How to encrypt cached web responses

[sha3rawi33]

is it possible by any chance to handle the response from the server and encrypt it then cache it encrypted?

I'll be caching sensitive data so I don't need them in plain text; I've 2 functions; one to encrypt and one to decrypt. I will be able to decrypt the string I get from the file; but how to cache the response encrypted firstly ??

[YuriHeiko]

You can store encrypted data in the Firebase storage instead

[sha3rawi33]

@YuriHeiko I need it to be saved locally for offline usage

[YuriHeiko]

@sha3rawi33 I still cannot see the issue - encrypt data when you send it to the storage, retrieve it encrypted to the cache and decrypt after you get it from the cache

[sha3rawi33]

Like this code:

 File cacheFile = await DefaultCacheManager().getSingleFile(url);
      response = cacheFile.readAsStringSync();
      extractedData = json.decode(response) as List;

the cache is saved automatically in the await DefaultCacheManager().getSingleFile(url) step; how can I encrypt it before it is saved to the file ?

[sha3rawi33]

@YuriHeiko I mean; when I use this method; the response is saved as a JSON file in the cache folder automatically; how can I control that response text before it is saved? I know how to encrypt/decrypt. but I can't handle the response text before it is saved as it is done automatically.

[YuriHeiko]

@sha3rawi33 Do you make requests to a third-party service? My point is if you are storing data to that backend service then it would be easier to store already encrypted data. Then you will have data encrypted in the cache as well. If you are using a third-party service you will need to somehow intercept HTTP requests and change data on that stage. I think it would be easier to create the extension point in the current package

[sha3rawi33]

@YuriHeiko aha I got your point; i should now edit my API simply to encrypt data before being sent to the app; so it is cached encrypted in the app; and when I use it; I just decrypt it using my key.

nice solution; gonna consider it if I didn't find another one related to the package itself. thanks!

[renefloor]

@sha3rawi33 I think it is indeed best to use to put and get functions of the cache manager to put and get the encrypted data and handle encryption yourself.

Closing this for now. If you have any other questions please reopen it.