earlyBootOnly
Early-boot-only restriction.
Corresponds to the Tag::EARLY_BOOT_ONLY authorization tag, which uses a tag ID value of 305.
ASN.1: earlyBootOnly [305] EXPLICIT NULL OPTIONAL. Present in key attestation versions 4, 100, 200, 300, 400.
Note: in this API, presence/absence of this field is represented by null vs non-null. See EarlyBootOnly.explicitTag.