PAM_GET_ITEM

Section: Linux\-PAM Manual (3)
Updated: 06/27/2006
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NAME

pam_get_item - getting PAM informations  

SYNOPSIS

#include <security/pam_modules.h>
int pam_get_item(const pam_handle_t *pamh, int item_type, const void **item);
 

DESCRIPTION

The pam_get_item function allows applications and PAM service modules to access and retrieve PAM informations of item_type. Upon successful return, item contains a pointer to the value of the corresponding item. Note, this is a pointer to the actual data and should not be free()'ed or over-written! The following values are supported for item_type:
PAM_SERVICE
The service name (which identifies that PAM stack that the PAM functions will use to authenticate the program).
PAM_USER
The username of the entity under whose identity service will be given. That is, following authentication, PAM_USER 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 PAM_USER after each call to a PAM function.
PAM_USER_PROMPT
The string used when prompting for a user's name. The default value for this string is a localized version of "login: ".
PAM_TTY
The terminal name: prefixed by /dev/ if it is a device file; for graphical, X-based, applications the value for this item should be the $DISPLAY variable.
PAM_RUSER
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.

PAM_RUSER@PAM_RHOST should always identify the requesting user. In some cases, PAM_RUSER may be NULL. In such situations, it is unclear who the requesting entity is.

PAM_RHOST
The requesting hostname (the hostname of the machine from which the PAM_RUSER entity is requesting service). That is PAM_RUSER@PAM_RHOST does identify the requesting user. In some applications, PAM_RHOST may be NULL. In such situations, it is unclear where the authentication request is originating from.
PAM_AUTHTOK
The authentication token (often a password). This token should be ignored by all module functions besides pam_sm_authenticate(3) and 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.
PAM_OLDAUTHTOK
The old authentication token. This token should be ignored by all module functions except pam_sm_chauthtok(3).
PAM_CONV
The pam_conv structure. See pam_conv(3).
PAM_FAIL_DELAY
A function pointer to redirect centrally managed failure delays. See pam_fail_delay(3).

If a service module wishes to obtain the name of the user, it should not use this function, but instead perform a call to pam_get_user(3).

Only a service module is privileged to read the authentication tokens, PAM_AUTHTOK and PAM_OLDAUTHTOK.  

RETURN VALUES

PAM_BAD_ITEM
The application attempted to set an undefined or inaccessible item.
PAM_BUF_ERR
Memory buffer error.
PAM_PERM_DENIED
The value of item was NULL.
PAM_SUCCESS
Data was successful updated.
PAM_SYSTEM_ERR
The pam_handle_t passed as first argument was invalid.
 

SEE ALSO

pam_set_item(3), pam_strerror(3)


 

Index

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUES
SEE ALSO

linux.jgfs.net manual pages