Depending on the speed of your program conducting this comparison (likely on CPU) it is possible it might still be faster to just brute force the SHA-256 hash using a cracking program like Hashcat and a good GPU. Looks like that approach should enable you to reach speeds of around 2,876,000,000 - 4,330,000,000 hashes/sec, or better, which would mean about 18 - 27 days to crack all password possibilities. I doubt your program would be slower than this, since you have so many fewer candidates to test, but it's something to watch for if you can estimate your candidates compared per second.