Tired of constantly logging into your applications? Don’t you wish they would just remember you each time you visit, logging you right in? It isn’t as always easy to achieve such a status. There are multiple ways remember me can be implemented. Lets take a look at some of them.
One of the most common ways for a site to implement the remember me functionality is to remember the username only. The username is typically stored in a cookie on the client’s computer. Remembering the username helps speed up the authentication process, but doesn’t eliminate it. The user still has to enter their password to gain access to the application. Although this is a common technique, some organizations may have data classification policies that don’t allow displaying the username in the application. This can also carry over to the username and the login screen. For these organizations, they may not implement a remember me feature at all. Remembering the username does contain some risk, as it instantly provides the username to an attacker on the user’s computer. This leaves just the password for the attacker to determine, which may be feasible if the user re-uses passwords that have been previously breached.
Long-term Auth Cookies
Another common technique for remembering a user is to set an authentication cookie that has a long life. Once you login, a cookie is created that may not expire for a year or longer. This allows you to be automatically logged in each time you visit the site. I am sure you can think of a few sites that provide this functionality. It is common among some of the social media sites people visit all the time. This is not recommended for any type of sensitive applications because it would allow immediate access to anyone that gains access to the user’s device.
Storing Password Locally (Remember Password)
Another option, that probably shouldn’t be an option, is storing the password on the user’s computer. This was recently seen on a web application, however we won’t mention the site that did this. We can, however learn from their decisions. In the application, they used CryptoJS to encrypt and decrypt this type of sensitive data. In this case, they stored the password in a cookie. With the encryption routines available on the client, it is possible to use them to decrypt the encrypted password with very little effort. This is typically the case any time the routines are made available, especially if the keys are available as well. While I am sure this was done with good intentions, the implementation is not very secure. As a matter of fact, it provides more of a false sense of security. This is most likely due to the use of encryption. It is not recommended to perform this type of encryption client-side, nor is it recommended to store the user’s password on the client like this.
There are multiple options to help ease the burden of frequently logging into an application. Depending on the type of application, data stored, and sensitivity of the transactions, the options should be considered carefully. Providing the option to remember a username is convenient with some residual risk. Keeping a user logged in for extended periods of time increase the risk, but may be acceptable depending on the application and its use. Stay away from storing the user’s password locally on the computer they are using. Secure implementation is not easy or straightforward, increasing the risk levels.
Jardine Software helps companies get more value from their application security programs. Let’s talk about how we can help you. James Jardine is the CEO and Principal Consultant at Jardine Software Inc. He has over 15 years of combined development and security experience. If you are interested in learning more about Jardine Software, you can reach him at firstname.lastname@example.org or @jardinesoftware on twitter.