I've had a look around the forum, but I'm struggling to find information on it, more precisely, what exactly is it for?

Is it just a bnet emulator for testing bots on, or does it provide logon information for the real b.net to bots based on b.net responses to login requests?

This should help you.

http://www.valhallalegends.com/yoni/BNLSProtocolSpec.txt

[quote author=Sanguine link=topic=10459.msg98592#msg98592 date=1107781843]
I've had a look around the forum, but I'm struggling to find information on it, more precisely, what exactly is it for?

Is it just a bnet emulator for testing bots on, or does it provide logon information for the real b.net to bots based on b.net responses to login requests?
[/quote]

It is not a Battle.net emulator; rather, it provides functions for calculating the values required for logging into Battle.net.  It does not provide log-on information (you provide it to BNLS) -- it just transforms your input into the "secure" method Battle.net provides (which is generally negated by the fact that you used plain text to send the data to BNLS in the first place).

As for what exactly its purpose is -- convenience.  A bot that implements BNLS hashing doesn't need to keep its hash files up-to-date; BNLS is generally updated within several hours of a patch release.  The user doesn't need to have the game installed or keep game files local for it.

Thanks, cleared that up.

Note: if you want a Battle.net emulator for testing bots on, you should take a look at TestBNCS.