Don't know if it can help but... If it's Audio CDs the problem is kinda solved in that you can make sure you extract a bit-perfect copy by verifying the checks

Don't know if it can help but... If it's Audio CDs the problem is kinda solved in that you can make sure you extract a bit-perfect copy by verifying the checksum with the checksums of other people who extracted the same CD. Even though the Audio CD format tried to make it "hard" to rip in a bit-perfect way, it's done precisely like that since years and years. There's a community of people ripping Audio CD to flac file and making sure all their rips are bit-perfect. I've ripped my own collection and used, as far as I remember, "whipper" on Fedora Linux (for whatever reason I couldn't make that software work on Debian back then). After ripping a track/CD the software would automatically verify the checksum with an online DB of rips. You say you can't use proprietary solution: as far as I know there are several free rippers on Linux and the online DB of checksum isn't proprietary either (?). In case you rip with an error, it's near impossible that someone else who ripped the CD would have read exactly the same error and end up with the same checksum. Now: for all the audio CDs I tried there was at least one other person who had already ripped it but it's not always the case. For example I've read about some collection of classical music CDs coming in pack of 300 CDs (!) and nobody had bothered, at home, to rip them / to share the checksum. But it can already help for all the "common" CDs you own.