Password Management

Function:
PAM_EXTERN int pam_sm_chauthtok(pam_handle_t* pamh,
                                                                int flags,
                                                                int argc,
                                                                const char** argv);
Macro used:
PAM_SM_PASSWORD


The function instructs the module that the user's authentication token should
be set. The input flags may contian any of the following (possibly OR'd with PAM_SILENT):
PAM_CHANGE_EXPIRED_AUTHTOK - the authentication token should be changed only if it expired.
PAM_PRELIM_CHECK - the module should only verify that changing the authentication token is possible (e.g. network connection to a password server is available).
PAM_UPDATE_AUTHTOK - the module should actually change the authentication token.

The PAM library will invoke this function twice - once with PAM_PRELIM_CHECK, and then with PAM_PRELIM_CHECK.