Battle.net Server Signature

[iago]

Last night and this morning I spent a little time and figured out how Battle.net's server signatures work.  It's a simple RSA decryption, r = s^k % n, where n is a 128-byte constant, k is a 4-byte constant, and s is the 128-byte signature.  See this document for more details:

http://www.javaop.com/~iago/ServerSig.html

[Blaze]

Silly blizzard. Good job iago.

[Adron]

I.e. it's a RSA signature... Might be good to add that

[iago]

Yeah, I should. I updated the document:
- Now mentions RSA a couple times
- Now has a sample implementation

And incidentally, this won't help people create pirate servers (that'll work with the actual game client) unless somebody feels like brute-forcing Blizzard's private key

[Networks]

[22:33] iago: So if you had every atom in the Universe, and all the time in the Universe, you still couldn't brute force the key

You've wasted you time you nub!!!!!! <3

[iago]

Incidentally, if you're wondering why they pad it with 0xBB, think about this.  As a signed byte, 0xBB is -69.  I think somebody as blizzard has a dirty mind

[Blaze]

The character &HBB is also the >> symbol.

[Lenny]

[22:33] iago: So if you had every atom in the Universe, and all the time in the Universe, you still couldn't brute force the key

You've wasted you time you nub!!!!!! <3

Actually if you had an infinite amount of time, at some point a monkey on a type writer would crack it 

[iago]

0xBB isn't any standard character.  Anything over 0x7F isn't standard.  I still think they like the -69

Lenny -- I didn't say infinite time I said all the time in the Universe.  Something like 50 billion years.

[Networks]

[22:33] iago: So if you had every atom in the Universe, and all the time in the Universe, you still couldn't brute force the key

You've wasted you time you nub!!!!!! <3

Actually if you had an infinite amount of time, at some point a monkey on a type writer would crack it 

nah...the monkey would die, maybe several billion monkeys.

[iago]

nah...the monkey would die, maybe several billion monkeys.

You're thinking way too small.  A billion is nothing when we're talking about 1024-bit encryption. 

[Warrior]

I guessed and got it right
lmao

[Networks]

nah...the monkey would die, maybe several billion monkeys.

You're thinking way too small.  A billion is nothing when we're talking about 1024-bit encryption. 

Oh right we went over this 1 billion to the power of 1 billion? (that might be medium)

[iago]

That's a little too big

It's on the order of 10**300 possible keys

[TaGBaN]

There I cracked it:
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Oh wait, that was my mom's wedding goblet. Sorry I thought we were tallking about drinking cups.

~Tagban