Shodan is essentially a vulnerability search engine. By providing it with a name, an IP address, or even a port, it returns all the systems in its databases that match. This makes it one of the most effective sources for intelligence when it comes to infrastructure. It's like Google for internet-connected devices. Shodan constantly scans the Internet and saves the results into a public database. Whilst this database is searchable from the Shodan website (https://www.shodan.io), the results and services reported on are limited, unless you access it through the Application Programming Interface (API).
Our task for this section will be to gain information about the Packt Publishing website by using the Shodan API.
At the time of writing this, Shodan membership is $49, and this is needed to get an API key. If you're serious about security, access to Shodan is invaluable.
If you don't already have an API key for Shodan, visit www.shodan.io...