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Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘Mobile Development’ Category

Best android apps for zabbix – AndroidMeta

Posted by jpluimers on 2020/05/28

If I land a project using Zabbix again, one of the things I need to look into is [WayBackBest android apps for zabbix – AndroidMeta.

–jeroen

Posted in *nix, Android, Android Devices, Development, Linux, Mobile Development, Monitoring, Power User, Zabbix | Leave a Comment »

appletv – How can I show a read-only version of Google Calendar on Apple TV 4th generation? – Ask Different

Posted by jpluimers on 2020/05/14

Two calendars and three weather frames.Based on [WayBack] appletv – How can I show a read-only version of Google Calendar on Apple TV 4th generation? – Ask Different there is one choice that might work on Apple TV 3rd generation and 4th generation:

This is the only practical solution I dissected from [WayBackHow to surf the web and use Safari on Apple TV – Macworld UK: Here is how to browse the internet and watch web services on your Apple TV.

Installing requires a few steps as described at

Limiting to only Apple TV 4, another solution is also possible:

However the last solution is not a real web browser, so it does not allow a layout I’m using for the calendar, or actually two calendars:

  • weekly calendar on the left so my brother sees his detailed activities for the upcoming days
  • monthly calendar on the top right for an overview of the past and upcoming weeks
  • three weather frames on the bottom right with two weather radars from different sources and a weather overview for the upcoming days

The reason I need this is because my brother is mentally retarded having problems with abstract concepts like relative time and scheduling. Like me he is also easily distracted and not good at repeating tasks. So looking at a schedule at least once a day is tough for him.

He is very good at concrete topics, especially ones he can put to practice right away like “will it rain on my way to work”. That makes him look at this web page in the first place.

Currently this calendar is shown on a monitor by a Raspberry Pi attached to it.

But I might go for the Apple TV 3 route later on.

–jeroen

Posted in Apple, Apple TV, Development, iOS, iOS Development, Mobile Development, Power User | Leave a Comment »

SMS Backup+ – Apps on Google Play

Posted by jpluimers on 2020/03/04

Simple but cool app: [Archive.isSMS Backup+ – Apps on Google Play:

Automatically backup your SMS, MMS and call history with a separate label in Gmail and Google Calendar.

Later you can restore the saved data (except MMS) back to the phone, especially useful when switching to a new device.

IMAP access needs to be manually enabled in Gmail, see the website and FAQ for more information. You can of course use your own IMAP server for backups, giving you full control over your data.

SMS Backup+ is a free open-source project which has been in active development since the early days of Android, completely ad and tracking-free, supported through voluntary donations.

Sourcecode: [WayBack] GitHub – jberkel/sms-backup-plus: Backup Android SMS, MMS and call log to Gmail / Gcal / IMAP

Via: [WayBack] Wirre Telefongespräche für 500. Ich kriege ja nicht mehr oft Anrufe auf der deutschen Telefonnummer, und so liegt das Telefon jetzt daheim und hängt am… – Kristian Köhntopp – Google+

–jeroen

Posted in Android, Development, Mobile Development, Software Development | Leave a Comment »

Commander One review: A superior alternative to Android File Transfer on Mac

Posted by jpluimers on 2020/01/10

On my list of software to try: [WayBackCommander One review: A superior alternative to Android File Transfer on Mac

Via: [WayBack] Looks like a must-have for anyone using a Mac (with MacOS) and an Android phone. – Roderick Gadellaa – Google+

–jeroen

Posted in Android, Android Devices, Apple, Development, iMac, Mac, Mac OS X / OS X / MacOS, MacBook, MacBook Retina, MacBook-Air, MacBook-Pro, MacMini, macOS 10.12 Sierra, macOS 10.13 High Sierra, Mobile Development, Software Development | Leave a Comment »

Some links on keystore, encryption and decryption on Android

Posted by jpluimers on 2019/02/06

For my link archive:

 

Basically:

  • storing encrypted data plus IV in preferences is OK
  • store the symmetric encryption key (for instance an AES one) in the keystore for the application
  • likely a salt is also needed, then store the salt with the IV and encrypted data

–jeroen

Presumptions:

  • The keystore of a specific application UUID is only accessible by only that application UUID when the device has been unlocked by the user
  • The keystore saves credentials in a secure way
  • It is OK to save both the encrypted data and associated IV

Approach (plain data is “hashed application PIN”, encrypted data is “encrypted hashed application PIN”:

  1. store a symmetric AES key in the application key store
  2. after entering application PIN:
    1. hash the application PIN
    2. use the hashed application PIN to to enter the application
    3. from the keystore, obtain the symmetric AES key
    4. create a cipher based on the AES key
    5. use the cipher to obtain an IV, and to encrypt the hashed application PIN
    6. store the encrypted hashed application PIN and IV both in the application preferences
  3. when needing to enter the application, present the user to either enter the application PIN again or proof that they can pass the device unlock sequence (using an unlock activity)
    1. if the user provided the application PIN, then:
      1. hash the application PIN
      2. try to enter the application with the hashed application PIN
    2. proved the device unlock, then:
      1. from the preferences, obtain the IV and encrypted hashed application PIN
      2. from the keystore, obtain the symmetric AES key
      3. create a cipher based on the AES key
      4. decrypt the encrypted hashed application PIN using the cipher and the IV into the hashed application PIN
      5. try to enter the application with the hashed application PIN

Posted in Android, Development, Mobile Development, Software Development | Leave a Comment »

 
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