[TOOL][WIN] Offline TXT FlightRecord to CSV Converter

[quaddamage]

Aren't they now encrypted with AES? And the key changes based on your device?

I've heard about that on other forums. If that's the case, it can be done, sure - but that's O-Gs level, as you have to reverse-engineer JNI libraries within the application.

 

[msinger]

Aren't they now encrypted with AES? And the key changes based on your device?

Yes.

 

[finlayson]

Yes.

If the (AES) key is different, depending on your device, then that would make it impossible for DJI - or anyone else - to analyze a log file that you uploaded to them. Instead, you would need to upload both a log file, and information about your device (from which they could derive the key).

The only alternative would be for the key (or the device-specific information from which the key is derived) to somehow be part of the log file - i.e., in plaintext. I.e., if DJI is still able to analyze log files that you upload to them, then you'd have to conclude that either (1) the AES key is static (i.e., the same for everyone), or else (2) it's in the log file somewhere.

 

[msinger]

If the (AES) key is different, depending on your device, then that would make it impossible for DJI - or anyone else - to analyze a log file that you uploaded to them.

Right. And it's only different by device since the device created the log file. No two devices can create the same log file.

Source:

 

[quaddamage]

Instead, you would need to upload both a log file, and information about your device

You seem to assume that DJI does not upload as much information as possible about you to Chinese servers. Not sure how it is now, but it was proven to not be the case in the past.

I didn't looked at the files myself, but heard that if you try to copy app data to another mobile, the app will not be able to read them. Not sure if it was about log files, or other data, or everything.

 

[finlayson]

Source:

OK, so from this we conclude that (a small) part of a (new-format) log file contains a (device-specific) AES key, encrypted using a public key. And this can be decrypted only by DJI (because only they have the corresponding public key).

So this means that 3rd-party log file analyzer tools will no longer be possible - unless they have an agreement with DJI :-(

 

[msinger]

So this means that 3rd-party log file analyzer tools will no longer be possible - unless they have an agreement with DJI

That is correct.

 

[crash1sttime]

I bet someone will crack it eventually

 

[msinger]

I bet someone will crack it eventually

I'm working with DJI to update my log viewers. While anything is possible (somehow), cracking this encryption would be highly unlikely.

 

[msinger]

FYI, my log viewer has been updated:

Free online DJI flight log viewer

My free online flight log viewer can be used to process and view flight log data from DJI TXT flight logs from any version of DJI Fly. These flight logs are automatically created on your mobile device when flying. After retrieving the TXT flight log from your mobile device and uploading it here...

phantompilots.com

 

[Hans 75]

Thank you for your work. I'm excited.
H.

 

[flying_pirate]

Hi folks, I'm glad to present you the result of my work.
A lot of us have been unhappy, because until now, there was no offline TXT FlightRecord to CSV Converter.
And after websites such as HealthyDrones and djilogs.com started to charge for their services, I decided I really need some offline converter. So I created it by myself.

It's quite simple, all you need to do is select input TXT file and output CSV file and press the GO button. There is also option to export JPG images, if they are present in the log.

I don't plan to add graphs, statistics or something like that.
My thanks goes to (for me) unknown person, who published some sources at this site, so I was able to put missing pieces together.

If you find any error, let me know.
Enjoy

Notice 1: It is confirmed that the TXT logs of Inspire, and also TXT logs from iOS app, have a little bit different structure (not known to me), so, please, don't be surprised when you see some strange values

Notice 2: Some of you requested the structure of the TXT log, so, here you have it too
- edit: since DJI GO 2.8.4, TXT logs are encrypted, so the structure file is useless

Notice 3: Tool can be also run from command line like this, example:
TXTlogToCSVtool "C:\temp\inputFile.txt" "C:\temp\outputFile.csv" J I G
It will try to read inputFile.txt and write the output into outputFile.csv.
Optional parameters:
J ... it will also export JPGs, if they are present in the log
I ... imperial units will be used
G ... it will also export GPX file

Notice 4: The tool is freeware and it is intended for your own personal use only.

Notice 5: Please, don't ask for decrypting algorithm. It's not shareable. Explanation here.

Notice 6: DJI is adding some misleading bytes into newer logs, so if primary version from TXTlogToCSVtool.zip doesn't work, try experimental version from TXTlogToCSVtool-exp.zip. For Mavic Mini logs, it's best to use TXTlogToCSVtoolMM.zip.

actual version is from 2020/01/24

Your converter outputs heading information. Is this true heading or magnetic heading? I have emailed with DJI and they have told me that their output is magnetic heading. I am wondering if your converter outputs the heading from DJI directly or if there is a correction for magnetic variation? Thank you.

 

[RodPad]

@flying_pirate
Kind of old thread?

Doesn't matter to me

Welcome to the forum!!

Rod ..