Hi, I have recently come across files with *.alf extension. I tried to read the contents of those files, but they are encrypted. I searched on internet about .alf extension but didn't get satisfactory information.

Actually, I would like to know how to create an .alf file, what encryption mechanism it follows and how to build a tool to read any given .alf file.

Thanks in advance. I need to know this asap!

Welcome to LinuxQuestions

I would guess the file is binary which means it does not contain ASCI readable characters i.e. A-Z etc that you would find in a regular text file and not encrypted. The alf file extension can be associated with more then one application so not enough information to help.

Please do not ask for help ASAP. We all volunteer our time and your question is not more important then everyone else.

1 members found this post helpful.

Thanks Michael for your prompt reply.

I am sorry for writing ASAP in my post.I understand

Why do you think they're "encrypted" and not just binary?

Does running "strings" on them give you any hints?

Also, why do you need to read them? The reason you need to be able to read them should give you more hints as to what type of file they are and what program created them.

Hi,

Whenever I open any .alf file it has its content in the following format:

"WAYAAI1ECYyYZ5Cvthwt2tIVTHN2RkTVnebUl68+OyK0h57IA"

This is one line from the whole file. These .alf files are used as license files for Altium softwares but I wanted to convert them into readable text so that I can understand the contents.

I tried searching online for MD5 decrypters to decrypt the contents of .alf file thinking it might be MD5 encrypted file, but it didn't work.

Thanks
-Akshay

Basically, they encrypt these files because they don't want you to see the content of the files.
What's more, with buying their products, you (implicitly) agreed not to try and crack their encryption.

Thanks NevemTeve.

I understand and agree to the point you mentioned. However, I do not wish to crack any license file. It was an example given of the usage of .alf files which I found through google search.

Basically, I am trying to understand the mechanism as to how encryption-decryption works for files with .alf extension and how can I create such kind of files if I want to create licenses for software after they are developed.

First of all, you need to "Google it" to determine where the file actually came from and what its content might be. It could, for example, be part of an Act! database file. Or, a file by AbacusLaw.

The binary information might be, say, an image or a music recording ... hence, there might be nothing readable in it, yet it is not per se "encrypted."

The three- or four-letter file extension does not uniquely describe the content or provenance of any file. The file command can be used to read the "magic bytes" that might be somewhere in the file, which might help you to identify it.

This should give you some ideas:

http://www.brandonstaggs.com/2007/07...tem-in-delphi/

https://github.com/cuda/Partial-Key-Verification

And to this discussion (about license verification systems) ... I would add this personal observation, which I have gleaned from selling a particular software product continuously(!) for the past 19 years.

Very shortly after my product, ChimneySweep (an automated database-repair tool for Paradox and xBase databases ...), was introduced, way back in 1996, someone posted a valid license key to the Internet. And, similar things have happened for every release since then. But ... it doesn't seem to have affected sales. Yes, people continue to buy the product, almost every day. (I have my own personal Energizer Bunny ... go figure.)

I spend zero time fretting about people who might have stolen it. "ChimneySweep has been very good to me," and I continue to support its many, many thousands of worldwide customers.

The license protection system is comparatively simple. It specifically does not attempt to detect features of the hardware to prevent re-installation. It does not "ping the network" to see if copies of itself have been installed elsewhere. If you want to buy one license and install it everywhere, the product will not technically prevent you. And yet ... customers don't.

Instead, they have on more than one occasion thanked me for keeping the product "very easy to install, even on isolated machines." This capability is very important to them, given the sort of situations they customarily encounter when using the product, and I find it most expedient to trust(!) them.

It is technically possible to use (even, off-the-shelf) licensing strategies that "fight a bloody war against" the "evil hackers" which, you assume, are champing at the bit to avail themselves of a free copy of your precious program. But it may well be that these onerous tools are simply ... well ... onerous.

I don't think it's a good idea to make your product "onerous."

Make a really good product that really does make a really-nasty problem go "bye-bye," then support the hell out of anyone who claims to be your customer. The word gets around. And yes, they've got money. (And they'd be insulted if you even suggested that they might steal anything.)

I don't think it's a good idea to insult your customers, either.

Now, you do need to have some license-key system, because Governments (in particular) are not permitted to use taxpayer money to buy anything that can be obtained for free. They need to receive from you an invoice confirmation of the sale, which includes either the actual license key or some unique serial-number or other code which the properly licensed and installed product will display, say, on its About... box. This is the information which they can then show to their compliance auditors. Governments around the planet are funny that way. (And I've sold a copy to most of them.)