chore(refactor): refactors go code (#2443)

internal/web/auth.go

@@ -0,0 +1,124 @@
+package web
+
+import (
+	"crypto/sha256"
+	"fmt"
+	"net/http"
+	"time"
+
+	"github.com/gorilla/sessions"
+	log "github.com/sirupsen/logrus"
+)
+
+var secured = false
+var store *sessions.CookieStore
+
+const authorityKey = "AUTH_TIMESTAMP"
+const sessionName = "session"
+
+func initializeAuth(h *handler) {
+	secured = false
+	if h.config.Username != "" && h.config.Password != "" {
+		store = sessions.NewCookieStore(generateSessionStorageKey(h.config.Username, h.config.Password))
+		store.Options.HttpOnly = true
+		store.Options.SameSite = http.SameSiteLaxMode
+		store.Options.MaxAge = 0
+		secured = true
+	}
+}
+
+func authorizationRequired(next http.Handler) http.Handler {
+	if secured {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			if isAuthorized(r) {
+				next.ServeHTTP(w, r)
+			} else {
+				http.Error(w, http.StatusText(http.StatusUnauthorized), http.StatusUnauthorized)
+			}
+		})
+	} else {
+		return next
+	}
+}
+
+func isAuthorized(r *http.Request) bool {
+	if !secured {
+		return true
+	}
+
+	session, _ := store.Get(r, sessionName)
+	if session.IsNew {
+		return false
+	}
+
+	if _, ok := session.Values[authorityKey]; ok {
+		// TODO check for timestamp
+		return true
+	}
+
+	return false
+}
+
+func (h *handler) isAuthorizationNeeded(r *http.Request) bool {
+	return secured && !isAuthorized(r)
+}
+
+func (h *handler) validateCredentials(w http.ResponseWriter, r *http.Request) {
+	if !secured {
+		log.Panic("Validating credentials without username and password should not happen")
+	}
+
+	if r.Method != "POST" {
+		log.Fatal("Expecting credential validation method to be POST")
+		http.Error(w, http.StatusText(http.StatusNotAcceptable), http.StatusNotAcceptable)
+		return
+	}
+
+	if err := r.ParseMultipartForm(4 * 1024); err != nil {
+		log.Fatalf("Error while parsing form data: %v", err)
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	user := r.PostFormValue("username")
+	pass := r.PostFormValue("password")
+	session, _ := store.Get(r, sessionName)
+
+	if user == h.config.Username && pass == h.config.Password {
+		session.Values[authorityKey] = time.Now().Unix()
+
+		if err := session.Save(r, w); err != nil {
+			log.Fatalf("Error while parsing saving session: %v", err)
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+
+		w.WriteHeader(http.StatusOK)
+		w.Write([]byte(http.StatusText(http.StatusOK)))
+		return
+	}
+
+	http.Error(w, http.StatusText(http.StatusUnauthorized), http.StatusUnauthorized)
+}
+
+func (h *handler) clearSession(w http.ResponseWriter, r *http.Request) {
+	if !secured {
+		log.Panic("Validating credentials with secured=false should not happen")
+	}
+
+	session, _ := store.Get(r, sessionName)
+	delete(session.Values, authorityKey)
+
+	if err := session.Save(r, w); err != nil {
+		log.Fatalf("Error while parsing saving session: %v", err)
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	http.Redirect(w, r, h.config.Base, http.StatusTemporaryRedirect)
+}
+
+func generateSessionStorageKey(username string, password string) []byte {
+	key := sha256.Sum256([]byte(fmt.Sprintf("%s:%s", username, password)))
+	return key[:]
+}