Upload/download large encrypted files on S3 with client-side-encryption

Hello. I am trying to upload and download large encrypted files to S3 using a client-side encryption (see code below). Uploading works but I get this error message when downloading:

operation error S3: GetObject, failed to load objectMetadata: bucket=0xc0002b6850; key=0xc0002b6860; err=operation error S3: GetObject, https response error StatusCode: 404, RequestID: JB2T72TFB82DWP7M, HostID: tpQaEDUb/ZxaxOE7ZI1/akdZFKoXRjs3vYlKma0GtTVTa2Gmn3yXH49axHJmuUJ6oNrLxRDrtGA=, NoSuchKey:

The same code works with small files, but I can't figure out how to make uploading/downloading large files work with client-side-encryption. Do you have any advice on how to solve this? Thank you in advance.

Code

I am using the Amazon S3 encryption client and the Upload Manager from the sdk for go.

func UploadLargeObject(S3EncryptionClient *client.S3EncryptionClientV3, bucketName string, objectKey string, largeFileName string) error {
    largeFile, _ := os.Open(largeFileName)

    uploader := manager.NewUploader(S3EncryptionClient, func(u *manager.Uploader) {
        u.PartSize = 10 * 1024 * 1024
    })
    _, err := uploader.Upload(context.TODO(), &s3.PutObjectInput{
        Bucket: aws.String(bucketName),
        Key:    aws.String(objectKey),
        Body:   largeFile,
    })
    if err != nil {
        return fmt.Errorf("error uploading object %q to %q: %w", largeFileName, objectKey, err)
    }
    log.Printf("File %q uploaded successfully to bucket %s.\n", largeFileName, bucketName)
    return nil
}

func DownloadLargeObject(S3EncryptionClient *client.S3EncryptionClientV3, bucketName string, objectKey string, largeFile_dest string) error {
    largeFile, _ := os.Create(largeFile_dest)

    downloader := manager.NewDownloader(S3EncryptionClient, func(d *manager.Downloader) {
        d.PartSize = 10 * 1024 * 1024
    })
    _, err := downloader.Download(context.TODO(), largeFile, &s3.GetObjectInput{
        Bucket: aws.String(bucketName),
        Key:    aws.String(objectKey),
    })
    if err != nil {
        return fmt.Errorf("error downloading object %q from bucket %q: %w", objectKey, bucketName, err)
    }
    log.Printf("File %q downloaded successfully.\n", largeFile_dest)
    return nil
}

func main() {
    cfg, _ := config.LoadDefaultConfig(context.TODO())

    cmm, _ := materials.NewCryptographicMaterialsManager(materials.NewKmsKeyring(kms.NewFromConfig(cfg), "arn:aws:kms:eu-west-3:111122223333:key/1234abcd-12ab-34cd-56ef-1234567890ab", func(options *materials.KeyringOptions) {
        options.EnableLegacyWrappingAlgorithms = false
    }))
    s3EncryptionClient, _ := client.New(s3.NewFromConfig(cfg), cmm)

    err := UploadLargeObject(s3EncryptionClient, "cryptai-bucket", "largeFile", "largeFile")
    if err != nil {
        log.Fatal(err)
    }

    err = DownloadLargeObject(s3EncryptionClient, "cryptai-bucket", "largeFile", "largeFile_downloaded")
    if err != nil {
        log.Fatal(err)
    }
}