For an existing iOS generic-password Keychain item, what documented public API or query contract can establish that its returned SecAccessControl has no additional authentication, application-password, or operation-specific constraints? The item must remain WhenUnlockedThisDeviceOnly, in an exact access group and identity, and non-synchronizing. An unknown or unverified item must be refused without modifying, deleting, or replacing it.
An attribute-only creation with no explicit access-control object can return a SecAccessControl when data and attributes are read. We observed this on an iOS 26.5 Simulator. The returned object compared different from a freshly created zero-flags object. We are not treating either that comparison or a successful no-UI read as proof of its complete constraints.
The public interface we reviewed exposes creation and type identification; constraint inspection and serialization appear in private headers. Evaluating one operation also does not describe the item's complete policy. Is there a supported discriminator we have missed? If not, is there a documented creation-provenance and persistent-item-identity contract that establishes this property across relaunch, and what limitations apply to existing or recreated items?
Please clarify the supported contract rather than private implementation details. We need to preserve refusal of unverified existing items while using the public Keychain APIs correctly.