Implement multi-purpose simulation for crypto operations (#59)

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

stub/src/main/java/android/hardware/security/keymint/BlockMode.java

@@ -0,0 +1,8 @@
+package android.hardware.security.keymint;
+
+public @interface BlockMode {
+    public static final int ECB = 1;
+    public static final int CBC = 2;
+    public static final int CTR = 3;
+    public static final int GCM = 32;
+}

stub/src/main/java/android/hardware/security/keymint/PaddingMode.java

@@ -0,0 +1,10 @@
+package android.hardware.security.keymint;
+
+public @interface PaddingMode {
+    public static final int NONE = 1;
+    public static final int RSA_OAEP = 2;
+    public static final int RSA_PSS = 3;
+    public static final int RSA_PKCS1_1_5_ENCRYPT = 4;
+    public static final int RSA_PKCS1_1_5_SIGN = 5;
+    public static final int PKCS7 = 64;
+}

stub/src/main/java/android/system/keystore2/CreateOperationResponse.java

@@ -0,0 +1,38 @@
+package android.system.keystore2;
+
+import android.os.Parcel;
+import android.os.Parcelable;
+
+import androidx.annotation.NonNull;
+
+public class CreateOperationResponse implements Parcelable {
+    public IKeystoreOperation iOperation;
+
+    public OperationChallenge operationChallenge;
+
+    public KeyParameters parameters;
+
+    public byte[] upgradedBlob;
+
+    public static final Creator<CreateOperationResponse> CREATOR = new Creator<CreateOperationResponse>() {
+        @Override
+        public CreateOperationResponse createFromParcel(Parcel in) {
+            throw new UnsupportedOperationException("STUB!");
+        }
+
+        @Override
+        public CreateOperationResponse[] newArray(int size) {
+            throw new UnsupportedOperationException("STUB!");
+        }
+    };
+
+    @Override
+    public int describeContents() {
+        throw new UnsupportedOperationException("STUB!");
+    }
+
+    @Override
+    public void writeToParcel(@NonNull Parcel parcel, int i) {
+        throw new UnsupportedOperationException("STUB!");
+    }
+}

stub/src/main/java/android/system/keystore2/Domain.java

@@ -0,0 +1,9 @@
+package android.system.keystore2;
+
+public @interface Domain {
+    public static final int APP = 0;
+    public static final int GRANT = 1;
+    public static final int SELINUX = 2;
+    public static final int BLOB = 3;
+    public static final int KEY_ID = 4;
+}

stub/src/main/java/android/system/keystore2/IKeystoreOperation.java

@@ -0,0 +1,33 @@
+package android.system.keystore2;
+
+import android.os.IBinder;
+import android.os.Binder;
+import android.os.IInterface;
+
+public interface IKeystoreOperation extends IInterface {
+    public static final java.lang.String DESCRIPTOR = "android.system.keystore2.IKeystoreOperation";
+
+    public void updateAad(byte[] aadInput);
+
+    public byte[] update(byte[] input);
+
+    public byte[] finish(byte[] input, byte[] signature);
+
+    public void abort() throws android.os.RemoteException;
+
+    abstract class Stub extends Binder implements IKeystoreOperation {
+        public static IKeystoreOperation asInterface(IBinder b) {
+            throw new UnsupportedOperationException("STUB!");
+        }
+
+        @Override
+        public IBinder asBinder() {
+            return this;
+        }
+
+        @Override
+        public void updateAad(byte[] aadInput) {
+            throw new UnsupportedOperationException("STUB!");
+        }
+    }
+}

stub/src/main/java/android/system/keystore2/KeyParameters.java

@@ -0,0 +1,34 @@
+package android.system.keystore2;
+
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.hardware.security.keymint.KeyParameter;
+
+import androidx.annotation.NonNull;
+
+public class KeyParameters implements Parcelable {
+    public KeyParameter[] keyParameter;
+
+    public static final Creator<KeyParameters> CREATOR = new Creator<KeyParameters>() {
+        @Override
+        public KeyParameters createFromParcel(Parcel in) {
+            throw new UnsupportedOperationException("STUB!");
+        }
+
+        @Override
+        public KeyParameters[] newArray(int size) {
+            throw new UnsupportedOperationException("STUB!");
+        }
+    };
+
+    @Override
+    public int describeContents() {
+        throw new UnsupportedOperationException("STUB!");
+    }
+
+    @Override
+    public void writeToParcel(@NonNull Parcel parcel, int i) {
+        throw new UnsupportedOperationException("STUB!");
+    }
+}
+

stub/src/main/java/android/system/keystore2/OperationChallenge.java

@@ -0,0 +1,32 @@
+package android.system.keystore2;
+
+import android.os.Parcel;
+import android.os.Parcelable;
+
+import androidx.annotation.NonNull;
+
+public class OperationChallenge implements Parcelable {
+    public long challenge = 0L;
+
+    public static final Creator<OperationChallenge> CREATOR = new Creator<OperationChallenge>() {
+        @Override
+        public OperationChallenge createFromParcel(Parcel in) {
+            throw new UnsupportedOperationException("STUB!");
+        }
+
+        @Override
+        public OperationChallenge[] newArray(int size) {
+            throw new UnsupportedOperationException("STUB!");
+        }
+    };
+
+    @Override
+    public int describeContents() {
+        throw new UnsupportedOperationException("STUB!");
+    }
+
+    @Override
+    public void writeToParcel(@NonNull Parcel parcel, int i) {
+        throw new UnsupportedOperationException("STUB!");
+    }
+}