whois

The whois tool provides a commandline client for the WHOIS (RFC 3912) protocol, querying online servers for contact details of domains and IP address assignments. It intelligently selects the appropriate WHOIS server for most queries, supporting recursion and various lookup options for detailed network object information.

Mkpasswd serves as an overfeatured front end to crypt(3), enabling flexible password encryption with multiple methods, salts, and rounds. It is useful for generating hashed passwords interactively or from input.

These tools are valuable in penetration testing for reconnaissance, such as gathering domain ownership details or creating password hashes during assessments.

Whois connects to specified WHOIS servers (defaulting to intelligent selection) over the WHOIS protocol (RFC 3912) to retrieve object data like domain contacts and IP assignments. It supports recursion from registry to registrar servers, inverse lookups, and RIPE-specific flags for refined queries. Mkpasswd applies crypt(3) with user-specified methods (e.g., md5crypt), salts, and rounds to encrypt passwords.