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Welcome to my website - open resources, teacher education, technology, and other interests.

This is my personal website, so while some of the items here related to my work, much of it does not. On the whole, you'll find things about education, open access, digital technology and ICT, as well as about media, maths and science, across primary, secondary and higher education, both in European, African, and global contexts. If you dig for long enough, you'll also find things about music, languages, and archaeology.

To find out more about my company and consultancy, see Open Development and Education.

 

Blog post: 20180506 Backing up WhatsApp on the commandline for Android 7

1 Backing up WhatsApp on the commandline for Android 7

This is a write-up of [1]. This recipe works if:

  • You're on Android.
  • You know how to use the command line and adb
  • You get these scripts https://github.com/EliteAndroidApps
  • You have a spare pre Android 7 phone, such as an Android 6 phone, or a phone with a lower version than 6 (temporarily).

Why this recipe is needed:

  • From Android 7 onwards, WhatsApp cannot be downgraded. The above script 'WhatsApp-Key-DB-Extractor' relies on this, and so script won't work now (and probably never will) under Android 7+.
  • This article [2] also suggests that the adb backup functionality is disabled.

However, here's some good news. The whatsapp message store (msgstore.db.crypt12) is kept on internal SD card: It's put there when WhatsApp backs up (to SD card, and optionally to Google Drive). Therefore, once you have the key, you can then decrypt that file using 'WhatsApp-Crypt12-Decrypter' [3].


2 Step I: Getting the key.

  1. What device do you have?
    1. If you have an Android 6 device (or lower), the script from [4] will work. You may still want to follow the steps below, so you don't have to keep downgrading WhatsApp every time.
    2. If you have an Android 7+ device (with WhatsApp) and an Android 6 device, sync your WhatsApp to Google Drive, and then transfer to the Android 6 device.
  2. You now have your WhatsApp data on the Android 6 device. Use 'WhatsApp-Key-DB-Extractor' to extract the key (and backup up your messages of course).
  3. Then transfer your WhatsApp back to the Android 7 device.

3 Step II: Using the key.

Whenever you want to do further backups (on your Android 7 device):

  • Back up WhatsApp to internal storage (it's in the WhatsApp settings)
  • Get the msgstore.db.crypt12 from internal storage
adb pull -a  /storage/emulated/0/WhatsApp/Databases

(The correct adb command may depend on your Android version and phone type.) Then use WhatsApp-Crypt12-Decrypter [5] to decrypt your store.

4 Some notes

  • One caveat to this is that I don't know whether the WhatsApp key might change as you upgrade, or change devices in the future. Also, I guess WhatsApp may eventually become unavailable for Android 6, blocking this recipe altogether.
  • You may need an older version of adb e.g. if your older Android phone is e.g. Android 4 (such as adb 1.0.31).
  • Once you have the database, you'll need to work out how to read your messages. There are some scripts around that can convert to the database to HTML.

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