|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:
The Internet of Everything is re-shaping technology trends–moving away from “request/response” architecture to an “always-on” Streaming Web where data is in constant motion and secure, reliable communication is an absolute necessity. As more and more THINGS go online, the challenges that developers will need to address will only increase exponentially. In his session at @ThingsExpo, Todd Greene, Founder & CEO of PubNub, exploreed the current state of IoT connectivity and review key trends and technology requirements that will drive the Internet of Things from hype to reality.
Nov. 26, 2015 06:45 AM EST Reads: 389
Two weeks ago (November 3-5), I attended the Cloud Expo Silicon Valley as a speaker, where I presented on the security and privacy due diligence requirements for cloud solutions. Cloud security is a topical issue for every CIO, CISO, and technology buyer. Decision-makers are always looking for insights on how to mitigate the security risks of implementing and using cloud solutions. Based on the presentation topics covered at the conference, as well as the general discussions heard between sessions, I wanted to share some of my observations on emerging trends. As cyber security serves as a fou...
Nov. 26, 2015 06:15 AM EST Reads: 295
Continuous processes around the development and deployment of applications are both impacted by -- and a benefit to -- the Internet of Things trend. To help better understand the relationship between DevOps and a plethora of new end-devices and data please welcome Gary Gruver, consultant, author and a former IT executive who has led many large-scale IT transformation projects, and John Jeremiah, Technology Evangelist at Hewlett Packard Enterprise (HPE), on Twitter at @j_jeremiah. The discussion is moderated by me, Dana Gardner, Principal Analyst at Interarbor Solutions.
Nov. 26, 2015 03:45 AM EST Reads: 690
Too often with compelling new technologies market participants become overly enamored with that attractiveness of the technology and neglect underlying business drivers. This tendency, what some call the “newest shiny object syndrome” is understandable given that virtually all of us are heavily engaged in technology. But it is also mistaken. Without concrete business cases driving its deployment, IoT, like many other technologies before it, will fade into obscurity.
Nov. 26, 2015 03:00 AM EST Reads: 303
With all the incredible momentum behind the Internet of Things (IoT) industry, it is easy to forget that not a single CEO wakes up and wonders if “my IoT is broken.” What they wonder is if they are making the right decisions to do all they can to increase revenue, decrease costs, and improve customer experience – effectively the same challenges they have always had in growing their business. The exciting thing about the IoT industry is now these decisions can be better, faster, and smarter. Now all corporate assets – people, objects, and spaces – can share information about themselves and thei...
Nov. 26, 2015 02:00 AM EST Reads: 185
The Internet of Things is clearly many things: data collection and analytics, wearables, Smart Grids and Smart Cities, the Industrial Internet, and more. Cool platforms like Arduino, Raspberry Pi, Intel's Galileo and Edison, and a diverse world of sensors are making the IoT a great toy box for developers in all these areas. In this Power Panel at @ThingsExpo, moderated by Conference Chair Roger Strukhoff, panelists discussed what things are the most important, which will have the most profound effect on the world, and what should we expect to see over the next couple of years.
Nov. 26, 2015 01:30 AM EST Reads: 431
Growth hacking is common for startups to make unheard-of progress in building their business. Career Hacks can help Geek Girls and those who support them (yes, that's you too, Dad!) to excel in this typically male-dominated world. Get ready to learn the facts: Is there a bias against women in the tech / developer communities? Why are women 50% of the workforce, but hold only 24% of the STEM or IT positions? Some beginnings of what to do about it! In her Day 2 Keynote at 17th Cloud Expo, Sandy Carter, IBM General Manager Cloud Ecosystem and Developers, and a Social Business Evangelist, wil...
Nov. 26, 2015 12:00 AM EST Reads: 521
PubNub has announced the release of BLOCKS, a set of customizable microservices that give developers a simple way to add code and deploy features for realtime apps.PubNub BLOCKS executes business logic directly on the data streaming through PubNub’s network without splitting it off to an intermediary server controlled by the customer. This revolutionary approach streamlines app development, reduces endpoint-to-endpoint latency, and allows apps to better leverage the enormous scalability of PubNub’s Data Stream Network.
Nov. 26, 2015 12:00 AM EST Reads: 282
Discussions of cloud computing have evolved in recent years from a focus on specific types of cloud, to a world of hybrid cloud, and to a world dominated by the APIs that make today's multi-cloud environments and hybrid clouds possible. In this Power Panel at 17th Cloud Expo, moderated by Conference Chair Roger Strukhoff, panelists addressed the importance of customers being able to use the specific technologies they need, through environments and ecosystems that expose their APIs to make true change and transformation possible.
Nov. 26, 2015 12:00 AM EST Reads: 483
Microservices are a very exciting architectural approach that many organizations are looking to as a way to accelerate innovation. Microservices promise to allow teams to move away from monolithic "ball of mud" systems, but the reality is that, in the vast majority of organizations, different projects and technologies will continue to be developed at different speeds. How to handle the dependencies between these disparate systems with different iteration cycles? Consider the "canoncial problem" in this scenario: microservice A (releases daily) depends on a couple of additions to backend B (re...
Nov. 25, 2015 10:00 PM EST Reads: 392
I recently attended and was a speaker at the 4th International Internet of @ThingsExpo at the Santa Clara Convention Center. I also had the opportunity to attend this event last year and I wrote a blog from that show talking about how the “Enterprise Impact of IoT” was a key theme of last year’s show. I was curious to see if the same theme would still resonate 365 days later and what, if any, changes I would see in the content presented.
Nov. 25, 2015 09:00 PM EST Reads: 366
Apps and devices shouldn't stop working when there's limited or no network connectivity. Learn how to bring data stored in a cloud database to the edge of the network (and back again) whenever an Internet connection is available. In his session at 17th Cloud Expo, Ben Perlmutter, a Sales Engineer with IBM Cloudant, demonstrated techniques for replicating cloud databases with devices in order to build offline-first mobile or Internet of Things (IoT) apps that can provide a better, faster user experience, both offline and online. The focus of this talk was on IBM Cloudant, Apache CouchDB, and ...
Nov. 25, 2015 08:30 PM EST Reads: 366
Container technology is shaping the future of DevOps and it’s also changing the way organizations think about application development. With the rise of mobile applications in the enterprise, businesses are abandoning year-long development cycles and embracing technologies that enable rapid development and continuous deployment of apps. In his session at DevOps Summit, Kurt Collins, Developer Evangelist at Built.io, examined how Docker has evolved into a highly effective tool for application delivery by allowing increasingly popular Mobile Backend-as-a-Service (mBaaS) platforms to quickly crea...
Nov. 25, 2015 05:00 PM EST Reads: 302
With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo 2016 in New York and Silicon Valley. 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 Nov 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 17th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The Internet of Things (IoT) is the most profound cha...
Nov. 25, 2015 02:45 PM EST Reads: 498
Internet of @ThingsExpo, taking place June 7-9, 2016 at Javits Center, New York City and Nov 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with the 18th International @CloudExpo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world and ThingsExpo New York Call for Papers is now open.
Nov. 25, 2015 02:30 PM EST Reads: 508
The cloud. Like a comic book superhero, there seems to be no problem it can’t fix or cost it can’t slash. Yet making the transition is not always easy and production environments are still largely on premise. Taking some practical and sensible steps to reduce risk can also help provide a basis for a successful cloud transition. A plethora of surveys from the likes of IDG and Gartner show that more than 70 percent of enterprises have deployed at least one or more cloud application or workload. Yet a closer inspection at the data reveals less than half of these cloud projects involve production...
Nov. 25, 2015 02:15 PM EST Reads: 426
Cloud computing delivers on-demand resources that provide businesses with flexibility and cost-savings. The challenge in moving workloads to the cloud has been the cost and complexity of ensuring the initial and ongoing security and regulatory (PCI, HIPAA, FFIEC) compliance across private and public clouds. Manual security compliance is slow, prone to human error, and represents over 50% of the cost of managing cloud applications. Determining how to automate cloud security compliance is critical to maintaining positive ROI. Raxak Protect is an automated security compliance SaaS platform and ma...
Nov. 25, 2015 02:00 PM EST Reads: 356
In his keynote at @ThingsExpo, Chris Matthieu, Director of IoT Engineering at Citrix and co-founder and CTO of Octoblu, focused on building an IoT platform and company. He provided a behind-the-scenes look at Octoblu’s platform, business, and pivots along the way (including the Citrix acquisition of Octoblu).
Nov. 25, 2015 01:30 PM EST Reads: 469
There are over 120 breakout sessions in all, with Keynotes, General Sessions, and Power Panels adding to three days of incredibly rich presentations and content. Join @ThingsExpo conference chair Roger Strukhoff (@IoT2040), June 7-9, 2016 in New York City, for three days of intense 'Internet of Things' discussion and focus, including Big Data's indespensable role in IoT, Smart Grids and Industrial Internet of Things, Wearables and Consumer IoT, as well as (new) IoT's use in Vertical Markets.
Nov. 25, 2015 12:00 PM EST Reads: 523
Today air travel is a minefield of delays, hassles and customer disappointment. Airlines struggle to revitalize the experience. GE and M2Mi will demonstrate practical examples of how IoT solutions are helping airlines bring back personalization, reduce trip time and improve reliability. In their session at @ThingsExpo, Shyam Varan Nath, Principal Architect with GE, and Dr. Sarah Cooper, M2Mi’s VP Business Development and Engineering, explored the IoT cloud-based platform technologies driving this change including privacy controls, data transparency and integration of real time context with p...
Nov. 25, 2015 12:00 PM EST Reads: 367