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PAM_SM_SETCRED

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

pam_sm_setcred - PAM service function to alter credentials

SYNOPSIS

#define PAM_SM_AUTH

#include <security/pam_modules.h>

int pam_sm_setcred(pam_handle_t *pamh, int flags, int argc, const char **argv);

DESCRIPTION

The pam_sm_setcred function is the service module's implementation of the pam_setcred(3) interface.

This function performs the task of altering the credentials of the user with respect to the corresponding authorization scheme. Generally, an authentication module may have access to more information about a user than their authentication token. This function is used to make such information available to the application. It should only be called after the user has been authenticated but before a session has been established.

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

PAM_SILENT

: Do not emit any messages.

PAM_ESTABLISH_CRED

: Initialize the credentials for the user.

PAM_DELETE_CRED

: Delete the credentials associated with the authentication service.

PAM_REINITIALIZE_CRED

: Reinitialize the user credentials.

PAM_REFRESH_CRED

: Extend the lifetime of the user credentials.

The way the auth stack is navigated in order to evaluate the pam_setcred() function call, independent of the pam_sm_setcred() return codes, is exactly the same way that it was navigated when evaluating the pam_authenticate() library call. Typically, if a stack entry was ignored in evaluating pam_authenticate(), it will be ignored when libpam evaluates the pam_setcred() function call. Otherwise, the return codes from each module specific pam_sm_setcred() call are treated as required.

RETURN VALUES

PAM_CRED_UNAVAIL

: This module cannot retrieve the user's credentials.

PAM_CRED_EXPIRED

: The user's credentials have expired.

PAM_CRED_ERR

: This module was unable to set the credentials of the user.

PAM_SUCCESS

: The user credential was successfully set.

PAM_USER_UNKNOWN

: The user is not known to this authentication module.

These, non-PAM_SUCCESS, return values will typically lead to the credential stack failing. The first such error will dominate in the return value of pam_setcred().