Android Reverse Algorithm Decryption Introduction

Android Reverse Algorithm Decryption Introduction

Why decrypt the algorithm

1. To do protocol analysis is to do offline protocols, such as the automatic login and automatic sign-in functions of a website.
2. Do data security analysis
3. The connected algorithm decrypts the order
4. Wait, wait, too much

Difficulty factor

I personally think there are a few points:

Is the algorithm app shell you encounter a common one?

1. If you are interested in learning, and the app you encounter has no confusion or shell, congratulations, this kind of app should be a flash kill, and the tool will be directly killed when you open it (difficulty factor: ⭐)
2. The app has a shell list and it is a commonly used or very old shell. This is also a flash kill, because the tools for shelling have already existed in the market. If you can’t find it, it’s because your circle ability has not yet reached. Congratulations. Can be done quickly. (Difficulty factor: ⭐⭐)

The algorithm app shell encountered is from a big factory and is a paid version

1. You can find the shell, but you can’t find the tool, and you can’t catch the package, such as a certain bang bang, which requires a certain amount of knowledge reserve ability. If you really want to be yourself but don't have the ability to store knowledge, then you can rely on the boss to enjoy the cool. We have to sacrifice what's in our pockets to rely on the boss. (Difficulty factor: ⭐⭐⭐)
   2. Find the entrance of the algorithm but can't understand the redemption, and can't find the key points. Some algorithms have been modified by others. These have to calm down and analyze. After all, other people's safety knowledge is not learned in vain. (Difficulty factor: ⭐⭐⭐)

Ah, yes, yes, stop talking about dry goods (directly dry and have goods)

Personal understanding still needs to understand a certain process, first analyze which category it belongs to. If you want to win the match, you must understand your opponent. Erqi, you must be better than him.

The following begins to introduce common solutions

1. The full name of the most common algorithm MD5 is message-digest algorithm 5 (information-digest algorithm)

For example:
X-Sign in the protocol header: X8efe40ac90c7df2a07c0c5a1ffa73c41
Sign in the protocol header: X8efe40ac90c7df2a07c0c5a1ffa73c41
PassWord: X8efe40ac90c7df2a07c0c5a1ffa73c41
Let’s put it this way, 80% like this Both are MD5 encryption, because the length of his ciphertext is 32 bits, which is MD5 encryption one of the greatest features.
Here we discuss the java layer for the time being. I haven't seen a way to kill at the SO level.
One tool directly at the java layer is done:

Attach the tutorial link: click to watch directly

2. Symmetric algorithm AES DES 3DES
   What we often do for this type of algorithm is to find the key place. What are you looking for. directly on the picture,

If everyone, I don’t know much about this kind of algorithm and have no idea to watch the video tutorial first: Click to watch directly

4. RSA symmetric encryption (reversible)
   I feel that this type of algorithm is better manually. But there are still tools, just find the publickey and you’re done.
   You can use Baidu’s rsa encryption call to implement it, and implement it in java language. Because I haven’t done this for a long time, I won’t share it.

how to shell it

Analyze the three shelling tools and watch the video specifically. For novices, the introduction principle is purely pure. . . .
How to use the first tool and
how to use the second tool
Wait for the update

The mistakes in the article are welcome to point out. The last sentence, the tool can be downloaded from Baidu. This article will be updated later. . It took over an hour to get here.