asp.net - SSL 期间 IE9 中的下载文件行为更改

Question

我目前有一个 .NET http 处理程序，用于处理将文件传递到 Web 浏览器进行下载。 IE6+、FireFox、Chrome 和 Safari 都可以使用此代码，但新的 IE9 无法下载，但仅在 SSL 中时。

当我点击链接下载文件时:https://rootwebsite/taskmanager/DownloadFiles.ashx?fileId=3b2c7e41-f51a-445d-9627-f4f4481e1425
IE9 打开保存对话框并显示给我 DownloadFiles_ashx?fileId=3b2c7e41-f51a-445d-9627-f4f4481e1425作为文件名，但拒绝下载文件。

如果我将链接更改为 http://然后代码工作正常，文件下载。

有什么不同？我错过了什么？

这是我的代码:

public void WriteByteArrayToHttp(HttpResponse response, string fileName, string contentType, Stream file, bool downloadFile)
{
    using (file)
    {
        if (downloadFile)
        {
            response.Clear();
            response.ClearHeaders();
            response.ClearContent();
            response.AddHeader("Content-Disposition",
                               string.Format("attachment; filename={0}", HttpUtility.UrlEncode(fileName)));
        }
        response.AddHeader("Content-Length", file.Length.ToString());

        // Added with suggestion of YSlow FireFox plug-in
        // Specifies how long the file is valid for in cache in seconds
        // http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html
        // See 14.9 Cache-Control
        // 6 Hours
        response.AddHeader("max-age", "21600");
        response.ContentType = contentType;

        // At the time of this writing, we are running IIS6, BUT if we decide to go to IIS7
        // there is a 28.6MB limit to content size both up and down by default
        // See http://msdn.microsoft.com/en-us/library/ms689462.aspx
        // This would be a problem for a number of files we serv up with the Original method
        // so this chunking method replaces that.
        // See http://support.microsoft.com/kb/812406 as the base for this change.
        // Tested with file between 1MB and 3GB

        // Total bytes to read:
        long dataToRead = file.Length;

        // Buffer to read 10K bytes in chunk:
        byte[] buffer = new Byte[10000];

        try
        {
            while (dataToRead > 0)
            {
                // Verify that the client is connected.
                if (response.IsClientConnected)
                {
                    // Read the data in buffer.
                    // Length of the file:
                    int length = file.Read(buffer, 0, 10000);

                    // Write the data to the current output stream.
                    response.OutputStream.Write(buffer, 0, length);

                    // Flush the data to the HTML output.
                    response.Flush();

                    buffer = new Byte[10000];
                    dataToRead = dataToRead - length;
                }
                else
                {
                    //prevent infinite loop if user disconnects
                    dataToRead = -1;
                }
            }
        }
        catch (HttpException hex)
        {
            if (!hex.Message.StartsWith("The remote host closed the connection"))
            {
                throw;
            }
        }
    }
}

web.config 将处理程序定义为:

 <system.webServer>
    <validation validateIntegratedModeConfiguration="false"/>
    <handlers>
      <add name="DownloadFiles.ashx" path="DownloadFiles.ashx" verb="*" type="Russound.Web.HttpHandlers.DownloadFileHandler" resourceType="Unspecified" preCondition="integratedMode"/>
    </handlers>
  </system.webServer>
</configuration>

Answer 1

可能与

一些 cache control headers (或 this one ；另见此 question )或

一个 Internet Explorer 选项，可防止 SSL 加密的页面被缓存/存储在磁盘上，或

他们俩...

昨天让我头疼(这是我的第二个)。

如果你问我，这个 Internet Explorer 选项 Do not save encrypted pages to disk应该只适用于缓存而不是故意下载......但是，嘿，这是我们正在谈论的微软，所以无论如何它不需要任何意义。

看这里: http://blogs.msdn.com/b/ieinternals/archive/2009/10/03/internet-explorer-cannot-download-over-https-when-no-cache.aspx :

Update Feb. 2011: I've modified the file download logic for IE9. IE9 should be able to successfully download a file regardless of HTTPS or Cache-Control headers unless you have the "Do not save encrypted pages to disk" option set.