Contact emails

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Explainer

The Federated Credential Management (FedCM) API currently only allows one 
identity provider (IDP) to be used when performing federated login in a 
website. We would like to experiment with allowing multiple providers to be 
specified in a single JavaScript get() call, which allows FedCM to be used 
in cases for which the website supports multiple IDPs for federation. See 
also additional context in https://github.com/fedidcg/FedCM/issues/319.

Specification

https://fedidcg.github.io/FedCM

Summary

Allows FedCM to show multiple IDPs in the same dialog. This provides 
developers with a convenient way to present all supported identity 
providers to users. In this I2E, we are tackling the simple case of having 
all providers in the same get() call, while building much of the UX 
infratructure that will allow us to tackle more sophisticated production 
structures later.


Blink component

Blink>Identity>FedCM 
<https://bugs.chromium.org/p/chromium/issues/list?q=component:Blink%3EIdentity%3EFedCM>

TAG review

https://github.com/w3ctag/design-reviews/issues/803

TAG review status

Pending

Risks

Interoperability and Compatibility

This should not have additional interop risks on top of the existing FedCM 
API which is generally supported but not yet implemented by Firefox and 
Safari. In order to determine whether multiple IDPs are supported in a 
browser which supports FedCM, the developer can attempt to first call get() 
with multiple IDPs. It will be rejected immediately if not supported and 
the RP can retry with a single IDP.


Gecko: No signal (https://github.com/mozilla/standards-positions/issues/730)

WebKit: No signal (https://github.com/WebKit/standards-positions/issues/120)

Web developers: Positive (https://github.com/fedidcg/FedCM/issues/319)

Other signals:

Ergonomics

Using this API will just require expanding the get() to use more providers, 
so it will benefit from the ergonomics of the initial FedCM API.


Activation

The main activation issue is having to include all IDPs in the same get() 
call, which may be challenging in some cases because IDPs generally are 
independent from each other. That said, we do have developers who can use 
the single get() call, so we wish to start with the simpler version of 
multi IDP support.


Security

The security considerations are similar to those of the single IDP case. We 
do not require users to input usernames and passwords due to spoofing 
concerns, and we also have input protection to prevent accidental click 
right after the UI is shown.


WebView application risks

Does this intent deprecate or change behavior of existing APIs, such that 
it has potentially high risk for Android WebView-based applications?

n/a, FedCM is not supported on WebView


Goals for experimentation

We want to ensure that the single get() call is sufficient for the use 
cases we are targeting, where the multiple IDPs are owned by a single 
entity, as well as gather developer feedback before fully shipping. The 
multiple independent IDPs scenario is out of scope for experimentation, as 
we anticipate that it will be hard to impossible to use FedCM in a single 
get() call in such a scenario.

A successful trial would result in our partner requesting us to ship this 
feature to allow using FedCM with their multiple IDPs.

Ongoing technical constraints

None


Debuggability

The debug tools are similar to that of original FedCM: console messages and 
DevTools issues. Seeing FedCM network requests is not supported in DevTools 
but can be achieved via chrome://net-export.


Will this feature be supported on all six Blink platforms (Windows, Mac, 
Linux, ChromeOS, Android, and Android WebView)?

No

As with the initial FedCM, we do not support Android WebView.


Is this feature fully tested by web-platform-tests 
<https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md>
?

Yes

https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/web_tests/external/wpt/credential-management/fedcm-multi-idp/
 
Some of these tests are not relevant as they are related to the multi-get() 
approach.


Flag name on chrome://flags

FedCmMultiIdp

Finch feature name

FedCmMultipleIdentityProviders

Requires code in //chrome?

True

Tracking bug

https://bugs.chromium.org/p/chromium/issues/detail?id=1348262

Launch bug

https://launch.corp.google.com/launch/4229762

Estimated milestones

DevTrial on desktop

122

  OT desktop 124 - 128

  OT Android 125 - 128

Link to entry on the Chrome Platform Status

https://chromestatus.com/feature/5067784766095360

This intent message was generated by Chrome Platform Status 
<https://chromestatus.com/>.

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