I neglected the bit which admitted that EAC is closed-source, but did want to emphasize that cdparanoia is just about as good as EAC... as long as your goal is simply determining if you have a bad rip. What you can't do is rely on cdparanoia to properly correct your data. I've encountered at least one disc which was deterministically "mis-corrected" on one of my drives but ripped without any errors (corrected or otherwise) on the other. But I know for a fact that of the 288 CDs in my collection that I believe to have been ripped accurately so far, I have yet to come across a CD which cdparanoia claimed ripped completely cleanly (i.e. with not even a single "corrected" error) which failed to match AccurateRip hashes generated by the same disc on a Windows machine.
Even ignoring the occasional "your CD matches no known pressing" hits I get with AccurateRip, I've come across only two discs which ripped cleanly and failed to match any known hash stored in AccurateRip, but even in those cases, the same "non-matching" hashes were generated on Windows with a completely different CD drive. The discs in question only had one and two hashes stored in the AccurateRip database, raising the more probable possibility that the hashes in the AccurateRip database were wrong rather than my rips.