Easy Live

Reykjavik

10 points

61 Solves

Reverse Engineering

Easy

kcbowhunter ctflearn++ badge

Community Rating: 4.76 / 5

Good beginning Reversing challenge - jump into gdb and start looking for the flag!

Reykjavik.zip

First 10 Solvers

Rank Username
1 Londek
2 Rivit
3 thekidofarcrania moderator badge
4 ill_advisor
5 ebouteillon
Rank Username
6 SunTzu
7 beneathaboringsky
8 heyzec
9 rasyidmf
10 mchl12

  • Londek

    Thats not hard, very beginner reverse but still fun

    • kcbowhunter ctflearn++ badge

      It's meant as a simple introductory problem for people new to Reversing. Have you tried my Rainbow challenge yet?

      • Londek

        I've tried but i think mine 30 minutes werent enough for this challange ;/ However i will comeback to it tomorrow or smth ;)

  • Rivit

    Ez, just follow the given tip ;)

  • ill_advisor

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    • kcbowhunter ctflearn++ badge

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  • beneathaboringsky

    Learnt some new gdb commands, thank you. And LiveOverflow is an excellent resource.

    • kcbowhunter ctflearn++ badge

      Glad you liked it; and for sure LiveOverflow is pretty awesome!

    • impregnable

      I set the $rax=0 in 0x1119 but still it is showing "you found wrong flag". Any suggestions....

      • impregnable

        i think i am facing porblem in xor in 0x1204 Kindly help as I am very new to reverse engineering

  • ebouteillon

    Nice to discover gdb or ghidra. Thanks kcbowhunter!

  • kcbowhunter ctflearn++ badge

    This problem is loosely based on this example from LiveOverflow on YouTube: https://www.youtube.com/watch?v=VroEiMOJPm8

  • kcbowhunter ctflearn++ badge

    This is helpful too: https://www.youtube.com/watch?v=3NTXFUxcKPc

    • impregnable

      I set the $rax=0 in 0x1119 but still it is showing "you found wrong flag". Any suggestions....

      • kcbowhunter ctflearn++ badge

        Try stepping through gdb and look at the registers just after the calls to strcmp.

        • impregnable

          Done bro ...... and it is really a good challenge for beginners. I learnt alot.

  • naikordian

    I can't decrypt source file. openssl say "bad decrypt"

    • kcbowhunter ctflearn++ badge

      Send me a DM on Twitter or Discord @kcbowhunter with the openssl command you are using

    • kcbowhunter ctflearn++ badge

      Do you still need help decrypting the source file?

      • naikordian

        yes! can you tell me what command you use to decrypt?

        • kcbowhunter ctflearn++ badge

          I prefer to do that via a private chat so that we don't give the answer away to everyone. Can you send me a private message on Twitter or Discord @kcbowhunter with the exact openssl command that you are using?

        • kcbowhunter ctflearn++ badge

          openssl enc -d -aes-256-cbc -pbkdf2 -in sources.zip.enc -out sources.zip -k flag where flag is the flag from the challenge of the format CTFlearn{...} (please do not post the challenge flag here if you are still having problems) Also, you can use openssl enc -help for help with openssl commands or visit https://wiki.openssl.org/index.php/Enc for more information

          openssl enc -e -aes-256-cbc -pbkdf2 -k flag -in sources.zip -out sources.zip.enc was used to encrypt the sources, the command above is used to decrypt

          • kcbowhunter ctflearn++ badge

            I posted the openssl command above in case you are not on twitter or discord

  • WiMaH

    This is my first reverse engineering experience.. i learnt many new things.. thank you

    • impregnable

      I set the $rax=0 in 0x1119 but still it is showing "you found wrong flag". Any suggestions....

    • kcbowhunter ctflearn++ badge

      You're welcome, it's a very interesting type of challenge and a great way to learn assembly.

  • neon_spandex

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