Under Article I, Section 8 of the Constitution, Congress has the power "to make all Laws which shall be necessary and proper for carrying into Execution the foregoing Powers, and all other Powers vested by this Constitution in the Government of the United States, or any Department or Officer thereof".
See the CRS/LII Annotated Constitution on the Necessary and Proper Clause.
See legislative power.
To see the Supreme Court's application of the clause, see McCulloch v. Maryland: https://www.law.cornell.edu/supremecourt/text/17/316