Re: Q&A (a DOS database program)

Hello All, does anyone know much about the this program? I would like to be able to pick the passwords out of the database file.

One of the purposes of cypherpunks is to figure out stuff like this and to help others learn how to do it. In short, you figure it out, and tell us. To begin with, make a database with some permissions. Make a complete copy of that database in another directory. Now change exactly one password by exactly one letter. Use a differencing tool to find the differences. Save this copy as well. Change the same password again. Check to see if the differences are in the same place. Do the same with different passwords. Correlate this information with the database structures. Write some software to generate plaintext/ciphertext pairs. Get at least a thousand, preferably lots more. You'll use these later to verify that your reconstruction of the algorithm is correct. If the encryption isn't obvious by now (yes, some of this stuff is extremely weak) hook up a debugger to the executable and start looking for the routine which does password encryption. When you find it, reverse engineer it and write a C routine that matches the functionality. Now you'll be considered having done your homework. If you still don't know how to crack passwords after knowing the algorithm, post the algorithm here and we'll look at it. Eric