Android 13+ LocalOnlyHotspot custom config

UnhiddenSoftApConfigurationBuilder.kt

/**
 * Reflection workaround to access hidden SoftApConfiguration.Builder so it can be used to set
 * LocalOnlyHotspot on Android 13+
 *
 * LocalOnlyHotspotConfig is generated here by Android:
 * https://cs.android.com/android/platform/superproject/+/refs/heads/master:packages/modules/Wifi/service/java/com/android/server/wifi/WifiApConfigStore.java;drc=7bb4243a97d53af6cbd4de21bcc61556a758898b;l=423
 */
@RequiresApi(30)
class UnhiddenSoftApConfigurationBuilder {

    @SuppressLint("PrivateApi")
    private val builderClass = Class.forName("android.net.wifi.SoftApConfiguration\$Builder")

    private val builderInstance = builderClass.newInstance()

    fun setBand(band: Int) : UnhiddenSoftApConfigurationBuilder {
        builderClass.getMethod("setBand", Int::class.javaPrimitiveType).invoke(
            builderInstance, band
        )
        return this
    }

    fun setAutoshutdownEnabled(enabled: Boolean) : UnhiddenSoftApConfigurationBuilder  {
        builderClass.getMethod("setAutoShutdownEnabled", Boolean::class.javaPrimitiveType).invoke(
            builderInstance, enabled
        )
        return this
    }

    fun setPassphrase(passphrase: String, securityType: Int) : UnhiddenSoftApConfigurationBuilder  {
        builderClass.getMethod(
            "setPassphrase", String::class.java, Int::class.javaPrimitiveType
        ).invoke(
            builderInstance, passphrase, securityType
        )

        return this
    }

    fun setBssid(macAddress: MacAddress) : UnhiddenSoftApConfigurationBuilder {
        builderClass.getMethod("setBssid", MacAddress::class.java).invoke(
            builderInstance, macAddress
        )
        return this
    }

    fun setMacRandomizationSetting(randomizationSetting: Int): UnhiddenSoftApConfigurationBuilder  {
        builderClass.getMethod("setMacRandomizationSetting", Int::class.java).invoke(
            builderInstance, randomizationSetting
        )
        return this
    }

    fun setSsid(ssid: String) : UnhiddenSoftApConfigurationBuilder {
        builderClass.getMethod("setSsid", String::class.java).invoke(
            builderInstance, ssid
        )
        return this
    }

    fun build(): SoftApConfiguration {
        return builderClass
            .getMethod("build")
            .invoke(builderInstance) as SoftApConfiguration
    }

    companion object {

        //Band constants as per
        // https://cs.android.com/android/platform/superproject/+/android-13.0.0_r54:packages/modules/Wifi/framework/java/android/net/wifi/SoftApConfiguration.java;l=78
        const val BAND_2GHZ = 1.shl(0)

        const val BAND_5GHZ = 1.shl(1)

        const val BAND_6GHZ = 1.shl(2)

        const val BAND_60GHZ = 1.shl(3)

        const val BAND_ANY = BAND_2GHZ.or(BAND_5GHZ).or(BAND_6GHZ).or(BAND_60GHZ)

        /*
         * Randomization settings as per
         * https://cs.android.com/android/platform/superproject/+/android-13.0.0_r54:packages/modules/Wifi/framework/java/android/net/wifi/SoftApConfiguration.java;l=344
         */
        const val RANDOMIZATION_NONE = 0

        const val RANDOMIZATION_PERSISTENT = 1

        const val RANDOMIZATION_NON_PERSISTENT = 2

        /*
         * Security types as per
         * https://cs.android.com/android/platform/superproject/+/android-13.0.0_r54:packages/modules/Wifi/framework/java/android/net/wifi/SoftApConfiguration.java;l=406
         */
        /**
         * THe definition of security type OPEN.
         */
        const val SECURITY_TYPE_OPEN = 0

        /**
         * The definition of security type WPA2-PSK.
         */
        const val SECURITY_TYPE_WPA2_PSK = 1

        /**
         * The definition of security type WPA3-SAE Transition mode.
         */
        const val SECURITY_TYPE_WPA3_SAE_TRANSITION = 2

        /**
         * The definition of security type WPA3-SAE.
         */
        const val SECURITY_TYPE_WPA3_SAE = 3

        /**
         * The definition of security type WPA3-OWE Transition.
         */
        const val SECURITY_TYPE_WPA3_OWE_TRANSITION = 4

        /**
         * The definition of security type WPA3-OWE.
         */
        const val SECURITY_TYPE_WPA3_OWE = 5

    }

}

WifiManagerLocalOnlyHotspotExt.kt

/**
 * Start a LocalOnlyHotspot using a configuration to set the band, ssid, bssid, etc. This
 * a hidden API and works only with Android 13+. The API requires one of three permissions:
 * NETWORK_SETTINGS, NETWORK_SETUP_WIZARD, or NEARBY_WIFI_DEVICES. The first two are reserved for
 * system apps. NEARBY_WIFI_DEVICES permission is a runtime permission that is available from
 * Android 12 and up.
 *
 * This calls the hidden function startLocalOnlyHotspot(SoftApConfig, Executor, callback):
 * https://cs.android.com/android/platform/superproject/+/android-13.0.0_r1:packages/modules/Wifi/framework/java/android/net/wifi/WifiManager.java;l=4764
 *
 * Unfortunately Android 12 does not accept NEARBY_WIFI_DEVICES permission - if the platform or target
 * is less than SDK 33, it will fail as per the implementation of WifiServiceImpl on Android 12:
 * https://cs.android.com/android/platform/superproject/+/android-12.0.0_r1:packages/modules/Wifi/service/java/com/android/server/wifi/WifiServiceImpl.java;l=2045;bpv=1;bpt=0
 *
 * From Android 13 the check is changed to accept NEARBY_WIFI_DEVICES permission (provided that the
 * device and target SDK is Android 13 or higher) when a configuration is provided:
 * https://cs.android.com/android/platform/superproject/+/android-13.0.0_r1:packages/modules/Wifi/service/java/com/android/server/wifi/WifiServiceImpl.java;l=2472
 *
 * ===It is NOT possible to avoid a random MAC for LocalOnlyHotspot on Android 11/12.===
 *
 * It might be possible to use the accessibility service to automatically dismiss accept dialogs
 * to mitigate this for large deployments etc.
 *
 * see: https://developer.android.com/guide/topics/ui/accessibility/service
 * e.g. https://tooploox.com/unusual-ways-using-android-accessibility-services
 *
 * Avenues explored:
 *
 * Option 1: use WifiManager.setWifiApConfiguration to set the default tethering ap configuration,
 * and set mac randomization to NONE. This is blocked by a requirement for OVERRIDE_WIFI_CONFIG
 * permission (which is not available to third party app). See WifiServiceImpl#setSoftApConfiguration
 * https://cs.android.com/android/platform/superproject/+/android-13.0.0_r54:packages/modules/Wifi/service/java/com/android/server/wifi/WifiServiceImpl.java;l=2727
 *
 * Option 2: try to disable Wifi Mac randomization so that the generateLocalOnlyHotspotConfig will
 * set randomization to NONE. Won't work: AP config util uses a system resource
 * R.bool.config_wifi_ap_mac_randomization_supported as per:
 * https://cs.android.com/android/platform/superproject/+/android-12.0.0_r1:packages/modules/Wifi/service/java/com/android/server/wifi/util/ApConfigUtil.java;l=699
 * The only way to override that would be a "Runtime Resourc Overlay" RRO, which can only be installed
 * with system level permission.
 *
 * Option 3: Try using global settings as per
 * https://stackoverflow.com/questions/61748195/android-10-how-to-disable-randomized-mac-address-in-source-code
 * Won't work on Android 11/12 - Mac Randomization is now a per-network setting, not a global setting.
 * Might work on Android 9 as per
 *  https://github.com/elastic/AndroidSDKMirror-28/blob/master/com/android/server/wifi/WifiStateMachine.java
 *
 * Option 4: Use adb command / network settings app to change the default tethering, but the
 * settings app itself does not change this:
 * https://cs.android.com/android/platform/superproject/+/master:packages/apps/Settings/src/com/android/settings/wifi/tether/WifiTetherSettings.java;l=231
 * adb shell cmd wifi also does not support changing this.
 *
 */
@RequiresApi(33)
fun WifiManager.startLocalOnlyHotspotWithConfig(
    config: SoftApConfiguration,
    executor: Executor?,
    callback: LocalOnlyHotspotCallback
) {
    WifiManager::class.java.getMethod(
        "startLocalOnlyHotspot", SoftApConfiguration::class.java, Executor::class.java,
        LocalOnlyHotspotCallback::class.java,
    ).invoke(this, config, executor, callback)
}


/**
 * It is NOT possible to workaround the random MAC problem on Android 11/12.
 *
 * Option 1: use WifiManager.setWifiApConfiguration to set the default tethering ap configuration,
 * and set mac randomization to NONE. This is blocked by a requirement for OVERRIDE_WIFI_CONFIG
 * permission (which is not available to third party app). See WifiServiceImpl#setSoftApConfiguration
  https://cs.android.com/android/platform/superproject/+/android-13.0.0_r54:packages/modules/Wifi/service/java/com/android/server/wifi/WifiServiceImpl.java;l=2727
 *
 * Option 2: try to disable Wifi Mac randomization so that the generateLocalOnlyHotspotConfig will
 * set randomization to NONE. Won't work: AP config util uses a system resource
 * R.bool.config_wifi_ap_mac_randomization_supported as per:
 * https://cs.android.com/android/platform/superproject/+/android-12.0.0_r1:packages/modules/Wifi/service/java/com/android/server/wifi/util/ApConfigUtil.java;l=699
 * The only way to override that would be a "Runtime Resourc Overlay" RRO, which can only be installed
 * with system level permission.
 *
 * Option 3: Try using global settings as per
 * https://stackoverflow.com/questions/61748195/android-10-how-to-disable-randomized-mac-address-in-source-code
 * Won't work on Android 11/12 - Mac Randomization is now a per-network setting, not a global setting.
 * Might work on Android 9 as per
 *  https://github.com/elastic/AndroidSDKMirror-28/blob/master/com/android/server/wifi/WifiStateMachine.java
 *
 * Option 4: Use adb command / network settings app to change the default tethering, but the
 * settings app itself does not change this:
 * https://cs.android.com/android/platform/superproject/+/master:packages/apps/Settings/src/com/android/settings/wifi/tether/WifiTetherSettings.java;l=231
 *
 */