krb5_c_valid_cksumtype
if (!krb5_c_valid_cksumtype(his_cksum->checksum_type))
return krb5_c_valid_cksumtype (ctype);
if (!krb5_c_valid_cksumtype(sumtype))
if (!krb5_c_valid_cksumtype(message->checksum->checksum_type)) {
krb5_boolean KRB5_CALLCONV krb5_c_valid_cksumtype