The
pam_set_data function associates a pointer to an opaque object with an arbitrary string specified by the
module_data_name argument, in the PAM context specified by the
pamh argument.
If not
NULL, the
cleanup argument should point to a function responsible for releasing the resources associated with the object.
This function and its counterpart
pam_get_data(3) are useful for managing data that are meaningful only to a particular service module.