mahasak

tmux cheatsheet

start new:

tmux

start new with session name:

tmux new -s myname

mahasak

# inside your .bashrc or .zshrc (on the server side) add:

# start tmux if we ssh into the box
if [[ -n "$PS1" ]] && [[ -z "$TMUX" ]] && [[ -n "$SSH_CONNECTION" ]]; then
    tmux attach-session -t $USER || tmux new-session -s $USER
fi

# this will attach to an ongoing tmux session or start a new one
# the session name will be the name of the user ($USER)

mahasak

#                        _oo0oo_
#                       o8888888o
#                       88" . "88
#                       (| -_- |)
#                       0\  =  /0
#                     ___/`---'\___
#                   .' \|     |// '.
#                  / \|||  :  |||// \
#                 / _||||| -:- |||||- \
#                |   | \\  -  /// |   |

mahasak

FWIW: I'm not the author of the content presented here (which is an outline from Edmond Lau's book). I've just copy-pasted it from somewhere over the Internet, but I cannot remember what exactly the original source is. I was also not able to find the author's name, so I cannot give him/her the proper credits.

---

Effective Engineer - Notes

• By Edmond Lau
• Highly Recommended 👍
• http://www.theeffectiveengineer.com/

What's an Effective Engineer?

mahasak

hanoi :: Int -> [(Int,Int)]
hanoi n = hanoi' n 1 2 3
hanoi' 0 _ _ _ []
hanoi' n src temp dest = top_to_temp ++ botton_to_dest : top_to_dest
  where top_to_temp = hanoi' (n-1) src dest temp
        bottom_to_dest = (src, dest)
        tops_to_dest = (hanoi' (n-1) temp src dest)

mahasak

Keybase proof

I hereby claim:

• I am mahasak on github.
• I am mahasak (https://keybase.io/mahasak) on keybase.
• I have a public key ASAkVvops8DrRCKonDvu-FSdEGRNTmBgukB8CCFnehK5BQo

To claim this, I am signing this object:

mahasak

#!/bin/bash

if [[ ! -n $REIMPORTDB_PATH  ]]; then
export REIMPORTDB_PATH=/usr/local/bin/
fi

${REIMPORTDB_PATH}dropdb --if-exists {DB_NAME}
${REIMPORTDB_PATH}createdb -U{DB_USER} -O{DB_USER} {DB_NAME}
${REIMPORTDB_PATH}psql -U{DB_USER} {DB_NAME} < database/schema_postgres.sql

mahasak

fetch("https://api-customer.thaichana.com/shop/search", {
  "headers": {
    "accept": "application/json, text/plain, */*",
    "accept-language": "en-US,en;q=0.9,th;q=0.8,fr;q=0.7",
    "content-type": "application/json;charset=UTF-8",
    "sec-fetch-dest": "empty",
    "sec-fetch-mode": "cors",
    "sec-fetch-site": "same-site"
  },
  "referrer": "https://merchant.thaichana.com/search?size=10&page=0&category=%E0%B8%97%E0%B8%B8%E0%B8%81%E0%B8%9B%E0%B8%A3%E0%B8%B0%E0%B9%80%E0%B8%A0%E0%B8%97&province=%E0%B8%81%E0%B8%A3%E0%B8%B8%E0%B8%87%E0%B9%80%E0%B8%97%E0%B8%9E%E0%B8%A1%E0%B8%AB%E0%B8%B2%E0%B8%99%E0%B8%84%E0%B8%A3&rating=0&passQuestionnaire=false&lockLatLong=false",

mahasak

IO Netgarage Level 11

Whoo! This was a fun challenge with loads to learn. :)

Understanding the given code

The given code level11.c checks whether the two inputs (as argv[1] and argv[2]) both MD5 hash to the same value or not. If they do, it uses both inputs as brainfuck code, and executes them. Then it checks if the outputs differ. Upon differing outputs, they are checked against the strings "io.sts Rules!" and "io.sts Sucks!". If prog1's output is the first, and prog2's output is the second, we are granted shell.

Understanding the vulnerability

mahasak

FROM centos:5

RUN yum -y install ld-linux.so.2

ADD ./j2sdk-1_4_2_19-linux-i586-rpm.bin /
RUN chmod +x /j2sdk-1_4_2_19-linux-i586-rpm.bin
RUN (echo yes) | sh /j2sdk-1_4_2_19-linux-i586-rpm.bin
RUN rpm -Uvh /j2sdk-1_4_2_19-linux-i586.rpm

ENV JAVA_HOME /usr/java/j2sdk1.4.2_19