SetContentMD5 is no use in my program

[lucaspeng12138]

I tried to use real md5 and fake md5 to set into request. But both can work normally.

void put_object_buf(Aws::String& bucketName, Aws::String& objectName, S3::S3Client& s3_client)
{
    Aws::S3::Model::PutObjectRequest putObjectRequest;
    putObjectRequest.SetBucket(bucketName);

    std::shared_ptr<Aws::IOStream> bigStream = Create5MbStreamForUploadPart("La");

    putObjectRequest.SetBody(bigStream);
    putObjectRequest.SetContentLength(static_cast<long>(putObjectRequest.GetBody()->tellp()));
    putObjectRequest.SetContentMD5(Aws::Utils::HashingUtils::Base64Encode(Aws::Utils::HashingUtils::CalculateMD5(*putObjectRequest.GetBody())));
    putObjectRequest.SetContentMD5("123");  // still put success
    putObjectRequest.SetKey(objectName);

    Aws::S3::Model::PutObjectOutcome outcome = s3_client.PutObject(putObjectRequest);

    if (!outcome.IsSuccess()) {
        std::cerr << "Error: PutObjectBuffer: " <<
                  outcome.GetError().GetMessage() << std::endl;
    }
    else {
        std::cout << "Success: Object '" << objectName << "' uploaded to bucket '" << bucketName << "'." << std::endl;
        std::cout << "outcome crc32: " << outcome.GetResult().GetChecksumCRC32() << std::endl;
        std::cout << "outcome etag: " << outcome.GetResult().GetETag() << std::endl;
    }
}

[lucaspeng12138]

Could you please help me out? @sdavtaker

[lucaspeng12138]

I think this may be caused by AddChecksumToRequest? @sdavtaker

[WolfgangVogl]

I've made to PUT requests with this code:

void d3srv::S3Uploader::putObject(const std::string& bucketName, const std::string& objectKey)
{
   Aws::S3::Model::PutObjectRequest putObjectRequest;
   putObjectRequest.SetBucket(bucketName);
   putObjectRequest.SetKey(objectKey);
   auto data = Aws::MakeShared<Aws::StringStream>("PutObjectInputStream",
                                                  std::stringstream::in | std::stringstream::out | std::stringstream::binary);
   std::string content{"fooBarBaz"};
   data->write(reinterpret_cast<char*>(content.data()), content.size());
   putObjectRequest.SetBody(data);
   putObjectRequest.SetContentMD5("123"); // First PUT: 'abc', Second PUT '123'
   auto& s3Client = getS3Client();
   auto outcome = s3Client.PutObject(putObjectRequest);
   if (!outcome.IsSuccess())
      std::cerr << "Error PutObject: " << outcome.GetError().GetMessage() << std::endl;
   else
      std::cout << "SUCCESS PutObject" << std::endl;
}

and watched the requests via fiddler. Here's the diff of both requests

--- Clipboard
+++ Selection
@@ -1,17 +1,17 @@
-PUT https://--myHost--.s3.eu-central-1.amazonaws.com/2023_04_17__09_27_s3upload.test HTTP/1.1
+PUT https://--myHost--.s3.eu-central-1.amazonaws.com/2023_04_17__09_22_s3upload.test HTTP/1.1
 Cache-Control: no-cache
 Connection: Keep-Alive
 Pragma: no-cache
 Content-Type: binary/octet-stream
 Content-MD5: wmw6re5NYXXGvCVKnwVgrQ==
 Accept: */*
-Authorization: AWS4-HMAC-SHA256 Credential=.../20230417/eu-central-1/s3/aws4_request, SignedHeaders=amz-sdk-invocation-id;amz-sdk-request;content-length;content-md5;content-type;host;x-amz-content-sha256;x-amz-date;x-amz-security-token, Signature=...SIG-A
+Authorization: AWS4-HMAC-SHA256 Credential=.../20230417/eu-central-1/s3/aws4_request, SignedHeaders=amz-sdk-invocation-id;amz-sdk-request;content-length;content-md5;content-type;host;x-amz-content-sha256;x-amz-date;x-amz-security-token, Signature=...SIG-B
 Host: --myHost--.s3.eu-central-1.amazonaws.com
 User-Agent: aws-sdk-cpp/1.11.51 Windows/10.0.19041.2604 AMD64 MSVC/1929
-amz-sdk-invocation-id: 6DA7FECC-C9D9-4620-B8A2-7BC87AEF22E7
+amz-sdk-invocation-id: 966C96B0-C91A-4342-8F58-47EB0C8332CC
 amz-sdk-request: attempt=1
 x-amz-content-sha256: UNSIGNED-PAYLOAD
-x-amz-date: 20230417T092714Z
+x-amz-date: 20230417T092219Z
 x-amz-security-token: ...
 Content-Length: 9

It seems the manually specified MD5 hash isn't part of the data that goes to s3.

[lucaspeng12138]

Yes, so this SetContentMD5 is no use in current version

[jmklix]

@github-actions proposed-answer

@lucaspeng12138 sorry for the late reply. We were recalculating the md5 previously, but we fixed that here: #2788
Can you try updating to the latest version of this sdk and see if you run into any unexpected behaviors with SetContentMD5

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