fix encryption stream for 2.0

[DeepDiver1975]

follow up of #15303

@schiesbn @nickvergessen @jknockaert

[jknockaert]

@DeepDiver1975 That's quite a bit more changes than I submit in #15303

[jknockaert]

This line updating the ecryptionStorage should be moved to stream_close() right after $this->flush().

[DeepDiver1975]

@jknockaert your changes are in here: b57f469

I added unit testing on top

[jknockaert]

@DeepDiver1975 OK

[DeepDiver1975]

@jknockaert see e4ec4ca

[jknockaert]

@DeepDiver1975 Thanks

[DeepDiver1975]

I added unit testing on top

I'll move this to it's own pr

[jknockaert]

@DeepDiver1975 Ah, that's why it's gone again; I already wondered...

[jknockaert]

@DeepDiver1975 I think this PR could be labelled for review now. @schiesbn Could you test the big file issue? I think there also needs to be done some testing with unseekable encrypted streams; I don't have such a setup here.

[jknockaert]

@DeepDiver1975 Reviewing my own code I noticed that I forgot to initialise the protected variables I added; so could you pls add $this->cache = ''; and $this->writeFlag = false; somewhere in stream_open(), perhaps after $this->position = 0;? Thanks.

[DeepDiver1975]

@jknockaert quick testing this with a big file shows that this doesn't really help yet

[DeepDiver1975]

there is something missing on the chunk border

[DeepDiver1975]

The issue is within the calcs of $positionInFile .... this change doesn't seem to help

[jknockaert]

@DeepDiver1975 Not entirely sure what's happening here. Does this only happen with big files? What is big? Bigger than 6kb? Or bigger than 6MB? I would suggest to add the initialisation commented above; on top of that I am still unsure whether $this->sizeand this->unencryptedSize get initialised correctly for new files; you may want to try uncommenting these lines.
For testing it may be an idea to single out if the bug is in reading or writing. Could you test reading on a big file that was correctly encoded (i.e. with an older version of the code)?

[DeepDiver1975]

that file has a size of 1.7MB

[jknockaert]

@DeepDiver1975 Pls also add in stream_write(): $this->size+=$this->util->getBlockSize() right after $this->writeHeader();. I guess this is what causes the problem you observed (but pls still add the initialisations suggested in #15305 (comment))

[schiessle]

I cherry-picked this state over to #14472

I tested it with some large files and it worked great here. But we should still investigate the problem at the chonk border mentioned by @DeepDiver1975

@jknockaert Thanks a lot for your contribution!

There is another issue which might or might not be related to the stream wrapper.
If I share a text file with user2, user2 can read it but if user2 edits the file with the internal text editor the file gets corrupted. It looks like it starts to encrypt already the header and then continues with encrtypting already encrypted content. For the owner it works just fine.

[jknockaert]

Maybe this PR should be closed now that it has been ported to #14472?

[schiessle]

agree