asp.net-mvc-3 - 在 MVC3 中检查上传文件是否有病毒

Question

如何在存储之前检查上传文件是否有病毒？

我以前读过这个主题，但我怎样才能以编程方式进行并为用户返回结果？

The best way to avoid problems with user uploaded files of any kind is to have a command line virus scanner on the server, which you use to scan the files after upload. If the scanner result is positive, delete the file and so on

Answer 1

我正在寻找解决一个非常相似的问题，但在内存扫描方面没有找到太多。我发现的大多数示例都涉及将文件写入磁盘，然后通过将一些变量传递给另一个进程来扫描磁盘上的文件。

所以在我使用的解决方案中，我只使用 HttpPostedFileBase.InputStream ，并将其发送到 ClamAv 进行扫描。没有太多代码可以让它在 MVC 及其 QED 中工作。

所以在你的 MVC Controller 中，你会有这样的东西:

/// Main controller
public class HomeController : Controller {

    /// Get the upload view
    [HttpGet]
    public ActionResult Index() {
        return View();
    }

    /// Handle the file upload
    [HttpPost]
    public ActionResult Index(UploadViewModel model, HttpPostedFileBase file) {
        var scanner = VirusScannerFactory.GetVirusScanner();
        var result = scanner.ScanStream(file.InputStream);

        if(result.IsVirusFree) {
            // save to disk
        } else {
            // don't save to disk and tell user they uploaded a virus
        }

        return View(model);
    }
}

VirusScannerFactory 的实现可以扩展为适合您的 AV 供应商。

public class VirusScannerFactory {
    public static IScanViruses GetVirusScanner() {
        //Currently we only have one Antivirus implementation, 
        //but later we want to include AVG, SOPHOS and metascan 
        return new ClamAvScanner();
    }
}

public interface IScanViruses {

    ScanResult ScanFile(string fullPath);

    ScanResult ScanBytes(byte[] bytes);

    ScanResult ScanStream(Stream stream);
}

我以 nClam 和 ClamAv 为例。完整的 ClamAv 实现可以是 found on github ，但下面是你如何让它为内存流工作的片段

public class ClamAvScanner : IScanViruses{
    ... snip ...
    /// Scans your data stream for virus
    public ScanResult ScanStream(Stream stream) {
        var clam = new ClamClient("localhost", 3310);
        return MapScanResult(clam.SendAndScanFile(stream));
    }
    ...snip ...
    /// helper method to map scan result
    private ScanResult MapScanResult(ClamScanResult scanResult) {
        var result = new ScanResult();
        switch (scanResult.Result) {
            case ClamScanResults.Unknown:
                result.Message = "Could not scan file";
                result.IsVirusFree = false;
            break;
            case ClamScanResults.Clean:
                result.Message = "No Virus found";
                result.IsVirusFree = true;
                break;
            case ClamScanResults.VirusDetected:
                result.Message = "Virus found: " + scanResult.InfectedFiles.First().VirusName;
                result.IsVirusFree = false;
                break;
            case ClamScanResults.Error:
                result.Message = string.Format("VIRUS SCAN ERROR! {0}", scanResult.RawResult);
                result.IsVirusFree = false;
                break;
           }
        return result;
    }
}

我创建了一个 blog post有关如何使用 ClamAv 执行此操作的完整详细信息。