polonskiy

Transparent Git Encryption

This document has been modified from its [original format][m1], which was written by Ning Shang (geek@cerias.net). It has been updated and reformatted into a [Markdown][m2] document by [Woody Gilk][m3] and [republished][m4].

Description

When working with a remote git repository which is hosted on a third-party storage server, data confidentiality sometimes becomes

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# values from https://www.ibm.com/developerworks/community/wikis/home?lang=en#!/wiki/Welcome%20to%20High%20Performance%20Computing%20%28HPC%29%20Central/page/Linux%20System%20Tuning%20Recommendations
# install (root): curl -s https://gist.githubusercontent.com/polonskiy/00a71bab32360ffcb79f/raw/10-custom.conf > /etc/sysctl.d/10-custom.conf
# apply (root): sysctl -p /etc/sysctl.d/10-custom.conf

net.ipv4.neigh.default.gc_thresh1 = 30000
net.ipv4.neigh.default.gc_thresh2 = 32000
net.ipv4.neigh.default.gc_thresh3 = 32768

net.ipv6.neigh.default.gc_thresh1 = 30000
net.ipv6.neigh.default.gc_thresh2 = 32000

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#!/usr/bin/php
<?php

exec('git diff --name-only --diff-filter=ACM --cached', $files);
$status = 0;
foreach ($files as $file) {
	if (pathinfo($file, PATHINFO_EXTENSION) != 'php') continue;
	$file = escapeshellarg($file);
	$message = array();
	exec("git show :$file | php -l 2>&1", $message, $code);

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#!/usr/bin/php
<?php

$argv += [1 => 'localhost', 2 => 11211];
$memcached = new Memcached;
$memcached->addServer($argv[1], $argv[2]);
$result = [];
foreach($memcached->getAllKeys() as $k) $result[$k] = $memcached->get($k);
var_export($result);
echo ";\n";

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<?php

class Runner {

    public function __construct() {
        pcntl_signal(SIGCHLD, SIG_IGN);
    }

    public function go() {
        if (pcntl_fork()) return;

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Quick and easy way of making Chrome send bittorrent magnet links to a remote Transmission instance using its API on Ubuntu with xdg. This method does not require modifying any system files or xdg's scripts, whereas most of the examples I found on the Internet did require such hacks.

Chrome does not handle default applications, instead relying on the OS to manage that. The default handler in Ubuntu is xdg, which maps the MIME type to the default application. Extra tooling is required because xdg requires a registered desktop file, so you can't simply give it a command to run.

Steps:

1. Install the shell script transmission-remote-magnet ideally in /usr/local/bin: ln -s ~/src/transmission-remote-magnet.bash transmission-remote-magnet

2. Install the desktop file, which is required for xdg to work and will likely require sudo: desktop-file-install ./transmission-remote-magnet.desktop

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#!/bin/bash

LC_ALL=C grep '^[a-z]\+$' /usr/share/dict/words | shuf --random-source=/dev/urandom -n 4 | paste -s -d-

grep '^[abcdefghijklmnopqrstuvwxyz]\{3,7\}$' /usr/share/dict/words | shuf -n 6 | xargs | sed 's/ /-/g'

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<?php

register_tick_function(function() {
    $bt = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 1);
    $last = reset($bt);
    echo sprintf("%s +%d\n", $last['file'], $last['line']);
});

declare(ticks=1);

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<?php

$data = file_get_contents('php://stdin');
$password = 'ps8T0G/39oHgRehuV0TjUv2lyeA=';

$c = rkxor($data, $password);
$x = rkxor($c, $password);
var_dump($c,$x);

function rkxor($data, $password) {

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find . -name '*.php' -exec php -l {} \; | grep -v '^No'