admin login

admin.go

@@ -0,0 +1,72 @@
+package main
+
+import (
+	"database/sql"
+	"encoding/base64"
+	"net/http"
+	"regexp"
+)
+
+func adminLoginHandler(w http.ResponseWriter, r *http.Request) {
+	if r.Method == http.MethodGet {
+		http.ServeFile(w, r, "templates/adminLogin.html")
+		return
+	} else if r.Method == http.MethodPost {
+		err := r.ParseForm()
+		if err != nil {
+			http.Error(w, "Error parsing form", http.StatusBadRequest)
+			return
+		}
+		username := r.FormValue("username")
+		password := r.FormValue("password")
+		err = db.QueryRow("SELECT 1 FROM admins WHERE username=? AND PASSWORD=?", username, hashPassword(password)).Scan(new(int))
+		if err == sql.ErrNoRows {
+			http.Error(w, "Invalid credentials", http.StatusUnauthorized)
+			return
+		} else if err != nil {
+			http.Error(w, "Database error", http.StatusInternalServerError)
+			return
+		}
+		http.SetCookie(w, &http.Cookie{Name: "admin_session",
+			Value:    base64.StdEncoding.EncodeToString([]byte(username + ":" + hashPassword(password))),
+			Path:     "/admin/",
+			HttpOnly: true,
+			MaxAge:   3600})
+		http.Redirect(w, r, "/admin/", http.StatusSeeOther)
+		return
+	}
+}
+
+func adminLogoutHandler(w http.ResponseWriter, r *http.Request) {
+	http.SetCookie(w, &http.Cookie{Name: "admin_session", Value: "", Path: "/admin/", HttpOnly: true, MaxAge: -1})
+	http.Redirect(w, r, "/admin/login", http.StatusSeeOther)
+}
+
+func isAdmin(r *http.Request) bool {
+	cookie, err := r.Cookie("admin_session")
+	if err != nil {
+		return false
+	}
+	decoded, err := base64.StdEncoding.DecodeString(cookie.Value)
+	if err != nil {
+		return false
+	}
+	var username, passwordHash string
+	regexp := regexp.MustCompile(`^([^:]+):([a-f0-9]+)$`)
+	matches := regexp.FindStringSubmatch(string(decoded))
+	if len(matches) != 3 {
+		return false
+	}
+	username = matches[1]
+	passwordHash = matches[2]
+	err = db.QueryRow("SELECT 1 FROM admins WHERE username=? AND PASSWORD=?", username, passwordHash).Scan(new(int))
+	return err != sql.ErrNoRows && err == nil
+}
+
+func adminHandler(w http.ResponseWriter, r *http.Request) {
+	if !isAdmin(r) {
+		http.Redirect(w, r, "/admin/login", http.StatusSeeOther)
+		return
+	}
+	w.Write([]byte("Welcome to the admin panel!"))
+}