if r.ContentLength > encryptBufferThreshold {
		// The encryption reads in blocks of 64KB.
		// We add a buffer on bigger files to reduce the number of syscalls upstream.
		content = bufio.NewReaderSize(content, encryptBufferSize)
	}

	var (
		key   []byte
		keyID string
		ctx   kms.Context
		err   error
	)