使用MD5哈希上传流导致"您指定的Content-MD5无效"

Question

我正在使用一个实现Amazon S3.我使用了Amazon C# SDK,我尝试使用putObject方法上传创建的ZIP文件.

当我上传文件时,我收到以下错误:

{Amazon.S3.AmazonS3Exception: The Content-MD5 you specified was invalid

我生成了一个精细且有效的内存流,我可以毫无错误地将其上传到Amazon S3.但是,当我提供以下行时,它给我带来了问题:

request.MD5Digest = md5;

我证明MD5是正确的方法吗？我的MD5代是否正确？或者还有其他错误吗？

我上传代码的要求:

Once the Zip file has been created and you have calculated an MD5 sum value of that file, you should 
transfer the file to the AWS S3 bucket identified in the S3Access XML. 
Transfer the file using the AmazonS3, PutObjectRequest and TransferManagerclasses. 
Ensure the following meta data attributes are included via adding an ObjectMetaDataclass instance to the
PutObjectRequest:
• MD5Sum (via setContentMD5)
• Mime ContentType (setContentType)

我的上传代码

client.PutObject()给出错误:

public void UploadFile(string bucketName, Stream uploadFileStream, string remoteFileName, string md5)
        {
            using (client = Amazon.AWSClientFactory.CreateAmazonS3Client(accessKeyID, secretAccessKeyID, config))
            {
                try
                {
                    StringBuilder stringResp = new StringBuilder();

                    PutObjectRequest request = new PutObjectRequest();
                   // request.MD5Digest = md5;
                    request.BucketName = bucketName;
                    request.InputStream = uploadFileStream;
                    request.Key = remoteFileName;
                    request.MD5Digest = md5;

                    using (S3Response response = client.PutObject(request))
                    {
                        WebHeaderCollection headers = response.Headers;
                        foreach (string key in headers.Keys)
                        {
                            stringResp.AppendLine(string.Format("Key: {0}, value: {1}", key,headers.Get(key).ToString()));
                            //log headers ("Response Header: {0}, Value: {1}", key, headers.Get(key));
                        }
                    }
                }
                catch (AmazonS3Exception amazonS3Exception)
                {
                    if (amazonS3Exception.ErrorCode != null && (amazonS3Exception.ErrorCode.Equals("InvalidAccessKeyId") || amazonS3Exception.ErrorCode.Equals("InvalidSecurity")))
                    {
                        //log exception - ("Please check the provided AWS Credentials.");
                    }
                    else
                    {
                        //log exception -("An error occurred with the message '{0}' when writing an object", amazonS3Exception.Message);
                    }
                }
            }
        }

总体方法

我的处理方法(看整体流程).抱歉,代码的当前状态是伪代码而不是生产代码:

 public void Process(List<Order> order)
    {
        var zipName = UserName + "-" + DateTime.Now.ToString("yy-MM-dd-hhmmss") + ".zip";
        var zipPath = HttpContext.Current.Server.MapPath("~/Content/zip-fulfillment/" + zipName);

        CreateZip(order, zipPath);


        var s3 = GetS3Access();

        var amazonService = new AmazonS3Service(s3.keyid, s3.secretkey, "s3.amazonaws.com");
        var fileStream = new MemoryStream(HelperMethods.GetBytes(zipPath));
        var md5val = HelperMethods.GetMD5HashFromStream(fileStream);
        fileStream.Position = 0;
        amazonService.UploadFile(s3.bucket, fileStream, zipName, md5val);

        var sqsDoc = DeliveryXml(md5val, s3.bucket, "Test job");

        amazonService.SendSQSMessage(sqsDoc.ToString(), s3.postqueue);
    }

MD5哈希方法:

此方法用于从我的内存流创建MD5哈希:

    public static string GetMD5HashFromStream(Stream stream)
    {

        MD5 md5 = new MD5CryptoServiceProvider();
        byte[] retVal = md5.ComputeHash(stream);

        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < retVal.Length; i++)
        {
            sb.Append(retVal[i].ToString("x2"));
        }
        return sb.ToString();
    }

编辑:

刚刚在整个方法中添加了fileStream.Position = 0.尽管如此仍然完全相同.

Answer 1

我怀疑问题可能是在计算流的散列之后,流被留在数据的末尾 ......所以当稍后从其中读取任何内容时,将没有数据.尝试在调用后添加此项GetMD5HashFromStream

fileStream.Position = 0;

这将"回放"流,以便您可以再次阅读它.

编辑:只是看看文档,虽然上面是一个问题,但它并不是唯一的问题.目前,您附加了MD5哈希的十六进制表示 - 但文档说明:

Content-MD5:消息的base64编码的128位MD5摘要

请注意"base64编码"部分.因此,您需要将MD5代码更改为:

public static string GetMD5HashFromStream(Stream stream)
{
    using (MD5 md5 = MD5.Create())
    {
        byte[] hash = md5.ComputeHash(stream);
        return Convert.ToBase64String(hash);
    }
}