Thanks, people!
if you tell us what you are trying to do we can help you better. for example why do you want to create so many WIFs?
the text conversion specially when base58 is involved will be very slow and since it is not a normal thing, the chances of finding a program that does what you ask here is little to none. but for example if you were trying to brute force a key, there are better tools available without needing this method. or if you were trying to create a paper wallet, then you should use deterministic setup and only have one master key.
Actually all the fuzz is about restoring physically damaged paper wallet. WIFC key, some symbols here and there are damaged and there is no way to restore them physically. There are couple of leads that could narrow down the search, but not much. My idea was:
1) generate all possible combinations
2) decode base58
3) remove all strings without 01 byte before the checksum
4) remove all strings there checksum doesn't match
5) if the number of possibilities will be still too huge: generate list of adresses for these keys
6) compare the list with the list of alive bitcoin wallets and find my own)
I guess this would take a load of uptime, but I'm not much in the hurry. There isn't much money on the wallet, so it's more like a challenge and also money is money:)
Right now I'm planing to use fix-base58check feature in bitcoin-tool. Looks promising. Though if I could show it which symbols are definitely correct this probably would save much time during bruteforce process.
I'm not sure if it fits all your requirements, but bitcoin-tool is probably a good start. I don't want to provide a link, because I'm not sure if the Github link I find is the official one. I downloaded my copy years ago. Just to be sure: run it in a VM to protect your (offline) host.
I tried to search this tool there are many similar names but I found only one link from github that I think this is the official one.
Here's the link
https://github.com/matja/bitcoin-toolThanks! This thing looks very promising in my situation:)