pam_sm_authenticate.3 (2010 09)

p
pam_sm_authenticate(3) pam_sm_authenticate(3)
NAME
pam_sm_authenticate - Service provider implementation for pam_authenticate
SYNOPSIS
cc [ flag ... ] file ...
-lpam [ library ... ]
#include <security/pam_appl.h>
#include <security/pam_modules.h>
int pam_sm_authenticate(pam_handle_t *
pamh, int flags, int argc
,
const char **
argv);
DESCRIPTION
In response to a call to pam_authenticate(3), the PAM framework calls
pam_sm_authenticate()
from the modules listed in the pam.conf (4) file. The authentication provider supplies the back-end func-
tionality for this interface function.
The function,
pam_sm_authenticate()
, is called to verify the identity of the current user. The user
is usually required to enter a password or similar authentication token depending upon the authentica-
tion scheme configured within the system. The user in question is specified by a prior call to
pam_start(), and is referenced by the authentication handle, pamh.
If the user is unknown to the authentication service, the service module should mask this error and con-
tinue to prompt the user for a password. It should then return the error,
PAM_USER_UNKNOWN
.
The following flag may be passed in to
pam_sm_authenticate()
:
PAM_SILENT
The authentication service should not generate any messages.
PAM_DISALLOW_NULL_AUTHTOK
The authentication service should return
PAM_AUTH_ERROR if the user has a null authentication
token.
The argc argument represents the number of module options passed in from the configuration file
pam.conf (4). argv specifies the module options, which are interpreted and processed by the authentica-
tion service. Please refer to the specific module manual pages for the various available options. If any
unknown option is passed in, the module should log the error and ignore the option.
Before returning,
pam_sm_authenticate()
should call pam_get_item() and retrieve
PAM_AUTHTOK. If it has not been set before (ie. the value is NULL), pam_sm_authenticate()
should set it to the password entered by the user using pam_set_item()
.
An authentication module may save the authentication status (success or reason for failure) as state in
the authentication handle using
pam_set_data(). This information is intended for use by
pam_setcred().
APPLICATION USAGE
Refer to pam(3) for information on thread-safety of PAM interfaces.
NOTES
Modules should not retry the authentication in the event of a failure. Applications handle authentication
retries and maintain the retry count. To limit the number of retries, the module can return a
PAM_MAXTRIES error.
RETURN VALUES
Upon successful completion,
PAM_SUCCESS must be returned. In addition, the following values may be
returned:
PAM_MAXTRIES Maximum number of authentication attempts exceeded.
PAM_AUTH_ERR Authentication failure.
PAM_CRED_INSUFFICIENT Can not access authentication data due to insufficient credentials.
PAM_AUTHINFO_UNAVAIL Underlying authentication service can not retrieve authentication infor-
mation.
PAM_USER_UNKNOWN User not known to underlying authentication module.
HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1