Basically I made a purchase with bitcoins back in ~2014 and I remember that I had a little bit leftover. However all documentation I have is a file labelled wallet with a huge string of characters. But when I try and access it on any application I get the non base-58 character error. There are a bunch of +'s and /'s. Does anyone have any idea what I could try to see if this is it? Sorry for not having more advance knowledge.
There are a bunch of +'s and /'s.
That strongly suggests it is data in Base64 encoding. Note that, in this case encoding does not mean encryption, just a specific printable representation of binary data.
Does anyone have any idea what I could try to see if this is it?
It seems several different wallets might use Base64 encoding, including:
Of those, I'd guess the first is most likely. But that's just a guess. There are probably numerous other possibilities.
I think I'd try the Blockchain.info recovery process first then, if that didn't work, try decoding the file from Base64 into binary and using a hex editor to look for patterns that might give some clues to the software that produced it. If the file is encrypted using a wallet password this probably would not be fruitful.
You can try this "dirty" trick to figure out what the data corresponds to type of wallet.
Get Python, john the ripper and hashcat. put your text in a file called wallet.json
With the run tools in JTR try the following on the strings:
python bitcoin2john.py wallet.json > bitcoinhash.txt python blockchain2john.py wallet.json > blockchainhash.txt python electrum2john.py wallet.json > electrumhash.txt
now with the hashes try your password with hashcat. if it accepts the hash and your password then you know which one it is.
for blockchain check if the wallet version is 1 or 2, they use different mode and if its v1 it will most likely fail to decrypt as both hashcat and btcrecover does not cover all v1 wallets correctly.