Network Trusted Computing Base

The Network Trusted Computing Base (NTCB) consists of hardware and software for ensuring network security. This section defines the components of the NTCB as they relate to TCP/IP.

The hardware security features for the network are provided by the network adapters used with TCP/IP. These adapters control incoming data by receiving only data destined for the local system and broadcast data receivable by all systems.

The software component of the NTCB consists of only those programs that are considered as trusted. The programs and associated files that are part of a secure system are listed in the following tables on a directory-by-directory basis.

/etc directory
Name Owner Group Mode Permissions
gated.conf root system 0664 rw-rw-r—
gateways root system 0664 rw-rw-r—
hosts root system 0664 rw-rw-r—
hosts.equiv root system 0664 rw-rw-r—
inetd.conf root system 0644 rw-r—r—
named.conf root system 0644 rw-r—r—
named.data root system 0664 rw-rw-r—
networks root system 0664 rw-rw-r—
protocols root system 0644 rw-r—r—
rc.tcpip root system 0774 rwxrwxr—
resolv.conf root system 0644 rw-rw-r—
services root system 0644 rw-r—r—
3270.keys root system 0664 rw-rw-r—
3270keys.rt root system 0664 rw-rw-r—
/usr/bin directory
Name Owner Group Mode Permissions
host root system 4555 r-sr-xr-x
hostid bin bin 0555 r-xr-xr-x
hostname bin bin 0555 r-xr-xr-x
finger root system 0755 rwxr-xr-x
ftp root system 4555 r-sr-xr-x
netstat root bin 4555 r-sr-xr-x
rexec root bin 4555 r-sr-xr-x
ruptime root system 4555 r-sr-xr-x
rwho root system 4555 r-sr-xr-x
talk bin bin 0555 r-xr-xr-x
telnet root system 4555 r-sr-xr-x
/usr/sbin directory
Name Owner Group Mode Permissions
arp root system 4555 r-sr-xr-x
fingerd root system 0554 r-xr-xr—
ftpd root system 4554 r-sr-xr—
gated root system 4554 r-sr-xr—
ifconfig bin bin 0555 r-xr-xr-x
inetd root system 4554 r-sr-xr—
named root system 4554 r-sr-x—
ping root system 4555 r-sr-xr-x
rexecd root system 4554 r-sr-xr—
route root system 4554 r-sr-xr—
routed root system 0554 r-xr-x—-
rwhod root system 4554 r-sr-xr—
securetcpip root system 0554 r-xr-xr—
setclock root system 4555 r-sr-xr-x
syslogd root system 0554 r-xr-xr—
talkd root system 4554 r-sr-xr—
telnetd root system 4554 r-sr-xr—
/usr/ucb directory
Name Owner Group Mode Permissions
tn root system 4555 r-sr-xr-x
/var/spool/rwho directory
Name Owner Group Mode Permissions
rwho (directory) root system 0755 drwxr-xr-x