Radare2’s Visual Mode

Radare2’s Visual Mode

So far, I’ve been using strictly the command line prompt of radare2. I do believe this was the perfect choice to start learning how it works, to learn the basics so I can have a strong base of knowledge in this tool. But let’s be honest, as you evolve, it become tedious use just the command line and I started to feel this in Crackme0x03 when I needed to debug the shift function. An option, was to put a breakpoint…

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Crackme0x03 Dissected with Radare2

Crackme0x03 Dissected with Radare2

Crackme0x03 is the first of this series of exercises to have more that one function. It actually has three (important) functions, described below: main function, where the core code is test function, which tests our input and decides the flow of the program shift function, responsible for decrypt the string Getting the Crackme0x03 password through analysis From now on, I’ll jump the part where I check what the program does, because they all test a string/value. So, let’s check the…

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Crackme0x02 Dissected with Radare2

Crackme0x02 Dissected with Radare2

For the Crackme0x02, I’ll follow two approaches. First, I’m going to find out the password through analysis. Then, I’ll modify the program in order to accept any password. If you’re not acquainted with any of the commands used in this post, you can always take a look at Radare Basics. Let’s start and first of all, we need to run the program.  Like the previous exercise, this one is a password challenge.   Getting the Crackme0x02 password through analysis To…

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Crackme0x01 Dissected with Radare2

Crackme0x01 Dissected with Radare2

In order to have some insight of what are we dealing with, let’s run the Crackme0x01 program first. Password Challenge! Apparently, its just a simple program that tests a password entered by the user. Let’s dig in, starting Radare2 with analyze and debug options (check Radare Basics to find out how). Analysis So, first thing, let’s look at the functions present in the binary. IMHO, it’s always a good idea take a peek in the program functions with the aim…

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An excuse to learn Radare2

An excuse to learn Radare2

Four weeks ago, the opportunity to learn something about Reverse Engineering presented itself, I was asked to analyze and, if possible, modify a DOS executable. I saw this as a great excuse to tune my skills in assembly, so I began to search for a tool fitted for this task and as a main goal, I wanted to teach myself how to use it. A few searches lead me to Radare2. At that point, I had already heard about IDA,…

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Radare Basics

Radare Basics

After some googling and testing, I have compiled a list of commands that enabled me to look deeply into the code and get useful information. I intend to update this list while I’m learning new commands. r2 -Ad ./crackme0x01 Opens r2 in debug mode with the Analyze all flag active Note: If I hadn’t passed A flag, aa would be the first command to execute after running Radare First of all, let me state that it’s always possible to use…

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