Attachment Decryption outside Forum Install?

[TechXPlays]

I have an old forum backed up that I realized I need some old files from. I've realized SMF renames the attachments to some sort of hash and removes file extension. The backup was done using Filzila, just downloading all files and folders. My idiot self forgot to backup the SQL Database, so I don't ahve that to go off of.

I have tried just adding the extension, but that doesn't work. I know these files should open in 7zip, but they only partially open. A ton of stuff is missing due to what I'm guessing is the encryption.

Is there a way to get these files back to their normal selves?

[Sir Osis of Liver]

The files are not encrypted or zipped, only the file name is hashed.  If you add the correct extension (.jpg, .pdf, etc.) the files should open normally.  If you downloaded the files using FileZilla without selecting binary transfer type, the files will be damaged.

[TechXPlays]

i can tell you they were downloaded simply by drag and drop when doing all the folders and files at once of the host. The files were APK's, when I open them now in 7zip, its definitely not the original file.

[Kindred]

If you downloaded the files using FileZilla without selecting binary transfer type, the files will be damaged.

The only thing to do, if you still have the original files on the server,  is to re-download them in the proper, BINARY format

[Illori]

Take a look at https://www.simplemachines.org/community/index.php?topic=374178.0

[Sir Osis of Liver]

The only thing to do, if you still have the original files on the server,  is to re-download them in the proper, BINARY format

 ^ If you use default transfer setting (Auto) in FZ to d/l attachments, they will be corrupted.  FZ has a second setting (well hidden) that causes files without extensions to be d/l'd as ASCII, which ruins the attachments.

[TechXPlays]

The only thing to do, if you still have the original files on the server,  is to re-download them in the proper, BINARY format

 ^ If you use default transfer setting (Auto) in FZ to d/l attachments, they will be corrupted.  FZ has a second setting (well hidden) that causes files without extensions to be d/l'd as ASCII, which ruins the attachments.

I've been using Filza for probably 15 years, I've never had an issue like this until specifically with SMForum

Also from the context clues, I'm sure people could easily guess the original server is gone lol

[shawnb61]

If you still have an export of the SMF Attachments table, you can use that info to rename the files to the original filenames.

Approach described here:
https://www.simplemachines.org/community/index.php?msg=3927825

And yeah, depending on the settings used, Filezilla can corrupt the files.

[Kindred]

the problem with Filezilla is that it doesn't properly interpret a file with no extension.  It tries to use ASCII format, it the file has no extension and the setting in filezilla is "auto".
(it's a stupid setting, IMO. Everything should always be BINARY, since that doesn't screw up anything, but ASCII will screw things up)

We "fixed" this in 2.1.x by adding a .dat extension -- but the 2.0 format (with no extension) will have the problem if you download before upgrading.

[Sir Osis of Liver]

In FZ -

  Edit > Settings > Transfers > File Types > Treat files without extensions as ASCII file

This overrides the Auto transfer type and corrupts the attachments.  Shouldn't be there, but it is.