Security Management Guide (G06.29+, H06.08+, J06.03+)

Guardian System Security

Security Management Guide — 522283-021

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Controlled and Orderly Access to Resources

The operating system uses privileged operations to control access to hardware and

certain software resources.

The operating system prevents user programs and terminal users from directly

performing privileged operations.

When a user program needs to perform a privileged operation (for example, when

accessing a disk or terminal), it must request that the operating system perform the

operation.

To access hardware resources, user programs request operating system services by

executing Guardian procedure calls.

To access software resources, terminal users request operating system services by

executing licensed system programs, such as ADDUSER, BACKUP, DEFAULT,

DELUSER, FUP, PASSWORD, RESTORE, RPASSWRD, and USERS.

The Licensing Operation

Licensing is accomplished through the FUP program.

For example, to license a program stored in PROGFILE, the super ID issues this

command:

1> FUP LICENSE PROGFILE

To revoke the license, the super ID issues this command:

2> FUP REVOKE PROGFILE

Effect of Copying a Licensed Program

If a licensed program is duplicated (using FUP), the duplicate loses its license (unless

the super ID makes the copy with the correct FUP options). Even if an intruder

modifies a copy of a licensed program, the copy cannot be run.

Security Implications

Licensing a program that uses privileged operations can seriously compromise both

system integrity and security. Such a program can gather and modify information

anywhere in the system, disrupt the system, disrupt the network, and do anything the

super ID can do (including license another program).

Licensing a program that performs no privileged operations has no effect on security

because the program gains no privileges that it did not already have.

Licensing a program allows the program to:



Execute privileged instructions, such as SEND and EIO, that directly access the

interprocessor bus and I/O devices