[SNMP4J] [snmp4j] USM.removeUser not really working

[Kelsey Abe]

Hello,

I was running some tests on a userTarget by adding and removing the USM
users to ensure that we had correctly set up a list of
Users/passwords/authentication on the router.


   1. Adding a single user worked as expected, but when placing a
   snmp.getUSM().removeUser() [or .getUSM().getUserTable().removeUser()] in
   between two snmp.getBulk requests, both requests were successful.
   (unexpected behavior)
   2. However, after using a removeUser, when using the getUser/removeUser
   functions, they return null, indicating that the user should have been
   removed from the USM. (expected behavior)
   3. As a side note, the removeAllUsers() caused the program to throw a
   MessageException, which showed that the user was actually removed. (expected
   behavior)

I have a feeling that the problem lies within the removeUser function.


thanks for your help!
Kelsey


Code:
package temp;

import org.snmp4j.CommunityTarget;
import org.snmp4j.PDU;
import org.snmp4j.ScopedPDU;
import org.snmp4j.Snmp;
import org.snmp4j.TransportMapping;
import org.snmp4j.UserTarget;
import org.snmp4j.mp.MPv3;
import org.snmp4j.security.AuthMD5;
import org.snmp4j.security.PrivDES;
import org.snmp4j.security.SecurityLevel;
import org.snmp4j.security.SecurityModels;
import org.snmp4j.security.SecurityProtocols;
import org.snmp4j.security.USM;
import org.snmp4j.security.UsmUser;
import org.snmp4j.smi.OID;
import org.snmp4j.smi.OctetString;
import org.snmp4j.smi.UdpAddress;
import org.snmp4j.smi.VariableBinding;
import org.snmp4j.transport.DefaultUdpTransportMapping;

public class Main {
  public static int printoutNumber;
  private static OctetString authEngineID = OctetString
      .fromHexString("80:00:00:09:03:00:54:75:D0:6D:3B:80");
  private static OctetString localEngineID = new
OctetString(MPv3.createLocalEngineID());

  public static void main(String[] args) {

    try {

      OctetString securityName = new OctetString("authNoPrivMd5");
      UserTarget utarget = Build.craftTarget("192.168.1.197/161",
securityName,
          authEngineID.toByteArray(), SecurityLevel.AUTH_NOPRIV);

/* where Build.craftTarget does the following:
 *  UdpAddress uAdd = new UdpAddress(address);
 *       UserTarget utarget = new UserTarget(uAdd, securityName,
authEngineID, securityLevel);
 *       utarget.setRetries(1);
 *       utarget.setTimeout(1000);
 *      utarget.setVersion(SnmpConstants.version3);
 */
      USM usm = new USM(SecurityProtocols.getInstance(), localEngineID, 0);
      SecurityModels.getInstance().addSecurityModel(usm);

      TransportMapping transport = Build.craftTransport(8088);
      Snmp snmp = new Snmp(transport);

/*where Build.craftTransport(i) does the following:
 *trans = new DefaultUdpTransportMapping(new UdpAddress("172.16.67.76/"
+i));
 *      trans.listen();
 */

      ScopedPDU sPdu = Build.craftSPDU();
/*where Build.craftSPDU does the following
 *ScopedPDU sPdu = new ScopedPDU();
 *       List<VariableBinding> list = Arrays.asList(new VariableBinding(new
OID("1.3.6.1.2.1.2.1")),
 *              new VariableBinding(new OID("1.3.6.1.2.1.2.2.1.10")),
 *              new VariableBinding(new OID("1.3.6.1.2.1.2.2.1.16")));
 *      sPdu = craftSPDU(list);
 *      sPdu.setType(PDU.GETBULK);
 *      sPdu.setMaxRepetitions(50);
 *      sPdu.setNonRepeaters(1);
 */
      // add user to the USM
      snmp.getUSM().addUser(
          new OctetString("authNoPrivMd5"),
          new UsmUser(new OctetString("authNoPrivMd5"), AuthMD5.ID,
              new OctetString("ImpressivePassword"), PrivDES.ID, new
OctetString("ImpressivePassword")));

      Test.sendAndPrintResponse(snmp, sPdu, utarget);

      System.out.println(snmp.getUSM().removeUser(authEngineID, new
OctetString("authNoPrivMd5")));
//
System.out.println(snmp.getUSM().getUserTable().removeUser(authEngineID, new
OctetString("authNoPrivMd5")));
//    System.out.println(snmp.getUSM().removeUser(authEngineID, new
OctetString("authNoPrivMd5")));
//    System.out.println(snmp.getUSM().getUserTable().getUser(authEngineID,
new OctetString("authNoPrivMd5")));
//    snmp.getUSM().removeAllUsers();

      Test.sendAndPrintResponse(snmp, sPdu, utarget);

    }
    catch (Exception e) {
      System.out.println(e.toString());
      e.printStackTrace();
    }
  }// end main