question about krb5_verify_authenticator_checksum

[John Hascall]

Can somebody explain the what is going on with
    "if(authenticator->cksum == NULL) return -17;"
(see below).  I am getting this wierd error -17 out
of NetBSD's telnetd when trying to connect with
Hummingbird's telnet client.  Is an authenticator
checksum optional?  Or is it truly an error?

Thannks,
John


krb5_error_code krb5_verify_authenticator_checksum(krb5_context context, 
                                   krb5_auth_context ac, 
                                   void *data, 
                                   size_t len) 
{ 
    krb5_error_code ret; 
    krb5_keyblock *key; 
    krb5_authenticator authenticator; 
    krb5_crypto crypto; 
     
    ret = krb5_auth_con_getauthenticator (context, 
                                      ac, 
                                      &authenticator); 
    if(ret) 
        return ret; 
    if(authenticator->cksum == NULL) 
        return -17;

          ...(more)...