(g)
			var methods []string
			methods = append(methods, fooType.String())
			for i := 0; i < fooType.NumMethod(); i++ {
				method := fooType.Method(i)
				fmt.Println(method.Name)
				methods = append(methods, method.Name)
			}
			return methods
		},
		"ToJSON": func(g interface{}) template.HTML {
			data, _ := json.Marshal(g)
			return template.HTML(string(data))
		},
		"underscore": func(html string) string {
			return utils.UnderScoreString(html)
		},
		"URL": func() string {
			return r.URL.String()
		},
		"CHART_DATA": func() string {
			return ""
		},
		"Error": func() string {
			return ""
		},
		"ToString": func(v interface{}) string {
			return utils.ToString(v)
		},
		"Ago": func(t time.Time) string {
			return utils.Timestamp(t).Ago()
		},
		"Duration": func(t time.Duration) string {
			duration, _ := time.ParseDuration(fmt.Sprintf("%vs", t.Seconds()))
			return utils.FormatDuration(duration)
		},
		"ToUnix": func(t time.Time) int64 {
			return t.UTC().Unix()
		},
		"FromUnix": func(t int64) string {
			return utils.Timezoner(time.Unix(t, 0), core.CoreApp.Timezone).Format("Monday, January 02")
		},
		"NewService": func() *types.Service {
			return new(types.Service)
		},
		"NewUser": func() *types.User {
			return new(types.User)
		},
		"NewCheckin": func() *types.Checkin {
			return new(types.Checkin)
		},
		"NewMessage": func() *types.Message {
			return new(types.Message)
		},
		"NewGroup": func() *types.Group {
			return new(types.Group)
		},
	}
}

var mainTmpl = `{{define "main" }} {{ template "base" . }} {{ end }}`

// ExecuteResponse will render a HTTP response for the front end user
func ExecuteResponse(w http.ResponseWriter, r *http.Request, file string, data interface{}, redirect interface{}) {
	utils.Http(r)
	if url, ok := redirect.(string); ok {
		http.Redirect(w, r, url, http.StatusSeeOther)
		return
	}

	if usingSSL {
		w.Header().Add("Strict-Transport-Security", "max-age=63072000; includeSubDomains")
	}

	templates := []string{"base.gohtml", "head.gohtml", "nav.gohtml", "footer.gohtml", "scripts.gohtml", "form_service.gohtml", "form_notifier.gohtml", "form_group.gohtml", "form_user.gohtml", "form_checkin.gohtml", "form_message.gohtml"}
	javascripts := []string{"charts.js", "chart_index.js"}

	render, err := source.TmplBox.String(file)
	if err != nil {
		utils.Log(4, err)
	}

	// setup the main template and handler funcs
	t := template.New("main")
	t.Funcs(handlerFuncs(w, r))
	t, err = t.Parse(mainTmpl)
	if err != nil {
		utils.Log(4, err)
	}

	// render all templates
	for _, temp := range templates {
		tmp, _ := source.TmplBox.String(temp)
		t, err = t.Parse(tmp)
		if err != nil {
			utils.Log(4, err)
		}
	}

	// render all javascript files
	for _, temp := range javascripts {
		tmp, _ := source.JsBox.String(temp)
		t, err = t.Parse(tmp)
		if err != nil {
			utils.Log(4, err)
		}
	}

	// render the page requested
	_, err = t.Parse(render)
	if err != nil {
		utils.Log(4, err)
	}

	// execute the template
	err = t.Execute(w, data)
	if err != nil {
		utils.Log(4, err)
	}
}

// executeJSResponse will render a Javascript response
func executeJSResponse(w http.ResponseWriter, r *http.Request, file string, data interface{}) {
	render, err := source.JsBox.String(file)
	if err != nil {
		utils.Log(4, err)
	}
	if usingSSL {
		w.Header().Add("Strict-Transport-Security", "max-age=63072000; includeSubDomains")
	}
	t := template.New("charts")
	t.Funcs(template.FuncMap{
		"safe": func(html string) template.HTML {
			return template.HTML(html)
		},
		"Services": func() []types.ServiceInterface {
			return core.CoreApp.Services
		},
	})
	_, err = t.Parse(render)
	if err != nil {
		utils.Log(4, err)
	}

	err = t.Execute(w, data)
	if err != nil {
		utils.Log(4, err)
	}
}

// error404Handler is a HTTP handler for 404 error pages
func error404Handler(w http.ResponseWriter, r *http.Request) {
	if usingSSL {
		w.Header().Add("Strict-Transport-Security", "max-age=63072000; includeSubDomains")
	}
	w.WriteHeader(http.StatusNotFound)
	ExecuteResponse(w, r, "error_404.gohtml", nil, nil)
}