This commit introduces a comprehensive simulation engine for Keystore's `createOperation`, enabling the simulator to correctly handle multiple cryptographic purposes (SIGN, VERIFY, ENCRYPT, DECRYPT) for software-generated keys.
The implementation correctly mimics the AOSP framework's internal key identification mechanism. Instead of relying on an alias, a unique `keyId` is generated and embedded in the `nspace` field of the KeyDescriptor during `generateKey`. The `createOperation` hook then uses this `keyId` to dispatch requests: if the ID matches a known software key, the operation is simulated; otherwise, it is forwarded to the hardware service.
To support this, the `SoftwareOperation` engine was architected using a Strategy Pattern. A `CryptoPrimitive` interface defines common actions, with concrete implementations for `Signer`, `Verifier`, and `CipherPrimitive`. The main `SoftwareOperation` class acts as a controller, instantiating the correct primitive based on the `KeyPurpose` tag from the incoming operation parameters. A `JcaAlgorithmMapper` was added to centralize the logic for converting KeyMint constants into JCA algorithm strings.
For operations on real hardware-backed keys, a lightweight `OperationInterceptor` is now used for observation. It attaches to the genuine `iOperation` binder for logging and properly unregisters itself upon completion to prevent resource leaks. This is supported by new binder unregistration capabilities in the core `BinderInterceptor`.
This change also includes necessary stub files and minor regression fixes to make the simulation more robust and accurate.
See AOSP source for key identification logic:
https://cs.android.com/android/platform/superproject/main/+/main:frameworks/base/keystore/java/android/security/keystore2/AndroidKeyStoreKey.java
