PAM_GET_USER(3PAM) PAM Library Functions PAM_GET_USER(3PAM)

NAME

pam_get_user - PAM routine to retrieve user name

SYNOPSIS

cc [ flag ... ] file ... -lpam [ library ... ]
#include <security/pam_appl.h>


int pam_get_user(pam_handle_t *pamh,
const char **user, const char *prompt);

DESCRIPTION

The pam_get_user() function is used by PAM service modules to
retrieve the current user name from the PAM handle. If the user name
has not been set with pam_start() or pam_set_item(), the PAM
conversation function will be used to prompt the user for the user
name with the string "prompt". If prompt is NULL, then
pam_get_item() is called and the value of PAM_USER_PROMPT is used for
prompting. If the value of PAM_USER_PROMPT is NULL, the following
default prompt is used:

Please enter user name:


After the user name is gathered by the conversation function,
pam_set_item() is called to set the value of PAM_USER. By
convention, applications that need to prompt for a user name should
call pam_set_item() and set the value of PAM_USER_PROMPT before
calling pam_authenticate(). The service module's
pam_sm_authenticate() function will then call pam_get_user() to
prompt for the user name.


Note that certain PAM service modules, such as a smart card module,
may override the value of PAM_USER_PROMPT and pass in their own
prompt. Applications that call pam_authenticate() multiple times
should set the value of PAM_USER to NULL with pam_set_item()
before calling pam_authenticate(), if they want the user to be
prompted for a new user name each time. The value of user retrieved
by pam_get_user() should not be modified or freed. The item will be
released by pam_end().

RETURN VALUES

Upon success, pam_get_user() returns PAM_SUCCESS; otherwise it
returns an error code. Refer to pam(3PAM) for information on error
related return values.

ATTRIBUTES

See attributes(7) for description of the following attributes:


+--------------------+-------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-------------------------+
|Interface Stability | Stable |
+--------------------+-------------------------+
|MT-Level | MT-Safe with exceptions |
+--------------------+-------------------------+

SEE ALSO

pam(3PAM), pam_authenticate(3PAM), pam_end(3PAM), pam_get_item(3PAM),
pam_set_item(3PAM), pam_sm(3PAM), pam_sm_authenticate(3PAM),
pam_start(3PAM), attributes(7)

NOTES

The interfaces in libpam are MT-Safe only if each thread within the
multithreaded application uses its own PAM handle.

July 6, 2024 PAM_GET_USER(3PAM)