Questions tagged [radare2]

Opensource reverse engineering framework to disassemble, debug, analyze, manipulate binary files and more.

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Radare2 substituting second operand of lea instruction with a random register

I was trying to debug a crackme with radare2. I found an interesting function which radare2 flagged as sym.xxx. The following listing is trimmed version of disassembled output of the function sym.xxx. ...
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42 views

Differences between IDA Pro and Radare2

I am familiar with Hopper Disassembler and OllyDbg as favorite and simple tools, but I would like to try switching to IDA to work on Windows. However, I know about radare2 and that it is open source,...
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1answer
23 views

How to set search scope in radare2

Iam wondering how to change search scope in radare2. I`ve made some research and set variables search.from and search.to, according to Radare2 Book, but it doesn't work at all! Could you help me ...
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18 views

How can I iterate over syscalls (as returned with `axt`) and rewrite them?

Let's say I want to list all calls that issue kill, axt @ sym.imp.kill How can I now NOP out the syscall at all of the addresses given? I want to strip the program of calls to kill.
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Radare2 ptrace can not attach

First my setup: Linux Mint 64bit 4.15.0-20-generic radare2 the newest version from github /etc/sysctl.d/10-ptrace.conf = 0 Executable: ELF 64-bit LSB executable, x86-64 read write and ...
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radare2 (v3.6.0) on windows(x64) not change registers values in debug mode

Whats wrong: d:\radare2\bin\radare2 -A -d d:\test.exe Spawned new process with pid 7192, tid = 8572 ... [0x014eb83c]> pd 5 ┌ (fcn) entry0 2066 │ entry0 (); │ bp: 0 (vars 0, args 0) │ sp: 0 (...
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How to do debug a running java process in linux?

TLDR I want to do live debugging of a java program on a linux machine, and don't how/what debugger to attach to the JVM to get this done. I expect that this is a well-solved problem, but I lack the ...
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1answer
84 views

Change instruction test eax, eax to text eax, 1

I'm trying to change an instruction in assembly. Try with test eax, eax to test eax, 1. I try modify the opcodes. For example opcode of test eax, eax: 85c0 Try to understand why is 85c0 with this ...
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54 views

write radare2 output to a file

I am trying to write all the write logs of a binary program into a file for further analysis. I am using radare2 for it. I don't know what's the issue, I am not able to write the 'dte' output to a ...
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1answer
43 views

What is actually loaded here and different hexdump outputs on util-linux hexdump and on cutter and ghidra's hexdump

I was trying to understand what segment of file gets loaded by fourth LOAD header on phdr array. First 6 headers are shown below from readelf Program Headers: Type Offset ...
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2answers
51 views

Radare2 show current RIP and current instruction while stepping

How can I get the same behavior as in gdb when using disassemble-next-line on? When I step in radare2, I just see: [0x7fea91263220]> ds [0x7fea91263220]> ds [0x7fea91263220]> ds Why doesn'...
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1answer
80 views

Illegal instruction error in simple buffer overflow

I using following C code for testing stack based simple buffer overflow #include<stdio.h> #include<string.h> void copier(char *arg){ char buffer[100]; strcpy(buffer,arg); } int ...
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58 views

radare2 wrong output

I saw rasm2 giving different output each time for x64 Take a look at this: C:\WINDOWS\system32>rasm2 -a x86 -b 64 -d "41f6c7FF" test r15b, 0xff C:\WINDOWS\system32>rasm2 -a x86 -b 64 "test ...
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1answer
59 views

Invert stack view in radare2

Is it possible to invert the stack view when debugging in radare2 such that higher addresses are at the top?
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47 views

How to view registers values in string

Is it possible that radare2 will show registers values also in strings ? For example, when I run ar I am getting the liste of registers and I have: rax = 0x000000042 Is there a way to also show ...
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1answer
68 views

radare2 shows main function arguments argv as pointer to char on the stack, not as pointer to pointer to char

Well, I've been digging around process command line arguments as well as environment variables a bit these last days, especially looking up the way main function arguments were pushed onto the stack. ...
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1answer
82 views

function call trace with radare2 or break on all function call

I want to script with python using r2pipe. Is there a way that when debugging I can break on each call function, thus I can get the parameter? What's more, I won't jump into system library. Or is ...
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37 views

How to increment and decrement machine code in radare2?

I watched a video (I believe it was a talk by the author of radare2) of how to increment machine code in radare2 very easily, simply by hitting 'c' and then using + and - to respectively increment and ...
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1answer
46 views

How to write sequence of machine code in radare2?

I know how to write an opcode and how to increment and decrement machine code using plus and minus keys. However, how do I write a sequence of machine code at an offset? E.g. if I want to write five ...
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2answers
114 views

crackme disassembly - are these local variables ever initialized?

I'm working on a crackme, where the objective is to find the valid password given a program. I'm using radare2 to reverse engineering the program. To do so, I need to enter a password that forces this ...
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1answer
61 views

When reopening file lose all information in radare2

I have problem with my radare2, when I try to reopen file in debug mode (ood) my radare loses all informations about that file. any help to avoid this?
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108 views

How do I type in hex input into radare2 debug mode?

#include<stdio.h> #include<stdlib.h> int main() { puts("Enter input: "); char buf[100]; fgets(buf, 100, stdin); printf("%s", buf); } Suppose I am debugging a program, such ...
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1answer
65 views

How to examine/edit stack memory contents using radare2 in debug mode?

How can i examine/edit stack contents using radare2, just like gdb ? Is there a way to examine memory using $rbp or $rsp register like below. x $rbp-10 <--- something like this which can dump from ...
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1answer
45 views

Passing hex strings to Radare2

I can quickly test hex string arguments in gdb like this: r $'\x61\x61\x61\x61' I'd like to do something similar in radare2 but all I can figure out is regular strings: doo aaaa I tried this but ...
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161 views

Illegal instruction fault in stack based buffer overflow

I wrote this short C program to practice buffer overflow exploits: #include <stdio.h> #include <string.h> #include <stddef.h> #include <inttypes.h> char *decode(char *s){ ...
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50 views

How to debug programs that load from another one? with radare2/gdb

I'm reversing engendering a plugin. This plugin is loaded into memory by the main program. I disassemble the plugin with radare2 but I don't know how to debug it. I try with gdb but same problem. I ...
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1answer
61 views

Is there watchpoints in radare2?

Is there any way to put breakpoints in radare2 that trigger when an address is read/write? In GDB those are call watchpoints ('rwatch' or 'awatch") I got this from radare2 [0xB7F08810]> !dr? ...
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1answer
144 views

Reassembling reversed ASM

I am trying to reassemble code reversed from an executable using radare2. I have managed to extract the asm and am using nasm for reassembling. The question is, the code also contains commands like ...
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1answer
34 views

What this “arw” line means when processing Mach-0 file with Radare2 or Rabin2?

Processing a Mach-0 file with Rabin2 I'm obtaining the following result: $ rabin2 -I mybinaryfile arw ...
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1answer
71 views

debugging with radare2

I am using radare2 for disassemble an x86 binary: $ r2 ./mynbinary [0x00001000]> aaa ... [0x00001000]> pdf ;-- section..text: ;-- section.LOAD1: ;-- rip: / (...
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1answer
202 views

How to print eax value with Radare2?

I am solving a crack me challenge but I am stuck. The challenge executes several jne tests. The first test is the simpliest but I don't arrive to print the eax value to know the content of cmp ...
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2answers
85 views

What does layout of Cutter/Radare2's function dissasembly mean?

Cutter displays functions like this: I'm having trouble understanding the layout of the functions For example: What does 184 mean? What does the green | mean at the beginning of each line? Why ...
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1answer
104 views

How to use aaa in radare2 while in -d (debug) mode?

This might be a stupid question, but I am trying to learn by myself and I encountered a problem which I cannot solve for the life of me. I tried googling and I can't find anything relevant, so here ...
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1answer
93 views

How to set a breakpoint in an execve'd program in radare2?

If I have a program A, which uses execve to run program B. How can I set a breakpoint in program B's main routine if I'm debugging program A? After a certain point in the execve routine, program B ...
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113 views

Password is right, but still wrong?

i am trying to find the password of a binary with radare2 - a crackme again :-) I already thought I've found the password ('pass'), but this seems to be not the right one. Or there is a trick I didn'...
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1answer
893 views

How to print the value of register with Radare 2

I am trying to solve this ELF - Ptrace challenge. I use Radare 2. This is the commands I execute to print the assembly code. radare2 ch3.bin [0x080482f0]> aaa [[anal.jmptbl] Missing cjmp bb in ...
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1answer
106 views

Radare2 does not display the entire assembler code

I am trying to solve this ELF - Ptrace crack me. Here are the commands I use : I start radare2 with the crack me as argument. radare2 ch3.bin I decide to go to the main and print the assembly code ...
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1answer
123 views

Setting register names in Radare2

I am reverse-engineering an 8051 architecture program of a specific chip. The disassembly naturally doesn't contain any function names, and the register names are minimal. For example, address 0xb3 is ...
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162 views

how to use core file in radare2?

In gdb i can backtrace with core file and executable file. It seems radare2 can read core file. like this $ r2 core Setting up coredump: asm.arch <-> x86 and asm.bits <-> 64 Setting up ...
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1answer
66 views

radare2 how to interpret ascii-art color bars?

I can't understand the meaning of ascii-art color bars. what is the meaning of the # charaters? [0x08000210]> iS= 00 0x08000000 |---------------------------------| 0x08000000 0 --- 01 ...
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1answer
241 views

Radare2 Disassembler How Do You Organize Visual Panels (V!)?

I would like to use Radare2 to learn about how C is assembled into assembly but I am having trouble with the layout. I think the V! mode would be very handy as you can watch the registers update as ...
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1answer
126 views

Function names syntax returned by radare2's afl?

Radare2's afl command returns function names with a specific syntax that I could not find documentation on: For example: radare2 -2 -A -q -c "aflj" C:/Windows/system32/advapi32.dll 0x77cce13c 22 ...
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1answer
305 views

Print string at address with radare2

I have created a very basic golang program which display a message with fmt.Println(). Here is what is see in radare2: lea rcx, obj.main.statictmp_0 ; 0x4c84b0 ; "y[K" mov qword [local_48h], rcx lea ...
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2answers
108 views

How does this command modify the condition?

I'm new to radare2 here. Just started learning and I was trying out a challenge. What does the 3 columns in the radare2 visual mode represent? May I know how the command below: wa je 0x400976 @...
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1answer
94 views

rip adress not visible with dr command

I just finished this challenge. This is the content of main function : [0x08048a86]> pdf / (fcn) main 417 | main (int argc, char **argv, char **envp); | ; var int local_16h @ ebp-0x16 |...
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1answer
77 views

Debug point not hit with radare2

I am doing this reverse engenering challenge. I executed theses commands to analyse the main function : radare2.exe ch15.exe aaa s main pdf This is the output of the pdf command : [0x004017b8]> ...
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1answer
74 views

Why does -A (aaa) analysis show much more information, when using the -d (debug) CLI option in Radare2?

Why does -A (aaa) analysis show much more information, when using the -d (debug) CLI option in Radare2? I'm using the newest version of Radare2 to analyze the Windows application. As can be seen ...
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1answer
608 views

Impossible to execute a program with radare2 : TO DO continue

I am trying to crack a crackme. I already catch the flag because I seen the string variable which represants flag. I would like to catch the flag on an other way, I want to set a breakpoint when there ...
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1answer
267 views

Analyze all functions with radare2

I have a big library in which IDA found ~84300 functions but using aa in radare2 I was just able to found ~3000. I tried setting anal.hasnext to true, anal.from and anal.to to the start and the end ...
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1answer
194 views

How to make Radare2 automatically disassemble next instruction after each `ds` debug single-step?

How to make Radare2 automatically disassemble next instruction after each ds debug single-step? I thought that e asm.bytes=1 would achieve this, but that doesn't help. In particular, GDB supports ...