Passkeys do not work with Microsoft 365

(Note, I happened to be on page 1 on an old open tab when I started this, and didn't see the replies just above from alcyone7 and duscu and others with similar information, but I gathered a few more details (and words, haha) even though they appear to be just as accurate, so the below is an "also" and not entirely new to the thread--wish I'd seen the above replies before my conversation with JefTek, it would have helped clarify a bit!)

I wanted to update this to let folks know that Microsoft has enabled Passkeys as a preview for Microsoft 365/Entra ID accounts, BUT only "device-bound" Passkeys and ONLY initially using the Microsoft Authenticator app on iOS and Android. You also need to make the Authenticator app, on iOS at least, your "primary" additional Passkey app (other than iCloud Keychain, which can also be simultaneously enabled), but you can only have ONE non-Apple Passkey app. And 1Password is mine. Which means I can't use Microsoft 365 Entra ID Passkeys yet, because I'd have to make MS Authenticator the Passkey provider on iOS and not 1Password.

However, Microsoft said that before the end of 2024 they will also roll out "syncable" Passkey support (the kind that 1Password uses, along with many other password managers and some of the platform tools/browsers. However, they will need to be explicitly enabled (as device-bound ones do now) by an administrator.

And, you'll have to/need to determine which "AAGUID" values you'll accept--every Passkey provider generates a unique AAGUID for authenticators with the same features. So Yubico's Yubikeys (which also can save device-bound Passkeys and have worked with Microsoft Entra ID for years as FIDO2 keys) have AAGUIDs per "family" depending on the features of each key. You can authorize as many or as few AAGUIDs as you want for a particular Microsoft tenant (or even a Custom Authentication Strength you can define and assign to particular groups/users or even certain applications), so administrators have control over which Passkeys they will accept instead of usernames and passwords. I think this control for business accounts is a good thing, but I'm disappointed I can't enable the 1Password AAGUID yet! (Well, I can and did, but it doesn't work since Microsoft only enables those for Authenticator--you actually have to add iOS and Android Authenticator App AAGUIDs to your allow list explicitly even to test the public beta!).

If you're curious, you can see a list of known password manager AAGUIDs here, including 1Password's:

https://passkeydeveloper.github.io/passkey-authenticator-aaguids/explorer/

That is generated from this GitHub repository collecting them for easy use, and they are available in several programmer-friendly formats also: https://github.com/passkeydeveloper/passkey-authenticator-aaguids

And you can see how Yubikeys have various AAGUIDs based on which model/features each hardware keys has from Yubico's own list, here: https://support.yubico.com/hc/en-us/articles/360016648959-YubiKey-Hardware-FIDO2-AAGUIDs

The Microsoft information above was pulled from a reasonably long discussion I had in the last few weeks with Jef Kazimer (JefTek) of https://jeftek.com/ (he's a Principal Project Manager for Microsoft Entra ID at Microsoft) in an Entra-related Discord server, and is a summery of a longer discussion. I really hope (and asked for) syncable Passkey support ASAP!

Oh, and Microsoft's official documentation to enable Passkey support is located at https://learn.microsoft.com/en-us/entra/identity/authentication/how-to-enable-passkey-fido2 and the purple callout near the top does (if you know what they are!) explicitly list that device-bound Microsoft Authenticator Passkeys (in addition to physical security keys) are the only ones supported now but that synced passkey is being worked on:

For reference I have a screenshot of the iOS Passkey app configuration screen showing where you can enable or disable iCloud Keychain (I have it disabled in the screenshot) and ONE other Passkey app--I have 1Password selected, but if I choose Authenticator, 1Password switches to disabled and vice-versa:

I don't know if there's a way for 1Password to detect if a credential that's saved for login.microsoftonline.com right now is for a Microsoft Personal/Family account (used to be a Live ID many years ago), or if the credential is for a Microsoft 365 Work/Entra ID business tenant account. If they can tell automatically, it would be nice for their "Passkey is available!" alert at the top of a saved item for Microsoft to be smarter about not presenting that alert for Entra ID accounts until synced passkeys are supported in Entra ID, and when they are, to link to the setup page (like the above document) because each tenant will need explicit configuration before 1Password Passkeys (or any!) will work--maybe they should write a blog post at that time and walk people through the steps for 1Password at least.

Oh, and one more thing, and you can do this now! I went to https://www.apple.com/feedback/iphone/ and submitted the following feature request to Apple about allowing multiple secondary (non-iCloud Keychain) Passkey apps in a future iOS update, and you can easily submit the same request so they get more feedback! Mine looked like this as an example: