picoCTF 2018

#50pt (7)#general (4)#ascii (2)#bases (2)#forensics (2)#reversing (2)#75pt (1)#bc (1)#cryptography (1)#unzip (1)

Overview

https://2018game.picoctf.com/problems solved in bash and js.

Forensics Warmup 1

#forensics #50pt #unzip

Can you unzip this file for me and retreive the flag?
picoCTF{welcome_to_forensics}

unzip flag.zip
# get flag in image

Forensics Warmup 2

#forensics #50pt

Hmm for some reason I can't open this PNG? Any ideas?
picoCTF{extensions_are_a_lie}

file flag.png
mv flag.png flag.jpeg
# get flag in image

General Warmup 1

#general #50pt #bc #ascii

If I told you your grade was 0x41 in hexadecimal, what would it be in ASCII?
picoCTF{A}

echo "41" | xxd -r -p

General Warmup 2

#general #50pt #bases

Can you convert the number 27 (base 10) to binary (base 2)?
picoCTF{11011}

echo "obase=2; ibase=10; 27" | bc

General Warmup 3

#general #50pt #bases

What is 0x3D (base 16) in decimal (base 10).
picoCTF{61}

echo "obase=10; ibase=16; 3D" | bc

Resources

#general

We put together a bunch of resources to help you out on our website! If you go over there, you might even find a flag! https://picoctf.com/resources (link)
picoCTF{xiexie_ni_lai_zheli}

Reversing Warmup 1

#reversing #50pt

Throughout your journey you will have to run many programs. Can you navigate to /problems/reversing-warmup-1_0_f99f89de33522c93964bdec49fb2b838 on the shell server and run this program to retreive the flag?
picoCTF{welc0m3_t0_r3VeRs1nG}

Simply run ./run in the shell server

Reversing Warmup 2

#reversing #50pt #ascii

Can you decode the following string dGg0dF93NHNfczFtcEwz from base64 format to ASCII?
picoCTF{th4t_w4s_s1mpL3}

echo "dGg0dF93NHNfczFtcEwz" | base64 -D

Crypto Warmup 1

#cryptography #75pt

Crpyto can often be done by hand, here's a message you got from a friend, llkjmlmpadkkc with the key of thisisalilkey. Can you use this table to solve it?.
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