It’s 2023, and MD5 is already the most basic signature algorithm, but if you still only do a simple MD5 on the input, you will definitely be laughed at by your peers. Adding salt is a basic improvement, but in this era of severe employment, just adding salt is definitely not enough.
Today we will talk about the modified MD5 to make this algorithm more advanced.
The simplest way to modify it is to change the initial parameters of MD5.
Older generations of Windows reverse engineers have been analyzing the Windows kernel one after another, dreaming of taking a look at the Windows source code, but so far they can only see leaked source code from several generations ago. The mobile era is a blessing, the latest version of Android source code is open to you, and you can’t just look at it, you have to touch it.
This sample is somewhat similar to the previous short video app. The signature name and algorithm are probably the same. So if you understand this, you can probably understand the latest version of the short video app.
So what is the difference between reading novels and watching short videos?
The more I read novels, the sleepier I feel. The more I watch short videos, the more awake I feel. This proves that AI knows you better than you know yourself.
It has been a while since I wrote an article related to unidbg. This sample is quite suitable, with moderate difficulty and a small pit for you. So the following is a series of articles, including unidbg environment supplement, Trace Block comparison process, Trace Code location difference. Mastering this series of routines, Native analysis can be considered an entry.
This time, let’s run so with unidbg
v6.1.0
IDA openslibencrypt.soGo to the offset addresses 0x24424 and 0x2B1BC corresponding to the two functions checkcode and decheckcode we want to analyze. We will find a strange problem that there is no assembly code at these two addresses, both are 0x00.
Boss: I just bought a new car recently. The app that came with it is quite interesting. Would you like to take a look at it?
Me: Oh my god, it’s packed, it’s quite interesting, let me try it.
v6.1.0
My packet capture environment is Mac 10.14.6 + httpToolKit, and I captured the packet smoothly in this step.
1:main
As you can see, both the http request and the return value are encrypted. This is our goal.requestandresponseThe origin of .