Brute force password-guessing. 
The program is a .NET Core 2.2 app.
It will as quickly as possible try as many passwords as it can, salting & SHA512-hashing them, in an attempt to guess the original password.
Input to the program:
- a salt
- a hashed password (as if they came from a leaked credentials database)
and then
- an alphabet (which characters to cycle through)
- from length (which password length to start cycling from)
- to length (which password length to end with)