Properly handle pin code pairing on Android

Most likely this paring variant was forgotten when Android support
for QBluetoothLocalDevice was implemented. This variant is rather uncommon
and Android's default pairing handler are likely to automatically
handle such requests too.

Fixes: QTBUG-70295
Change-Id: I618242da415574245e5a213a6e34f190c685c8e9
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>

2 files changed, 42 insertions, 0 deletions

diff --git a/src/bluetooth/android/localdevicebroadcastreceiver.cpp b/src/bluetooth/android/localdevicebroadcastreceiver.cpp
index c6cb3680..2d247574 100644
--- a/src/bluetooth/android/localdevicebroadcastreceiver.cpp
+++ b/src/bluetooth/android/localdevicebroadcastreceiver.cpp
@@ -39,6 +39,7 @@
 
 #include <QtCore/QLoggingCategory>
 #include <QtCore/private/qjnihelpers_p.h>
+#include <QtCore/qrandom.h>
 #include "localdevicebroadcastreceiver_p.h"
 #include "android/jni_android_p.h"
 
@@ -186,6 +187,46 @@ void LocalDeviceBroadcastReceiver::onReceive(JNIEnv *env, jobject context, jobje
         switch (variant) {
         case -1: //ignore -> no pairing variant set
             return;
+        case 0: //BluetoothDevice.PAIRING_VARIANT_PIN
+        {
+            //generate a random key
+            const QString pin = QStringLiteral("%1").arg(QRandomGenerator::global()->bounded(1000000),
+                                                         6, 10, QLatin1Char('0'));
+            const QAndroidJniObject javaPin = QAndroidJniObject::fromString(pin);
+
+            //get BluetoothDevice
+            keyExtra = valueForStaticField(JavaNames::BluetoothDevice, JavaNames::ExtraDevice);
+            QAndroidJniObject bluetoothDevice =
+                    intentObject.callObjectMethod("getParcelableExtra",
+                                                  "(Ljava/lang/String;)Landroid/os/Parcelable;",
+                                                  keyExtra.object<jstring>());
+            if (!bluetoothDevice.isValid())
+                return;
+
+            QAndroidJniObject bytePin = QAndroidJniObject::callStaticObjectMethod("android/bluetooth/BluetoothDevice",
+                                                                                  "convertPinToBytes",
+                                                                                  "(Ljava/lang/String;)[B",
+                                                                                  javaPin.object<jstring>());
+            if (!bytePin.isValid()) {
+                if (env->ExceptionCheck()) {
+                    env->ExceptionDescribe();
+                    env->ExceptionClear();
+                }
+                return;
+            }
+
+            jboolean result = bluetoothDevice.callMethod<jboolean>("setPin", "([B)Z", bytePin.object<jbyteArray>());
+            if (!result) {
+                if (env->ExceptionCheck()) {
+                    env->ExceptionDescribe();
+                    env->ExceptionClear();
+                }
+                return;
+            }
+
+            const QBluetoothAddress address(bluetoothDevice.callObjectMethod<jstring>("getAddress").toString());
+            emit pairingDisplayPinCode(address, pin);
+        }
         case 2: //BluetoothDevice.PAIRING_VARIANT_PASSKEY_CONFIRMATION
         {
             keyExtra = valueForStaticField(JavaNames::BluetoothDevice,
diff --git a/src/bluetooth/android/localdevicebroadcastreceiver_p.h b/src/bluetooth/android/localdevicebroadcastreceiver_p.h
index c6ae424d..09e50fb1 100644
--- a/src/bluetooth/android/localdevicebroadcastreceiver_p.h
+++ b/src/bluetooth/android/localdevicebroadcastreceiver_p.h
@@ -72,6 +72,7 @@ signals:
     void pairingStateChanged(const QBluetoothAddress &address, QBluetoothLocalDevice::Pairing pairing);
     void connectDeviceChanges(const QBluetoothAddress &address, bool isConnectEvent);
     void pairingDisplayConfirmation(const QBluetoothAddress &address, const QString& pin);
+    void pairingDisplayPinCode(const QBluetoothAddress &address, const QString& pin);
 private:
     int previousScanMode;
     QAndroidJniObject pairingDevice;