Share how awesome the crack me was or where you struggle to finish it! Stay polite and do not spoil the solution/flag!
Author:
cbm-hackers
Language:
C/C++
Upload:
6:54 AM 09/01/2018
Platform
Unix/linux etc.
Difficulty:
1.3
Quality:
4.7
Arch:
x86-64
Description
an easy crackme
fack on 3:04 PM 09/10/2018: this challange is under-rated atleast 2 by me
kellek on 1:42 PM 09/15/2018: I have to disagree with fack. The level for this particular crackme is just fine. As long as you are able to read basic asm operations you should be just fine.
jimsktsmith on 2:14 PM 09/15/2018: password?
f00 on 7:15 AM 09/23/2018: bro that add rax, 4 had me confused lol there is a shorter way to do that. was a good learning experience tho thanks
cbm-hackers on 6:21 AM 09/25/2018: fack this is a easy challange that is why i named it easy_reverse and give it level 1..
WiK on 2:12 PM 10/05/2018: Fin
sourmonday on 2:20 PM 10/09/2018: @jimsktsmith crackmes.one
tornado711 on 8:35 PM 10/16/2018: So, I'm not quite sure if I'm doing it wrong but the format seems to be ./(rev50programname) but even if I feed it a fake password and break at the main method of the assembly, it just immediately tells me my syntax is incorrect and to try again
tornado711 on 9:55 PM 10/16/2018: Nevermind, I misunderstood something disregard my last comment
arnish on 8:08 AM 10/20/2018: what is the password??
kuroguro on 8:54 AM 10/20/2018: Read the FAQ...
abc123me on 5:54 PM 10/29/2018: Great crackme, took me an hour to solve becuase I had to learn Cutter for Radare
revivalfx on 11:43 AM 10/30/2018: I chose this one as my first crackme. It has no instructions and other than patching the executable I'm not sure what to do. Is that even allowed?
ScarPunk on 5:40 PM 11/03/2018: Nice m8 i crack it!
puddl3glum on 8:50 PM 11/06/2018: @revivalfx Patching is ez mode (not hard to patch a jump to the success message). Try to figure out the right password or the characteristics for correct passwords. It's there if you look :)
revivalfx on 3:18 AM 11/07/2018: @puddl3glum facepalm! I didn't see it until I stepped through it with radare2. Then went back to IDA and shook my head that I missed it. Thanks.
surx on 9:17 PM 11/17/2018: Cool, that was the first crackme I tried.
MaksLoboda on 2:45 PM 11/18/2018: A simple and fun introduction to reversing
doni on 8:42 PM 11/19/2018: This is awesome as an introductory challenge. Thank you
Terminal_junkie on 12:55 AM 11/26/2018: So think I Cracked it but the flag is whatever I put in.. Is this wrong? output: "Nice Job!! flag{hi}"
nz4r on 4:00 PM 12/11/2018: i don't know how to do it :(
silencedogood on 4:44 PM 12/13/2018: @nz4r I would recommend watching live-overflow's binary hacking tutorial and really study what he's saying. This is a relatively easy challenge as long as you put some thought into it.
bahha on 11:01 PM 12/17/2018: Thanks, I had a lot of fun figuring it out. the check if an argument is given and its length were obvious at each cmp instruction, but that last cmp that jumps to "nice Job ! " was trivial . I was looking for the source of that 0x40 value. after trying different arguments I figured it out, that add 0x4 got me . I had to use an ascii table :) .
mosh on 6:27 PM 01/15/2019: really enjoy it, thank you
cmasterisk on 1:51 PM 02/26/2019: i literally laugh when i saw it. @_@
amrul03 on 5:48 AM 03/10/2019: "
BLZ on 5:11 AM 03/19/2019: I've found at least two different passwords that can work.
chankruze on 11:18 PM 03/21/2019: It my debut to CTF world. I am happy that i captured the flag. And here millions of flags.
fhomolka on 8:34 PM 03/27/2019: Not going to lie, got me very confused at first, but when it clicked in my head I just bursted out laughing. Think horses, not zebras.
w4tch_d0g on 2:37 PM 04/07/2019: Learning RE for the first time and i must say this challenge was an easy one
everystone on 10:50 AM 04/23/2019: Great, perfect for a beginner
JoshUK on 4:49 PM 04/24/2019: This was fun for a beginner
m3hd1 on 3:09 PM 05/23/2019: that was fun, a pen and paper are your best friends.
igogo on 9:25 PM 05/29/2019: Ghidra sudo-code reveals all simple logic and password. if (sVar1 == 10) -- password has to be 10 characters long. Same character repeated 10 times and then the actual character listed as well a couple lines later with ==.
neighborino on 11:02 AM 07/21/2019: Thanks for taking the time to make this, I learned a lot
Saket_Upadhyay on 4:24 PM 07/30/2019: this was my first Linux binary reverse. good for start
jazzlikepro on 11:19 PM 09/17/2019: Awesome my first crackme and got the flag, can't stop smiling.
qu3st1on on 9:33 AM 11/06/2019: Good for beginners like me thanks :D
michaelcracker on 8:08 PM 02/09/2020: First CrackMe! :D
kamazoultane on 5:29 PM 02/18/2020: it was really easy
D00M on 1:39 PM 05/28/2020: The challenge is good for an introduction to Ghidra. It is necessary of course, of basic knowledge in C and to know how the arguments of the main function work (argc, argv).
tynkute on 8:14 AM 10/17/2020: huh, at first I didn't understand, but then it turned out that I was stupid :)
SUPERPEKKA782 on 3:09 PM 02/17/2021: Done!
adenosinetp10 on 6:19 AM 02/27/2022: An easy crackme for people who are getting into reverse engineering newly like me.
JerneV on 10:17 AM 04/15/2022: Done! Great first reversing challenge.
fleshnbones on 9:48 AM 04/23/2023: it was great , like onion layers , enjoyed it
fleshnbones on 9:48 AM 04/23/2023: it was great , like onion layers , enjoyed it
lihe07 on 3:04 AM 05/11/2023: A nice beginning for me!
skooben on 7:07 PM 05/18/2023: Good for a beginner. Used ghidra to crack it.
baronator on 9:26 AM 08/01/2023: Pretty easy indeed.
jfaltz on 6:20 PM 01/09/2024: As a novice I really enjoyed this. It allowed me to get my feet wet with out losing hair.
Chibureshka on 1:01 PM 07/28/2024: Nice one for learning
Felb312 on 7:35 PM 08/20/2024: The password is the name of the page: crackmes.one
IBOGRO on 1:38 PM 12/08/2024: simple but good , the password for the zip file it's "crackmes.one" and for the program , if you want a spoiler it's "K4FlAXxF4LZ" :))
You must me logged to submit a solution
Solution by kellek:
Solution attached.
Contains the reverse engineered crackme (source file) and gdb dump comments.
Solution by Tristan:
obviously, no keygen.py is required for this one
Solution by TristanRice:
Solution attached
Solution by mogamiriver:
Analysis of the main section and a one-liner keygen
Solution by MaksLoboda:
My first ever solution(attached)
Solution by nutcake:
Text file with walkthrough.
Solution by thehood:
Text File Walkthrough with the radare2 assembly code.
Solution by Yuri:
My Solution, text file with source and gdb dump.
Solution by niedziol:
Solution by calo:
Was fun. Write up includes, challenge rewrite, flag_generator python script and commented assembly (r2)
Solution by D4RKFL0W:
Solution by migsaldivar:
Solution by chankruze:
changing the implementation-defined signature to did the magick.
Solution by elprofesor:
You will find: "decompilation.txt" which is the decompilation of main function.
"readme.md" which explains the whole process.
"keygen.py" which generate 10 keys.
Solution by Antricks:
I pasted a controll-flow graph from radare 2 here so maybe some text editors will not show this file correctly. With vscode or kate it should work :D
Solution by neighborino:
Solution attached. Solution includes disassembled main function with comments
Solution by usr404:
Decompiled using Ghidra & performed simple examination of control flow of `main` function
Solution by vastopol:
Solution by Bkamp:
Very cool crackme. Enjoyed quite a bit :)
Solution by richardcanuck:
Decompiled using Ghidra. The file contains the commented code and the solution!
Solution by 4rr4y:
First crackme
Solution by tgsm:
Solution by rek:
Solution by arkountos:
Solution by toolb0x:
thanks, it was funny
Solution by qjig:
Solution by oracle:
first solution
Solution by redkage:
Used Cutter for disassembly
Solution by pilot538:
Solution by ntk:
Solution by MANA624:
This is very simple RE problem. Here's a simple solution :)