AES Encrypt/Decrypt Extension

[Srk Sharma]

I want to make an App using appinventor2 with csv file, also want to encrypt the csv file so that no one use that csv file without using this app.

For this I have visited https://puravidaapps.com/aes.php, where I found AES Encrypt/Decrypt Extension, but I am not able to use this extension to encrypt my csv file which is in assets folder of the app. 

[Taifun]

the extension is to encrypt/decrypt text, but not files...

It would really help if you provided a screenshot of your relevant blocks, so we can see what you are trying to do, and where the problem may be.

Taifun

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Trying to push the limits of App Inventor! Snippets, Tutorials and Extensions from Pura Vida Apps by Taifun. 

[Srk Sharma]

Actually I have create an app with mit app inventor, where I use a CSV file to store Question Answers for test series. when I install it on my mobile CSV file is located on AppInventor Assets folder of my mobile, from where any app user can easily copy that CSV file and may modify the same which may hamper the knowledge of my students, that's why I want to Encrypt the CSV file only, o no one can modify the same without our permission. 

     Please tell me the process how to encrypt/Decrypt the CSV file...

Thank You...……...

[JK SolutionAdvanced]

Hola, encriptar como tal el archvio no es posible con esa extemsion, lo que puede encriptar es el texto que va en su interior con esto los usuarios estaran obligados a desencriptar con tu app.

[Chris Ward]

Hi Srk Sharma

The CSV File is in a "public" location only because it's on the Developer's test device - the App Inventor Companion stores the Assets on the virtual SD drive. When the application is released, all Assets are stored in the App's "private" folder. Only your App can see/access them. Of course, a good hacker with the right tools can too but that's the same everywhere.

If you still believe you need to make the CSV file FBI proof, encrypt each question before writing (appending) to the file. When reading the file, (read as a text, not using AI's CSV functions), split it at the line endings into a List, decrypt each List Item when the App demands a question.

[Srk Sharma]

Thanku Chris 

You are right to the extent that Assets are stored in the App's "private" folder, But when you change the .apk extension to .zip it will show you all assets file, from where it can easily be copied and modified.

I have attached the CSV file with some examples kindly look into and suggest me what i have to do, so csv file and some other like Fusion Table key file will be encrypted, so that no one can misuse my App data. 

[Taifun]

But when you change the .apk extension to .zip it will show you all assets file, from where it can easily be copied and modified.

a hacker would be able to do this on a rooted device

but that hacker also would be able to find your key to decrypt your encrypted files from the assets...
there is no 100% safe method

[Srk Sharma]

Thanx Taifun

I only want to protect my assets file because it contains google fusion table key file (.p12), i know hackers may break any security, but normal user would not be able to decrypt if file once encrypted. Is any way to encrypt may assets folder please suggest me the Procedures.

Thank you.

[Srk Sharma]

Hi can you suggest me how to use password protected CSV file in Mit Appinventor.

[Chris Ward]

Hi Srk Sharma

There is no such thing as a password protected CSV file - they are effectively a specially formatted text file, nothing more.

If you have seen them on your desktop computer, what you are really seeing is an executable with CSV data stored inside, essentially disguised as a CSV.

Since you are encrypting the content of your CSV, why on earth would you want a password setup too? Are you trying to avoid investigation by the CIA or what?

[Srk Sharma]

Hi Chris Ward

Actually I have created s lot of test series in csv file. All questions, optional answers and its right answers contains in a csv file. so I wants to protect it. on another hand I have use a Fusion table key file which is also in assets folder, this needs to be protected in any way, so that no any normal user misuse it....

Is any possibility to use password protected zip file instead of open single-single unprotected file.....

Please suggest me the process.

Thank you. 

[Chris Ward]

Srk

You are going way beyond any action necessary for the "normal" User. I'm not going to offer you my help because I am suspicious of your reasons.

[Srk Sharma]

i Think you have no any solution regarding this issue, that's why you are suspected me.

By the way thank you for your response. I have resolve my issue myself.

[Taifun]

I have resolve my issue myself.

you might want to present your solution here in the forum... this might help others with the same question in future

Taifun