Added a check for unreasonably high payloads

RISE-V2G-EVCC/src/main/java/com/v2gclarity/risev2g/evcc/transportLayer/StatefulTransportLayerClient.java

@@ -48,7 +48,6 @@ public abstract class StatefulTransportLayerClient  extends Observable implement
 	private byte[] v2gTPMessage;
 	private InputStream inStream;
 	private OutputStream outStream;
-	private final int MASK = 0x80;
 	private int payloadLength;
 	private int bytesReadFromInputStream;
 	private Inet6Address clientAddress;
@@ -91,18 +90,21 @@ public abstract class StatefulTransportLayerClient  extends Observable implement
 	
 		/*
 		 * The payload length is written to the last 4 bytes (v2gTPHeader[4] to v2gTPHeader[7])
-		 * of the V2GTP header. The most significant bit of v2gTPHeader[4] should never be set!
-		 * If it was set, then this would mean that a V2GTP message of a size of at least 2 GB 
-		 * was intended to be transferred ... and this cannot be, no V2G message has this size!
-		 * Since the most significant bit should never be set, we do not need to care about
-		 * signed integers in Java at this point!
+		 * of the V2GTP header. The biggest ISO 15118 message in size is the CertificateInstallationRes, which in EXI
+		 * consumes usually 3.000 to 4.000 bytes max. Let's use a threshold of 10.000 just to be safe to 
+		 * check for unreasonably high payload lengths.
+		 * 
+		 * Change this value if you use a V2GTP payload type for a proprietary, manufacturer-specific use (see Table 10 of ISO 15118-2)
+		 * that requires bigger payloads! 
 		 */
-		if ((getV2gTPHeader()[4] & getMASK()) == getMASK()) {
-			stopAndNotify("Payload length of V2GTP message is inappropiately high! There must be " +
-						  "an error in the V2GTP message header!", null);
+		setPayloadLength(ByteUtils.toIntFromByteArray(Arrays.copyOfRange(getV2gTPHeader(), 4, 8)));
+		
+		if (getPayloadLength() > 10000) {
+			stopAndNotify("Payload length of V2GTP message is inappropiately high (" + getPayloadLength() + " bytes)! " +
+						 "There must be an error in the V2GTP message header!", null);
 			return false;
 		} else {
-			setPayloadLength(ByteUtils.toIntFromByteArray(Arrays.copyOfRange(getV2gTPHeader(), 4, 8)));
+			getLogger().debug("Length of V2GTP payload in bytes according to V2GTP header: " + getPayloadLength());
 			setV2gTPPayload(new byte[getPayloadLength()]);
 		
 			getInStream().read(getV2gTPPayload());
@@ -213,10 +215,6 @@ public abstract class StatefulTransportLayerClient  extends Observable implement
 	public void setBytesReadFromInputStream(int bytesReadFromInputStream) {
 		this.bytesReadFromInputStream = bytesReadFromInputStream;
 	}
-
-	public int getMASK() {
-		return MASK;
-	}
 	
 	public Inet6Address getClientAddress() {
 		return clientAddress;

RISE-V2G-SECC/src/main/java/com/v2gclarity/risev2g/secc/transportLayer/ConnectionHandler.java

@@ -50,7 +50,6 @@ public class ConnectionHandler extends Observable implements Runnable {
 	private byte[] v2gTpHeader; 
 	private byte[] v2gTPPayload;
 	private byte[] v2gTPMessage;
-	private final int MASK = 0x80;
 	private int payloadLength;
 	private int bytesReadFromInputStream;
 	private boolean stopAlreadyInitiated;
@@ -84,7 +83,7 @@ public class ConnectionHandler extends Observable implements Runnable {
 	
 	
 	@Override
-	public void run() {
+	public void run() {	
 		while (!Thread.interrupted()) { 
 			/*
 			 * Read header (8 bytes) of incoming V2GTPMessage to further allocate a byte array with  
@@ -109,18 +108,20 @@ public class ConnectionHandler extends Observable implements Runnable {
 				
 				/*
 				 * The payload length is written to the last 4 bytes (v2gTPHeader[4] to v2gTPHeader[7])
-				 * of the V2GTP header. The most significant bit of v2gTPHeader[4] should never be set.
-				 * If it was set, then this would mean that a V2GTP message of a size of at least 2 GB 
-				 * was intended to be transferred ... and this cannot be, no V2G message has this size.
-				 * Since the most significant bit should never be set, we do not need to care about
-				 * signed integers in Java at this point!
+				 * of the V2GTP header. The biggest ISO 15118 message in size is the CertificateInstallationRes, which in EXI
+				 * consumes usually 3.000 to 4.000 bytes max. Let's use a threshold of 10.000 just to be safe to 
+				 * check for unreasonably high payload lengths.
+				 * 
+				 * Change this value if you use a V2GTP payload type for a proprietary, manufacturer-specific use (see Table 10 of ISO 15118-2)
+				 * that requires bigger payloads! 
 				 */
-				if ((getV2gTpHeader()[4] & MASK) == MASK) {
-					stopAndNotify("Payload length of V2GTP message is inappropiately high! There must be " +
-								 "an error in the V2GTP message header!", null);
+				setPayloadLength(ByteUtils.toIntFromByteArray(Arrays.copyOfRange(getV2gTpHeader(), 4, 8)));
+				
+				if (getPayloadLength() > 10000) {
+					stopAndNotify("Payload length of V2GTP message is inappropiately high (" + getPayloadLength() + " bytes)! " +
+								 "There must be an error in the V2GTP message header!", null);
 					break;
 				} else {
-					setPayloadLength(ByteUtils.toIntFromByteArray(Arrays.copyOfRange(getV2gTpHeader(), 4, 8)));
 					getLogger().debug("Length of V2GTP payload in bytes according to V2GTP header: " + getPayloadLength());
 					setV2gTPPayload(new byte[getPayloadLength()]);