the Ministério da Previdência Social maintains an official webpage on this link. 

on this link, the publication 'overview of the Brazilian social welfare' explains in the detail the program.

set up in the mid-twentieth century as a branch of the ministry of finance, the receita federal do brasil was an original venture, created to assume responsibility of all things related to federal taxes and custom controls.

the main function is tax and custom administration and income-tax collection, with the agency's purview stretching to regulation and investigation of illegal activities such as tax evasion, smuggling, and trafficking, amongst others.