[gree] Use GCM encryption when bind fails (#17398)

* [gree]: use GCM encryption when binding fails

Signed-off-by: Zhivka Dimova <zhivka.dimova@myforest.net>

bundles/org.openhab.binding.gree/README.md

@@ -19,15 +19,18 @@ No binding configuration is required.
 
 ## Thing Configuration
 
-| Channel Name             | Type       | Description                                                                                   |
+| Channel Name             | Type            | Description                                                                                   |
-|--------------------------|------------|-----------------------------------------------------------------------------------------------|
+|--------------------------|-----------------|-----------------------------------------------------------------------------------------------|
-| ipAddress                | IP Address | IP address of the unit.                                                                       |
+| ipAddress                | IP Address      | IP address of the unit.                                                                       |
-| broadcastAddress         | IP Address | Broadcast address being used for discovery, usually derived from the IP interface address.    |
+| broadcastAddress         | IP Address      | Broadcast address being used for discovery, usually derived from the IP interface address.    |
-| refresh                  | Integer    | Refresh interval in seconds for polling the device status.                                    |
+| refresh                  | Integer         | Refresh interval in seconds for polling the device status.                                    |
-| currentTemperatureOffset | Decimal    | Offset in Celsius for the current temperature value received from the device.                 |
+| currentTemperatureOffset | Decimal         | Offset in Celsius for the current temperature value received from the device.                 |
+| encryptionType           | EncryptionTypes | Encryption type (ECB or GCM) used for communicating with the AC device                        |
 
 The Air Conditioner's IP address is mandatory, all other parameters are optional.
 If the broadcast is not set (default) it will be derived from openHAB's network setting (Check Network Settings in the openHAB UI).
+The binding tries to automatically detect the encryption type when communicating with the AC.
+If this fails, you might need need to set the encryption type manually.
 Only change this if you have a good reason to.
 
 ## Channels
@@ -64,7 +67,7 @@ When changing mode, the air conditioner will be turned on unless "off" is select
 ### Things
 
 ```java
-Thing gree:airconditioner:a1234561 [ ipAddress="192.168.1.111", refresh=2 ]
+Thing gree:airconditioner:a1234561 [ ipAddress="192.168.1.111", refresh=2, encryptionType="ECB" ]
 ```
 
 ### Items

bundles/org.openhab.binding.gree/src/main/java/org/openhab/binding/gree/internal/GreeBindingConstants.java

@@ -12,7 +12,11 @@
  */
 package org.openhab.binding.gree.internal;
 
+import java.util.Map;
 import java.util.Set;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.openhab.core.thing.ThingTypeUID;
@@ -39,6 +43,8 @@ public class GreeBindingConstants {
     public static final String PROPERTY_IP = "ipAddress";
     public static final String PROPERTY_BROADCAST = "broadcastAddress";
 
+    public static final String PROPERTY_ENCRYPTION_TYPE = "encryptionType";
+
     // List of all Channel ids
     public static final String POWER_CHANNEL = "power";
     public static final String MODE_CHANNEL = "mode";
@@ -174,4 +180,17 @@ public class GreeBindingConstants {
      *      for more details.
      */
     public static final double INTERNAL_TEMP_SENSOR_OFFSET = -40.0;
+
+    public enum EncryptionTypes {
+        UNKNOWN,
+        ECB,
+        GCM;
+
+        private static final Map<String, EncryptionTypes> MAP = Stream.of(EncryptionTypes.values())
+                .collect(Collectors.toMap(Enum::name, Function.identity()));
+
+        public static EncryptionTypes of(final String name) {
+            return MAP.getOrDefault(name, UNKNOWN);
+        }
+    };
 }

bundles/org.openhab.binding.gree/src/main/java/org/openhab/binding/gree/internal/GreeConfiguration.java

@@ -12,6 +12,8 @@
  */
 package org.openhab.binding.gree.internal;
 
+import static org.openhab.binding.gree.internal.GreeBindingConstants.*;
+
 import java.math.BigDecimal;
 
 import org.eclipse.jdt.annotation.NonNullByDefault;
@@ -32,10 +34,11 @@ public class GreeConfiguration {
      * of the temperature sensor.
      */
     public BigDecimal currentTemperatureOffset = new BigDecimal(0.0);
+    public EncryptionTypes encryptionType = EncryptionTypes.UNKNOWN;
 
     @Override
     public String toString() {
         return "Config: ipAddress=" + ipAddress + ", broadcastAddress=" + broadcastAddress + ", refresh=" + refresh
-                + ", currentTemperatureOffset=" + currentTemperatureOffset;
+                + ", currentTemperatureOffset=" + currentTemperatureOffset + ", encryptionType=" + encryptionType;
     }
 }

bundles/org.openhab.binding.gree/src/main/java/org/openhab/binding/gree/internal/GreeCryptoUtil.java

@@ -12,6 +12,8 @@
  */
 package org.openhab.binding.gree.internal;
 
+import static org.openhab.binding.gree.internal.GreeBindingConstants.EncryptionTypes;
+
 import java.nio.charset.StandardCharsets;
 import java.security.InvalidAlgorithmParameterException;
 import java.security.InvalidKeyException;
@@ -45,11 +47,6 @@ public class GreeCryptoUtil {
     private static final String GCM_ADD = "qualcomm-test";
     private static final int TAG_LENGTH = 16;
 
-    public enum EncryptionTypes {
-        ECB,
-        GCM
-    };
-
     public static byte[] getAESGeneralKeyByteArray() {
         return AES_KEY.getBytes(StandardCharsets.UTF_8);
     }
@@ -86,6 +83,10 @@ public class GreeCryptoUtil {
     }
 
     public static <T extends GreeBaseDTO> String decrypt(T response, EncryptionTypes encType) throws GreeException {
+        if (encType == EncryptionTypes.UNKNOWN) {
+            encType = getEncryptionType(response);
+        }
+
         if (encType == EncryptionTypes.GCM) {
             return decrypt(getGCMGeneralKeyByteArray(), response, encType);
         } else {
@@ -95,6 +96,10 @@ public class GreeCryptoUtil {
 
     public static <T extends GreeBaseDTO> String decrypt(byte[] keyarray, T response, EncryptionTypes encType)
             throws GreeException {
+        if (encType == EncryptionTypes.UNKNOWN) {
+            encType = getEncryptionType(response);
+        }
+
         if (encType == EncryptionTypes.GCM) {
             return decryptGCMPack(keyarray, response.pack, response.tag);
         } else {

bundles/org.openhab.binding.gree/src/main/java/org/openhab/binding/gree/internal/GreeException.java

@@ -106,7 +106,7 @@ public class GreeException extends Exception {
 
     private Class<?> getCauseClass() {
         Throwable cause = getCause();
-        if (getCause() != null) {
+        if (cause != null) {
             return cause.getClass();
         }
         return GreeException.class;

bundles/org.openhab.binding.gree/src/main/java/org/openhab/binding/gree/internal/discovery/GreeDeviceFinder.java

@@ -61,7 +61,8 @@ public class GreeDeviceFinder {
     public GreeDeviceFinder() {
     }
 
-    public void scan(DatagramSocket clientSocket, String broadcastAddress, boolean scanNetwork) throws GreeException {
+    public void scan(DatagramSocket clientSocket, String broadcastAddress, boolean scanNetwork,
+            EncryptionTypes encryptionTypeConfig) throws GreeException {
         InetAddress ipAddress;
         try {
             ipAddress = InetAddress.getByName(broadcastAddress);
@@ -103,7 +104,8 @@ public class GreeDeviceFinder {
                     }
 
                     // Decrypt message - a GreeException is thrown when something went wrong
-                    String decryptedMsg = scanResponseGson.decryptedPack = GreeCryptoUtil.decrypt(scanResponseGson);
+                    String decryptedMsg = scanResponseGson.decryptedPack = GreeCryptoUtil.decrypt(scanResponseGson,
+                            encryptionTypeConfig);
 
                     logger.debug("Response received from address {}: {}", remoteAddress.getHostAddress(), decryptedMsg);
 

bundles/org.openhab.binding.gree/src/main/java/org/openhab/binding/gree/internal/discovery/GreeDiscoveryService.java

@@ -87,7 +87,7 @@ public class GreeDiscoveryService extends AbstractDiscoveryService {
     @Override
     protected void startScan() {
         try (DatagramSocket clientSocket = new DatagramSocket()) {
-            deviceFinder.scan(clientSocket, broadcastAddress, true);
+            deviceFinder.scan(clientSocket, broadcastAddress, true, EncryptionTypes.UNKNOWN);
 
             int count = deviceFinder.getScannedDeviceCount();
             logger.debug("{}", messages.get("discovery.result", count));
@@ -112,6 +112,7 @@ public class GreeDiscoveryService extends AbstractDiscoveryService {
             properties.put(Thing.PROPERTY_MAC_ADDRESS, device.getId());
             properties.put(PROPERTY_IP, ipAddress);
             properties.put(PROPERTY_BROADCAST, broadcastAddress);
+            properties.put(PROPERTY_ENCRYPTION_TYPE, device.getEncryptionType());
             ThingUID thingUID = new ThingUID(THING_TYPE_GREEAIRCON, device.getId());
             DiscoveryResult result = DiscoveryResultBuilder.create(thingUID).withProperties(properties)
                     .withRepresentationProperty(Thing.PROPERTY_MAC_ADDRESS).withLabel(device.getName()).build();

bundles/org.openhab.binding.gree/src/main/java/org/openhab/binding/gree/internal/handler/GreeAirDevice.java

@@ -64,7 +64,7 @@ public class GreeAirDevice {
     private final InetAddress ipAddress;
     private int port = 0;
     private String encKey = "";
-    private GreeCryptoUtil.EncryptionTypes encType = GreeCryptoUtil.EncryptionTypes.ECB;
+    private EncryptionTypes encType = EncryptionTypes.UNKNOWN;
     private Optional<GreeScanResponseDTO> scanResponseGson = Optional.empty();
     private Optional<GreeStatusResponseDTO> statusResponseGson = Optional.empty();
     private Optional<GreeStatusResponsePackDTO> prevStatusResponsePackGson = Optional.empty();
@@ -148,7 +148,7 @@ public class GreeAirDevice {
         }
     }
 
-    public void bindWithDevice(DatagramSocket clientSocket) throws GreeException {
+    public void bindWithDevice(DatagramSocket clientSocket, EncryptionTypes encryptionTypeConfig) throws GreeException {
         try {
             // Prep the Binding Request pack
             GreeBindRequestPackDTO bindReqPackGson = new GreeBindRequestPackDTO();
@@ -158,6 +158,7 @@ public class GreeAirDevice {
             String bindReqPackStr = GSON.toJson(bindReqPackGson);
 
             // Encrypt and send the Binding Request pack
+            setEncryptionType(encryptionTypeConfig);
             String[] encryptedBindReqData = GreeCryptoUtil.encrypt(GreeCryptoUtil.getGeneralKeyByteArray(encType),
                     bindReqPackStr, encType);
             DatagramPacket sendPacket = createPackRequest(1, encryptedBindReqData);
@@ -174,7 +175,12 @@ public class GreeAirDevice {
             // save the outcome
             isBound = true;
         } catch (IOException | JsonSyntaxException e) {
-            throw new GreeException("Unable to bind to device", e);
+            if (encType != EncryptionTypes.GCM) {
+                logger.debug("Unable to bind to device - changing the encryption mode to GCM and trying again", e);
+                bindWithDevice(clientSocket, EncryptionTypes.GCM);
+            } else {
+                throw new GreeException("Unable to bind to device", e);
+            }
         }
     }
 
@@ -460,7 +466,7 @@ public class GreeAirDevice {
         request.uid = 0;
         request.tcid = getId();
         request.pack = data[0];
-        if (encType == GreeCryptoUtil.EncryptionTypes.GCM) {
+        if (encType == EncryptionTypes.GCM) {
             if (data.length > 1) {
                 request.tag = data[1];
             } else {
@@ -519,6 +525,24 @@ public class GreeAirDevice {
         return isBound;
     }
 
+    public void setEncryptionType(EncryptionTypes value) {
+        if (value == EncryptionTypes.UNKNOWN) {
+            logger.debug("Trying to set encryption type to 'UNKNOWN' for device: {}, current value: {}", getName(),
+                    encType);
+            if (encType == EncryptionTypes.UNKNOWN) {
+                logger.debug("Falling back to 'ECB' for device: {}", getName());
+                encType = EncryptionTypes.ECB;
+            }
+        } else {
+            logger.debug("Change encryption type for device: {}, from : {}, to: {}", getName(), encType, value);
+            encType = value;
+        }
+    }
+
+    public EncryptionTypes getEncryptionType() {
+        return encType;
+    }
+
     public byte[] getKey() {
         return encKey.getBytes(StandardCharsets.UTF_8);
     }
@@ -528,7 +552,12 @@ public class GreeAirDevice {
     }
 
     public String getName() {
-        return scanResponseGson.isPresent() ? scanResponseGson.get().packJson.name : "";
+        if (scanResponseGson.isPresent()) {
+            String name = scanResponseGson.get().packJson.name;
+            return name.trim().isEmpty() ? getId() : name;
+        }
+
+        return "";
     }
 
     public String getVendor() {

bundles/org.openhab.binding.gree/src/main/java/org/openhab/binding/gree/internal/handler/GreeHandler.java

@@ -108,12 +108,12 @@ public class GreeHandler extends BaseThingHandler {
                 clientSocket.get().setSoTimeout(DATAGRAM_SOCKET_TIMEOUT);
             }
             // Find the GREE device
-            deviceFinder.scan(clientSocket.get(), config.ipAddress, false);
+            deviceFinder.scan(clientSocket.get(), config.ipAddress, false, config.encryptionType);
             GreeAirDevice newDevice = deviceFinder.getDeviceByIPAddress(config.ipAddress);
             if (newDevice != null) {
                 // Ok, our device responded, now let's Bind with it
                 device = newDevice;
-                device.bindWithDevice(clientSocket.get());
+                device.bindWithDevice(clientSocket.get(), config.encryptionType);
                 if (device.getIsBound()) {
                     updateStatus(ThingStatus.ONLINE);
                     return;
@@ -138,7 +138,7 @@ public class GreeHandler extends BaseThingHandler {
     @Override
     public void handleCommand(ChannelUID channelUID, Command command) {
         if (command instanceof RefreshType) {
-            // The thing is updated by the scheduled automatic refresh so do nothing here.
+            initializeThing();
         } else {
             logger.debug("{}: Issue command {} to channe {}", thingId, command, channelUID.getIdWithoutGroup());
             String channelId = channelUID.getIdWithoutGroup();
@@ -377,8 +377,9 @@ public class GreeHandler extends BaseThingHandler {
                 }
             } catch (GreeException e) {
                 String subcode = "";
-                if (e.getCause() != null) {
+                Throwable cause = e.getCause();
-                    subcode = " (" + e.getCause().getMessage() + ")";
+                if (cause != null) {
+                    subcode = " (" + cause.getMessage() + ")";
                 }
                 String message = messages.get("update.exception", e.getMessageString() + subcode);
                 if (getThing().getStatus() == ThingStatus.OFFLINE) {

bundles/org.openhab.binding.gree/src/main/resources/OH-INF/i18n/gree.properties

@@ -1,12 +1,15 @@
-# GREE Binding
+# add-on
+
 addon.gree.name = GREE Binding
-addon.gree.description = This binding integrates the GREE series of air conditioners
+addon.gree.description = This is the binding for GREE air conditioners.
 
 # thing types
+
 thing-type.gree.airconditioner.label = Air Conditioner
 thing-type.gree.airconditioner.description = A GREE Air Conditioner with WiFi Module
 
 # thing type config description
+
 thing-type.config.gree.airconditioner.ipAddress.label = IP Address
 thing-type.config.gree.airconditioner.ipAddress.description = IP Address of the GREE unit.
 thing-type.config.gree.airconditioner.broadcastAddress.label = Subnet Broadcast Address
@@ -15,8 +18,13 @@ thing-type.config.gree.airconditioner.refresh.label = Refresh Interval
 thing-type.config.gree.airconditioner.refresh.description = Interval to query an update from the device.
 thing-type.config.gree.airconditioner.currentTemperatureOffset.label = Offset for Current Temperature
 thing-type.config.gree.airconditioner.currentTemperatureOffset.description = The offset in Celsius for the current temperature value received from the device.
+thing-type.config.gree.airconditioner.encryptionType.label = Encryption type
+thing-type.config.gree.airconditioner.encryptionType.description = The encryption type used for encrypting the data send to the AC device.
+thing-type.config.gree.airconditioner.encryptionType.state.option.ECB = ECB
+thing-type.config.gree.airconditioner.encryptionType.state.option.GCM = GCM
 
 # channel types
+
 channel-type.gree.power.label = Power
 channel-type.gree.power.description = Turn power on/off
 channel-type.gree.mode.label = Unit Mode
@@ -70,7 +78,7 @@ channel-type.gree.swingupdown.option.11 = Swing Upmost
 channel-type.gree.swingleftright.label = Horizontal Swing Mode
 channel-type.gree.swingleftright.description = Sets the horizontal swing action on the Air Conditioner: 0=OFF, 1=Full Swing, 2=Left, 3=Mid-Left, 4=Mid, 5=Mid-Right, 6=Right
 channel-type.gree.swingleftright.option.0 = OFF
-channel-type.gree.swingleftright.option.1 = Full Swing 
+channel-type.gree.swingleftright.option.1 = Full Swing
 channel-type.gree.swingleftright.option.2 = Left
 channel-type.gree.swingleftright.option.3 = Mid-Left
 channel-type.gree.swingleftright.option.4 = Mid
@@ -83,7 +91,8 @@ channel-type.gree.light.description = Enable/disable the front display on the Ai
 channel-type.gree.health.label = Health Mode
 channel-type.gree.health.description = Set on/off the Air Conditioner's Health function if applicable to the Air Conditioner model.
 
-# User Messages
+# user messages
+
 message.thinginit.failed = Unable to connect to air conditioner
 message.thinginit.invconf = Invalid configuration data
 message.thinginit.exception = Thing initialization failed: {0}
@@ -92,5 +101,5 @@ message.command.exception = Unable to execute command {0} for channel {1}
 message.update.exception = Unable to perform auto-update: {0}
 message.channel.exception = Unable to update channel {0} with {1}
 message.discovery.result = {0} units discovered.
-message.discovery.newunit = Device {0} discovered at {1}, MAC={2} 
+message.discovery.newunit = Device {0} discovered at {1}, MAC={2}
-message.discovery.exception = Device Discovery failed: {0} 
+message.discovery.exception = Device Discovery failed: {0}

bundles/org.openhab.binding.gree/src/main/resources/OH-INF/thing/thing-types.xml

@@ -41,6 +41,13 @@
 				<unitLabel>Degrees Celsius</unitLabel>
 				<advanced>true</advanced>
 			</parameter>
+			<parameter name="encryptionType" type="text">
+				<options>
+					<option value="ECB">@text/thing-type.config.gree.airconditioner.encryptionType.state.option.ECB</option>
+					<option value="GCM">@text/thing-type.config.gree.airconditioner.encryptionType.state.option.GCM</option>
+				</options>
+				<advanced>true</advanced>
+			</parameter>
 		</config-description>
 
 	</thing-type>