private bool AddFailedLoginForEventViewerXml(IPAddressEvent info, XmlDocument doc)
{
if (string.IsNullOrWhiteSpace(info.IPAddress))
{
return(false);
}
else if (string.IsNullOrWhiteSpace(info.Source))
{
XmlNode sourceNode = doc.SelectSingleNode("//Source");
if (sourceNode != null)
{
info.Source = sourceNode.InnerText.Trim();
}
}
if (string.IsNullOrWhiteSpace(info.UserName))
{
XmlNode userNameNode = doc.SelectSingleNode("//Data[@Name='TargetUserName']");
if (userNameNode == null)
{
userNameNode = doc.SelectSingleNode("//TargetUserName");
}
if (userNameNode != null)
{
info.UserName = userNameNode.InnerText.Trim();
}
}
service.HandleIPAddressEvent(info);
return(true);
}
Task IIPAddressEventHandler.HandleIPAddressEvent(IPAddressEvent info)
{
if (info.Flag.HasFlag(IPAddressEventFlag.SuccessfulLogin))
{
successIPAddresses.Add(info);
}
else
{
failedIPAddresses.Add(info);
}
return(Task.CompletedTask);
}
private bool ParseRegex(Regex regex, string line, bool notifyOnly)
{
if (regex != null)
{
IPAddressEvent info = IPBanService.GetIPAddressInfoFromRegex(dns, regex, line);
if (info.FoundMatch)
{
info.Flag = (notifyOnly ? IPAddressEventFlag.SuccessfulLogin : IPAddressEventFlag.FailedLogin);
info.Source = info.Source ?? Source;
IPBanLog.Debug("Log file found match, ip: {0}, user: {1}, source: {2}, count: {3}, flag: {4}",
info.IPAddress, info.UserName, info.Source, info.Count, info.Flag);
loginHandler.HandleIPAddressEvent(info);
return(true);
}
}
return(false);
}
/// <summary>
/// Process event viewer XML
/// </summary>
/// <param name="xml">XML</param>
public void ProcessEventViewerXml(string xml)
{
IPBanLog.Info("Processing event viewer xml: {0}", xml);
XmlDocument doc = ParseXml(xml);
IPAddressEvent info = ExtractEventViewerXml(doc);
if (info != null && info.FoundMatch)
{
if (info.Flag.HasFlag(IPAddressEventFlag.FailedLogin))
{
// if fail to add the failed login (bad ip, etc.) exit out
if (!AddFailedLoginForEventViewerXml(info, doc))
{
return;
}
}
else
{
service.IPBanDelegate?.LoginAttemptSucceeded(info.IPAddress, info.Source, info.UserName).ConfigureAwait(false).GetAwaiter();
}
IPBanLog.Info("Event viewer found: {0}, {1}, {2}", info.IPAddress, info.Source, info.UserName);
}
}
private IPAddressEvent ExtractEventViewerXml(XmlDocument doc)
{
XmlNode keywordsNode = doc.SelectSingleNode("//Keywords");
string keywordsText = keywordsNode.InnerText;
if (keywordsText.StartsWith("0x"))
{
keywordsText = keywordsText.Substring(2);
}
ulong keywordsULONG = ulong.Parse(keywordsText, NumberStyles.AllowHexSpecifier, CultureInfo.InvariantCulture);
IPAddressEvent info = null;
bool foundNotifyOnly = false;
if (keywordsNode != null)
{
// we must match on keywords
foreach (EventViewerExpressionGroup group in service.Config.WindowsEventViewerGetGroupsMatchingKeywords(keywordsULONG))
{
foreach (EventViewerExpression expression in group.Expressions)
{
// find all the nodes, try and get an ip from any of them, all must match
XmlNodeList nodes = doc.SelectNodes(expression.XPath);
if (nodes.Count == 0)
{
IPBanLog.Info("No nodes found for xpath {0}", expression.XPath);
info = null;
break;
}
// if there is a regex, it must match
if (string.IsNullOrWhiteSpace(expression.Regex))
{
// count as a match, do not modify the ip address if it was already set
IPBanLog.Info("No regex, so counting as a match");
}
else
{
info = null;
// try and find an ip from any of the nodes
foreach (XmlNode node in nodes)
{
// if we get a match, stop checking nodes
info = IPBanService.GetIPAddressInfoFromRegex(service.DnsLookup, expression.RegexObject, node.InnerText);
if (info.FoundMatch)
{
if (group.NotifyOnly)
{
foundNotifyOnly = true;
}
else if (foundNotifyOnly)
{
throw new InvalidDataException("Conflicting expressions in event viewer, both failed and success logins matched keywords " + group.Keywords);
}
break;
}
}
if (info != null && !info.FoundMatch)
{
// match fail, null out ip, we have to match ALL the nodes or we get null ip and do not ban
IPBanLog.Info("Regex {0} did not match any nodes with xpath {1}", expression.Regex, expression.XPath);
info = null;
foundNotifyOnly = false;
break;
}
}
}
if (info != null && info.FoundMatch && info.IPAddress != null)
{
info.Source = info.Source ?? group.Source;
break;
}
info = null; // set null for next attempt
}
}
if (info != null)
{
info.Flag = (foundNotifyOnly ? IPAddressEventFlag.SuccessfulLogin : IPAddressEventFlag.FailedLogin);
}
return(info);
}
