|By Patrick Correia||
|June 5, 2006 04:00 PM EDT||
How to Implement Basic Authentication with ColdFusion
The first time a Web browser requests a page that's protected by Basic authentication, the Web server needs a way to tell it that it should stop and ask the user for login information. It does this by sending a response to the initial request with the status code 401 ("Access Denied"). In this response, it also sends information about what types of authentication it's willing to accept (this is the "WWW-Authenticate" header). In this article, we're only discussing Basic Authentication, but other more complex (and more secure) methods exist such as Digest authentication and Microsoft's proprietary NTLM authentication. Along with the 401 response the server also sends a user-friendly (or at least user-readable) explanation of why access is being denied.
When the browser gets the 401 response, before showing the user the "Access Denied" message, it prompts for a user name and password. If the user provides credentials, the browser repeats the request and includes the user name and password in an "Authorization" request header. If the credentials are sufficient, the server then sends the requested page with a 200 ("OK") status code. If the credentials aren't acceptable to the server, it simply sends back the same 401 response, which makes the browser prompt the user again. If the user declines to provide credentials (by clicking a "Cancel" button on the password prompt, for example), or fails to provide acceptable credentials a certain number of times (usually three, although it's up to the Web browser to decide), the browser stops prompting the user and shows the user the "Access Denied" message provided by the server.
Listing 1 shows the code needed to implement Basic Authentication. This code should be included at the top of any page that needs to be protected by authentication (an Application.cfm file is a good place, for example).
The first lines use the built-in ColdFusion function GetHttpRequestData() to retrieve complete information on the request headers sent by the client and ensure that our session-level user variable is initialized. Then the code checks to see if the client has provided the "Authorization" header that contains the login and password. The "Authorization" header consists of two parts separated by a single space: first, the authentication scheme (in this case "Basic"); and second, the user name and password separated by a colon and Base64-encoded to protect them from character set issues during transmission. The user name and password are decoded using the ToBinary() and ToString() functions, and the application verifies that they're correct (obviously this part will vary from application to application). If the user hasn't been logged in either by providing incorrect credentials or by not providing any at all, the response code is set to 401 and the "WWW-Authenticate" response header is added. Finally, a user-friendly "Access Denied" message is added to the response and execution is stopped so the server sends only the "Access Denied" message back to the client.
Even if the user has cookies disabled, so the user's session doesn't persist from request to request, the user won't be prompted again for a login and password. However, in this case, you won't be able to store any other data in the session scope without resorting to passing session identifiers as URL parameters.
Since the browser is getting accurate response codes throughout the transaction, there's no need to write code to redirect the user after a successful login. This is an additional benefit of using Basic authentication and means that your application fully supports deep linking and bookmarking without any extra code.
The Authentication Realm
There's one additional piece of information that the server sends in the "WWW-Authenticate" header: the authentication realm. The realm is defined as a string that uniquely identifies the set of resources on the server that all use the same user account source. The browser assumes that if it has prompted the user for a login and password for a resource on a given server, it can reuse the same credentials for another resource in the same realm on the same server.
Although the specification for Basic authentication discourages the use of the realm for any purpose other than matching it for equality against other realm values, in practice the realm actually has another important function. When most browsers prompt the user for login credentials, they show the realm as a description of the application the user is logging in to. So it's a good idea to set the realm in your authentication code to a brief description of your application (this description would replace the string "MyApplication" in Listing 1).
Caching of Credentials: The End of Session Expiration
When a browser gets a 401 ("Access Denied") message in response to a request for a given resource, it checks to see if the realm specified in the "WWW-Authenticate" header matches any realms it has already authenticated against on the current server for the current browser session. If it finds credentials that have been accepted for that realm, it retries the request using those credentials (prompting the user for credentials only if the cached credentials are rejected by the server). The browser also assumes that resources in subdirectories below the resources for which it has already been prompted to authenticate will be part of the same realm and preemptively sends the cached credentials the first time it requests these resources. These two facts contribute to one of the biggest advantages of Basic authentication: the end of session expiration messages.
Examine Listing 1 again and consider what happens if the user has been previously authenticated but has been inactive enough that the session expired. On the next request, a new session is initiated by the ColdFusion server and SESSION.loggedInUserName is set to an empty string. If the browser has previously requested the page, it will have preemptively sent the login credentials; if not, it will check its cache and see that it already has credentials for the specified realm and it will repeat the request, providing the cached credentials. In either case, the user has been automatically logged back into the application without being prompted! This provides a much smoother and less confusing experience for the user.
Keep in mind that this may have some affect on your application architecture. If you're using the session scope only to cache information that's already stored in a database somewhere, your application can probably be converted to Basic authentication with no issues. However, if you store temporary data in the session scope (such as shopping cart information), you may have to consider a different approach since the user may have multiple ColdFusion sessions over the course of what they consider a single session of interacting with the Web application. Just remember that a user session might be initialized on any page of your application.
Limitations of Basic Authentication
Basic authentication isn't without its limitations. First and foremost, it's important to realize that the user name and password is transmitted from the browser to the Web server in unencrypted clear text. (The Base64 encoding isn't a security measure - it's designed to be easily reversible.) If you consider the data in your application to be sensitive, you should definitely use an additional security layer such as SSL to protect the transmission of the user name and password (as well as the data). That being said, this lack of encryption is a limitation that's common to both forms-based and Basic authentication.
The other significant limitation of Basic authentication, and the only major drawback to using it over forms-based authentication, is that it provides much less opportunity for context around the login and password. A forms-based solution can show information around the login box explaining the format of the login and, in the case of password errors, can provide detailed information about what went wrong. Additionally, the login prompt can be customized to match the look-and-feel of the rest of the application. When implementing HTTP Basic authentication, you should provide an entry page that isn't authenticated that provides this information so the user is prepared to enter the appropriate login and password information.
Basic authentication provides an alternative to traditional forms-based authentication methods. By sticking closely to the HTTP specification, this method leverages features built in to the Web browser to prevent confusing session expiration problems and the need to code around other limitations in non-standard forms-based authentication methods.
|MikeR 06/08/06 11:43:56 PM EDT|
Interesting article but it failed to mention the huge flaw with basic auth.
Basic authentication can't be used for most real-world sites because:
SYS-CON Events announced today that Catchpoint, a leading digital experience intelligence company, has been named “Silver Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Catchpoint Systems is a leading Digital Performance Analytics company that provides unparalleled insight into your customer-critical services to help you consistently deliver an amazing customer experience. Designed for digital business, C...
Jan. 21, 2017 11:45 AM EST Reads: 1,844
More and more brands have jumped on the IoT bandwagon. We have an excess of wearables – activity trackers, smartwatches, smart glasses and sneakers, and more that track seemingly endless datapoints. However, most consumers have no idea what “IoT” means. Creating more wearables that track data shouldn't be the aim of brands; delivering meaningful, tangible relevance to their users should be. We're in a period in which the IoT pendulum is still swinging. Initially, it swung toward "smart for smart...
Jan. 21, 2017 11:30 AM EST Reads: 2,803
WebRTC sits at the intersection between VoIP and the Web. As such, it poses some interesting challenges for those developing services on top of it, but also for those who need to test and monitor these services. In his session at WebRTC Summit, Tsahi Levent-Levi, co-founder of testRTC, reviewed the various challenges posed by WebRTC when it comes to testing and monitoring and on ways to overcome them.
Jan. 21, 2017 11:15 AM EST Reads: 6,117
The emerging Internet of Everything creates tremendous new opportunities for customer engagement and business model innovation. However, enterprises must overcome a number of critical challenges to bring these new solutions to market. In his session at @ThingsExpo, Michael Martin, CTO/CIO at nfrastructure, outlined these key challenges and recommended approaches for overcoming them to achieve speed and agility in the design, development and implementation of Internet of Everything solutions with...
Jan. 21, 2017 10:00 AM EST Reads: 5,663
Every successful software product evolves from an idea to an enterprise system. Notably, the same way is passed by the product owner's company. In his session at 20th Cloud Expo, Oleg Lola, CEO of MobiDev, will provide a generalized overview of the evolution of a software product, the product owner, the needs that arise at various stages of this process, and the value brought by a software development partner to the product owner as a response to these needs.
Jan. 21, 2017 07:30 AM EST Reads: 1,306
In 2014, Amazon announced a new form of compute called Lambda. We didn't know it at the time, but this represented a fundamental shift in what we expect from cloud computing. Now, all of the major cloud computing vendors want to take part in this disruptive technology. In his session at 20th Cloud Expo, John Jelinek IV, a web developer at Linux Academy, will discuss why major players like AWS, Microsoft Azure, IBM Bluemix, and Google Cloud Platform are all trying to sidestep VMs and containers...
Jan. 21, 2017 07:15 AM EST Reads: 939
SYS-CON Events announced today that MobiDev, a client-oriented software development company, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place June 6-8, 2017, at the Javits Center in New York City, NY, and the 21st International Cloud Expo®, which will take place October 31-November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. MobiDev is a software company that develops and delivers turn-key mobile apps, websites, web services, and complex softw...
Jan. 21, 2017 06:45 AM EST Reads: 1,954
Smart Cities are here to stay, but for their promise to be delivered, the data they produce must not be put in new siloes. In his session at @ThingsExpo, Mathias Herberts, Co-founder and CTO of Cityzen Data, discussed the best practices that will ensure a successful smart city journey.
Jan. 21, 2017 06:00 AM EST Reads: 2,097
Technology vendors and analysts are eager to paint a rosy picture of how wonderful IoT is and why your deployment will be great with the use of their products and services. While it is easy to showcase successful IoT solutions, identifying IoT systems that missed the mark or failed can often provide more in the way of key lessons learned. In his session at @ThingsExpo, Peter Vanderminden, Principal Industry Analyst for IoT & Digital Supply Chain to Flatiron Strategies, will focus on how IoT depl...
Jan. 21, 2017 03:45 AM EST Reads: 1,992
Big Data, cloud, analytics, contextual information, wearable tech, sensors, mobility, and WebRTC: together, these advances have created a perfect storm of technologies that are disrupting and transforming classic communications models and ecosystems. In his session at @ThingsExpo, Erik Perotti, Senior Manager of New Ventures on Plantronics’ Innovation team, provided an overview of this technological shift, including associated business and consumer communications impacts, and opportunities it m...
Jan. 21, 2017 02:00 AM EST Reads: 5,829
Manufacturers are embracing the Industrial Internet the same way consumers are leveraging Fitbits – to improve overall health and wellness. Both can provide consistent measurement, visibility, and suggest performance improvements customized to help reach goals. Fitbit users can view real-time data and make adjustments to increase their activity. In his session at @ThingsExpo, Mark Bernardo Professional Services Leader, Americas, at GE Digital, discussed how leveraging the Industrial Internet and...
Jan. 21, 2017 01:30 AM EST Reads: 6,573
"Tintri was started in 2008 with the express purpose of building a storage appliance that is ideal for virtualized environments. We support a lot of different hypervisor platforms from VMware to OpenStack to Hyper-V," explained Dan Florea, Director of Product Management at Tintri, in this SYS-CON.tv interview at 18th Cloud Expo, held June 7-9, 2016, at the Javits Center in New York City, NY.
Jan. 21, 2017 01:15 AM EST Reads: 4,923
There will be new vendors providing applications, middleware, and connected devices to support the thriving IoT ecosystem. This essentially means that electronic device manufacturers will also be in the software business. Many will be new to building embedded software or robust software. This creates an increased importance on software quality, particularly within the Industrial Internet of Things where business-critical applications are becoming dependent on products controlled by software. Qua...
Jan. 21, 2017 01:15 AM EST Reads: 5,065
Fact is, enterprises have significant legacy voice infrastructure that’s costly to replace with pure IP solutions. How can we bring this analog infrastructure into our shiny new cloud applications? There are proven methods to bind both legacy voice applications and traditional PSTN audio into cloud-based applications and services at a carrier scale. Some of the most successful implementations leverage WebRTC, WebSockets, SIP and other open source technologies. In his session at @ThingsExpo, Da...
Jan. 21, 2017 01:15 AM EST Reads: 2,894
A critical component of any IoT project is what to do with all the data being generated. This data needs to be captured, processed, structured, and stored in a way to facilitate different kinds of queries. Traditional data warehouse and analytical systems are mature technologies that can be used to handle certain kinds of queries, but they are not always well suited to many problems, particularly when there is a need for real-time insights.
Jan. 21, 2017 12:15 AM EST Reads: 6,383
In his General Session at 16th Cloud Expo, David Shacochis, host of The Hybrid IT Files podcast and Vice President at CenturyLink, investigated three key trends of the “gigabit economy" though the story of a Fortune 500 communications company in transformation. Narrating how multi-modal hybrid IT, service automation, and agile delivery all intersect, he will cover the role of storytelling and empathy in achieving strategic alignment between the enterprise and its information technology.
Jan. 21, 2017 12:00 AM EST Reads: 4,723
IoT is at the core or many Digital Transformation initiatives with the goal of re-inventing a company's business model. We all agree that collecting relevant IoT data will result in massive amounts of data needing to be stored. However, with the rapid development of IoT devices and ongoing business model transformation, we are not able to predict the volume and growth of IoT data. And with the lack of IoT history, traditional methods of IT and infrastructure planning based on the past do not app...
Jan. 20, 2017 10:45 PM EST Reads: 941
WebRTC is bringing significant change to the communications landscape that will bridge the worlds of web and telephony, making the Internet the new standard for communications. Cloud9 took the road less traveled and used WebRTC to create a downloadable enterprise-grade communications platform that is changing the communication dynamic in the financial sector. In his session at @ThingsExpo, Leo Papadopoulos, CTO of Cloud9, discussed the importance of WebRTC and how it enables companies to focus o...
Jan. 20, 2017 08:45 PM EST Reads: 4,406
The Internet of Things can drive efficiency for airlines and airports. In their session at @ThingsExpo, Shyam Varan Nath, Principal Architect with GE, and Sudip Majumder, senior director of development at Oracle, discussed the technical details of the connected airline baggage and related social media solutions. These IoT applications will enhance travelers' journey experience and drive efficiency for the airlines and the airports.
Jan. 20, 2017 05:45 PM EST Reads: 2,113
With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo 2016 in New York. Learn what is going on, contribute to the discussions, and ensure that your enterprise is as "IoT-Ready" as it can be! Internet of @ThingsExpo, taking place June 6-8, 2017, at the Javits Center in New York City, New York, is co-located with 20th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry p...
Jan. 20, 2017 05:15 PM EST Reads: 3,837