Error: [50152] RP ID cannot be validated on `Android`

[timmyjose]

Platform: Android (Device/Emulator), iOS works.

(Note: Using expo with a prebuild/CNG flow).

When I try to create the account (using the example code):

Error: [50152] RP ID cannot be validated.

I've tried:

• Setting up a firebase project hosting the assetlinks.json file
• Tried on Android 11 and Emulator (different Android version)
• Configure strings.xml to have the asset_statements string.
• All the suggestions in this thread - Android-Specific Error Encountered in Passkey Registration Process #29

Testing https://webauthn.io in the Emulator worked.

I'm out of ideas. I can't find any information on this error beyond Native Android threads, which still don't give any concrete help.

[timmyjose]

Also, does the app need to have been published in the Play Store? Right now, I'm using the debug keystore SHA256, and the Google assets validator (https://developers.google.com/digital-asset-links/tools/generator) shows:

[mdipanjan]

I'm testing a basic version myself and I'm also getting this same error on Andoid emulator as well as on a real android device.

[timmyjose]

@mdipanjan

I did read somewhere that only Android 14 and above is supported, but even with an emulator on Android 15, we still get this error.

I think the issue might be with the SHA-256 for the debug build (for assetlinks.json), but can't be sure. I tried creating an internal build in the Play Store for the prototype I'm working on, but that didn't work either.

[mdipanjan]

It did work for me on Andorid 15 emulator on my local debug build @timmyjose

[timmyjose]

@mdipanjan Nice! That's encouraging to hear.

How did you set up the assetlinks.json part? Could you please share some details?

For me:

• I created a custom domain in firebase cloud
• I created an assetlinks.json file inside /.well-known like so:

[{
  "relation": ["delegate_permission/common.get_login_creds"],
  "target" : { "namespace": "android_app", "package_name": "<android package name here>",
               "sha256_cert_fingerprints": ["<SHA-256 from keytool output using debug keystore"] }
},
{
  "relation": ["delegate_permission/common.get_login_creds"],
  "target" : { "namespace": "web", "site": "<my firebase custom domain>" }
}]

(I'm using expo, but that shouldn't make a different, I suppose).

[timmyjose]

(Just tried with Android 16 as well - same error for me).

[mdipanjan]

Hello @timmyjose so in my case I'm using an node.js server and that looks like this:

fastify.get("/.well-known/assetlinks.json", async (request) => {
  return [{
    relation: [
      "delegate_permission/common.handle_all_urls",
      "delegate_permission/common.get_login_creds"
    ],
    target: {
      namespace: "android_app",
      package_name: process.env.APP_PACKAGE_NAME,
      sha256_cert_fingerprints: [process.env.WEBAUTHN_ANDROID_CERT_FINGERPRINTS]
    }
  }];
});

And in the android file:

myApp/android/app/src/main/res/values/strings.xml

Have included this (for https serving over ngrok):

<resources>
    <string name="app_name">myApp</string>
    <string name="asset_statements" translatable="false">
        [{
            \"include\": \"https://xyz.ngrok-free.app/.well-known/assetlinks.json\"
        }]
    </string>
</resources>

I hope this helps to resolve your issue.

[timmyjose]

Thank you, @mdipanjan! Appreciate it!

That is very helpful indeed! So I made the changes by comparing your assetlinks.json and strings.xml:

 ERROR  {"error": "Native error", "message": "Error: The incoming request cannot be validated"}

a different error now, but that's still some progress! I'll try and debug this issue and see.

Since your setup is working, it gives me confidence that my issue must be some annoying configuration issue!

[mdipanjan]

@timmyjose you got this. The error you see now, I was getting it at some point and some change the configuration might resolved it for me.

I'm certain you need some tweek in the config and it'll work. My registration was working but had issue with login and this issue thread helped me. Leaving it here if this might help you too.

Also take a look at this medium article series which helped me a lot in my POC implementation. Hope these help.

[timmyjose]

Thank you, @mdipanjan ! I'll have a look at the linked resources, and hopefully it should steer me towards resolving these nagging issues!

[wilmxre]

@timmyjose hi, i just faced the same Error: [50152] RP ID cannot be validated error, did you manage to fix this issue?

[timmyjose]

@wilmxre Sadly, no. I tried everything, including the excellent resources linked to by @mdipanjan , but no luck.

[wilmxre]

@timmyjose in the meanwhile i discovered on a Samsung device, that if i go with Samsung Pass as the passkey manager, i can register the passkey successfully. with the Google Password Manager option, i still get Error: [50152] RP ID cannot be validated. so there must be something with how GPM is validating the credentials.

[abc910804]

I get this same error and have already tried every solution I could find online, but I still can’t fix it. I’m not sure if anyone has managed to solve it.