non-working rewind of stream for checksum validation

Author: sbiscigl

src/aws-cpp-sdk-transfer/include/aws/transfer/TransferHandle.h

@@ -373,6 +373,7 @@ namespace Aws
              * Return empty string on success, string with error message on error.
              */
             Aws::String WritePartToDownloadStream(Aws::IOStream* partStream, uint64_t writeOffset);
+            void AddChecksumForPart(Aws::IOStream* partStream, const PartPointer& shared);
 
             void ApplyDownloadConfiguration(const DownloadConfiguration& downloadConfig);
 

src/aws-cpp-sdk-transfer/source/transfer/TransferHandle.cpp

@@ -3,12 +3,14 @@
  * SPDX-License-Identifier: Apache-2.0.
  */
 
-#include <aws/transfer/TransferHandle.h>
 #include <aws/core/utils/logging/LogMacros.h>
 #include <aws/core/utils/memory/stl/SimpleStringStream.h>
+#include <aws/transfer/TransferHandle.h>
 
 #include <cassert>
 
+#include "aws/core/utils/crypto/CRC64.h"
+
 namespace Aws
 {
     namespace Transfer
@@ -423,6 +425,16 @@ namespace Aws
             return "";
         }
 
+        void TransferHandle::AddChecksumForPart(Aws::IOStream* partStream, const PartPointer& partState) {
+          partStream->seekg(0);
+          if (GetChecksumAlgorithm() == S3::Model::ChecksumAlgorithm::CRC64NVME) {
+            //TODO: fix this
+            partState->SetChecksum(Aws::Utils::Crypto::CRC64::Calculate(partStream->rdbuf()));
+          }
+          partStream->clear();
+          partStream->seekg(0);
+        }
+
         void TransferHandle::ApplyDownloadConfiguration(const DownloadConfiguration& downloadConfig)
         {
             SetVersionId(downloadConfig.versionId);

src/aws-cpp-sdk-transfer/source/transfer/TransferManager.cpp

@@ -1262,26 +1262,9 @@ namespace Aws
                     Aws::IOStream* bufferStream = partState->GetDownloadPartStream();
                     assert(bufferStream);
 
+                    handle->AddChecksumForPart(bufferStream, partState);
                     Aws::String errMsg{handle->WritePartToDownloadStream(bufferStream, partState->GetRangeBegin())};
                     if (errMsg.empty()) {
-                        partState->SetChecksum([&]() -> Aws::String {
-                        if (!outcome.GetResult().GetChecksumCRC32().empty()) {
-                          return outcome.GetResult().GetChecksumCRC32();
-                        }
-                        if (!outcome.GetResult().GetChecksumCRC32C().empty()) {
-                          return outcome.GetResult().GetChecksumCRC32C();
-                        }
-                        if (!outcome.GetResult().GetChecksumCRC64NVME().empty()) {
-                          return outcome.GetResult().GetChecksumCRC64NVME();
-                        }
-                        if (!outcome.GetResult().GetChecksumSHA1().empty()) {
-                          return outcome.GetResult().GetChecksumSHA1();
-                        }
-                        if (!outcome.GetResult().GetChecksumSHA256().empty()) {
-                          return outcome.GetResult().GetChecksumSHA256();
-                        }
-                        return "";
-                        }());
                         handle->ChangePartToCompleted(partState, outcome.GetResult().GetETag());
                     } else {
                         Aws::Client::AWSError<Aws::S3::S3Errors> error(Aws::S3::S3Errors::INTERNAL_FAILURE,