bitcartel

// Sign CAlert with stored private key
bool SignAlert(CAlert &alert)
{
    // key in WIF format
    const char* pszPrivKey = "";

    // serialize alert data
    CDataStream sMsg(SER_NETWORK, PROTOCOL_VERSION);
    sMsg << *(CUnsignedAlert*)&alert;
    alert.vchMsg = std::vector<unsigned char>(sMsg.begin(), sMsg.end());

bitcartel

How to test bitcoin alerts

Motivation

Programming for bitcoin can be a bit of a pain at times. There's a lot of esoteric knowledge required and not everything is documented that well, though with some of the newer documentation projects like the [bitcoin developer documentation][devdocs], it's getting easier.

One thing I ran into recently is the existence of bitcoin alerts. These are alerts that are sent by the core developers onto the entire bitcoin network to warn of serious security events. They don't come up very often (there's [only been 8][alertlist] in the entire history of bitcoin as of this writing), but if your application is built on top of it, you'd better handle it.

The problem, though, is that the alerts are actually signed by a key controlled by the core developers. You can't just create new alerts for testnet, for example, as every other bitcoin client, including your own, will ignore them. So how do you test them?

bitcartel

#include "headers.h"
#include "net.h"

static const int64 DAYS = 24 * 60 * 60;

void ThreadSendAlert();

class CSendAlert
{
public:

bitcartel

{
  "OP_DUP OP_HASH160 20 OP_EQUALVERIFY OP_CHECKSIG": 319721182,
  "OP_HASH160 20 OP_EQUAL": 10083919,
  "65 OP_CHECKSIG": 887766,
  "OP_RETURN": 288521,
  "OP_1 33 33 33 OP_3 OP_CHECKMULTISIG": 224438,
  "": 219175,
  "OP_1 33 33 OP_2 OP_CHECKMULTISIG": 206415,
  "33 OP_CHECKSIG": 101306,
  "OP_RETURN 40": 65287,

bitcartel

/*
So you need to broadcast an alert...
... here's what to do:

1. Copy sendalert.cpp into your bitcoind build directory

2. Decrypt the alert keys
  copy the decrypted file as alertkeys.h into the src/ directory.

3. Modify the alert parameters in sendalert.cpp

bitcartel

#!/usr/bin/env sh

##
# This is script with usefull tips taken from:
#   https://github.com/mathiasbynens/dotfiles/blob/master/.osx
#
# install it:
#   curl -sL https://raw.github.com/gist/2108403/hack.sh | sh
#

bitcartel

-- TLC - The Tiny Lua Cocoa bridge
-- Note: Only tested with LuaJit 2 Beta 9 on x86_64 with OS X >=10.7.3 & iPhone 4 with iOS 5

-- Copyright (c) 2012, Fjölnir Ásgeirsson

-- Permission to use, copy, modify, and/or distribute this software for any
-- purpose with or without fee is hereby granted, provided that the above
-- copyright notice and this permission notice appear in all copies.

-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES

bitcartel

- (UIImage *)resizedImage:(CGSize)newSize interpolationQuality:(CGInterpolationQuality)quality {
    BOOL drawTransposed;
    CGAffineTransform transform = CGAffineTransformIdentity;
    
    if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 5.0) {
        // Apprently in iOS 5 the image is already correctly rotated, so we don't need to rotate it manually
        drawTransposed = NO;  
    } else {    
        switch (self.imageOrientation) {
            case UIImageOrientationLeft:

bitcartel

//
//  UIImage+Additions.h
//  Sparrow
//
//  Created by Shilo White on 10/16/11.
//  Copyright 2011 Shilocity Productions. All rights reserved.
//

#define COLOR_PART_RED(color)    (((color) >> 16) & 0xff)
#define COLOR_PART_GREEN(color)  (((color) >>  8) & 0xff)