Yuri's Simple Keygen

Author:
Yuri

Language:
C/C++

Upload:
2019-01-01 02:08

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Platform:
Unix/linux etc.

Difficulty:
1.5

Quality:
5.0

Arch:
x86-64

Downloads:
492

Size:
2.79 KB

Writeups:
11

Comments:
25

Description

64 bit ELF keygen. Understand the algorithm, write a keygen for it

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Comments (25)
Writeups (11)

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indigo on 2019-01-03 23:40: To me as a beginner, this was just about the right difficulty. Could probably even be difficulty 1. Definitely fun!

s4r on 2019-01-04 08:44: I modified the difficulty, thanks for the feedback

Tritone on 2019-01-08 17:30: This was a lot of fun as a beginner. Thanks!

mosh on 2019-01-11 13:00: really enjoy it, thank you

ekalien on 2019-01-14 12:28: anybody knows what's the password?

mosh on 2019-01-15 17:32: @ekalien you have solutions on the right

Gifroy on 2019-01-27 13:18: Alright, finally solved it! This was my very first crackme. It took me a good 5 hours to solve but I learned a lot of basics in the progress (including researching x86 assembly, debugging tools etc). Thanks!

zer0sun on 2019-02-03 04:45: 1212121212121212 长度是16个字符串，并且从offset 0开始的每2个字符串差1

tanmaybhushan on 2019-02-12 20:11: *c = char of Rand(0-100) len = 0 while len

tanmaybhushan on 2019-02-12 20:12: [Click to reveal]

cIsForCookies on 2019-02-14 22:46: Nice one! was my first try at a crackme and took me about an hour to get a good serial, though I haven't cracked it entirely. Anyway, it was a lot of fun, Thx!

cmasterisk on 2019-02-16 09:27: [Click to reveal]

wirehack7 on 2019-02-24 19:12: What is the password of the archive? It's missing in description

tenghaooo on 2019-03-07 11:54: Who wants to know what the password is, please read FAQ first

Foxar on 2019-04-04 15:43: Quick and easy, perfect for beginners. Example serial codes: abababababababab bcbcbcbcbcbcbcbc cdcdcdcdcdcdcdcd dededededededede efefefefefefefef

Sn0kr45h on 2019-04-30 02:10: Thanks for the good puzzle Yuri. It took me about 3 hours to figure out the algorithm without looking at answers. Sometimes the disassemblers make some really funky code, but with debugging and observation the answer becomes pretty apparent with patience. Writing a keygen that works with it was also quite fun and simple.

oscar on 2019-06-01 15:40: Very fun, enjoyed trying to understand the serial checking algorithm. Wish I hadn't read the comments as they kind of spoil it.

ttotons on 2020-05-07 20:59: It was really awesome and fun. This is actually my first crack me. It took me about 25min to get to the right serial keys. Thank you a lot. As this is my first solve I feel very good and happy.:) Btw I used "ghidra" to crack this.

trizas on 2020-09-22 08:17: import string import random import time import os while True: chars = string.ascii_letters key = "" for i in range(8): c1 = random.choice(chars) c2 = chr(ord(c1) + 1) key += c1 + c2 print(key) cmd = "./SimpleKeyGen " + key os.system(cmd) time.sleep(2)

trizas on 2020-09-22 08:18: THX Yuri, so good for a begginer, very funny =)

chris.dinozzi on 2023-04-18 18:52: fun crackme :)

PhongNguyenQUang on 2023-05-28 04:00: [Click to reveal]

Turbonator on 2024-05-12 11:35: Pretty easy, certainly not 1.6 but not 1 either, enjoyed a lot :)

SirWardrake on 2024-05-23 01:35: extremely easy

carougeno on 2025-01-06 14:53: Quite funny and enjoyable for a first try on crackmes !

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Solution by indigo on 2019-01-04 00:05:
Walkthrough to a solution via static analysis in radare2.

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Solution by niedziol on 2019-01-12 02:49:
Hope that this format is OK

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Solution by danxyz on 2019-02-05 20:49:
Key-gen in python3. Reversed using radare2 disassembler.

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Solution by onom4stic0n on 2019-02-05 21:28:

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Solution by calo on 2019-02-06 09:47:
Format of answer based on Yuri's write ups

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Solution by kawaii-flesh on 2019-06-21 16:17:
Solution with radare2 and keygen on C++

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Solution by 4rr4y on 2020-02-25 00:58:
Static analysis to obtain a good serial

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Solution by TheChrississin on 2020-05-19 21:41:
Solved using Ghidra and keygen is written in Java. Zip includes screenshots of Ghidra and output, .java file, the binary and a writeup.

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Solution by carougeno on 2025-01-06 15:11:
Solution in a .txt (Cutter)

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Solution by Adriik on 2026-02-02 19:56:
A static analysis, first using objdump and then Ghidra. The program that generates valid keys is written in C.

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Solution by comradeluca on 2026-05-28 02:42:
Contains the writeup, source code and compiled binary for the keygen, and a python script to test the generated keys against the binary.

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crackmes.one

crackmes.one

Yuri's Simple Keygen