krb5_fcc_read_principal
static krb5_error_code krb5_fcc_read_principal
kret = krb5_fcc_read_principal(context, id, &princ);
kret = krb5_fcc_read_principal(context, id, &creds->client);
kret = krb5_fcc_read_principal(context, id, &creds->server);
kret = krb5_fcc_read_principal(context, id, princ);