4 ms·

I spent 3 weeks stepping through a program to reverse their blowfish encryption a long time ago... So I won’t say he messed up by stepping through code for 6 h

I spent 3 weeks stepping through a program to reverse their blowfish encryption a long time ago... So I won’t say he messed up by stepping through code for 6 hours to find the AES decrypt sequence but the instruction he could have scanned for is a special CPU instruction now! aesdec xmm0,xmm1 How many separate routines could they have that directly call AES instructions?

duskwuff 7y ago
Not all AES implementations will use AESNI instructions. Support for those instructions is relatively new -- many systems in productions still lack them -- and they're hardly necessary for a non-performance-critical implementation like this one. A better signal is the presence of the S-box tables (63 7C 77 7B...). Even that won't detect applications which use an implementation from a shared library, though.
- SlowRobotAhead 7y ago
  Yea, that’s how I did a blowfish program, just looked for the big constant table, but you know there are some clowns out there that “make their own” s-box :) you know, to “be even more secure”.