Stack Smash 101

Reverse a small Linux license-check binary to recover the key it accepts, without the source.

Scenario

Larkspur Logistics shipped a command-line tool that refuses to run without a license key. The vendor is gone and no one has the key. You have only the compiled, stripped 64-bit Linux binary.

Your job is to reverse the license check, recover a key it will accept, and run it to reveal the flag. There is no network service and nothing to connect to; everything is inside the binary.