added nitrophone and fido2 docs

source/components/nitrokeys/features/fido2/index.rst

@@ -10,3 +10,4 @@ FIDO2
     Website Login <website>
     Nextcloud Login <nextcloud>
     Passwordless Microsoft Login (Windows only) <passwordless-microsoft>
+    Android / NitroPhone <nitrophone>

source/components/nitrokeys/features/fido2/nitrophone.rst

@@ -0,0 +1,36 @@
+FIDO2 on Android / NitroPhone
+*****************************
+
+.. Note::
+    For more information about FIDO2, FIDO2 U2F and Passkeys, check our `blog article  <https://www.nitrokey.com/blog/2022/fido2-webauthn-passkeys-2022-and-2023>`_.
+
+In order to use FIDO2 on GrapheneOS you need to install the Google Play services via GrapheneOS App Store.
+
+.. Note::
+    You don't have to grant Play services the network permission in order for FIDO2 to work.
+
+.. important::
+   Play services do not support PIN functionality over NFC.
+
+Multi-Factor Authentication With FIDO2, FIDO U2F
+################################################
+
+Registration and sign-in works seamlessly with USB and NFC, in Vanadium and in apps. No further steps are required.
+
+FIDO2 Passkeys
+##############
+
+**If no third-party autofill service is enabled:**
+
+Signing in with passkeys and Vanadium should work without having to change any settings.
+
+**If a third-party autofill service is enabled:**
+
+Disable Vanadium's support for passkeys with password managers by changing an experimental setting:
+
+1. In the address bar, type: ``chrome://flags`` and press enter.
+2. In the search bar, type "passkeys".
+3. A setting called "Android Credential Management for passkeys" will appear. Change this setting to "Disabled".
+4. Select "Relaunch".
+
+In order to test if FIDO2 works on your Android / NitroPhone you can use `WebAuthn.io  <https://webauthn.io/>`_.

source/components/nitrophone/faq.rst

@@ -57,4 +57,9 @@ NitroPhone FAQ
 
    Microphones are usually used to convert mechanical vibrations into electrical signals. The mechanical construction of loudspeakers is essentially the same as that of microphones, so that loudspeakers can also be used as microphones. In loudspeakers, electrical signals cause the diaphragm to vibrate, thus generating sound. Conversely, this process can be used to transmit the electrical signal from the diaphragm to the device, as with a microphone. However, this method is not possible if an amplifier is installed, as this does not allow the signal to be transmitted from the loudspeaker to the device. All Nitrophones only have speakers with built-in amplifiers and are therefore harmless.
 
+.. faq:: How to use FIDO2 with Android / NitroPhone?
+
+   Please refer to our guide :doc:`../nitrokeys/features/fido2/nitrophone`.
+
+
 .. _all major carriers: https://support.google.com/pixelphone/answer/7107188?hl=en