Section: Linux-PAM Manual (3)
pam_get_item - getting PAM information
int pam_get_item(const pam_handle_t *pamh, int item_type, const void **item);
function allows applications and PAM service modules to access and retrieve PAM information of
item_type. Upon successful return,
contains a pointer to the value of the corresponding item. Note, this is a pointer to the
data and should
free()'ed or over-written! The following values are supported for
The service name (which identifies that PAM stack that the PAM functions will use to authenticate the program).
The username of the entity under whose identity service will be given. That is, following authentication,
identifies the local entity that gets to use the service. Note, this value can be mapped from something (eg., "anonymous") to something else (eg. "guest119") by any module in the PAM stack. As such an application should consult the value of
after each call to a PAM function.
The string used when prompting for a user's name. The default value for this string is a localized version of "login: ".
The terminal name: prefixed by
if it is a device file; for graphical, X-based, applications the value for this item should be the
The requesting user name: local name for a locally requesting user or a remote user name for a remote requesting user.
Generally an application or module will attempt to supply the value that is most strongly authenticated (a local account before a remote one. The level of trust in this value is embodied in the actual authentication stack associated with the application, so it is ultimately at the discretion of the system administrator.
should always identify the requesting user. In some cases,
may be NULL. In such situations, it is unclear who the requesting entity is.
The requesting hostname (the hostname of the machine from which the
entity is requesting service). That is
does identify the requesting user. In some applications,
may be NULL. In such situations, it is unclear where the authentication request is originating from.
The authentication token (often a password). This token should be ignored by all module functions besides
pam_sm_chauthtok(3). In the former function it is used to pass the most recent authentication token from one stacked module to another. In the latter function the token is used for another purpose. It contains the currently active authentication token.
The old authentication token. This token should be ignored by all module functions except
The pam_conv structure. See
The following additional items are specific to Linux-PAM and should not be used in portable applications:
A function pointer to redirect centrally managed failure delays. See
The name of the X display. For graphical, X-based applications the value for this item should be the
variable. This value may be used independently of
for passing the name of the display.
A pointer to a structure containing the X authentication data required to make a connection to the display specified by
PAM_XDISPLAY, if such information is necessary. See
The default action is for the module to use the following prompts when requesting passwords: "New UNIX password: " and "Retype UNIX password: ". The example word
can be replaced with this item, by default it is empty. This item is used by
If a service module wishes to obtain the name of the user, it should not use this function, but instead perform a call to
Only a service module is privileged to read the authentication tokens, PAM_AUTHTOK and PAM_OLDAUTHTOK.
The application attempted to set an undefined or inaccessible item.
Memory buffer error.
The value of
Data was successful updated.
passed as first argument was invalid.