Android7.0 指纹framework流程及修改

回调流程

FingerprintService启动同时启动FingerprintDaemon并传入核心回调接口——IFingerprintDaemonCallback（8.1是IBiometricsFingerprintClientCallback）
该接口用于向ClientMonitor的4大实现类分发回调事件。

• AuthenticationClient：指纹验证
• EnrollClient：指纹录入
• EnumerateClient ：
• RemovalClient：指纹移除

1. IFingerprintDaemonCallback

  private IFingerprintDaemonCallback mDaemonCallback = new IFingerprintDaemonCallback.Stub() {

        @Override
        public void onEnrollResult(final long deviceId, final int fingerId, final int groupId,
                final int remaining) {
            mHandler.post(new Runnable() {
                @Override
                public void run() {
                    handleEnrollResult(deviceId, fingerId, groupId, remaining);
                }
            });
        }

        @Override
        public void onAcquired(final long deviceId, final int acquiredInfo) {
            mHandler.post(new Runnable() {
                @Override
                public void run() {
                    handleAcquired(deviceId, acquiredInfo);
                }
            });
        }

        @Override
        public void onAuthenticated(final long deviceId, final int fingerId, final int groupId) {
            mHandler.post(new Runnable() {
                @Override
                public void run() {
                    handleAuthenticated(deviceId, fingerId, groupId);
                }
            });
        }

        @Override
        public void onError(final long deviceId, final int error) {
            mHandler.post(new Runnable() {
                @Override
                public void run() {
                    handleError(deviceId, error);
                }
            });
        }

        @Override
        public void onRemoved(final long deviceId, final int fingerId, final int groupId) {
            mHandler.post(new Runnable() {
                @Override
                public void run() {
                    handleRemoved(deviceId, fingerId, groupId);
                }
            });
        }

        @Override
        public void onEnumerate(final long deviceId, final int[] fingerIds, final int[] groupIds) {
            mHandler.post(new Runnable() {
                @Override
                public void run() {
                    handleEnumerate(deviceId, fingerIds, groupIds);
                }
            });
        }
    };

各个client接收到回调事件，则会调用第二个接口FingerprintServiceReceiver

2. FingerprintServiceReceiver

FingerprintServiceReceiver是FingerprintManager中总的回调接口，用于回调EnrollmentCallback，AuthenticationCallback等上层接口

 private IFingerprintServiceReceiver mServiceReceiver = new Stub() {
        public void onEnrollResult(long deviceId, int fingerId, int groupId, int remaining) {
            FingerprintManager.this.mHandler.obtainMessage(100, remaining, 0, new Fingerprint((CharSequence)null, groupId, fingerId, deviceId)).sendToTarget();
        }

        public void onAcquired(long deviceId, int acquireInfo) {
            FingerprintManager.this.mHandler.obtainMessage(101, acquireInfo, 0, deviceId).sendToTarget();
        }

        public void onAuthenticationSucceeded(long deviceId, Fingerprint fp, int userId) {
            FingerprintManager.this.mHandler.obtainMessage(102, userId, 0, fp).sendToTarget();
        }

        public void onAuthenticationFailed(long deviceId) {FingerprintManager.this.mHandler.obtainMessage(103).sendToTarget();
        }

        public void onError(long deviceId, int error) {
            FingerprintManager.this.mHandler.obtainMessage(104, error, 0, deviceId).sendToTarget();
        }

        public void onRemoved(long deviceId, int fingerId, int groupId) {
            FingerprintManager.this.mHandler.obtainMessage(105, fingerId, groupId, deviceId).sendToTarget();
        }
    };

录入指纹流程：

调用：

FingerprintManager.enroll(userId,receiver,...)
->service.enroll(userId,receiver,...)
->startEnrollment(userId,receiver,...)

• startEnrollment(userId,receiver,...)

private void startEnrollment(IBinder token, byte [] cryptoToken, int userId,
            IFingerprintServiceReceiver receiver, int flags, boolean restricted,
            String opPackageName) {
        updateActiveGroup(userId, opPackageName);
        //注意groupId = userId
        final int groupId = userId; // default group for fingerprint enrollment
        //保存receiver
        EnrollClient client = new EnrollClient(getContext(), mHalDeviceId, token, receiver,
                userId, groupId, cryptoToken, restricted, opPackageName) {
       }
      

-> 初始化一个EnrollClient,调用startClient()
->client.start()
-> daemon.enroll(mCryptoToken, getGroupId(), timeout)开始录入
（FingerprintManager中回调接口IFingerprintServiceReceiver会保存在EnrollClient中以待回调）

回调：

IFingerprintDaemonCallback
->onEnrollResult（fingerid ，deviceid，groupid，remaining）
-> client.onEnrollResult()

• client.onEnrollResult(fingerId, groupId, remaining)：

1. 若录入完成，将id等信息保存xml

public boolean onEnrollResult(int fingerId, int groupId, int remaining) {
        if (groupId != getGroupId()) {
            Slog.w(TAG, "groupId != getGroupId(), groupId: " + groupId +
                    " getGroupId():" + getGroupId());
        }
        //录入完成
        if (remaining == 0) {
        //#1
           FingerprintUtils.getInstance().addFingerprintForUser(getContext(), fingerId,
                    getTargetUserId());
        }
        return sendEnrollResult(fingerId, groupId, remaining);
    }

#1：保存该指纹信息

 public void addFingerprintForUser(Context ctx, int fingerId, int userId) {
        //#2:getStateForUser:获取UserState，若没有则初始化一个UserState。
        //构造方法中会根据该userId查询之前保存的指纹File（xml）,初始化一个mFingerprints集合。
        
        //#3:addFingerprint：添加进mFingerprints集合，写入File。
        //注意写入的groupId就是userId。
        getStateForUser(ctx, userId).addFingerprint(fingerId, userId);
    }

2. sendEnrollResult
   ->receiver.onEnrollResult
   ->FingerprintManafger.sendEnrollResult

   private void sendEnrollResult(Fingerprint fp, int remaining) {
            if (FingerprintManager.this.mEnrollmentCallback != null) {
                    FingerprintManager.this.mEnrollmentCallback.onEnrollmentProgress(remaining);
            }

    }

验证指纹流程：

调用：

FingerprintManager.authenticate(userId,receiver,...)
->service.authenticate (userId,receiver,...)
->初始化一个AuthenticationClient , 调用startClient(userId,receiver,...)
->client.start()
->daemon.authenticate(mOpId, getGroupId())开始验证
（FingerprintManager中回调接口IFingerprintServiceReceiver同样会保存在AuthenticationClient中以待回调）

回调：

IFingerprintDaemonCallback
->onAuthenticated（fingerid ，deviceid，groupid，token）
->client.onAuthenticated

• client.onAuthenticated：
  根据指纹结果回调Receiver中的onAuthenticationSucceeded，onAuthenticationFailed等方法。

---

修改

enroll录入

因为EnrollmentCallback没有获取正在录制的指纹id参数接口，所以自己提供一个获取方法。

1. 新增enrollFingerId变量

private int enrollFingerId = -1;

2. 新增getEnrollFingerId方法:

public int getEnrollFingerId() {
        return this.enrollFingerId;
    }

3. enroll方法重置enrollFingerId

 public void enroll(byte[] token, CancellationSignal cancel, int flags, int userId, FingerprintManager.EnrollmentCallback callback) {
        this.enrollFingerId = -1;
}

4. sendEnrollResult中enrollFingerId保存fingerId

  private void sendEnrollResult(Fingerprint fp, int remaining) {
            if (FingerprintManager.this.mEnrollmentCallback != null) {
               //+++
               FingerprintManager.this.enrollFingerId = fp.getFingerId();
                FingerprintManager.this.mEnrollmentCallback.onEnrollmentProgress(remaining);
            }

        }

authenticate验证

因为在AuthenticationClient.onAuthenticated(int fingerId, int groupId)中isRestricted=true，从而在FingerprintManager的AuthenticationCallback.onAuthenticationSucceeded参数中的Fingerprint对象为null。

   Fingerprint fp = !getIsRestricted()
                            ? new Fingerprint("" /* TODO */, groupId, fingerId,
                                    FingerprintUtils.isSoterSimulated() ?
                                            548398617248L : getHalDeviceId())
                            : null;

FingerprintService修改:

        private boolean isRestricted() {
            // Only give privileged apps (like Settings) access to fingerprint info
// ---           final boolean restricted = !hasPermission(MANAGE_FINGERPRINT);
// ---           return restricted;

//  +++
            return false;
        }