Method ipset2cidr

src/main/java/burp/IPAddressUtils.java:169–204

(Set<String> IPSet)

	To get a smaller network with a set of IP addresses
	 */
	private static String ipset2cidr(Set<String> IPSet) {
		try {
			if (IPSet == null || IPSet.size() <=0){
				return null;
			}
			if (IPSet.size() ==1){
				return IPSet.toArray(new String[0])[0];
			}
			List<String> list = new ArrayList<String>(IPSet);
			SubnetUtils oldsamllerNetwork =new SubnetUtils(list.get(0).trim()+"/24");
			for (int mask=24;mask<=32;mask++){
				//System.out.println(mask);
				SubnetUtils samllerNetwork = new SubnetUtils(list.get(0).trim()+"/"+mask);
				for (String ip:IPSet) {
					ip = ipClean(ip);
					if (!isValidIP(ip)) {
						System.out.println(ip + "invalid IP address, skip to handle it!");
						continue;
					}
					if (samllerNetwork.getInfo().isInRange(ip) || samllerNetwork.getInfo().getBroadcastAddress().equals(ip.trim()) || samllerNetwork.getInfo().getNetworkAddress().equals(ip.trim())){
						//52.74.179.0 ---sometimes .0 address is a real address.
						continue;
					}
					else {
						String networkaddress = oldsamllerNetwork.getInfo().getNetworkAddress();
						String tmpmask = oldsamllerNetwork.getInfo().getNetmask();
						return new SubnetUtils(networkaddress,tmpmask).getInfo().getCidrSignature();
					}
				}
				oldsamllerNetwork = samllerNetwork;
			}
			return null;
		}catch (Exception e) {
			throw e;
		}
	}

	public static String ipClean(String ip){
		ip = ip.trim();