Asp cookie software

In general, it is used to store the username, telephone number, email id, etc that is user information on the client machine. Cookies are mainly classified in two types is Persistent cookies and Non — persistent cookies. Persistent cookies contain expiry date for its expiration.

It will remain on the client machine as it is even after closing the browser. We can set the expiry date to the cookie which determines how long it could stay. Userinfo may be the username for which we want to save cookie and value is what we want to pass or save for the userinfo.

We can also create cookies as per our convenience. For creating asp. Therefore, in these ways, we can create cookies in ASP. However, what if your browser is not supporting the cookies. If your application deals with a different browser, which is not supported for the cookies, then we will need to use other ways. We need to pass the information from one page to another via other methods. We can use this method to create. Let us take an example and understand how we can use it.

In this example, we will create a cookie and try to retrieve it after the expiration time. Because different browsers store cookies differently, different browsers on the same computer won't necessarily be able to read each other's cookies.

For example, if you use Internet Explorer to test a page one time, but then later use a different browser to test again, the second browser won't find the cookies saved by Internet Explorer.

Reading the value of a subkey in a cookie is likewise similar to setting it. The following code example shows one way to get the value of a subkey:. In the preceding example, the code reads the value of the subkey lastVisit, which was set earlier to the string representation of a DateTime value. Cookies store values as strings, so if you want to use the lastVisit value as a date, you have to convert it to the appropriate type, as in this example:.

The subkeys in a cookie are typed as a collection of type NameValueCollection. Therefore, another way to get an individual subkey is to get the subkeys collection and then extract the subkey value by name, as shown in the following example:. The browser is responsible for managing cookies, and the cookie's expiration time and date help the browser manage its store of cookies.

Therefore, although you can read the name and value of a cookie, you cannot read the cookie's expiration date and time. When the browser sends cookie information to the server, the browser does not include the expiration information.

The cookie's Expires property always returns a date-time value of zero. If you are concerned about the expiration date of a cookie, you must reset it, which is covered in the "Modifying and Deleting Cookies" section. You can read the Expires property of a cookie that you have set in the HttpResponse object, before the cookie has been sent to the browser. However, you cannot get the expiration back in the HttpRequest object.

You might occasionally need to read through all the cookies available to the page. To read the names and values of all the cookies available to the page, you can loop through the Cookies collection using code such as the following.

When you run this code, you might see a cookie named ASP. That is a cookie that ASP. NET uses to store a unique identifier for your session.

The session cookie is not persisted on your hard disk. For more about session cookies, see the "Cookies and Session State" later in this topic. You can read a cookie's HasKeys property to determine whether the cookie has subkeys. If so, you can read the subkey collection to get individual subkey names and values. You can read subkey values from the Values collection directly by index value. The corresponding subkey names are available in the AllKeys member of the Values collection, which returns an array of strings.

You can also use the Keys member of the Values collection. However, the AllKeys property is cached the first time it is accessed.

In contrast, the Keys property builds an array each time it is accessed. For this reason, the AllKeys property is much faster on subsequent accesses within the context of the same page request. The following example shows a modification of the preceding example. It uses the HasKeys property to test for subkeys, and if subkeys are detected, the example gets subkeys from the Values collection:.

Alternatively, you can extract the subkeys as a NameValueCollection object as shown in the following example:. You cannot directly modify a cookie. Instead, changing a cookie consists of creating a new cookie with new values and then sending the cookie to the browser to overwrite the old version on the client.

The following code example shows how you can change the value of a cookie that stores a count of the user's visits to the site:. Deleting a cookie—physically removing it from the user's hard disk—is a variation on modifying it. You cannot directly remove a cookie because the cookie is on the user's computer. However, you can have the browser delete the cookie for you. The technique is to create a new cookie with the same name as the cookie to be deleted, but to set the cookie's expiration to a date earlier than today.

When the browser checks the cookie's expiration, the browser will discard the now-outdated cookie. The following code example shows one way to delete all the cookies available to the application:. To delete an individual subkey, you manipulate the cookie's Values collection, which holds the subkeys. You first recreate the cookie by getting it from the Cookies object.

You can then call the Remove method of the Values collection, passing to the Remove method the name of the subkey to delete. You then add the cookie to the Cookies collection so it will be sent in its modified form back to the browser. The following code example shows how to delete a subkey. In the sample, the name of the subkey to remove is specified in a variable.

The security issues with cookies are similar to those of getting data from the client. In your application, cookies are another form of user input and are therefore subject to examining and spoofing. A user can as a minimum see the data that you store in a cookie, since the cookie is available on the user's own computer. The user can also change the cookie before the browser sends it to you.

You should never store sensitive data in a cookie, such as user names, passwords, credit card numbers, and so on. Do not put anything in a cookie that should not be in the hands of a user or of someone who might somehow steal the cookie. Similarly, be suspicious of information you get out of a cookie.

Do not assume that the data is the same as when you wrote it out; use the same safeguards in working with cookie values that you would with data that a user has typed into a Web page. The examples earlier in this topic showed HTML-encoding the contents of a cookie before displaying the value in a page, as you would before displaying any information you get from users. Cookies are sent between browser and server as plain text, and anyone who can intercept your Web traffic can read the cookie.

You can set a cookie property that causes the cookie to be transmitted only if the connection uses the Secure Sockets Layer SSL. SSL does not protect the cookie from being read or manipulated while it is on the user's computer, but it does prevent the cookie from being read while in transit because the cookie is encrypted.

Users can set their browser to refuse cookies. No error is raised if a cookie cannot be written. The browser likewise does not send any information to the server about its current cookie settings.

The Cookies property does not indicate whether cookies are enabled. It indicates only whether the current browser inherently supports cookies. One way to determine whether cookies are accepted is by trying to write a cookie and then trying to read it back again.

If you cannot read the cookie you wrote, you assume that cookies are turned off in the browser. The following code example shows how you might test whether cookies are accepted.

The sample consists of two pages. The first page writes out a cookie, and then redirects the browser to the second page. The second page tries to read the cookie. It in turn redirects the browser back to the first page, adding to the URL a query string variable with the results of the test. The page first tests to see if this is a postback, and if not, the page looks for the query string variable name AcceptsCookies that contains the test results. If there is no query string variable, the test has not been completed, so the code writes out a cookie named TestCookie.

A cookie is a small file that the server embeds on the user's computer. Each time the same computer requests a page with a browser, it will send the cookie too. With ASP, you can both create and retrieve cookie values. In the example below, we will create a cookie named "firstname" and assign the value "Alex" to it:. It is also possible to assign properties to a cookie, like setting a date when the cookie should expire:.

In the example below, we retrieve the value of the cookie named "firstname" and display it on a page:. In the example below, we will create a cookie collection named "user". The "user" cookie has Keys that contains information about a user:. Now we want to read all the cookies sent to a user. The example below shows how to do it note that the code below checks if a cookie has Keys with the HasKeys property :.

If your application deals with browsers that do not support cookies, you will have to use other methods to pass information from one page to another in your application.