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PAM_SETCRED

Section: Linux-PAM Manual (3)
Updated: 04/01/2016
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NAME

pam_setcred - establish / delete user credentials

SYNOPSIS

#include <security/pam_appl.h>

int pam_setcred(pam_handle_t *pamh, int flags);

DESCRIPTION

The pam_setcred function is used to establish, maintain and delete the credentials of a user. It should be called to set the credentials after a user has been authenticated and before a session is opened for the user (with pam_open_session(3)). The credentials should be deleted after the session has been closed (with pam_close_session(3)).

A credential is something that the user possesses. It is some property, such as a Kerberos ticket, or a supplementary group membership that make up the uniqueness of a given user. On a Linux system the user's UID and GID's are credentials too. However, it has been decided that these properties (along with the default supplementary groups of which the user is a member) are credentials that should be set directly by the application and not by PAM. Such credentials should be established, by the application, prior to a call to this function. For example, initgroups(2) (or equivalent) should have been performed.

Valid flags, any one of which, may be logically OR'd with PAM_SILENT, are:

PAM_ESTABLISH_CRED

: Initialize the credentials for the user.

PAM_DELETE_CRED

: Delete the user's credentials.

PAM_REINITIALIZE_CRED

: Fully reinitialize the user's credentials.

PAM_REFRESH_CRED

: Extend the lifetime of the existing credentials.

RETURN VALUES

PAM_BUF_ERR

: Memory buffer error.

PAM_CRED_ERR

: Failed to set user credentials.

PAM_CRED_EXPIRED

: User credentials are expired.

PAM_CRED_UNAVAIL

: Failed to retrieve user credentials.

PAM_SUCCESS

: Data was successful stored.

PAM_SYSTEM_ERR

: A NULL pointer was submitted as PAM handle, the function was called by a module or another system error occured.

PAM_USER_UNKNOWN

: User is not known to an authentication module.