usm.java

snmp4j 1.8.2版 The org.snmp4j classes are capable of creating, sending, and receiving SNMPv1/v2c/v3

                                   securityEngineID,
                                   securityName,
                                   securityLevel,
                                   scopedPDU,
                                   null,
                                   securityParameters,
                                   wholeMsg);
  }

  public UsmUserEntry getUser(OctetString engineID, OctetString securityName) {
    if (logger.isDebugEnabled()) {
      logger.debug("getUser(engineID="+engineID.toHexString()+
                   ", securityName="+securityName.toString()+")");
    }
    UsmUserEntry entry = userTable.getUser(engineID, securityName);
    if (entry == null) {
      entry = userTable.getUser(securityName);
      if ((entry == null) && (securityName.length() > 0)) {
        if (logger.isDebugEnabled()) {
          logger.debug("USM.getUser - User '"+securityName+"' unknown");
        }
        return null;
      }
      else {
        if ((entry == null) || (engineID.length() == 0)) {
          // do not add user
          entry = new UsmUserEntry();
          entry.setUserName(securityName);
          entry.setUsmUser(new UsmUser(securityName, null, null, null, null));
          return entry;
        }
        else {
          // add a new user
          OID authProtocolOID = entry.getUsmUser().getAuthenticationProtocol();
          OID privProtocolOID = entry.getUsmUser().getPrivacyProtocol();
          if (authProtocolOID != null) {
            byte[] authKey;
            if (entry.getUsmUser().isLocalized()) {
              authKey =
                  entry.getUsmUser().getAuthenticationPassphrase().getValue();
            }
            else {
              authKey = securityProtocols.passwordToKey(authProtocolOID,
                  entry.getUsmUser().getAuthenticationPassphrase(),
                  engineID.getValue());
            }
            byte[] privKey = null;
            if (privProtocolOID != null) {
              if (entry.getUsmUser().isLocalized()) {
                privKey = entry.getUsmUser().getPrivacyPassphrase().getValue();
              }
              else {
                privKey = securityProtocols.passwordToKey(privProtocolOID,
                    authProtocolOID,
                    entry.getUsmUser().getPrivacyPassphrase(),
                    engineID.getValue());
              }
            }
            entry = addLocalizedUser(engineID.getValue(), securityName,
                                     authProtocolOID, authKey,
                                     privProtocolOID, privKey);
          }
        }
      }
    }
    return entry;
  }

  public int generateResponseMessage(int snmpVersion,
                                     byte[] globalData,
                                     int maxMessageSize,
                                     int securityModel,
                                     byte[] securityEngineID,
                                     byte[] securityName,
                                     int securityLevel,
                                     BERInputStream scopedPDU,
                                     SecurityStateReference
                                     securityStateReference,
                                     SecurityParameters securityParameters,
                                     BEROutputStream wholeMsg) throws IOException {

    UsmSecurityParameters usmSecurityParams =
        (UsmSecurityParameters) securityParameters;
    if (securityStateReference != null) {
      // this is a response or report
      UsmSecurityStateReference usmSecurityStateReference =
          (UsmSecurityStateReference) securityStateReference;
      if (usmSecurityStateReference.getSecurityEngineID() == null) {
        usmSecurityParams.setAuthoritativeEngineID(securityEngineID);
        usmSecurityStateReference.setSecurityEngineID(securityEngineID);
      }
      if (usmSecurityStateReference.getSecurityName() == null) {
        OctetString userName = new OctetString(securityName);
        usmSecurityStateReference.setSecurityName(userName.getValue());
        usmSecurityParams.setUserName(userName);

        OctetString secName =
            getSecurityName(new OctetString(securityEngineID), userName);

        if ((secName != null) &&
            (secName.length() <= MAXLEN_USMUSERNAME)) {
          usmSecurityParams.setUserName(secName);
        }

      }
      else {
        usmSecurityParams.setUserName(new OctetString(usmSecurityStateReference.getSecurityName()));
      }
      usmSecurityParams.setAuthenticationProtocol(usmSecurityStateReference.
                                                  getAuthenticationProtocol());
      usmSecurityParams.setPrivacyProtocol(usmSecurityStateReference.
                                           getPrivacyProtocol());
      usmSecurityParams.setAuthenticationKey(usmSecurityStateReference.
                                             getAuthenticationKey());
      usmSecurityParams.setPrivacyKey(usmSecurityStateReference.getPrivacyKey());
    }
    else {
      OctetString secEngineID = new OctetString();
      if (securityEngineID != null) {
        secEngineID.setValue(securityEngineID);
      }
      OctetString secName = new OctetString(securityName);

      UsmUserEntry user;
      if (secEngineID.length() == 0) {
        if (isEngineDiscoveryEnabled()) {
          user = new UsmUserEntry();
        }
        else {
          if (logger.isDebugEnabled()) {
            logger.debug("Engine ID unknown and discovery disabled");
          }
          return SnmpConstants.SNMPv3_USM_UNKNOWN_ENGINEID;
        }
      }
      else {
        user = getUser(secEngineID, secName);
      }
      if (user == null) {
        if (logger.isDebugEnabled()) {
          logger.debug("Security name not found for engineID=" +
                       secEngineID.toHexString() + ", securityName=" +
                       secName.toHexString());
        }
        return SnmpConstants.SNMPv3_USM_UNKNOWN_SECURITY_NAME;
      }
      AuthenticationProtocol auth =
          securityProtocols.getAuthenticationProtocol(user.getUsmUser().getAuthenticationProtocol());
      PrivacyProtocol priv =
          securityProtocols.getPrivacyProtocol(user.getUsmUser().getPrivacyProtocol());
      usmSecurityParams.setAuthenticationProtocol(auth);
      usmSecurityParams.setPrivacyProtocol(priv);
      usmSecurityParams.setAuthenticationKey(user.getAuthenticationKey());
      usmSecurityParams.setPrivacyKey(user.getPrivacyKey());
      usmSecurityParams.setUserName(user.getUsmUser().getSecurityName());
      usmSecurityParams.setAuthoritativeEngineID(secEngineID.getValue());
    }

    // Check length of userName and engineID
    if (usmSecurityParams.getAuthoritativeEngineID().length > MPv3.MAXLEN_ENGINE_ID) {
      logger.error("Engine ID too long: "+
                   usmSecurityParams.getAuthoritativeEngineID().length+">"+
                   MPv3.MAXLEN_ENGINE_ID+ " for "+
                   new OctetString(usmSecurityParams.getAuthoritativeEngineID())
                   .toHexString());
      return SnmpConstants.SNMPv3_USM_ERROR;
    }
    if (securityName.length > MAXLEN_USMUSERNAME) {
      logger.error("Security name too long: "+
                   usmSecurityParams.getAuthoritativeEngineID().length+">"+
                   MAXLEN_USMUSERNAME+ " for "+
                   new OctetString(securityName).toHexString());
      return SnmpConstants.SNMPv3_USM_ERROR;
    }

    if (securityLevel >= SecurityLevel.AUTH_NOPRIV) {
      if (securityStateReference != null) {
        // request or response
        usmSecurityParams.setAuthoritativeEngineBoots(getEngineBoots());
        usmSecurityParams.setAuthoritativeEngineTime(getEngineTime());
      }
      else {
        // get engineBoots, engineTime
        OctetString secEngineID = new OctetString(securityEngineID);
        UsmTimeEntry entry = timeTable.getTime(secEngineID);
        if (entry == null) {
          entry =
              new UsmTimeEntry(secEngineID,
                               usmSecurityParams.getAuthoritativeEngineBoots(),
                               usmSecurityParams.
                               getAuthoritativeEngineTime());

          timeTable.addEntry(entry);
        }
        else {
          usmSecurityParams.setAuthoritativeEngineBoots(entry.getEngineBoots());
          usmSecurityParams.setAuthoritativeEngineTime(entry.
              getLatestReceivedTime());
        }
      }
    }

    if ((securityLevel >= SecurityLevel.AUTH_NOPRIV) &&
        (usmSecurityParams.getAuthenticationProtocol() == null)) {
      return SnmpConstants.SNMPv3_USM_UNSUPPORTED_SECURITY_LEVEL;
    }

    byte[] scopedPduBytes = buildMessageBuffer(scopedPDU);

    if (securityLevel == SecurityLevel.AUTH_PRIV) {
      if (usmSecurityParams.getPrivacyProtocol() == null) {
        if (logger.isDebugEnabled()) {
          logger.debug("Unsupported security level (missing or unsupported privacy protocol)");
        }
        return SnmpConstants.SNMPv3_USM_UNSUPPORTED_SECURITY_LEVEL;
      }
      logger.debug("RFC3414