Oracle8i Administrator's Guide
Release 8.1.5






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Establishing Security Policies

This chapter provides guidelines for developing security policies for database operation, and includes the following topics:

System Security Policy

This section describes aspects of system security policy, and includes the following topics:



Database User Management


User Authentication

Database users can be authenticated (verified as the correct person) by Oracle using the host operating system, network services, or the database. Generally, user authentication via the host operating system is preferred for the following reasons:

User authentication by the database is normally used when the host operating system cannot support user authentication.

See Also: For more information about network authentication, see Oracle8i Distributed Database Systems.

For more information about user authentication, see "Creating Users".

Operating System Security

If applicable, the following security issues must also be considered for the operating system environment executing Oracle and any database applications:

See Also: For more information about operating system security issues for Oracle databases, see your operating system-specific Oracle documentation.

Data Security Policy

Data security includes the mechanisms that control the access to and use of the database at the object level. Fine-grained access control can also limit data access to a more granular level. Your data security policy determines which users have access to a specific schema object, and the specific types of actions allowed for each user on the object. For example, user SCOTT can issue SELECT and INSERT statements but not DELETE statements using the EMP table. Your data security policy should also define the actions, if any, that are audited for each schema object.

Your data security policy will be determined primarily by the level of security you wish to establish for the data in your database. For example, it may be acceptable to have little data security in a database when you wish to allow any user to create any schema object, or grant access privileges for their objects to any other user of the system. Alternatively, it might be necessary for data security to be very controlled when you wish to make a database or security administrator the only person with the privileges to create objects and grant access privileges for objects to roles and users.


User Security Policy

This section describes aspects of user security policy, and includes the following topics:

General User Security


Password Security


Secure Connections with Encrypted Passwords

To better protect the confidentiality of your password, Oracle can be configured to use encrypted passwords for client/server and server/server connections.

By setting the following values, you can require that the password used to verify a connection always be encrypted:

If enabled at both the client and server, passwords will not be sent across the network "in the clear", but will be encrypted using a modified DES (Data Encryption Standard) algorithm.

The DBLINK_ENCRYPT_LOGIN parameter is used for connections between two Oracle servers (for example, when performing distributed queries). If you are connecting from a client, Oracle checks the ORA_ENCRYPT_LOGIN environment variable.

Whenever you attempt to connect to a server using a password, Oracle encrypts the password before sending it to the server. If the connection fails and auditing is enabled, the failure is noted in the audit log. Oracle then checks the appropriate DBLINK_ENCRYPT_LOGIN or ORA_ENCRYPT_LOGIN value. If it set to FALSE, Oracle attempts the connection again using an unencrypted version of the password. If the connection is successful, the connection replaces the previous failure in the audit log, and the connection proceeds. To prevent malicious users from forcing Oracle to re-attempt a connection with an unencrypted version of the password, you must set the appropriate values to TRUE.

Privilege Management



End-User Security

Security administrators must also define a policy for end-user security. If a database is large with many users, the security administrator can decide what groups of users can be categorized, create user roles for these user groups, grant the necessary privileges or application roles to each user role, and assign the user roles to the users. To account for exceptions, the security administrator must also decide what privileges must be explicitly granted to individual users.

Using Roles for End-User Privilege Management


Consider a situation where every user in the accounting department of a company needs the privileges to run the ACCTS_RECEIVABLE and ACCTS_PAYABLE database applications. Roles are associated with both applications, and contain the object privileges necessary to execute those applications.


  1. Create a role named ACCOUNTANT.

  2. Grant the roles for the ACCTS_RECEIVABLE and ACCTS_PAYABLE database applications to the ACCOUNTANT role.

  3. Grant each user of the accounting department the ACCOUNTANT role.

This security model is illustrated in Figure 22-1.

Figure 22-1 User Role

This plan addresses the following potential situations:

When possible, utilize roles in all possible situations to make end-user privilege management efficient and simple.

Administrator Security


Protection for Connections as SYS and SYSTEM

After database creation, immediately change the passwords for the administrative SYS and SYSTEM usernames to prevent unauthorized access to the database. Connecting as SYS and SYSTEM gives a user the powerful privileges to modify a database in many ways. Therefore, privileges for these usernames are extremely sensitive, and should only be available to select database administrators.

See Also: The passwords for these accounts can be modified using the procedures described in "Altering Users".

Protection for Administrator Connections

Only database administrators should have the capability to connect to a database with administrator privileges. Connecting as SYSDBA gives a user unrestricted privileges to do anything to a database (such as startup, shutdown, and recover) or the objects within a database (such as create, drop, and delete from). Only users with SYS-privileged connections can alter data dictionary tables (for example, connect as SYSDBA/SYSOPER).

Using Roles for Administrator Privilege Management

Roles are the easiest way to restrict the powerful system privileges and roles required by personnel administrating of the database.



  1. Six roles should be defined to contain the distinct privileges required to accomplish each type of job (for example, DBA_OBJECTS, DBA_TUNE, DBA_SECURITY, DBA_MAINTAIN, DBA_RECOV, DBA_NEW).

  2. Each role is granted the appropriate privileges.

  3. Each type of database administrator can be granted the corresponding role.


Application Developer Security

Security administrators must define a special security policy for the application developers using a database. A security administrator may grant the privileges to create necessary objects to application developers. Alternatively, the privileges to create objects may only be granted to a database administrator, who receives requests for object creation from developers.

Application Developers and Their Privileges


The Application Developer's Environment: Test and Production Databases

In many cases, application development is restricted to test databases and not allowed on production databases. This restriction ensures that application developers do not compete with end users for database resources, and that they cannot detrimentally affect a production database.


Free Versus Controlled Application Development


Free Development  

An application developer is allowed to create new schema objects, including tables, indexes, procedures, packages, and so on. This option allows the application developer to develop an application independent of other objects.  

Controlled Development  

An application developer is not allowed to create new schema objects. All required tables, indexes, procedures, and so on are created by a database administrator, as requested by an application developer. This option allows the database administrator to completely control a database's space usage and the access paths to information in the database.  


Roles and Privileges for Application Developers


Space Restrictions Imposed on Application Developers


See Also: Both limitations can be set by altering a developer's security domain. For more information, see "Altering Users".

Application Administrator Security

In large database systems with many database applications (for example, precompiler and Forms applications), you might want to have application administrators. An application administrator is responsible for the following types of tasks:

Often, an application administrator is also the application developer who designed the application. However, these jobs might not be the responsibility of the developer and can be assigned to another individual familiar with the database application.

Password Management Policy

Database security systems depend on passwords being kept secret at all times. Still, passwords are vulnerable to theft, forgery, and misuse.To allow for greater control over database security, Oracle's password management policy is controlled by DBAs.

This section describes the following aspects of Oracle password management:

Account Locking

When a particular user exceeds a designated number of failed login attempts, the server automatically locks that user's account. DBAs specify the permissible number of failed login attempts using the CREATE PROFILE statement. DBAs also specify the amount of time accounts remain locked.

In the following example, the maximum number of failed login attempts for the user ASHWINI is 4, and the amount of time the account will remain locked is 30 days; the account will unlock automatically after the passage of 30 days.

ALTER USER ashwini PROFILE prof;

If the DBA does not specify a time interval for unlocking the account, ACCOUNT_LOCK _TIME reverts to a default value. If the DBA specifies ACCOUNT_LOCK_TIME as UNLIMITED, then the system security officer must explicitly unlock the account. Thus, the amount of time an account remains locked depends upon how the DBA configures the resource profile assigned to the user.


The security officer can also explicitly lock user accounts. When this occurs, the account cannot be unlocked automatically; only the security officer should unlock the account.

See Also: For more information about the CREATE PROFILE statement, see the Oracle8i SQL Reference.

Password Aging and Expiration

DBAs use the CREATE PROFILE statement to specify a maximum lifetime for passwords. When the specified amount of time passes and the password expires, the user or DBA must change the password. The following statement indicates that ASHWINI can use the same password for 90 days before it expires:

ALTER USER ashwini PROFILE prof;

DBAs can also specify a grace period using the CREATE PROFILE statement. Users enter the grace period upon the first attempt to login to a database account after their password has expired. During the grace period, a warning message appears each time users try to log in to their accounts, and continues to appear until the grace period expires. Users must change the password within the grace period. If the password is not changed within the grace period, the account expires and no further logins to that account are allowed until the password is changed. Figure 22-2 shows the chronology of the password lifetime and grace period.

Figure 22-2 Chronology of Password Lifetime and Grace Period.

For example, the lifetime of a password is 60 days, and the grace period is 3 days. If the user tries to log in on any day after the 60th day (this could be the 70th day, 100th day, or another; the point here is that it is the first login attempt after the password lifetime), that user receives a warning message indicating that the password is about to expire in 3 days. If the user does not change the password within three days from the first day of the grace period, the user's account expires. The following statement indicates that the user must change the password within 3 days of its expiration:

ALTER USER ashwini PROFILE prof;

The security officer can also explicitly expire the account. This is particularly useful for new accounts.

See Also: For more information about the CREATE PROFILE statement, see Oracle8i SQL Reference.

Password History

DBAs use the CREATE PROFILE statement to specify a time interval during which users cannot reuse a password.

In the following statement, the DBA indicates that the user cannot reuse her password for 60 days.


The next statement shows that the number of password changes the user must make before her current password can be used again is 3.



If you specify PASSWORD_REUSE_TIME or PASSWORD_REUSE_MAX, you must set the other to UNLIMITED or not specify it at all.  

Password Complexity Verification

Oracle's password complexity verification routine can be specified using a PL/SQL script (utlpwdmg.sql), which sets the default profile parameters.

The password complexity verification routine performs the following checks:

Password Verification Routine Formatting Guidelines

DBAs can enhance the existing password verification complexity routine or create their own password verification routines using PL/SQL or third-party tools.

The DBA-authored PL/SQL call must adhere to the following format:

routine_name (
userid_parameter IN VARCHAR(30),
password_parameter IN VARCHAR (30),
old_password_parameter IN VARCHAR (30)



The password verify routine must be owned by SYS.

Password Verification Routine: Sample Script

The following sample script sets default password resource limits and provides minimum checking of password complexity. You can use this sample script as a model when developing your own complexity checks for a new password.

This script sets the default password resource parameters, and must be run to enable the password features. However, you can change the default resource parameters if necessary.

The default password complexity function performs the following minimum complexity checks:

This function must be created in SYS schema, and you must connect sys/<password> as sysdba before running the script.

(username varchar2, 
   password varchar2, 
   old_password varchar2) 
   RETURN boolean IS  
   n boolean; 
   m integer; 
   differ integer; 
   isdigit boolean; 
   ischar  boolean; 
   ispunct boolean; 
   digitarray varchar2(20); 
   punctarray varchar2(25); 
   chararray varchar2(52); 
   digitarray:= '0123456789'; 
   chararray:= 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'; 
   --Check if the password is same as the username 
IF password = username THEN 
   --Check for the minimum length of the password 
IF length(password) < 4 THEN 
   --that are too simple for the password.
IF NLS_LOWER(password) IN ('welcome', 'database', 'account', 'user', 'password', 'oracle', 
'computer', 'abcd') THEN raise_application_error(-20002, 'Password too simple'); 
END IF; --Check if the password contains at least one letter, one digit and one
--punctuation mark. --1. Check for the digit --You may delete 1. and replace with 2. or 3. isdigit:=FALSE; m := length(password); FOR i IN 1..10 LOOP FOR j IN 1..m LOOP IF substr(password,j,1) = substr(digitarray,i,1) THEN isdigit:=TRUE; GOTO findchar; END IF; END LOOP; END LOOP; IF isdigit = FALSE THEN raise_application_error(-20003, 'Password should contain at least one digit, one character and one punctuation'); END IF; --2. Check for the character <<findchar>> ischar:=FALSE; FOR i IN 1..length(chararray) LOOP FOR j IN 1..m LOOP IF substr(password,j,1) = substr(chararray,i,1) THEN ischar:=TRUE; GOTO findpunct; END IF; END LOOP; END LOOP; IF ischar = FALSE THEN raise_application_error(-20003, 'Password should contain at least one digit, one character and one punctuation'); END IF; --3. Check for the punctuation <<findpunct>> ispunct:=FALSE; FOR i IN 1..length(punctarray) LOOP FOR j IN 1..m LOOP IF substr(password,j,1) = substr(punctarray,i,1) THEN ispunct:=TRUE; GOTO endsearch; END IF; END LOOP; END LOOP; IF ispunct = FALSE THEN raise_application_error(-20003, 'Password should contain at least one \ digit, one character and one punctuation'); END IF; <<endsearch>> --Check if the password differs from the previous password by at least 3 letters IF old_password = '' THEN raise_application_error(-20004, 'Old password is null'); END IF; --Everything is fine; return TRUE ; differ := length(old_password) - length(password); IF abs(differ) < 3 THEN IF length(password) < length(old_password) THEN m := length(password); ELSE m:= length(old_password); END IF; differ := abs(differ); FOR i IN 1..m LOOP IF substr(password,i,1) != substr(old_password,i,1) THEN differ := differ + 1; END IF; END LOOP; IF differ < 3 THEN raise_application_error(-20004, 'Password should differ by at least 3 characters'); END IF; END IF; --Everything is fine; return TRUE ; RETURN(TRUE); END;

Auditing Policy



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