3

我有一个安全工具，可以通过电子邮件向用户发送他们的新密码。当阈值为 VERBOSE 时，生产电子邮件模块（我不拥有也不想更改）将使用 Log4Net 记录整个 html 电子邮件正文。由于电子邮件包含明文形式的域用户密码，我想在密码到达附加程序之前从日志消息中删除密码。

有没有办法让我临时将一个对象插入到 Log4Net 堆栈中，让我可以搜索 LoggingEvent 消息并对其进行更改以屏蔽我找到的任何密码？我想插入对象，调用电子邮件模块，然后删除对象。

4

7 回答 7

5

我有一个类似的问题，我通过继承ForwardingAppender然后修改LoggingEvent（使用反射）在传递它之前解决了它。

using System.Reflection;
using log4net.Appender;
using log4net.Core;

class MessageModifyingForwardingAppender : ForwardingAppender
{
    private static FieldInfo _loggingEventm_dataFieldInfo;

    public MessageModifyingForwardingAppender()
    {
        _loggingEventm_dataFieldInfo = typeof(LoggingEvent).GetField("m_data", BindingFlags.Instance | BindingFlags.NonPublic);
    }

    protected override void Append(LoggingEvent loggingEvent)
    {
        var originalRenderedMessage = loggingEvent.RenderedMessage;

        var newMessage = GetModifiedMessage(originalRenderedMessage);

        if (originalRenderedMessage != newMessage)
            SetMessageOnLoggingEvent(loggingEvent, newMessage);

        base.Append(loggingEvent);
    }

    /// <summary>
    /// I couldn't figure out how to 'naturally' change the log message, so use reflection to change the underlying storage of the message data
    /// </summary>
    private static void SetMessageOnLoggingEvent(LoggingEvent loggingEvent, string newMessage)
    {
        var loggingEventData = (LoggingEventData)_loggingEventm_dataFieldInfo.GetValue(loggingEvent);
        loggingEventData.Message = newMessage;
        _loggingEventm_dataFieldInfo.SetValue(loggingEvent, loggingEventData);
    }

    private static string GetModifiedMessage(string originalMessage)
    {
        // TODO modification implementation
        return originalMessage;
    }
}

它不是很漂亮，但它确实有效。

然后你需要一个看起来像这样的 log4net 配置

<log4net>
    <appender name="ModifyingAppender" type="Your.Lib.Log4Net.MessageModifyingForwardingAppender,Your.Lib">
        <appender-ref ref="ConsoleAppender" />
    </appender>
    <appender name="ConsoleAppender" type="log4net.Appender.ConsoleAppender">
        <layout type="log4net.Layout.PatternLayout">
            <conversionPattern value="%date %-5level [%thread] %logger: %message%newline"/>
        </layout>
    </appender>
    <root>
        <level value="INFO"/>
        <appender-ref ref="ModifyingAppender"/>
    </root>
</log4net>

并且GetModifiedMessage()满足您的需求的实施，您就走了！

于 2015-04-28T07:58:52.257 回答
3

Chris Priest 解决方案的一个小改进：不是从 ForwardingAppender 继承您的 appender，而是从基类 AppenderSkeleton 继承。它使配置更简单 - 您不需要从您的附加器中引用其他附加器，现在可以轻松地将其应用于不同的记录器

public class PasswordObfuscationAppender : AppenderSkeleton
{
    private static readonly FieldInfo LoggingEventmDataFieldInfo = typeof(LoggingEvent).GetField(
        "m_data",
        BindingFlags.Instance | BindingFlags.NonPublic);

    protected override void Append(LoggingEvent loggingEvent)
    {
        var originalRenderedMessage = loggingEvent.RenderedMessage;

        var newMessage = GetModifiedMessage(originalRenderedMessage);

        if (originalRenderedMessage != newMessage)
            SetMessageOnLoggingEvent(loggingEvent, newMessage);
    }

    /// <summary>
    /// I couldn't figure out how to 'naturally' change the log message, so use reflection to change the underlying storage of the message data
    /// </summary>
    private static void SetMessageOnLoggingEvent(LoggingEvent loggingEvent, string newMessage)
    {
        var loggingEventData = (LoggingEventData)LoggingEventmDataFieldInfo.GetValue(loggingEvent);
        loggingEventData.Message = newMessage;
        LoggingEventmDataFieldInfo.SetValue(loggingEvent, loggingEventData);
    }

    private static string GetModifiedMessage(string originalMessage)
    {
        // TODO modification implementation
        return originalMessage;
    }
}

用法

<appender name="PasswordObfuscationAppender" type="Foundation.PasswordObfuscationAppender,Foundation" />

<appender name="MainAppender" type="log4net.Appender.RollingFileAppender">
  <file value="..\Logs\File.log" />
</appender>

<root>
  <level value="DEBUG" />
  <appender-ref ref="PasswordObfuscationAppender" />
  <appender-ref ref="MainAppender" />
</root>
于 2016-03-24T13:50:53.237 回答
2

我可能会写一个模式转换器。你可以在这里找到一个例子。你的实现可能是这样的：

protected override void Convert(TextWriter writer, LoggingEvent loggingEvent)
{
    string msg = loggingEvent.RenderedMessage;
    // remove the password if there is any
    writer.Write(msg);
}
于 2010-10-06T10:52:35.253 回答
2

这改进了@jeremy-fizames，您无需担心在调用ILoggerFactoryany 之前是否设置了LogManager.GetLogger()。您可以使用 log4net 的插件框架来确保InterceptLoggerFactory在分配任何根记录器之前进行设置。该[assembly:]属性确保 log4net 在设置任何日志记录之前找到并加载插件。

此解决方案无需修改现有附加程序的配置方式即可工作，无论您是从 XML 加载 log4net 配置和/或在运行时以编程方式加载，它都可以工作。

// Register intercept as a log4net plugin
[assembly: log4net.Config.Plugin(typeof(InterceptPlugin))]

public class InterceptPlugin : log4net.Plugin.PluginSkeleton
{
    public InterceptPlugin() : base("Intercept") {}

    public override void Attach(ILoggerRepository repository)
    {
        base.Attach(repository);

        ((Hierarchy)repository).LoggerFactory = new InterceptLoggerFactory();
    }
}

// @jeremy-fizames's ILoggerFactory
public class InterceptLoggerFactory : ILoggerFactory
{
    public Logger CreateLogger(ILoggerRepository repository, string name)
    {
        if (name == null) return new InterceptRootLogger(repository.LevelMap.LookupWithDefault(Level.Debug));
        return new InterceptLogger(name);
    }

    class InterceptLogger : Logger
    {
        public InterceptLogger(string name) : base(name) {}

        protected override void CallAppenders(LoggingEvent loggingEvent)
        {
            // Implement interception of property on loggingEvent before any call to any appender (execution is sync).
            base.CallAppenders(loggingEvent);
        }
    }

    class InterceptRootLogger : RootLogger
    {
        public InterceptRootLogger(Level level) : base(level) {}

        protected override void CallAppenders(LoggingEvent loggingEvent)
        {
            // Implement interception of property on loggingEvent before any call to any appender (execution is sync).
            base.CallAppenders(loggingEvent);
        }
    }
}
于 2019-01-11T14:05:15.723 回答
1

另一种解决方案是在直接从 Logger 到达任何 appender 之前拦截 LoggingEvent。一个先决条件是能够在创建任何 Logger 之前修改 Root Hierarchy。

在下面的示例中，我们只是重新创建了一个新的 LoggingEvent，但如果您关心密集的内存复制，则没有必要，通过反射您可以访问底层的 LoggingEventData(is struct) 并直接为字段设置新值。

您只需要在任何 LogManager.GetLogger() 之前调用 InterceptLoggerFactory.Apply()。

public class InterceptLoggerFactory : ILoggerFactory
{
    public static void Apply() => Apply((Hierarchy)LogManager.GetRepository());
    public static void Apply(Hierarchy h) => h.LoggerFactory = new InterceptLoggerFactory();

    public Logger CreateLogger(ILoggerRepository repository, string name)
    {
        if (name == null) return new InterceptRootLogger(repository.LevelMap.LookupWithDefault(Level.Debug));
        return new InterceptLogger(name);
    }


    class InterceptLogger : Logger
    {
        public InterceptLogger(string name) : base(name)
        {
        }

        protected override void CallAppenders(LoggingEvent loggingEvent)
        {
            // Implement interception of property on loggingEvent before any call to any appender (execution is sync).
            /*
             * var loggingEventData = loggingEvent.GetLoggingEventData();
             * loggingEventData.Message = [EncryptMessage](loggingEventData.Message);
             * var newLoggingEvent = new LoggingEvent(loggingEventData);
             * base.CallAppenders(newLoggingEvent);
             * */
            base.CallAppenders(loggingEvent);
        }
    }

    class InterceptRootLogger : RootLogger
    {
        public InterceptRootLogger(Level level) : base(level)
        {
        }

        protected override void CallAppenders(LoggingEvent loggingEvent)
        {
            // Implement interception of property on loggingEvent before any call to any appender (execution is sync).
            base.CallAppenders(loggingEvent);
        }
    }
}
于 2017-12-06T17:38:16.693 回答
0

您可以尝试使用Unity Application Block 方法拦截器拦截对 log4net 的调用。或者您可以编写一个自定义 log4net 附加程序。

于 2010-10-05T18:32:16.127 回答
-4

log4net 是开源的，你可以修改它。

于 2010-10-05T18:09:53.760 回答