sal - Dave's Blog

Search
My timeline on Mastodon

Multiple Windows in Win10 JavaScript UWP apps

2018 Mar 10, 1:47

Win10 Changes

In Win8.1 JavaScript UWP apps we supported multiple windows using MSApp DOM APIs. In Win10 we use window.open and window and a new MSApp API getViewId and the previous MSApp APIs are gone:

Win10 Win8.1
Create new window window.open MSApp.createNewView
New window object window MSAppView
viewId MSApp.getViewId(window) MSAppView.viewId

WinRT viewId

We use window.open and window for creating new windows, but then to interact with WinRT APIs we add the MSApp.getViewId API. It takes a window object as a parameter and returns a viewId number that can be used with the various Windows.UI.ViewManagement.ApplicationViewSwitcher APIs.

Delaying Visibility

Views in WinRT normally start hidden and the end developer uses something like TryShowAsStandaloneAsync to display the view once it is fully prepared. In the web world, window.open shows a window immediately and the end user can watch as content is loaded and rendered. To have your new windows act like views in WinRT and not display immediately we have added a window.open option. For example
let newWindow = window.open("https://example.com", null, "msHideView=yes");

Primary Window Differences

The primary window that is initially opened by the OS acts differently than the secondary windows that it opens:

Primary Secondary
window.open Allowed Disallowed
window.close Close app Close window
Navigation restrictions ACUR only No restrictions

The restriction on secondary windows such that they cannot open secondary windows could change in the future depending on feedback.

Same Origin Communication Restrictions

Lastly, there is a very difficult technical issue preventing us from properly supporting synchronous, same-origin, cross-window, script calls. That is, when you open a window that's same origin, script in one window is allowed to directly call functions in the other window and some of these calls will fail. postMessage calls work just fine and is the recommended way to do things if that's possible for you. Otherwise we continue to work on improving this.

PermalinkComments

JavaScript Microsoft Store app StartPage

2017 Jun 22, 8:58

JavaScript Microsoft Store apps have some details related to activation that are specific to JavaScript Store apps and that are poorly documented which I’ll describe here.

StartPage syntax

The StartPage attributes in the AppxManifest.xml (Package/Applications/Application/@StartPage, Package/Applications/Extensions/Extension/@StartPage) define the HTML page entry point for that kind of activation. That is, Application/@StartPage defines the entry point for tile activation, Extension[@Category="windows.protocol"]/@StartPage defines the entry point for URI handling activation, etc. There are two kinds of supported values in StartPage attributes: relative Windows file paths and absolute URIs. If the attribute doesn’t parse as an absolute URI then it is instead interpreted as relative Windows file path.

This implies a few things that I’ll declare explicitly here. Windows file paths, unlike URIs, don’t have a query or fragment, so if you are using a relative Windows file path for your StartPage attribute you cannot include anything like ‘?param=value’ at the end. Absolute URIs use percent-encoding for reserved characters like ‘%’ and ‘#’. If you have a ‘#’ in your HTML filename then you need to percent-encode that ‘#’ for a URI and not for a relative Windows file path.

If you specify a relative Windows file path, it is turned into an ms-appx URI by changing all backslashes to forward slashes, percent-encoding reserved characters, and combining the result with a base URI of ms-appx:///. Accordingly the relative Windows file paths are relative to the root of your package. If you are using a relative Windows file path as your StartPage and need to switch to using a URI so you can include a query or fragment, you can follow the same steps above.

StartPage validity

The validity of the StartPage is not determined before activation. If the StartPage is a relative Windows file path for a file that doesn’t exist, or an absolute URI that is not in the Application Content URI Rules, or something that doesn’t parse as a Windows file path or URI, or otherwise an absolute URI that fails to resolve (404, bad hostname, etc etc) then the JavaScript app will navigate to the app’s navigation error page (perhaps more on that in a future blog post). Just to call it out explicitly because I have personally accidentally done this: StartPage URIs are not automatically included in the Application Content URI Rules and if you forget to include your StartPage in your ACUR you will always fail to navigate to that StartPage.

StartPage navigation

When your app is activated for a particular activation kind, the StartPage value from the entry in your app’s manifest that corresponds to that activation kind is used as the navigation target. If the app is not already running, the app is activated, navigated to that StartPage value and then the Windows.UI.WebUI.WebUIApplication activated event is fired (more details on the order of various events in a moment). If, however, your app is already running and an activation occurs, we navigate or don’t navigate to the corresponding StartPage depending on the current page of the app. Take the app’s current top level document’s URI and if after removing the fragment it already matches the StartPage value then we won’t navigate and will jump straight to firing the WebUIApplication activated event.

Since navigating the top-level document means destroying the current JavaScript engine instance and losing all your state, this behavior might be a problem for you. If so, you can use the MSApp.pageHandlesAllApplicationActivations(true) API to always skip navigating to the StartPage and instead always jump straight to firing the WebUIApplication activated event. This does require of course that all of your pages all handle all activation kinds about which any part of your app cares.

PermalinkComments

4 people are living in an isolated habitat for 30 days. Why? Science!

2016 Feb 1, 3:27

nasa:

This 30 day mission will help our researchers learn how isolation and close quarters affect individual and group behavior. This study at our Johnson Space Center prepares us for long duration space missions, like a trip to an asteroid or even to Mars.

image

The Human Research Exploration Analog (HERA) that the crew members will be living in is one compact, science-making house. But unlike in a normal house, these inhabitants won’t go outside for 30 days. Their communication with the rest of planet Earth will also be very limited, and they won’t have any access to internet. So no checking social media kids!

The only people they will talk with regularly are mission control and each other.

image

The crew member selection process is based on a number of criteria, including the same criteria for astronaut selection.

What will they be doing?

Because this mission simulates a 715-day journey to a Near-Earth asteroid, the four crew members will complete activities similar to what would happen during an outbound transit, on location at the asteroid, and the return transit phases of a mission (just in a bit of an accelerated timeframe). This simulation means that even when communicating with mission control, there will be a delay on all communications ranging from 1 to 10 minutes each way. The crew will also perform virtual spacewalk missions once they reach their destination, where they will inspect the asteroid and collect samples from it. 

A few other details:

  • The crew follows a timeline that is similar to one used for the ISS crew.
  • They work 16 hours a day, Monday through Friday. This includes time for daily planning, conferences, meals and exercises.  
  • They will be growing and taking care of plants and brine shrimp, which they will analyze and document.

But beware! While we do all we can to avoid crises during missions, crews need to be able to respond in the event of an emergency. The HERA crew will conduct a couple of emergency scenario simulations, including one that will require them to maneuver through a debris field during the Earth-bound phase of the mission. 

image

Throughout the mission, researchers will gather information about cohabitation, teamwork, team cohesion, mood, performance and overall well-being. The crew members will be tracked by numerous devices that each capture different types of data.

image

Past HERA crew members wore a sensor that recorded heart rate, distance, motion and sound intensity. When crew members were working together, the sensor would also record their proximity as well, helping investigators learn about team cohesion.

Researchers also learned about how crew members react to stress by recording and analyzing verbal interactions and by analyzing “markers” in blood and saliva samples.

image

In total, this mission will include 19 individual investigations across key human research elements. From psychological to physiological experiments, the crew members will help prepare us for future missions.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

PermalinkComments

4 people are living in an isolated habitat for 30 days. Why? Science!

2016 Feb 1, 3:27

nasa:

This 30 day mission will help our researchers learn how isolation and close quarters affect individual and group behavior. This study at our Johnson Space Center prepares us for long duration space missions, like a trip to an asteroid or even to Mars.

image

The Human Research Exploration Analog (HERA) that the crew members will be living in is one compact, science-making house. But unlike in a normal house, these inhabitants won’t go outside for 30 days. Their communication with the rest of planet Earth will also be very limited, and they won’t have any access to internet. So no checking social media kids!

The only people they will talk with regularly are mission control and each other.

image

The crew member selection process is based on a number of criteria, including the same criteria for astronaut selection.

What will they be doing?

Because this mission simulates a 715-day journey to a Near-Earth asteroid, the four crew members will complete activities similar to what would happen during an outbound transit, on location at the asteroid, and the return transit phases of a mission (just in a bit of an accelerated timeframe). This simulation means that even when communicating with mission control, there will be a delay on all communications ranging from 1 to 10 minutes each way. The crew will also perform virtual spacewalk missions once they reach their destination, where they will inspect the asteroid and collect samples from it. 

A few other details:

  • The crew follows a timeline that is similar to one used for the ISS crew.
  • They work 16 hours a day, Monday through Friday. This includes time for daily planning, conferences, meals and exercises.  
  • They will be growing and taking care of plants and brine shrimp, which they will analyze and document.

But beware! While we do all we can to avoid crises during missions, crews need to be able to respond in the event of an emergency. The HERA crew will conduct a couple of emergency scenario simulations, including one that will require them to maneuver through a debris field during the Earth-bound phase of the mission. 

image

Throughout the mission, researchers will gather information about cohabitation, teamwork, team cohesion, mood, performance and overall well-being. The crew members will be tracked by numerous devices that each capture different types of data.

image

Past HERA crew members wore a sensor that recorded heart rate, distance, motion and sound intensity. When crew members were working together, the sensor would also record their proximity as well, helping investigators learn about team cohesion.

Researchers also learned about how crew members react to stress by recording and analyzing verbal interactions and by analyzing “markers” in blood and saliva samples.

image

In total, this mission will include 19 individual investigations across key human research elements. From psychological to physiological experiments, the crew members will help prepare us for future missions.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

PermalinkComments

workjuice: Such whimsy! Video of the “Captain Laserbeam”...

2015 Sep 17, 3:02


workjuice:

Such whimsy! Video of the “Captain Laserbeam” segment of our April Fool’s Funaround is up; just click this sentence!
Starring Paul F. Tompkins​, John Hodgman​, Michael McMillian​, Lauren Lapkus​, Marc Evan Jackson​, Ben Schwartz​, Felicia Day​, Hal Lublin​, Annie Savage, Craig Cackowski, Busy Philipps​, and more!

Tickets are still on sale for our Improv show and other shows in NY in October. Get ‘em here.

PermalinkComments

workjuice: Such whimsy! Video of the “Captain Laserbeam”...

2015 Sep 17, 3:02


workjuice:

Such whimsy! Video of the “Captain Laserbeam” segment of our April Fool’s Funaround is up; just click this sentence!
Starring Paul F. Tompkins​, John Hodgman​, Michael McMillian​, Lauren Lapkus​, Marc Evan Jackson​, Ben Schwartz​, Felicia Day​, Hal Lublin​, Annie Savage, Craig Cackowski, Busy Philipps​, and more!

Tickets are still on sale for our Improv show and other shows in NY in October. Get ‘em here.

PermalinkComments

Tweet from David_Risney

2015 Jul 21, 12:13
I always thought BSG's Galactica disallowing networks and air gapping everything was lame. Starting to get it now.
PermalinkComments

Retweet of codinghorror

2015 Mar 30, 1:19
Pastebin single-payment lifetime accounts on sale. Check out pastebin's greatest hits: http://pastebin.com/trends/all 
PermalinkComments

Gamers Messed With The Steam Sale, Then Valve Changed The Rules

2014 Jun 24, 3:51

Applied game theory 101: Valve’s Steam Summer Sale involves a meta game with teams of Steam users competing for daily prizes. On Reddit the players join together to take turns winning daily. Valve gets wise and performs an existential attack, changing the rules to make it harder for players to want to coordinate.

Still, that all the players joined together to game the system gives me hope for humanity. Its a self organized solution to a tragedy of the commons problem. Only in this case the tragedy is by design and is updated to be more tragic.

PermalinkCommentsgame video-game game-theory valve

The Doritos origin story: Repurposed garbage from Disneyland

2014 May 6, 7:16

shortformblog:

A reminder that those Doritos you love are trash:

Shortly after Disneyland opened in 1955, the founder of Frito-Lay got permission from Walt Disney to open a restaurant in Frontierland with a Mexican-ish theme. “Casa de Fritos” was, unsurprisingly, all about the Fritos. Customers got free Fritos, and Fritos were incorporated into many of the dishes. Fritos were dispensed by an animatronic vending machine that featured the terrifying “Frito Kid”asking his assistant “Klondike” to bring the bag up from a mineshaft. I guess the conceit is that Fritos were mined by Forty-Niners?

Casa de Fritos contracted their tortilla production to a company called Alex Foods. One of the salesmen from Alex Foods, making a delivery to Casa de Fritos, noticed stale tortillas in the garbage and gave the cook a little tip: fry them and sell them as chips instead of throwing them away. Casa de Fritos began making these fried, seasoned chips to enormous success, but didn’t report this new menu item to the Frito-Lay company.

Eventually Frito-Lay found out what they were doing with the chips, packaged them, and sold them by the truckload. See, dumpster diving works out sometimes!

PermalinkComments

Windows Store on Windows 8 Fun For Independent Developers

2013 Jun 24, 1:00
Having worked on Windows 8 I'm not in a neutral position to review aspects of it, however I'll say from a high level I love taking the following various positives from smart phone apps and app stores and applying it to the desktop:
  • Independent developers can easily publish apps.
  • One trusted place for a user to find apps.
  • User can trust apps are limited to a declared set of capabilities.
  • One common and easy way for users to buy and try apps.
  • Easy mechanism for independent developers to collect revenue.
Relieving the independent developer of software development overhead, in this case Windows taking care of distribution and sales infrastructure is wonderful for me with my third party developer hat on. This combined with my new found fun of developing in JavaScript and the new Windows Runtime APIs means I've been implementing and finishing various ideas I've had - some for fun and some for productivity on my Surface. Development notes to follow.
PermalinkCommentsstore technical windows windows-store

Sci-fi short stories disguised as Internet docs

2013 May 29, 2:48
The recent short story Twitter API returning results that do not respect arrow of time by Tim May written as a Twitter bug report reminded me of a few other short sci-fi stories written in the style of some sort of Internet document:
PermalinkCommentscsc fiction sci-fi Scifi time-travel twitter

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

Content ID Run Amok: Isaac's Lip-Dub Proposal Removed from YouTube

2012 Jun 7, 3:14

Waxy roundup of DMCA takedown process stupidity.

So the Scripps TV broadcasts are indexed by YouTube, and the Content ID robots do the rest. And because Content ID disputes are judged by the copyright holder, complaints are routinely ignored or denied.”

PermalinkCommentscopyright youtube dmca tv

“Zero-day” exploit sales should be key point in cybersecurity debate

2012 Mar 30, 2:40

Intro to the world of the 0day exploit market.

PermalinkCommentssecurity technical 0day internet

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

Thread Local Storage, part 1: Overview « Nynaeve

2011 Aug 6, 1:53Description of the inner workings of both of Window's TLS options, the Win32 APIs like TlsAlloc as well as __declspec(thread). I didn't know that the max number of TLS indices is now 1088.PermalinkCommentsblog programming development windows debug tls thread-local-storage

_opt Mnemonic

2011 May 24, 11:00

​I always have trouble remembering where the opt goes in SAL in the __deref_out case. The mnemonic is pretty simple: the _opt at the start of the SAL is for the pointer value at the start of the function. And the _opt at the end of the SAL is for the dereferenced pointer value at the end of the function.






SAL foo == nullptr allowed at function start? *foo == nullptr allowed at function end?
__deref_out void **foo No No
__deref_opt_out void **foo Yes No
__deref_out_opt void **foo No Yes
__deref_opt_out_opt void **foo Yes Yes
.
PermalinkCommentssal technical programming

When Harry Met Sally 2 with Billy Crystal & Helen Mirren

2011 Apr 7, 2:28Better left unspoiled. Just watch...PermalinkCommentshumor parody video movie
Older Entries Creative Commons License Some rights reserved.