From a Cronos Dump to CSV: Recovering a Legacy Database Format

We constantly work with different datasets that we normalize into our data lake. Recently we received CronosPro database files (CroBank.dat, CroIndex.dat, and CroStru.dat) that were thought to be broken because existing tooling could not parse them correctly. Anyone who has worked with the CronosPro format, knows that its raw datafiles are notoriously difficult to convert into machine-readable formats such as CSV. A good amount of work has been put into the Cronos dump converter Cronodump alephdata/cronodump, but due to the version specific nuances of the database file structures, it doesn’t work 100% of the time. For the purpose of tackling this problem, we employed Codex for analyzing the dump structure and improved upon the Cronodump codebase to fix the parsing of the allegedly broken database. Cronodump converter could read much of the format, but it could not decode this particular dump correctly.