openid / openid4vp_ble

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Maximum length of Request is limited to 512 bytes -> add chunk suppor? #56

Open sschulz-t opened 6 months ago

sschulz-t commented 6 months ago

The current draft does not specify the maximum length for the request 00000005-5026-444A-9E0E-D6F2450F3A77

As per BT specification "3.2.9 Long attribute values"

... The maximum length of an attribute value shall be 512 octets. ...

Longer values as 512 bytes seem to work under linux/macosx but not on android (https://cs.android.com/android/platform/superproject/main/+/main:packages/modules/Bluetooth/system/stack/gatt/gatt_cl.cc;l=692;drc=7369db2599643b98b60b3b6237178919f9b7726d). In older android versions this limit was 600 bytes and was recently changed to 512 in order to comply with the bt spec.

Having only 512 bytes looks quite limiting to me, we should come up with some kind of chunking mechanism here as well.