I have an idea and it may work, but I don't know all the Chocolatey rules. So not sure if my idea is inline with chocolatey design or road map. So here is the idea, if we add a new attribute in nuspec e.g <additionalcommandline user="" password="">. Based on this number of attribute chocolatey UI shows text boxes along with install option. Then if user enters that value before clicking install we can set those value to env variables or some file that installer file(installer.ps1) will be looking into for these values.