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Retweet of mathias

2016 Jan 27, 10:29
Take any Facebook/Instagram photo URL.👉 append `.txt` → ASCII art👉 append `.html` → colored ASCII artE.g. https://scontent-ams3-1.cdninstagram.com/t51.2885-15/e35/11906246_1700002456899911_1391970345_n.jpg.html …
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Retweet of anildash

2016 Jan 3, 9:59
Oh! @jsnell is way ahead of me: https://sixcolors.com/post/2015/12/the-best-christmas-gift-in/ … Programming BB-8 with a kid-friendly app! Thanks to @anoopr for the link.
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Debugging anecdote - the color transparent black breaks accessibility

2014 May 22, 10:36

Some time back while I was working on getting the Javascript Windows Store app platform running on Windows Phone (now available on the last Windows Phone release!) I had an interesting bug that in retrospect is amusing.

I had just finished a work item to get accessibility working for JS WinPhone apps when I got a new bug: With some set of JS apps, accessibility appeared to be totally broken. At that time in development the only mechanism we had to test accessibility was a test tool that runs on the PC, connects to the phone, and dumps out the accessibility tree of whatever app is running on the phone. In this bug, the tool would spin for a while and then timeout with an error and no accessibility information.

My first thought was this was an issue in my new accessibility code. However, debugging with breakpoints on my code I could see none of my code was run nor the code that should call it. The code that called that code was a more generic messaging system that hit my breakpoints constantly.

Rather than trying to work backward from the failure point, I decided to try and narrow down the repro and work forwards from there. One thing all the apps with the bug had in common was their usage of WinJS, but not all WinJS apps demonstrated the issue. Using a binary search approach on one such app I removed unrelated app code until all that was left was the app's usage of the WinJS AppBar and the bug still occurred. I replaced the WinJS AppBar usage with direct usage of the underlying AppBar WinRT APIs and continued.

Only some calls to the AppBar WinRT object produced the issue:

        var appBar = Windows.UI.WebUI.Core.WebUICommandBar.getForCurrentView(); 
// appBar.opacity = 1;
// appBar.closeDisplayMode = Windows.UI.WebUI.Core.WebUICommandBarClosedDisplayMode.default;
appBar.backgroundColor = Windows.UI.Colors.white; // Bug!
Just setting the background color appeared to cause the issue and I didn't even have to display the AppBar. Through additional trial and error I was blown away to discover that some colors I would set caused the issue and other colors did not. Black wouldn't cause the issue but transparent black would. So would aqua but not white.

I eventually realized that predefined WinRT color values like Windows.UI.Colors.aqua would cause the issue while JS literal based colors didn't cause the issue (Windows.UI.Color is a WinRT struct which projects in JS as a JS literal object with the struct members as JS object properties so its easy to write something like {r: 0, g: 0, b: 0, a: 0} to make a color) and I had been mixing both in my tests without realizing there would be a difference. I debugged into the backgroundColor property setter that consumed the WinRT color struct to see what was different between Windows.UI.Colors.black and {a: 1, r: 0, g: 0, b: 0} and found the two structs to be byte wise exactly the same.

On a hunch I tried my test app with only a reference to the color and otherwise no interaction with the AppBar and not doing anything with the actual reference to the color: Windows.UI.Colors.black;. This too caused the issue. I knew that the implementation for these WinRT const values live in a DLL and guessed that something in the code to create these predefined colors was causing the issue. I debugged in and no luck. Now I also have experienced crusty code that would do exciting things in its DllMain, the function that's called when a DLL is loaded into the process so I tried modifying my C++ code to simply LoadLibrary the DLL containing the WinRT color definition, windows.ui.xaml.dll and found the bug still occurred! A short lived moment of relief as the world seemed to make sense again.

Debugging into DllMain nothing interesting happened. There were interesting calls in there to be sure, but all of them behind conditions that were false. I was again stumped. On another hunch I tried renaming the DLL and only LoadLibrary'ing it and the bug went away. I took a different DLL renamed it windows.ui.xaml.dll and tried LoadLibrary'ing that and the bug came back. Just the name of the DLL was causing the issue.

I searched for the DLL name in our source code index and found hits in the accessibility tool. Grinning I opened the source to find that the accessibility tool's phone side service was trying to determine if a process belonged to a XAML app or not because XAML apps had a different accessibility contract. It did this by checking to see if windows.ui.xaml.dll was loaded in the target process.

At this point I got to fix my main issue and open several new bugs for the variety of problems I had just run into. This is a how to on writing software that is difficult to debug.

PermalinkCommentsbug debug javascript JS technical windows winrt

URI functions in Windows Store Applications

2013 Jul 25, 1:00PermalinkCommentsc# c++ javascript technical uri windows windows-runtime windows-store

Ben Goldacre’s TED talk on publication bias, drug...

2012 Sep 28, 3:55


drug companies hiding the results of clinical trials.

(via I did a new talk at TED, on drug companies and hidden data.)

PermalinkCommentsscience video ted

AbleGamers creates how-to accessibility guide for devs, publishers | Joystiq

2012 Sep 14, 4:20

A howto on making your video game accessible to those with disabilities (blind, color blind, deaf, etc)

The AbleGamers Foundation has created a 48-page document it hopes will serve as a how-to guide for game developers and publishers on how to create more accessible games. The in-depth guide by the disability non-profit covers in great detail how to make games available to those with varying degrees of mobility, hearing, visual and cognitive issues.

PermalinkCommentsgame technical video-game programming accessibility howto

Stripe CTF - SQL injections (Levels 0 & 3)

2012 Sep 5, 9:10

Stripe's web security CTF's level 0 and level 3 had SQL injection solutions described below.

Level 0

Code

app.get('/*', function(req, res) {
var namespace = req.param('namespace');

if (namespace) {
var query = 'SELECT * FROM secrets WHERE key LIKE ? || ".%"';
db.all(query, namespace, function(err, secrets) {

Issue

There's no input validation on the namespace parameter and it is injected into the SQL query with no encoding applied. This means you can use the '%' character as the namespace which is the wildcard character matching all secrets.

Notes

Code review red flag was using strings to query the database. Additional levels made this harder to exploit by using an API with objects to construct a query rather than strings and by running a query that only returned a single row, only ran a single command, and didn't just dump out the results of the query to the caller.

Level 3

Code

@app.route('/login', methods=['POST'])
def login():
username = flask.request.form.get('username')
password = flask.request.form.get('password')

if not username:
return "Must provide username\n"

if not password:
return "Must provide password\n"

conn = sqlite3.connect(os.path.join(data_dir, 'users.db'))
cursor = conn.cursor()

query = """SELECT id, password_hash, salt FROM users
WHERE username = '{0}' LIMIT 1""".format(username)
cursor.execute(query)

res = cursor.fetchone()
if not res:
return "There's no such user {0}!\n".format(username)
user_id, password_hash, salt = res

calculated_hash = hashlib.sha256(password + salt)
if calculated_hash.hexdigest() != password_hash:
return "That's not the password for {0}!\n".format(username)

Issue

There's little input validation on username before it is used to constrcut a SQL query. There's no encoding applied when constructing the SQL query string which is used to, given a username, produce the hashed password and the associated salt. Accordingly one can make username a part of a SQL query command which ensures the original select returns nothing and provide a new SELECT via a UNION that returns some literal values for the hash and salt. For instance the following in blue is the query template and the red is the username injected SQL code:

SELECT id, password_hash, salt FROM users WHERE username = 'doesntexist' UNION SELECT id, ('5e884898da28047151d0e56f8dc6292773603d0d6aabbdd62a11ef721d1542d8') AS password_hash, ('word') AS salt FROM users WHERE username = 'bob' LIMIT 1
In the above I've supplied my own salt and hash such that my salt (word) plus my password (pass) hashed produce the hash I provided above. Accordingly, by providing the above long and interesting looking username and password as 'pass' I can login as any user.

Notes

Code review red flag is again using strings to query the database. Although this level was made more difficult by using an API that returns only a single row and by using the execute method which only runs one command. I was forced to (as a SQL noob) learn the syntax of SELECT in order to figure out UNION and how to return my own literal values.

PermalinkCommentssecurity sql sql-injection technical web-security

Alex takes a few steps

2012 Aug 16, 4:06
From: David Risney
Views: 75
0 ratings
Time: 00:43 More in People & Blogs
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Alex walking via walker

2012 Aug 6, 4:44
From: David Risney
Views: 69
0 ratings
Time: 00:53 More in People & Blogs
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ifc: This week on Comedy Bang! Bang! - Michael Cera!

2012 Jun 27, 3:38


ifc:

This week on Comedy Bang! Bang! - Michael Cera!

PermalinkCommentshumor comedy-bang-bang michael-cera video

wired: [via motherjones]: theweekmagazine: Sticking to an...

2012 Jun 7, 3:29


wired:

[via motherjones]:

theweekmagazine:

Sticking to an exercise routine takes dedication, and many fitness junkies swear that a running companion can be a huge help. That’s why researchers have developed “Joggobot,” a quad-rotor helicopter drone designed to motivate joggers by flying in front of them. 

The aerial robot uses its camera to spot a colorful pattern on a T-shirt worn by the jogger, and flies at a safe distance ahead. The runner can control Joggobot using a smartphone: In “companion mode,” the drone simply maintains the jogger’s pace; in “coach mode,” it pushes its human trainee a little faster.

Don’t worry, there’s a video

Science!

Maybe it should chase you instead?

PermalinkCommentshumor exercise robot future video

Play Fez

2012 May 7, 3:30

I'm done playing Fez. The style is atmospheric retro nastalgia and on the surface the gameplay is standard 2D platformer with one interesting Flatland style game mechanic but dig deeper to find Myst style puzzles. Despite the following I thoroughly enjoyed the game and would recommend it to anyone intrigued by the previous. Five eighths through the game I ran into one of the game's infamous Fez save game breaking issues, but I enjoyed the game enough that I started over before any patches were released and had no further issues.

While playing the game I created some tools to help keep track of my Fez notes (spoilers) including a Pixelated Image Creator that makes it easy to generate data URIs for large, black and white pixelated images, and (spoilers) a Fez Transliteration Tool to help me translate the in-game writing system.

PermalinkCommentsvideo-game fez game xbox

Another Comedy Bang Bang preview clip this time with Zach...

2012 Apr 18, 6:02


Another Comedy Bang Bang preview clip this time with Zach Galifianakis.

PermalinkCommentszach-galifianakis comedy-bang-bang video humor preview scott-aukerman tv clip

Free Universal Construction Kit is a set of 3D models you can...

2012 Mar 19, 4:05


Free Universal Construction Kit is a set of 3D models you can print on a 3D printer that allow you to connect Lego to Duplo to Lincoln Logs, etc.

PermalinkCommentstoy video 3d-printer

(via Defend our freedom to share (or why SOPA is a bad idea):...

2012 Jan 18, 3:21


(via Defend our freedom to share (or why SOPA is a bad idea): Clay Shirky on TED.com)

PermalinkCommentsvideo copyright clay-shirky sopa pipa legal politics mpaa ted

(via MakerBot Replicator, A New Larger 2 Color 3D Printer by...

2012 Jan 9, 5:43


(via MakerBot Replicator, A New Larger 2 Color 3D Printer by MakerBot)

PermalinkCommentsvideo maker-bot 3d-printer

Color Thief, script for grabbing the color palette from an image (lokeshdhakar.com)

2012 Jan 7, 6:42

Picks out dominant color or palette from an image. Not only is that cool, but it is in JavaScript using canvas, and is licensed under Creative Commons attribution.

PermalinkCommentstechnical color javascript canvas library

Alex tries baby food

2012 Jan 3, 12:02
Alex tries baby food for the first time.
From: David Risney
Views: 51
0 ratings
Time: 00:39 More in People & Blogs
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(via Instantly Redecorating a Living Room with Video Mapping)

2011 Dec 9, 6:59


(via Instantly Redecorating a Living Room with Video Mapping)

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Sleepy Alex

2011 Sep 10, 10:27
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