Sample code showing how to use Android ID Attestation

I was able to hack around and came up with an demo code that does Key/ID attestation. See https://github.com/monkey-jsun/android-id-attestation/tree/master

While the program runs, I have two problems at this moment,

• All the hardware ID are shown as "NOT PRESENT". See below. Clearly they are there. How to make them appear?
• Currently we generate a key and its attestation in one step (keyPairGenerator.generateKeyPair()) because we have to request attestation when initializing keyPairGenerator. It is very unnatural. Is there a way to request key/ID attestation after the key is created?

Here is a quick recap of my demo code just for quick reference:

• generate a key pair with challenge phrase in keystore
• fetch the key pair and its certificate chain
• display cert[0] extension data with bouncy castle library

I also attached the output the program for easy reference.

 Getting key 'key1' ...
 found the key with alias 'key1' ...
 private key : android.security.keystore.AndroidKeyStoreECPrivateKey@3467522e
 public key : MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEOfYzvOETzK0NGmlkk3vnuDb9FilG7iiRYGJX2pQy
    Syuyt2XZow5M3aseZEfD64iasieuumWx3Tn6/aiopre0cw==
 what is happening ...
 number certificates in the chain is 4
 Attestation version: 3
 Attestation Security Level: TRUSTED_ENVIRONMENT
 Keymaster Version: 4
 Keymaster Security Level: TRUSTED_ENVIRONMENT
 Attestation Challenge: hello, this is challenge phrase [jsun]
 Unique ID: []
 =========
    Software Enforced Authorization List:
    Purpose(s): NOT PRESENT
    Algorithm: NOT PRESENT
    Key Size: NOT PRESENT
    Digest: NOT PRESENT
    Padding: NOT PRESENT
    EC Curve: NOT PRESENT
    RSA Public Exponent: NOT PRESENT
    Rollback Resistance: false
    Active DateTime: NOT PRESENT
    Origination Expire DateTime: NOT PRESENT
    Usage Expire DateTime: NOT PRESENT
    No Auth Required: false
    User Auth Type: NOT PRESENT
    Auth Timeout: NOT PRESENT
    Allow While On Body: false
    Trusted User Presence Required: false
    Trusted Confirmation Required: false
    Unlocked Device Required: false
    All Applications: false
    Application ID: NOT PRESENT
    Creation DateTime: 2020-03-07T17:58:57.143Z
    Origin: NOT PRESENT
    Rollback Resistant: false
    OS Version: NOT PRESENT
    OS Patch Level: NOT PRESENT
    Attestation Application ID:
        Package Infos (<package name>, <version>): 
            net.junsun.idattestation, 1
        Signature Digests:
            GGv7HVeENa6GZO4irSicN64Wz38NJ7QHsmC0Z2G7s4g=
    Attestation Application ID Bytes: MEUxHzAdBBhuZXQuanVuc3VuLmlkYXR0ZXN0YXRpb24CAQExIgQgGGv7HVeENa6GZO4irSicN64Wz38NJ7QHsmC0Z2G7s4g=
    Attestation ID Brand: NOT PRESENT
    Attestation ID Device: NOT PRESENT
    Attestation ID Product: NOT PRESENT
    Attestation ID Serial: NOT PRESENT
    Attestation ID IMEI: NOT PRESENT
    Attestation ID MEID: NOT PRESENT
    Attestation ID Manufacturer: NOT PRESENT
    Attestation ID Model: NOT PRESENT
    Vendor Patch Level: NOT PRESENT
    Boot Patch Level: NOT PRESENT
 =========
    TEE Enforced Authorization List:
    Purpose(s): [2, 3]
    Algorithm: 3
    Key Size: 256
    Digest: NOT PRESENT
    Padding: NOT PRESENT
    EC Curve: 1
    RSA Public Exponent: NOT PRESENT
    Rollback Resistance: false
    Active DateTime: NOT PRESENT
    Origination Expire DateTime: NOT PRESENT
    Usage Expire DateTime: NOT PRESENT
    No Auth Required: true
    User Auth Type: NOT PRESENT
    Auth Timeout: NOT PRESENT
    Allow While On Body: false
    Trusted User Presence Required: false
    Trusted Confirmation Required: false
    Unlocked Device Required: false
    All Applications: false
    Application ID: NOT PRESENT
    Creation DateTime: NOT PRESENT
    Origin: 0
    Rollback Resistant: false
    OS Version: 100000
    OS Patch Level: 202002
    Attestation Application ID Bytes: NOT PRESENT
    Attestation ID Brand: NOT PRESENT
    Attestation ID Device: NOT PRESENT
    Attestation ID Product: NOT PRESENT
    Attestation ID Serial: NOT PRESENT
    Attestation ID IMEI: NOT PRESENT
    Attestation ID MEID: NOT PRESENT
    Attestation ID Manufacturer: NOT PRESENT
    Attestation ID Model: NOT PRESENT
    Vendor Patch Level: 20200205
    Boot Patch Level: 20200205