Tag: software development

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Making A Business Card Reader Using Tesseract

Business cards, those little cards with your contact information. I remember when I got my first box, I felt like a complete office professional! Giving and receiving them was a stringent ritual. I even had business card holders and organizers. But that was a long time ago. Do people still use those?!?

Well, apparently they still do. Yesterday, I got a big stack from my wife from her Singapore trip and she asked if I can encode the data into a spreadsheet. So me being me, instead of spending some time encoding, I spent a bit more time coding.

Continue reading “Making A Business Card Reader Using Tesseract”
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iOS 9 and Ionic Side Menus

I encountered an issue with Ionic side menus where a previous view would partially obscure the current view. I updated everything, checked all my JS and HTML templates, verified links and state transitions, all to no avail.

I was stuck for quite a while until I finally decided that it’s probably an iOS-specific issue. A search then led me to this Ionic blog entry from 2 months(!) ago: http://blog.ionic.io/ios-9-potential-breaking-change/. I downloaded and applied the patch and that was it.

The issue is caused by an iOS 9 bug that affects AngularJS and thus Ionic. It’s supposedly “isolated to intermittent UI/navigation issues on some apps”. And, of course, I was one of the lucky ones. I can’t believe it hasn’t been fixed yet!

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iOS 9 and the Firebase REST API

I was playing around with the Firebase REST APIs when I encountered the following SSL error:

NSURLSession/NSURLConnection HTTP load failed (kCFStreamErrorDomainSSL...

After some research, I found out that iOS 9 enforces App Transport Security or ATS which, according to Apple, “enforces best practices in the secure connections between an app and its back end”.

But I am using secure connections! After further research I found out that problem with the Firebase servers, specifically the SSL ciphers they allow.

By default, apps use only a specific set of ciphers for SSL communications:

TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA

Setting the NSAppTransportSecurity option will include the following ciphers, which the Firebase servers do allow:

TLS_DHE_RSA_WITH_AES_256_GCM_SHA384
TLS_DHE_RSA_WITH_AES_128_GCM_SHA256
TLS_DHE_RSA_WITH_AES_256_CBC_SHA256
TLS_DHE_RSA_WITH_AES_256_CBC_SHA
TLS_DHE_RSA_WITH_AES_128_CBC_SHA256
TLS_DHE_RSA_WITH_AES_128_CBC_SHA
TLS_RSA_WITH_AES_256_GCM_SHA384
TLS_RSA_WITH_AES_128_GCM_SHA256
TLS_RSA_WITH_AES_256_CBC_SHA256
TLS_RSA_WITH_AES_256_CBC_SHA
TLS_RSA_WITH_AES_128_CBC_SHA256
TLS_RSA_WITH_AES_128_CBC_SHA

Setting the NSAppTransportSecurity option entails adding the following into the app’s Info.plist:

<key>NSAppTransportSecurity</key>
<dict>
    <key>NSExceptionDomains</key>
    <dict>
        <key>firebaseio.com</key>
        <dict>
            <key>NSIncludesSubdomains</key>
            <true/>
            <key>NSThirdPartyExceptionRequiresForwardSecrecy</key>
            <false/>
        </dict>
    </dict>
</dict>

DHE stands for Diffie-Hellman Exchange. ECDHE stands for Elliptic-Curve Diffie Hellman Exchange. They both offer forward secrecy but ECDHE is just faster. So the NSThirdPartyExceptionRequiresForwardSecrecy is a bit of a misnomer.

Now I wonder why Firebase doesn’t just add support for ECDHE?

More at StackOverflow.

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iPhone Weekend

Michelle and Jeanne went to visit the grandparents and attend Tin and Jansen’s wedding. I was left at home suddenly with plenty of time. I still did some usual chores: laundry, cooking, washing the plates, washing the car, etc. But somehow I still had extra time. Okay, I know why :P

Anyway, what better to spend spare time on than continue learning iPhone software development! The two days, I played around with Objective-C, the Interface Builder, and of course XCode. Learned quite a lot!

And when I wasn’t studying, I was using the iPhone to watch How I Met Your Mother and to play Infinity Blade with its The Deathless Kings content pack (damn Zero Mech!).

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Smartphone Market Share

image Credit: Nielsen

Nielsen released data on smartphone market share as of Nov 2010 to Jan 2011. From an OS perspective, definitely it shows the Android juggernaut’s seemingly unstoppable rise to the top. From a hardware perspective, it’s interesting to note how Apple and Blackberry(!) still hold a huge chunk of the market. But HTC is waiting on the wings.

It seems that at this point, focusing on iOS development is still a good strategy. Noting, of course that the other iOS devices, iPad and iPad 2, are the leaders in the tablet space. But investing in Android development should already be in the pipeline.