pam_end man page
pam_end — termination of PAM transaction
int pam_end(pam_handle_t *pamh, int pam_status);
The pam_end function terminates the PAM transaction and is the last function an application should call in the PAM context. Upon return the handle pamh is no longer valid and all memory associated with it will be invalid.
The pam_status argument should be set to the value returned to the application by the last PAM library call.
The value taken by pam_status is used as an argument to the module specific callback function, cleanup() (See pam_set_data(3) and pam_get_data(3)). In this way the module can be given notification of the pass/fail nature of the tear-down process, and perform any last minute tasks that are appropriate to the module before it is unlinked. This argument can be logically OR'd with PAM_DATA_SILENT to indicate to indicate that the module should not treat the call too seriously. It is generally used to indicate that the current closing of the library is in a fork(2)ed process, and that the parent will take care of cleaning up things that exist outside of the current process space (files etc.).
This function free's all memory for items associated with the pam_set_item(3) and pam_get_item(3) functions. Pointers associated with such objects are not valid anymore after pam_end was called.
Transaction was successful terminated.
System error, for example a NULL pointer was submitted as PAM handle or the function was called by a module.
pam_get_data(3), pam_set_data(3), pam_start(3), pam_strerror(3)
pam(3), pam_authenticate(3), pam_get_data(3), pam_get_user(3), pam_set_data(3), pam_start(3).