sec_read_msg
sec_read_msg(buf, prot_safe);
sec_read_msg(buf, prot_private);
sec_read_msg(buf, prot_confidential);
sec_read_msg(reply_string, prot_safe);
sec_read_msg(reply_string, prot_private);
sec_read_msg(reply_string, prot_confidential);
int sec_read_msg (char *, int);