Aaron Parecki

#oauth2

• OAuth

  Aaron Parecki

  Sat, Feb 4, 2017 11:35am -08:00

  Hi, I'm Aaron Parecki. I write about OAuth here, and I give talks about OAuth 2.0. Below you'll find my recent posts about various OAuth-related things, including talks I'm giving. I've also written two community resources about OAuth:

  OAuth 2.0 Simplified is a guide to OAuth 2.0 focused on writing clients that gives a clear overview of the spec at an introductory level.

  In 2017, I published a longer version of this guide as a book, available on oauth.com as well as a print version. The book guides you through building an OAuth server, and covers many details that are not part of the spec. I published this book in conjunction with Okta.

  Portland, Oregon

  #oauth #oauth2

  Sat, Feb 4, 2017 11:35am -08:00

• Mark W. Schumann https://twitter.com/MarkWSchumann

  Excellent explanation by @aaronpk of @okta of why PKCE is important in #OAuth2. I feel like @nbarbettini, the guy on the left asking these questions.
  
  https://oauth.net/2/grant-types/implicit/

  Portland, Oregon • 43°F

  #OAuth2

  Sat, Jan 11, 2020 10:55pm +00:00 (liked on Sat, Jan 11, 2020 8:04pm -08:00)
• 

  Some more info on OAuth 2.1 from the @oktadev blog:
  
  OAuth 2.1: How many RFCs does it take to change a light bulb?
  
  https://developer.okta.com/blog/2019/12/13/oauth-2-1-how-many-rfcs

  Portland, Oregon • 46°F

  31 likes 5 reposts 6 replies 1 mention

  #oauth #oauth2

  Fri, Dec 13, 2019 10:29am -08:00
• Matt Raible https://twitter.com/mraible

  With OAuth 2.1:
  
  "...there should be no need to document the most secure way to implement OAuth, since that should be the only option available when you read the spec." 👍 #oauth2

  Portland, Oregon • 49°F

  #oauth2

  Fri, Dec 13, 2019 2:44am +00:00 (liked on Thu, Dec 12, 2019 6:45pm -08:00)

• It's Time for OAuth 2.1

  Aaron Parecki

  Thu, Dec 12, 2019 6:10pm -08:00

  Trying to understand OAuth often feels like being trapped inside a maze of specs, trying to find your way out, before you can finally do what you actually set out to do: build your application.

  

  While this can be incredibly frustrating, it’s no accident that OAuth is actually made up of many different RFCs, building upon each other and adding features in different ways.

  In fact, the “core” OAuth spec, RFC 6749, isn’t even called a specification, it’s technically a “framework” you can use to build specifications from. Part of the reason for this is because it leaves a lot of things optional, and requires that an implementer makes decisions about things like which grant types to support, whether or not refresh tokens are one-time use, and even whether access tokens should be Bearer tokens or use some sort of signed token mechanism.

  This has often been quoted as the biggest failure of OAuth, but is also a large part of the reason OAuth has been successfully deployed at the largest companies at scale over the last 10 years.

  OAuth has been patched and extended a lot in the last decade of experience deploying systems using it. It’s been extended in ways the original authors could never even see coming. Keep in mind that when OAuth 2.0 was published in 2012, the iPhone 5 was brand new, the latest browser from Microsoft was Internet Explorer 9, single-page apps were called “AJAX apps”, and CORS was not yet an established W3C standard.

  Since 2012, the web and mobile landscape has changed dramatically. More people access the internet from mobile devices than desktop devices, single-page apps are an extremely common way of creating web apps, and countless password database breaches have time and again demonstrated that storing passwords is dangerous.

  The Evolving OAuth 2.0 Landscape

  To address this changing landscape, the OAuth community has patched and added to the OAuth spec over the years. The OAuth core spec (RFC 6749) defines four grant types: Authorization Code, Implicit, Password, and Client Credentials. It used to be the case that the Implicit grant was recommended for both JavaScript apps as well as native apps.

  

  It became apparent that a better solution was needed for mobile apps, so PKCE (RFC 7636) was created to provide a way to use the Authorization Code flow without a client secret.

  

  Later, “OAuth 2.0 for Native Apps” (RFC 8252) was published, which recommends that native apps use the Authorization Code flow with the PKCE extension.

  

  A new class of device arose along with a need to use OAuth with them: devices that have no browser or lack a keyboard, such as an Apple TV or YouTube streaming video encoder. An entirely new OAuth grant was created to address this, called the Device Grant, published as RFC 8626.

  

  There are even more patches currently in the works. I am writing a draft for best practices for single-page apps, and the latest Security Best Current Practice (BCP) is currently in the final call. The single-page apps draft recommends using PKCE with JavaScript apps and says you should no longer use the Implicit flow. The Security BCP effectively deprecates the Implicit flow as well as the Password grant out of OAuth entirely, and further recommends using PKCE even for web server apps.

  So what started out as a list of four grant types has had things added and removed, and now looks more like this.

  

  Which, if you look closely, actually ends up distilling down to this:

  

  So what we’ve effectively done is taken the core OAuth RFC, added and removed things, and turned it into an entirely different set of recommendations. The problem is that it requires reading far too many RFCs to understand this landscape.

  If you want to implement a secure OAuth solution today, it requires reading: RFC 6749 (OAuth 2.0 Core), RFC 6750 (Bearer Tokens), RFC 6819 (Threat Model and Security Considerations), RFC 8252 (OAuth for Native Apps), RFC 8628 (Device Grant), OAuth for Browser-Based Apps, OAuth 2.0 Security Best Current Practice, RFC 7009 (Token Revocation), RFC 8414 (Authorization Server Metadata), and if you’re also implementing an OAuth server, then you need to read RFC 7519 (JWT), JWT Best Current Practice, JWT Profile for Access Tokens, and probably some others that I forgot. That’s a lot of material.

  Why not OAuth 3?

  So why am I suggesting an OAuth 2.1? Surely we should instead scrap this existing work and create something simpler and more streamlined?

  As it so happens, that effort is already under way as well, being led by Justin Richer under the name Transactional Authorization, or TXAuth, and likely to end up as OAuth 3. That effort takes a completely greenfield approach, rethinking how OAuth and all its related specs and extensions such as UMA might look if everything were not tied to being an extension of the original OAuth 2.0 RFC 6759. I’m definitely in support of this effort, there are a lot of nice patterns that emerge when you look at it this way, but as we all know, creating a new spec from scratch is not a quick process, much less getting broad adoption within the industry. So while effort on OAuth 3 is under way, which will take literal years to finish, there is room to tidy things up with OAuth 2 in the mean time.

  Creating OAuth 2.1

  At the OAuth working group meeting in Singapore last month (IETF 106), I led a discussion about OAuth 2.1 and what it should encompass.

  My main goal with OAuth 2.1 is to capture the current best practices in OAuth 2.0 as well as its well-established extensions under a single name. That also means specifically that this effort will not define any new behavior itself, it is just to capture behavior defined in other specs. It also won’t include anything considered experimental or still in progress.

  There was a general agreement from folks in the room that something like this is needed, and following the official meeting, I led a two-hour breakout session where a dozen or so of us dove into more details and started making a plan.

  Torsten, the author of the Security BCP made a comment which I thought framed the discussion well. His goal for OAuth 2.1 is that it should make the Security BCP irrelevant because it already includes everything the Security BCP says. In other words, there should be no need to document the most secure way to implement OAuth, since that should be the only option available when you read the spec.

  What is OAuth 2.1?

  We still need to discuss the specifics about what form this document will take, whether that is going to be an entirely new RFC that replaces RFC 6749, or a BCP that references the other specs, or something else entirely. However, the overarching goals are:

  • Give people a starting point which lays out a clear path for what they will need to read
  • Reduce the number of documents people have to read to understand OAuth and implement it securely
  • Get rid of the irrelevant content in old RFCs that has been deprecated, so that readers don’t get through an entire section only to discover a later RFC deprecated it
  • Labeling libraries or products as OAuth 2.1 is a lot simpler to understand than having to figure out whether it accurately implements OAuth 2.0 and all the desired extensions

  The specifics of what will be included in OAuth 2.1 are still up for discussion within the group, and will be in the agenda of the upcoming IETF meetings. The starting point for these discussions is roughly the below.

  • Start with OAuth 2.0 Core, RFC 6749
  • Include OAuth 2.0 Bearer Tokens, RFC 6750
  • Adopt the Security BCP, which removes the Password grant and the Implicit flow
  • Require PKCE for all client types, not just public clients (defined in the Security BCP)
  • Adopt the native app and browser-based app BCPs
  • Include the Device Grant as a top-level grant option available (RFC 8626)
  • Include Token Revocation (RFC 7009)
  • Include Authorization Server Metadata (RFC 8414)

  If an authorization server intends to interoperate with arbitrary resource servers, such as OAuth services and open source projects, then there is an additional set of requirements that includes:

  • Token Introspection (RFC 7662)
  • JWT Access Tokens (current working group draft)
  • JWT Best Current Practice (current working group draft)

  Of course all of these points are currently up for debate, so if you have feelings about them, you should definitely join the mailing list and discuss them!

  Currently the biggest question for the group is whether or not OAuth 2.1 should make technically breaking changes. It definitely won’t define anything new itself, but if you look at what the Security BCP says, it requires PKCE for all authorization code grants, even for confidential clients. Since most current deployments of OAuth 2.0 only support PKCE for public clients, that means most current deployments will not be compliant with OAuth 2.1 out of the gate. There are arguments on both sides of this, which was a large part of the discussion during the breakout session last month, with no clear consensus.

  These are the kinds of questions that will be discussed in the coming months within the group. If you have thoughts, I would be more than happy to hear them! Feel free to send an email to the list directly, or even write a blog post in response!

  I’m excited for this work to kick off, and looking forward to many more discussions going forward!

  Portland, Oregon • 49°F

  104 likes 57 reposts 1 bookmark 2 replies 13 mentions

  #oauth #oauth2 #oauth21

  Thu, Dec 12, 2019 6:10pm -08:00

• It's an OAuth week!

  Aaron Parecki

  Mon, Dec 9, 2019 1:28pm -08:00

  Now is your chance to join and ask me your OAuth questions!

  💻 Tuesday 11am-12pm PST: OktaDev Office Hours

  📕 Wednesday 10am-1pm PST: Intro to OAuth 2.0 with O'Reilly

  🔐 Thursday 11am-12pm PST: Protecting Your APIs with OAuth

  

  Okta Developer Office Hours

  Tue Dec 10 11am-12pm PST

  Join myself and Okta coworkers for our latest edition of virtual office hours! We'll be streaming on YouTube and taking questions via the chat! Make sure to subscribe to OktaDev on YouTube and click the bell icon to be notified when we go live! You can ask us anything about OAuth or user management in .NET!
  

  

  Hands-On Introduction to OAuth 2.0

  Wed Dec 11 10am-1pm PST

  In this three hour workshop hosted by O'Reilly, I'll be covering the basics of OAuth 2.0 and working through the most common grant types. We'll be doing some exercises to demonstrate the OAuth flows from scratch. Access to this workshop requires an O'Reilly Safari Online subscription.
  

  

  Protecting Your APIs with OAuth 2.0

  Thu Dec 12 11am-12pm PST

  In this free webinar, I'll be diving in to how you can use OAuth to protect your APIs, talking about things like how to use JWT access tokens and the tradeoffs that come with them, how to design scopes to allow granular access, and how to leverage a microservices architecture protected by OAuth at a gateway.

  We'll be giving away a copy of my book to one lucky winner as well!

  Register now!

  Portland, Oregon • 47°F

  5 likes 3 reposts 1 mention

  #oauth #oauth2

  Mon, Dec 9, 2019 1:28pm -08:00
• 

  If you missed my talk from @APIdaysAU last month, I just posted the video online!
  
  Securing Your APIs with #OAuth 2.0: https://youtu.be/PfvSD6MmEmQ

  Amsterdam, Noord-Holland, NLD • 63°F

  13 likes 2 reposts 2 mentions

  #oauth #apidays #apidaysau #oauth2

  Tue, Oct 1, 2019 1:58pm +02:00
• Matt Raible https://twitter.com/mraible

  What's going on with the OAuth 2.0 Implicit flow? From my awesome colleagues @aaronpk and @nbarbettini! https://youtu.be/CHzERullHe8 #oauth2 #implicitflow

  Portland, Oregon

  #oauth2 #implicitflow

  Tue, Jun 11, 2019 1:37am +00:00 (liked on Mon, Jun 10, 2019 6:50pm -07:00)
• Arindam Mukherjee https://twitter.com/ErrInDam

  If you've struggled to understand how #OAuth2 works, this one should help:
  
  https://aaronparecki.com/oauth-2-simplified/

  Portland, Oregon

  1 mention

  #OAuth2

  Sun, May 19, 2019 9:04am +00:00 (liked on Sun, May 19, 2019 9:20am -07:00)
• OktaDev https://twitter.com/oktadev

  Stop by the @okta booth at @devnexus to take our developer challenge! You can win an @oauth_2 book by @aaronpk or a @jhipster_book from @mraible. #oauth2 #jhipster #oktadevchallenge #hackforabook

  

  Portland, Oregon • 35°F

  #oauth2 #jhipster #oktadevchallenge #hackforabook

  Thu, Mar 7, 2019 3:30pm +00:00 (liked on Thu, Mar 7, 2019 8:48am -08:00)
• Josh Grossman 👻 https://twitter.com/JoshCGrossman

  "I'll just implement my own #OAuth2 authorisation server, how hard could it be?" - a client
  #AppSec

  

  New York, New York • 50°F

  #OAuth2 #AppSec

  Tue, Feb 5, 2019 12:32pm +00:00 (liked on Tue, Feb 5, 2019 8:25am -05:00)
• 

  If you've ever needed a link to send someone to explain why OAuth secrets aren't safe in mobile apps, I made you a thing: https://developer.okta.com/blog/2019/01/22/oauth-api-keys-arent-safe-in-mobile-apps

  San Francisco, California, USA • 59°F

  13 likes 10 reposts 3 replies

  #oauth #oauth2 #api #security

  Tue, Jan 22, 2019 4:09pm -08:00
• Vittorio https://twitter.com/vibronet

  Did you hear about the latest #OAuth2 security BPC and what it proposes for securing SPAs? Get a backgrounder on why it's time to consider retiring the implicit flow and how @Auth0 can help in this article https://auth0.com/blog/oauth2-implicit-grant-and-spa/

  

  Portland, Oregon • 41°F

  #OAuth2

  Tue, Jan 8, 2019 5:28pm +00:00 (liked on Tue, Jan 8, 2019 9:45am -08:00)
• Brock Allen https://twitter.com/BrockLAllen

  The State of the Implicit Flow in OAuth2 https://brockallen.com/2019/01/03/the-state-of-the-implicit-flow-in-oauth2/ #oauth2 #oidc #aspnetcore

  Portland, Oregon • 53°F

  #oauth2 #oidc #aspnetcore

  Thu, Jan 3, 2019 9:54pm +00:00 (liked on Thu, Jan 3, 2019 2:30pm -08:00)
• The State of the Implicit Flow in OAuth2 | brockallen (brockallen.com)

  Portland, Oregon • 53°F

  #oauth #oauth2

  Thu, Jan 3, 2019 2:27pm -08:00
• 

  Alright, I think we can call it. Between @tlodderstedt's OAuth Security Best Practices and OAuth 2.0 for Browser Apps, the Implicit Flow is dead.
  
  https://tools.ietf.org/html/draft-ietf-oauth-security-topics-09
  
  https://tools.ietf.org/html/draft-parecki-oauth-browser-based-apps-00
  
  https://medium.com/@torsten_lodderstedt/why-you-should-stop-using-the-oauth-implicit-grant-2436ced1c926

  Portland, Oregon, USA • 36°F

  4 likes 5 reposts 2 mentions

  #oauth #oauth2

  Fri, Nov 9, 2018 8:57am -08:00
• Moving On from OAuth 2? – Justin Richer – Medium (medium.com)

  Mountain View, California • 60°F

  #oauth #oauth2 #iiw

  Tue, Oct 23, 2018 10:47am -07:00
• Jim Shingler https://twitter.com/jshingler

  @aaronpk talking #Oauth2 and #OIDC at #cardinalhealth great meeting thanks @okta

  

  Columbus, Ohio • 72°F

  1 mention

  #Oauth2 #OIDC #cardinalhealth

  Thu, Oct 11, 2018 12:04am +00:00 (liked on Wed, Oct 10, 2018 8:23pm -04:00)
• 

  Next week I'll be hosting a workshop on @OAuth2 in Germany as part of Nürnberg Web Week festival @nueww! It's filling up fast but there are still some spots left! https://nuernberg.digital/festival/programm/2018/understanding-and-implementing-oauth-2-0-mit-aaron-parecki-42/

  Columbus, Ohio, USA • 72°F

  11 likes 6 reposts 3 replies

  #oauth #oauth2

  Wed, Oct 10, 2018 7:32pm -04:00
• OAuth.io https://try.oauth.io

  We will be talking about 'The Many Flavors of OAuth' at @APIdaysGlobal San Francisco about #oauth2 and briefly covering identity layers #openidconnect #oidc and #IndieAuth. We have a few tickets to giveaway. Please register with code 'Soonhin' at https://www.apidays.co/sanfrancisco. See you!

  Portland, Oregon • 95°F

  #oauth2 #openidconnect #oidc #IndieAuth

  Mon, Jul 30, 2018 1:47am +00:00 (liked on Sun, Jul 29, 2018 7:44pm -07:00)
• 

  OAuth for the Open Web
  
  A little about the challenges of using #OAuth2 in a distributed setting for WordPress, GitLab, Mastodon, and more. Spoiler: it's not all bad news. Let's make this happen!
  
  https://aaronparecki.com/2018/07/07/7/oauth-for-the-open-web

  Portland, Oregon, USA • 72°F

  61 likes 31 reposts 6 replies 2 mentions

  #oauth2

  Sat, Jul 7, 2018 9:41am -07:00