HP OpenVMS Guide to System Security |
Security for the System Administrator |
Controlling Access to System Data and Resources |
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Populating the Rights Database
Initially, the rights database is created at system installation and is located in the [SYSEXE] directory. At creation, it contains the names of the environmental identifiers. As you add users to the authorization file, one identifier is added for each authorized user. The identifier, called a UIC identifier, is associated with the user's UIC and user name.
There is also an identifier in the rights database equivalent to each UIC group name. When you add a new user as the first member of a new UIC group and you specify an account group name with the user, an identifier corresponding to the account group name is added to the rights database, as shown in the following example:
Because the account name MGMT is specified when adding ROB's account and no UIC group of that name exists, the MGMT identifier is added to the rights database.$SET DEFAULT SYS$SYSTEM$RUN AUTHORIZEUAF>ADD ROB/PASSWORD=SP0152/UIC=[014,006] -_UAF>/DIRECTORY=WORK:[ROB]/ACCOUNT=MGMTUAF-I-ADDMSG, user record successfully addedUAF-I-RDBADDMSGU, identifier ROB value: [000014,000006] added to RIGHTSLIST.DATUAF-I-RDBADDMSGU, identifier MGMT value: [000014,177777] added to RIGHTSLIST.DAT
Each site adapts its own rights database according to actual use and needs.
Note that when you use AUTHORIZE to add, remove, or change user names in the system user authorization file (SYSUAF.DAT), AUTHORIZE makes corresponding changes for you in RIGHTSLIST.DAT so that the rights list corresponds to SYSUAF.DAT.
Because of the automatic creation and maintenance of the rights database, you seldom need to use the AUTHORIZE command CREATE/RIGHTS. However, if the rights database is damaged or deleted, you can create a new one with this command. (See the HP OpenVMS System Management Utilities Reference Manual for more information.)
Displaying the Database ![]()
You should regularly display the rights database to check
that it is correct and current. Two AUTHORIZE commands are used
for this: SHOW/IDENTIFIER and SHOW/RIGHTS. To display all holders
of an identifier, use the SHOW/IDENTIFIER command, as shown in the
following example:
Use the asterisk (*) wildcard to display all holders of all identifiers on the system, as follows:UAF>SHOW/IDENTIFIER/FULL NETWORK
To display the identifiers held by a particular user, use the SHOW/RIGHTS command, as follows:UAF>SHOW/IDENTIFIER/FULL *
Use the asterisk wildcard to display all identifiers held by all users, as follows:UAF>SHOW/RIGHTS/USER=ROBIN
The first command displays users alphabetically. The second command displays users according to UICs.UAF>SHOW/RIGHTS/USER=*UAF>SHOW/RIGHTS/USER=[*,*]
Adding Identifiers ![]()
You add identifiers to the rights list with the AUTHORIZE
command ADD/IDENTIFIER, for example:
To grant users an identifier with any of the attributes described in Customizing Identifiers, you must name that attribute when adding the identifier. For example, to allow users to add or modify an identifier, specify the Dynamic attribute:UAF>ADD/IDENTIFIER PAYROLLidentifier PAYROLL value %X80080011 added to RIGHTSLIST.DAT
UAF>ADD/IDENTIFIER PROJECT_TEAM1 /ATTRIBUTES=DYNAMIC
Restoring the Rights Database ![]()
If you accidentally deleted the rights list and it cannot
be recovered from a backup copy, recreate RIGHTSLIST.DAT by entering
the CREATE/RIGHTS command, followed by the ADD/IDENTIFIER command,
as follows:
The ADD/IDENTIFIER command generates a UIC identifier in the rights list corresponding to each user name in SYSUAF.DAT. To complete the task, use the ADD/IDENTIFIER command to add all general identifiers that were lost. Then redefine the holders of the identifiers with GRANT/IDENTIFIER commands, as described in Assigning Identifiers to Users.UAF>CREATE/RIGHTS{message}UAF>ADD/IDENTIFIER/USER=* or ADD/IDENTIFIER/USER=[*,*]{messages}
Assigning Identifiers to Users ![]()
After adding identifiers, you associate users as holders of
the existing identifiers by using the AUTHORIZE command GRANT/IDENTIFIER,
as shown in the following example:
To give user Martin the EXECUTIVE identifier in addition to the PAYROLL identifier would require another use of the GRANT/IDENTIFIER command. You can introduce only one holder association at a time with the GRANT/IDENTIFIER command.UAF>GRANT/IDENTIFIER PAYROLL MARTINUAF-I-GRANTMSG, identifier PAYROLL granted to MARTINUAF>GRANT/IDENTIFIER PAYROLL IPPOLITOUAF-I-GRANTMSG, identifier PAYROLL granted to IPPOLITO
In all cases shown above, AUTHORIZE associates the PAYROLL identifier with the UIC identifier corresponding to the user, specifically Martin and Ippolito. Both the identifiers must exist in the rights database.
Removing Holder Records ![]()
When a user leaves the company, remove the UAF record for
that user. Notify the managers of all sites where that user has
access to proxy accounts to remove proxy access information in the
remote node's NETPROXY.DAT file. When you run AUTHORIZE to remove
a user's UAF record, AUTHORIZE also removes the user's connections
as a holder of identifiers in the rights database. However, if a
departed user is the only remaining holder of a given identifier,
remove that identifier to avoid future confusion.
Removing Identifiers ![]()
Before you remove an identifier from the rights database:
You receive errors for files that do not contain the ACE, but the ACE is deleted from all files that do contain it.$SET SECURITY/ACL=(IDENTIFIER=87SUMMER)-_$/DELETE/LOG *.*;*
UAF>REMOVE/IDENTIFIER 87TERM3{message}
Identifiers in hexadecimal format in an ACE indicate that a general identifier has been deleted from the rights database. Similarly, if you see an identifier displayed as a numeric UIC, the original identifier was a UIC that has been removed. Delete ACEs with numeric UIC or hexadecimal identifiers.
It is wise not to reuse UICs after an employee leaves. The new employee may gain some or all of the access rights of the previous employee through ACL entries that still reference the old UIC in numeric format.
To rename an identifier, use the AUTHORIZE command RENAME/IDENTIFIER in the following format: RENAME/IDENTIFIER old-identifier new-identifier
Renaming an identifier preserves the set of resources available through that identifier. ACLs containing the renamed identifier automatically display the new identifier name.
Customizing Identifiers ![]()
Whenever you add identifiers to the rights list or grant identifiers
to users, you can stipulate that the identifier carry special characteristics
called attributes. Although there are many
possible attributes, most sites commonly use the following ones:
Sites with high security requirements are likely to use two other attributes, which discourage users from scanning the rights database:
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Holder Hidden
attribute
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Prevents someone from getting
a list of users who hold an identifier unless that person owns the
identifier.
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Name Hidden attribute
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Allows holders of an identifier to have
it translated (either from binary to ASCII or vice versa), but prevents
unauthorized users from translating the identifier.
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Read access to RIGHTSLIST.DAT overrides the Holder Hidden and Name Hidden attributes. The rights list by default denies access to world users; it has a protection of S:RWED,O;RWED,G:R,W:.
The following sections describe each attribute and explain when you might want to add them to some of your site's identifiers.
Dynamic Attribute ![]()
Once you grant an identifier to a user, processes created
by that user hold the identifier for the life of the process. However,
if you grant the identifier with the Dynamic attribute, the user
who holds the identifier can use the DCL command SET RIGHTS_LIST
to add or remove the identifier or its attributes from the process rights
list as needed.
To allow users to modify an identifier, specify the Dynamic attribute when adding the identifier to the rights database by using AUTHORIZE, as shown in the following example:
To allow specific holders of the identifier to modify the identifier, include the Dynamic attribute when granting the identifier, as follows:$SET DEFAULT SYS$SYSTEM$RUN AUTHORIZEUAF>ADD/IDENTIFIER MGMT101 /ATTRIBUTES=DYNAMIC
User Schwartz could then use the following command to remove the MGMT101 identifier from the process rights list:UAF>GRANT/IDENTIFIER MGMT101/ATTRIBUTES=DYNAMIC SCHWARTZ
Users who hold identifiers with the Dynamic and Resource attributes can also use the SET RIGHTS_LIST command to remove only the Resource attribute on the identifier.$SET RIGHTS_LIST/DISABLE MGMT101
Because users might be able to circumvent intended security policy by removing their identifiers, be careful when granting users an identifier with the Dynamic attribute. If an identifier is used in an ACL to deny access to users who hold that identifier with the Dynamic attribute, users may be able to gain access to the object through another ACL entry by removing the identifier from their process rights lists.
Holder Hidden Attribute ![]()
Sites with high security requirements can conceal the holders
of certain identifiers, thereby preventing malicious users from
determining which accounts are more interesting to target for break-ins.
You place the attribute on an identifier the user holds by using the AUTHORIZE command MODIFY/IDENTIFIER, for example:
Now the prober cannot discover who is on the secret project.UAF>MODIFY/IDENTIFIER /ATTRIBUTES=HOLDER_HIDDEN SECRET_PROJECT
Name Hidden Attribute ![]()
Sites with high security requirements can hide the names of
identifiers. For example, sites implementing mandatory access controls
can hide the names of identifiers associated with their security
categories. This prevents people from seeing the names of identifiers
unless they personally hold them. When an identifier holds the Name
Hidden attribute, the operating system refuses to translate the
identifier from its binary value to ASCII or from ASCII to the binary
value unless the requesting process holds the identifier.
To assign the attribute to an identifier, use the AUTHORIZE command MODIFY/IDENTIFIER:
UAF>MODIFY/IDENTIFIER SECRET_NEWS /ATTRIBUTES=NAME_HIDDEN
No Access Attribute ![]()
The No Access attribute allows a process to hold an identifier
but not have the identifier considered in determining access rights
to the object.
For example, a user with the Resource and No Access attributes can charge disk space to the identifier but not have access to objects owned by the identifier. Or a system manager can manage data and perform tasks connected with the data but cannot read from or write to any of the files.
You can allow file space to be owned by and charged to an identifier yet prevent the files from being accessed in any way. Use AUTHORIZE to specify the No Access attribute with the Resource attribute when adding the identifier to the rights database, as shown in the following example:
To limit the rights of users holding an identifier with the Resource attribute, grant the identifier with the No Access attribute as well as the Resource attribute to all desired users:UAF>ADD/IDENTIFIER/ATTRIBUTES=(RESOURCE,NOACCESS)-_UAF>MGMT101
UAF>GRANT/IDENTIFIER/ATTRIBUTES=(RESOURCE,NOACCESS)-_UAF>MGMT101 SCHWARTZ
Resource Attribute ![]()
Consumption
of disk space is generally charged to the creator of each file by
subtracting the disk space from the file owner's disk quota. System
managers and security administrators might prefer to track the use of
disk space according to logical groups of users (such as departments
or projects) rather than individual users. General identifiers are
used to specify these groups. Thus, when general identifiers own
directories, disk space used by files created in the directories
may be charged to the identifier rather than the UIC of the file's
creator.
To allow file space to be owned by and charged to an identifier, use AUTHORIZE to specify the Resource attribute when adding the identifier to the rights database, as shown in the following example:
To allow specific holders of the identifier to charge disk space to the identifier, perform the following steps:UAF>ADD/IDENTIFIER MGMT101 /ATTRIBUTES=RESOURCE
UAF>GRANT/IDENTIFIER MGMT101/ATTRIBUTES=RESOURCE SCHWARTZ
$SET SECURITY/ACL=(-_$(IDENTIFIER=MGMT101,ACCESS=READ+WRITE ) -_$(IDENTIFIER=MGMT101,OPTIONS=DEFAULT,ACCESS=READ+WRITE))-_$INVENTORY.DIR
$SET SECURITY/OWNER=MGMT01 INVENTORY.DIR
Because resource identifier MGMT101 is going to own any file you create in directory INVENTORY.DIR, you use ACEs to determine the type of file access you receive. Include a Creator ACE (CREATOR,ACCESS=READ+WRITE+EXECUTE+DELETE) to set the access granted to the file's creator. Alternatively, you can let the system assign an ACE; its ACE grants control access to the file's creator plus the access specified in the owner field of the protection code. You can set up the protection code by including a Default Protection ACE in the ACL for INVENTORY.DIR, for example, (DEFAULT_PROTECTION, ACCESS=O:RW). (Refer to Setting Defaults for a Directory Owned by a Resource Identifier for further information.)
Not everyone who holds the identifier will also hold the Resource attribute associated with that identifier. If you create a file in a directory owned by an identifier but you do not have the Resource attribute for that identifier, the file will be owned by your UIC, and the required disk space is subtracted from your disk quota.
Subsystem
Attribute ![]()
You can authorize users to manage protected subsystems by
granting them a subsystem identifier with the Subsystem attribute.
This empowers users to enable images to access the objects managed
by the subsystem. (See
Using Protected Subsystems for a discussion of protected subsystems.)
In the following example, user Schwartz is given the authority to create a subsystem with the identifier MAIL_SUBSYSTEM. Schwartz is also given control access to the application image to set access controls.
$SET DEFAULT SYS$SYSTEM$RUN AUTHORIZEUAF>ADD/IDENTIFIER MAIL_SUBSYSTEM /ATTRIBUTES=SUBSYSTEMUAF>GRANT/IDENTIFIER MAIL_SUBSYSTEM -_UAF>/ATTRIBUTES=SUBSYSTEM SCHWARTZUAF>Exit$SET SECURITY/ACL=(IDENTIFIER=MAIL_SUBSYSTEM,ACCESS=CONTROL)-_$MEMBER_LIST.EXE
Modifying a System or Process Rights List ![]()
As a privileged security administrator, you can use the SET
RIGHTS_LIST command to modify the rights list of any process on
the system or to modify identifiers in the system rights list. Adding
an identifier to the system rights list effectively grants it to
all users. You can also use the SET RIGHTS_LIST command to add attributes
to existing identifiers.
A possible use of the system rights list is to enable site-specific environmental conditions. For example, a batch job scheduled to run at 8:00 a.m. could add the following identifier:
Another batch job scheduled for 5:00 p.m. could remove the identifier DAY_SHIFT:$SET RIGHTS_LIST/SYSTEM/ENABLE DAY_SHIFT
The effect is to enable access to protected objects with the identifier DAY_SHIFT during the 8:00 a.m. to 5:00 p.m. period.$SET RIGHTS_LIST/SYSTEM/DISABLE DAY_SHIFT
The command in the next example modifies a process rights list by adding the SALES identifier to the rights list of the process DEDNAM. Specifying the Resource attribute allows the holders of the SALES identifier to charge disk space to it.
$SET RIGHTS_LIST/ENABLE/ATTRIBUTES=RESOURCE/PROCESS=DEDNAM SALES
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