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package main
import (
"flag"
"github.com/gorilla/mux"
"net/http"
"fmt"
"strings"
"io/ioutil"
"time"
)
var (
port *int
)
func registerHTTPFlags() {
port = flag.Int("port", 8080, "The port for HTTP")
}
func runHTTPServer() (error) {
r := mux.NewRouter()
r.HandleFunc("/", indexHandler)
r.HandleFunc("/files/{file}", fileHandler)
r.HandleFunc("/login", loginGetHandler).Methods("GET")
r.HandleFunc("/login", loginPostHandler).Methods("POST")
r.HandleFunc("/logout", logoutHandler).Methods("GET")
address := fmt.Sprintf(":%d", *port)
return http.ListenAndServe(address, r)
}
// Host the index file
func indexHandler(w http.ResponseWriter, r *http.Request) {
session, cookieNotFoundError := r.Cookie("session")
if cookieNotFoundError != nil || !isValidSession(session.Value) {
// either no session cookie found, or it contains an invalid session token. Redirect.
http.Redirect(w, r, "/login", http.StatusTemporaryRedirect)
} else {
// valid session token found, redirect to frontpage
readFileToResponse(w, "/index.html")
}
}
// Static host files
func fileHandler(w http.ResponseWriter, r *http.Request) {
readFileToResponse(w, mux.Vars(r)["file"])
}
// Helper function to host files off of "hosted/" directory
func readFileToResponse(w http.ResponseWriter, path string) {
requestedFile := strings.Replace(path, "..", "", -1)
contents, readError := ioutil.ReadFile(fmt.Sprintf("hosted/%s", requestedFile))
if readError != nil {
w.Write([]byte(fmt.Sprintf("unable to read %s", requestedFile)))
} else {
w.Write([]byte(contents))
}
}
// Read login page
func loginGetHandler(w http.ResponseWriter, r *http.Request) {
session, cookieNotFoundError := r.Cookie("session")
// we need to verify that the client doesn't already have a valid session
if cookieNotFoundError == nil && isValidSession(session.Value) {
// session already valid, redirect the user
http.Redirect(w, r, "/", http.StatusTemporaryRedirect)
} else {
readFileToResponse(w, "/login.html")
}
}
// Process login data
func loginPostHandler(w http.ResponseWriter, r *http.Request) {
r.ParseForm()
username := r.Form.Get("username")
accessCode := r.Form.Get("accesscode")
session, cookieNotFoundError := r.Cookie("session")
validRedirect := false
// we need to verify that the client doesn't already have a valid session
if cookieNotFoundError == nil && isValidSession(session.Value) {
// session already valid, redirect the user
validRedirect = true
} else {
// no valid session present, check the given credentials
if verifyCredentials(username, accessCode) {
// credentials valid, create session
newSessionToken := createSession()
http.SetCookie(w, &http.Cookie{
Name: "session",
Value: newSessionToken,
Path: "/",
Expires: time.Now().Add(time.Hour * 24),
})
validRedirect = true
}
}
if validRedirect {
// Redirect to frontpage
http.Redirect(w, r, "/", http.StatusTemporaryRedirect)
return
} else {
// credentials invalid or database error occured
w.Write([]byte("Wrong credentials"))
return
}
// Something else weird happened.
w.WriteHeader(500)
w.Write([]byte("Server Error"))
}
// Process logout and deletion of cookie
func logoutHandler(w http.ResponseWriter, r *http.Request) {
session, cookieNotFoundError := r.Cookie("session")
if cookieNotFoundError == nil {
// cookie was found
if isValidSession(session.Value) {
// and it contains a valid session. Delete the session...
destroySession(session.Value)
}
// and delete the cookie
http.SetCookie(w, &http.Cookie{
Name: "session",
Value: "",
Path: "/",
Expires: time.Unix(0, 0),
})
}
http.Redirect(w, r, "/", http.StatusTemporaryRedirect)
}
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