If you only need valid CPFs for testing, development, or lab environments, you don't necessarily need to implement the algorithm yourself. There are several online tools that generate CPFs with valid check digits following the official validation rules.
I have used a gerador de cpf for testing registration forms and validation routines. The generated numbers are mathematically valid and useful for QA and development scenarios. Most generators simply create fictitious CPF numbers that pass the verification algorithm and can be used to validate forms, databases, and onboarding workflows.
If your goal is to build the function directly into an application or Cisco ISE process, then you would need to implement the CPF check-digit calculation in your preferred programming language. The online generators are basically automating that same validation logic.
