Guillaume Falourd GuillaumeFalourd

Write-up - CTF Zup 2022 - Alexandre Fidélis Vieira Bitencourt

se FOR fácil eu MATO - v2

Este desafio era sobre a utilização de um buffer overflow para sobrepor o valor de uma variável inteira. O código fonte da página era o seguinte:

Caso o atacante conseguisse sobrepor o valor da variável inteira que era iniciado com zero a flag seria revelada.

Pretende usar `UUID` como PK em vez de `Int/BigInt` no seu banco de dados? Pense novamente...

TL;TD

Não use UUID como PK nas tabelas do seu banco de dados.

Um pouco mais de detalhes

Problem

I have two Github accounts: oanhnn (personal) and superman (for work). I want to use both accounts on same computer (without typing password everytime, when doing git push or pull).

Solution

Use ssh keys and define host aliases in ssh config file (each alias for an account).

How to?

Generate ssh key pairs for accounts and add them to GitHub accounts.

	# IMPORTANT: GITHUB_TOKEN with "Update ALL user data" permission
	#
	# Dependencies:
	# - curl
	# - jq
	#
	# Run:
	# GITHUB_TOKEN=<token> GITHUB_USER=<username> ./github_billing.sh
	#

	# Local:
	# https://stackoverflow.com/questions/21151178/shell-script-to-check-if-specified-git-branch-exists
	# test if the branch is in the local repository.
	# return 1 if the branch exists in the local, or 0 if not.
	function is_in_local() {
	local branch=${1}
	local existed_in_local=$(git branch --list ${branch})

	if [[ -z ${existed_in_local} ]]; then
	echo 0

	SHELL:=/bin/bash
	VIRTUAL_ENV=env
	JUPYTER_ENV_NAME=env
	PORT=8888
	PYTHON=${VIRTUAL_ENV}/bin/python3

	# .ONESHELL:
	DEFAULT_GOAL: help
	.PHONY: help run clean build venv ipykernel update jupyter

	const { execSync } = require('child_process');

	function executeGitCommand(command) {
	return execSync(command)
	.toString('utf8')
	.replace(/[\n\r\s]+$/, '');
	}

	const BRANCH = executeGitCommand('git rev-parse --abbrev-ref HEAD');
	const COMMIT_SHA = executeGitCommand('git rev-parse HEAD');

	#!/usr/bin/env bash
	#
	# gh-dl-release! It works!
	#
	# This script downloads an asset from latest or specific Github release of a
	# private repo. Feel free to extract more of the variables into command line
	# parameters.
	#
	# PREREQUISITES
	#

	# The command finds the most recent tag that is reachable from a commit.
	# If the tag points to the commit, then only the tag is shown.
	# Otherwise, it suffixes the tag name with the number of additional commits on top of the tagged object
	# and the abbreviated object name of the most recent commit.
	git describe

	# With --abbrev set to 0, the command can be used to find the closest tagname without any suffix:
	git describe --abbrev=0

	# other examples

	sourceURL := "http://example.com"

	// Resolve URL up to 12 redirects.
	client := &http.Client{
	CheckRedirect: func() func(req http.Request, via []http.Request) error {
	redirects := 0
	return func(req http.Request, via []http.Request) error {
	if redirects > 12 {
	return errors.New("stopped after 12 redirects")
	}