Decrypt() public static method

public static Decrypt ( string encryptedTicket ) : System.Web.Security.FormsAuthenticationTicket
encryptedTicket string
return System.Web.Security.FormsAuthenticationTicket
Example #1
0
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                // 1. 读登录Cookie
                HttpCookie cookie = Request.Cookies[FA.FormsCookieName];
                if (cookie == null || string.IsNullOrEmpty(cookie.Value))
                {
                    return;
                }

                try
                {
                    string userData = null;
                    // 2. 解密Cookie值,获取FormsAuthenticationTicket对象
                    FormsAuthenticationTicket ticket = FA.Decrypt(cookie.Value);

                    if (ticket != null && string.IsNullOrEmpty(ticket.UserData) == false)
                    {
                        // 3. 还原用户数据
                        userData = ticket.UserData;
                    }

                    //反序列化对象

                    Context.User = null;
                }
                catch { /* 有异常也不要抛出,防止攻击者试探。 */ }
            }
        }
        ////////////////////////////////////////////////////////////
        ////////////////////////////////////////////////////////////
        ////////////////////////////////////////////////////////////
        // Private method for decrypting a cookie
        private static FormsAuthenticationTicket ExtractTicketFromCookie(HttpContext context, String name, out bool cookielessTicket)
        {
            FormsAuthenticationTicket ticket = null;
            string encValue      = null;
            bool   ticketExpired = false;
            bool   badTicket     = false;

            try {
                try {
                    ////////////////////////////////////////////////////////////
                    // Step 0: Check if we should use cookieless
                    cookielessTicket = CookielessHelperClass.UseCookieless(context, false, FormsAuthentication.CookieMode);

                    ////////////////////////////////////////////////////////////
                    // Step 1: Check URI/cookie for ticket
                    if (cookielessTicket)
                    {
                        encValue = context.CookielessHelper.GetCookieValue('F');
                    }
                    else
                    {
                        HttpCookie cookie = context.Request.Cookies[name];
                        if (cookie != null)
                        {
                            encValue = cookie.Value;
                        }
                    }

                    ////////////////////////////////////////////////////////////
                    // Step 2: Decrypt encrypted ticket
                    if (encValue != null && encValue.Length > 1)
                    {
                        try {
                            ticket = FormsAuthentication.Decrypt(encValue);
                        } catch {
                            if (cookielessTicket)
                            {
                                context.CookielessHelper.SetCookieValue('F', null);
                            }
                            else
                            {
                                context.Request.Cookies.Remove(name);
                            }
                            badTicket = true;
                            //throw;
                        }

                        if (ticket == null)
                        {
                            badTicket = true;
                        }

                        if (ticket != null && !ticket.Expired)
                        {
                            if (cookielessTicket || !FormsAuthentication.RequireSSL || context.Request.IsSecureConnection) // Make sure it is NOT a secure cookie over an in-secure connection
                            {
                                return(ticket);                                                                            // Found valid ticket
                            }
                        }

                        if (ticket != null && ticket.Expired)
                        {
                            ticketExpired = true;
                        }

                        // Step 2b: Remove expired/bad ticket
                        ticket = null;
                        if (cookielessTicket)
                        {
                            context.CookielessHelper.SetCookieValue('F', null);
                        }
                        else
                        {
                            context.Request.Cookies.Remove(name);
                        }
                    }


                    ////////////////////////////////////////////////////////////
                    // Step 3: Look in QueryString
                    if (FormsAuthentication.EnableCrossAppRedirects)
                    {
                        encValue = context.Request.QueryString[name];
                        if (encValue != null && encValue.Length > 1)
                        {
                            if (!cookielessTicket && FormsAuthentication.CookieMode == HttpCookieMode.AutoDetect)
                            {
                                cookielessTicket = CookielessHelperClass.UseCookieless(context, true, FormsAuthentication.CookieMode); // find out for sure
                            }
                            try {
                                ticket = FormsAuthentication.Decrypt(encValue);
                            } catch {
                                badTicket = true;
                                //throw;
                            }

                            if (ticket == null)
                            {
                                badTicket = true;
                            }
                        }

                        // Step 3b: Look elsewhere in the request (i.e. posted body)
                        if (ticket == null || ticket.Expired)
                        {
                            encValue = context.Request.Form[name];
                            if (encValue != null && encValue.Length > 1)
                            {
                                if (!cookielessTicket && FormsAuthentication.CookieMode == HttpCookieMode.AutoDetect)
                                {
                                    cookielessTicket = CookielessHelperClass.UseCookieless(context, true, FormsAuthentication.CookieMode); // find out for sure
                                }
                                try {
                                    ticket = FormsAuthentication.Decrypt(encValue);
                                } catch {
                                    badTicket = true;
                                    //throw;
                                }

                                if (ticket == null)
                                {
                                    badTicket = true;
                                }
                            }
                        }
                    }

                    if (ticket == null || ticket.Expired)
                    {
                        if (ticket != null && ticket.Expired)
                        {
                            ticketExpired = true;
                        }

                        return(null); // not found! Exit with null
                    }

                    if (FormsAuthentication.RequireSSL && !context.Request.IsSecureConnection) // Bad scenario: valid ticket over non-SSL
                    {
                        throw new HttpException(SR.GetString(SR.Connection_not_secure_creating_secure_cookie));
                    }

                    ////////////////////////////////////////////////////////////
                    // Step 4: Create the cookie/URI value
                    if (cookielessTicket)
                    {
                        if (ticket.CookiePath != "/")
                        {
                            FormsAuthenticationTicket tempTicket = FormsAuthenticationTicket.FromUtc(ticket.Version, ticket.Name, ticket.IssueDateUtc,
                                                                                                     ticket.ExpirationUtc, ticket.IsPersistent, ticket.UserData,
                                                                                                     "/");
                            ticket   = tempTicket;
                            encValue = FormsAuthentication.Encrypt(ticket);
                        }
                        context.CookielessHelper.SetCookieValue('F', encValue);
                        string strUrl = FormsAuthentication.RemoveQueryStringVariableFromUrl(context.Request.RawUrl, name);
                        context.Response.Redirect(strUrl);
                    }
                    else
                    {
                        HttpCookie cookie = new HttpCookie(name, encValue);
                        cookie.HttpOnly = true;
                        cookie.Path     = ticket.CookiePath;
                        if (ticket.IsPersistent)
                        {
                            cookie.Expires = ticket.Expiration;
                        }
                        cookie.Secure = FormsAuthentication.RequireSSL;
                        if (FormsAuthentication.CookieDomain != null)
                        {
                            cookie.Domain = FormsAuthentication.CookieDomain;
                        }
                        cookie.SameSite = FormsAuthentication.CookieSameSite;
                        context.Response.Cookies.Remove(cookie.Name);
                        context.Response.Cookies.Add(cookie);
                    }

                    return(ticket);
                } finally {
                    if (badTicket)
                    {
                        WebBaseEvent.RaiseSystemEvent(null, WebEventCodes.AuditFormsAuthenticationFailure,
                                                      WebEventCodes.InvalidTicketFailure);
                    }
                    else if (ticketExpired)
                    {
                        WebBaseEvent.RaiseSystemEvent(null, WebEventCodes.AuditFormsAuthenticationFailure,
                                                      WebEventCodes.ExpiredTicketFailure);
                    }
                }
            } catch {
                throw;
            }
        }
Example #3
0
        void OnAuthenticateRequest(object sender, EventArgs args)
        {
            HttpApplication app     = (HttpApplication)sender;
            HttpContext     context = app.Context;

            string cookieName;
            string cookiePath;
            string loginPage;
            bool   slidingExpiration;

            InitConfig(context);
            if (_config == null || _config.Mode != AuthenticationMode.Forms)
            {
                return;
            }

            cookieName        = _config.Forms.Name;
            cookiePath        = _config.Forms.Path;
            loginPage         = _config.Forms.LoginUrl;
            slidingExpiration = _config.Forms.SlidingExpiration;

            if (!VirtualPathUtility.IsRooted(loginPage))
            {
                loginPage = "~/" + loginPage;
            }

            string reqPath   = String.Empty;
            string loginPath = null;

            try {
                reqPath   = context.Request.PhysicalPath;
                loginPath = context.Request.MapPath(loginPage);
            } catch {}             // ignore

            context.SkipAuthorization = String.Compare(reqPath, loginPath, RuntimeHelpers.CaseInsensitive, Helpers.InvariantCulture) == 0;

            //TODO: need to check that the handler is System.Web.Handlers.AssemblyResourceLoader type
            string filePath = context.Request.FilePath;

            if (filePath.Length > 15 && String.CompareOrdinal("WebResource.axd", 0, filePath, filePath.Length - 15, 15) == 0)
            {
                context.SkipAuthorization = true;
            }

            FormsAuthenticationEventArgs    formArgs = new FormsAuthenticationEventArgs(context);
            FormsAuthenticationEventHandler eh       = events [authenticateEvent] as FormsAuthenticationEventHandler;

            if (eh != null)
            {
                eh(this, formArgs);
            }

            bool contextUserNull = (context.User == null);

            if (formArgs.User != null || !contextUserNull)
            {
                if (contextUserNull)
                {
                    context.User = formArgs.User;
                }
                return;
            }

            HttpCookie cookie = context.Request.Cookies [cookieName];

            if (cookie == null || (cookie.Expires != DateTime.MinValue && cookie.Expires < DateTime.Now))
            {
                return;
            }

            FormsAuthenticationTicket ticket = null;

            try {
                ticket = FormsAuthentication.Decrypt(cookie.Value);
            }
            catch (ArgumentException) {
                // incorrect cookie value, suppress the exception
                return;
            }
            if (ticket == null || (!ticket.IsPersistent && ticket.Expired))
            {
                return;
            }

            FormsAuthenticationTicket oldticket = ticket;

            if (slidingExpiration)
            {
                ticket = FormsAuthentication.RenewTicketIfOld(ticket);
            }

            context.User = new GenericPrincipal(new FormsIdentity(ticket), new string [0]);

            if (cookie.Expires == DateTime.MinValue && oldticket == ticket)
            {
                return;
            }

            cookie.Value = FormsAuthentication.Encrypt(ticket);
            cookie.Path  = cookiePath;
            if (ticket.IsPersistent)
            {
                cookie.Expires = ticket.Expiration;
            }

            context.Response.Cookies.Add(cookie);
        }