krb5_auth_con_getkey
err = krb5_auth_con_getkey(telnet_context,
retval = krb5_auth_con_getkey (context, auth_context, &session_key);
if ((code = krb5_auth_con_getkey(context, auth_context,
krb5_error_code KRB5_CALLCONV krb5_auth_con_getkey