The pam_setcred() function is used to establish, modify, or delete user credentials. It is typically called after the user has been authenticated and after a session has been opened. See pam_authenticate(3PAM), pam_acct_mgmt(3PAM), and pam_open_session(3PAM).

The user is specified by a prior call to pam_start() or pam_set_item(), and is referenced by the authentication handle, pamh. The following flags may be set in the flags field. Note that the first four flags are mutually exclusive:

PAM_ESTABLISH_CRED

Set user credentials for an authentication service.

PAM_DELETE_CRED

Delete user credentials associated with an authentication service.

PAM_REINITIALIZE_CRED

Reinitialize user credentials.

PAM_REFRESH_CRED

Extend lifetime of user credentials.

PAM_SILENT

Authentication service should not generate any messages.

If no flag is set, PAM_ESTABLISH_CRED is used as the default.

Upon success, pam_setcred() returns PAM_SUCCESS. In addition to the error return values described in pam(3PAM) the following values may be returned upon error:

PAM_CRED_UNAVAIL

Underlying authentication service can not retrieve user credentials unavailable.

PAM_CRED_EXPIRED

User credentials expired.

PAM_USER_UNKNOWN

User unknown to underlying authentication service.

PAM_CRED_ERR

Failure setting user credentials.

See attributes(5) for description of the following attributes:

pam(3PAM), pam_acct_mgmt(3PAM), pam_authenticate(3PAM), pam_open_session(3PAM), pam_set_item(3PAM), pam_start(3PAM), libpam(3LIB), attributes(5)

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