Cloud Data Imager: A unified answer to remote acquisition of cloud storage areas

The pervasive availability of cheap cloud computing services for data storage, either as persistence layer to applications or as mere object store dedicated to final users, is remarkably increasing the chance that cloud platforms potentially host evidence of criminal activity. Once presented a proper court order, cloud providers would be in the best position for extracting relevant data from their platforms in the most reliable and complete way. However, this kind of services are not so widespread to date and, therefore, the need to adopt a structured and forensically sound approach calls for innovative weaponry which leverage the data harvesting capabilities offered by the low level program interfaces exposed by providers. This paper describes the concepts and internals of the Cloud Data Imager Library, a mediation layer that offers a read only access to files and metadata of selected remote folders and currently supports access to Dropbox, Google Drive and Microsoft Skydrive storage facilities. A demo application has been build on top of the library which allows directory browsing, file content view and imaging of folder trees with export to widespread forensic formats.