Content-Type: text/plain Content-Disposition: inline Content-Transfer-Encoding: binary X-RT-Original-Encoding: iso-8859-1 Content-Length: 294 When starting the 1st iteration through the keytab file after calling krb5_kt_default(), calls to krb5_get_init_creds_keytab() will NULL out the FILE * in the krb5_keytab structure. Subsequent iterations will crash the program with a NULL pointer dereference. See attached sample program.