Find out key for decrypted text

[AxAn]

Hi.

I'm working with a software that uses a database.
I have full access to this database and store some values myself in tables that belongs to the main software using my own program.
These two softwares are going to be installed at customers.
So far so good. The main software does however store it's database connectionstring in a encrypted file. And since this can change would I like to be able to read the same file as the main software have from my own program.

Since the main program generates the encrypted file from a plaintext-file (UDL) I have both the plaintext-file and the encrypted file (same info in both) and my question is how/if I can figure out how the encryption is done and decrypt the file?
it should be possible since I have the same file before and after the encryption. Some things might be removed but I still think that there should exist some sort of bruteforce-program that can do this.

Anyone have any thoughts or info about this?

[erik_jensen]

Since the main program generates the encrypted file from a plaintext-file (UDL) I have both the plaintext-file and the encrypted file (same info in both) and my question is how/if I can figure out how the encryption is done and decrypt the file?
it should be possible since I have the same file before and after the encryption. Some things might be removed but I still think that there should exist some sort of bruteforce-program that can do this.

Anyone have any thoughts or info about this?

If you don't already know how the encryption is done why do you need to know it at all ?

In general reverse engineering is very difficult, I don't think anyone can help you much without knowing all the details of your project.

[runner4]

Hey AxAn,

Finding the formula of an encryption is never easy. But, it is possible if you a have a bunch of the encrypted messages and their corresponding deciphered messages, which you already seem to have. However, I don't recommend it unless you have a team of 30 genuises working on it 24/7 for a month.

It is not a good idea to directly populate a database of an off-the-shelf application from your own program because of all the relational links between the tables that you may not be aware of. However, some customizable applications provide an API to their own database, which your program can call. This may be the best and your only alternative.

[AxAn]

The reason I'm doing this is to simplify administration in two ways:
1. Only need to change connectionstring data in one place.
2. Only need one database.

I'm very aware of the database structure of the main program so that is not a problem.

But it seems that I have to make another solution.