Security is a large arena that includes network security for the connection, access, and execution control of operating system resources or of Java virtual machine (JVM)-defined and user-defined classes. Security also includes bytecode verification of Java Archive (JAR) files imported from an external source. The following sections describe the various security support available for Java applications within Oracle Database:
The two major aspects to network security are authentication and data confidentiality. The type of authentication and data confidentiality is dependent on how you connect to the database, either through Oracle Net or Java Database Connectivity (JDBC) connection. The following table provides the security description for Oracle Net and JDBC connections:
Once you are connected to the database, you must have the appropriate Java2 security permissions and database privileges to access the resources stored within the database. These resources include:
Database resources, such as tables and PL/SQL packages
Operating system resources, such as files and sockets
Oracle JVM classes
User-loaded classes
These resources can be protected by the following methods:
This section covers the following topics:
See Also:
Each user or schema must be assigned the proper permissions to access operating system resources, such as sockets, files, and system properties.
Java2 security provides a flexible and configurable security for Java applications. With Java2 security, you can define exactly what permissions on each loaded object that a schema or role will have. In Oracle8i Database release 8.1.5, the following secure roles are available:
Few permissions, including examining properties
Major permissions, including updating the Oracle JVM-protected packages
Note:
Both roles still exist within this release for backward compatibility. However, Oracle recommends that you specify each permission explicitly, rather than utilize these roles.Because Oracle JVM security is based on Java2 security, you assign permissions on a class-by-class basis. These permissions are assigned through database management tools. Each permission is encapsulated in a Permission
object and is stored within a Permission
table. Permission
contains the target
and action
attributes, which take String
values.
Java2 security was created for the non-database world. When you apply the Java2 security model within the database, certain differences manifest themselves. For example, Java2 security defines that all applets are implicitly untrusted and all classes within the CLASSPATH
are trusted. In Oracle Database, all classes are loaded within a secure database. As a result, no classes are trusted.
The following table describes the differences between the Sun Microsystems Java2 security and the Oracle Database security implementation:
As with Java2 security, Oracle Database supports the security classes. Normally, you set the permissions for the code base either using a tool or by editing the security policy file. In Oracle Database, you set the permissions dynamically using DBMS_JAVA
procedures, which modify a policy table in the database.
Two views have been created for you to view the policy table, USER_JAVA_POLICY
and DBA_JAVA_POLICY
. Both views contain information about granted and limitation permissions. The DBA_JAVA_POLICY
view can see all rows within the policy table. The USER_JAVA_POLICY
view can see only permissions relevant to the current user. The following is a description of the rows within each view:
Table Column | Description |
---|---|
Kind | GRANT or RESTRICT . Shows whether this permission is a positive or a limitation permission. |
Grantee | The name of the user, schema, or role to which the Permission object is assigned. |
Permission_schema | The schema in which the Permission object is loaded. |
Permission_type | The Permission class type, which is designated by a string containing the full class name, such as, java.io.FilePermission . |
Permission_name | The target attribute of the Permission object. You use this when defining the permission. When defining the target for a Permission object of type PolicyTablePermission , the name can become quite complicated.
See Also: "Acquiring Administrative Permission to Update Policy Table" |
Permission_action | The action attribute of the Permission object. Many permissions expect a null value if no action is appropriate for the permission. |
Status | ACTIVE or INACTIVE . After creating a row for a Permission object, you can disable or re-enable it. This column shows whether the permission is enabled or disabled. |
Key | Sequence number you use to identify this row. This number should be supplied when disabling, enabling, or deleting a permission. |
There are two ways to set permissions:
Note:
For absolute certainty about the security settings, implement the fine-grain definition. The general definition is easy to implement, but you may not get the exact security settings you require.Using fine-grain definition, you can grant each permission individually to specific users or roles. If you do not grant a permission for access, then the schema will be denied access. To set individual permissions within the policy table, you must provide the following information:
You can grant permissions using either SQL or Java. Each version returns a row key identifier that identifies the row within the permission table. In the Java version of DBMS_JAVA
, each method returns the row key identifier, either as a returned parameter or as an OUT
variable in the parameter list. In the PL/SQL DBMS_JAVA
package, the row key is returned only in the procedure that defines the key OUT
parameter. This key is used to enable and disable specific permissions.
After running the grant, if a row already exists for the exact permission, then no update occurs, but the key for that row is returned. If the row was disabled, then running the grant enables the existing row.
Note:
If you are grantingFilePermission
, then you must provide the physical name of the directory or file, such as /private/oracle
. You cannot provide either an environment variable, such as $ORACLE_HOME
, or a symbolic link. To denote all files within a directory, provide the *
symbol, as follows:
/private/oracle/*
To denote all directories and files within a directory, provide the -
symbol, as follows:
/private/oracle/-
You can grant permissions using the DBMS_JAVA
package, as follows:
procedure grant_permission ( grantee varchar2, permission_type varchar2, permission_name varchar2, permission_action varchar2 ) procedure grant_permission ( grantee varchar2, permission_type varchar2, permission_name varchar2, permission_action varchar2, key OUT number)
You can grant permissions using Java, as follows:
long oracle.aurora.rdbms.security.PolicyTableManager.grant ( java.lang.String grantee, java.lang.String permission_type, java.lang.String permission_name, java.lang.String permission_action); void oracle.aurora.rdbms.security.PolicyTableManager.grant ( java.lang.String grantee, java.lang.String permission_type, java.lang.String permission_name, java.lang.String permission_action, long[] key);
You can limit permissions using the DBMS_JAVA
package, as follows:
procedure restrict_permission ( grantee varchar2, permission_type varchar2, permission_name varchar2, permission_action varchar2) procedure restrict_permission ( grantee varchar2, permission_type varchar2, permission_name varchar2, permission_action varchar2, key OUT number)
You can limit permissions using Java, as follows:
long oracle.aurora.rdbms.security.PolicyTableManager.restrict ( java.lang.String grantee, java.lang.String permission_type, java.lang.String permission_name, java.lang.String permission_action); void oracle.aurora.rdbms.security.PolicyTableManager.restrict ( java.lang.String grantee, java.lang.String permission_type, java.lang.String permission_name, java.lang.String permission_action, long[] key);
Example 10-1 shows how to use the grant_permission()
method to grant permissions. Example 10-2 shows how to limit permissions using the restrict()
method.
Example 10-1 Granting Permissions
Assuming that you have appropriate permissions to modify the policy table, you can use the grant_permission()
method, which is in the DBMS_JAVA
package, to modify PolicyTable
to allow user access to the indicated file. In this example, the user, Larry
, has modification permission on PolicyTable
. Within a SQL package, Larry
can grant permission to Dave
to read and write a file, as follows:
connect larry/larry REM Grant DAVE permission to read and write the Test1 file. call dbms_java.grant_permission('DAVE', 'java.io.FilePermission', '/test/Test1', 'read,write'); REM commit the changes to PolicyTable commit;
Example 10-2 Limiting Permissions
You can use the restrict()
method to specify a limitation or exception to general rules. A general rule is a rule where, in most cases, the permission is true or granted. However, there may be exceptions to this rule. For these exceptions, you specify a limitation permission.
If you have defined a general rule that no one can read or write an entire directory, then you can define a limitation on an aspect of this rule through the restrict()
method. For example, if you want to allow access to all files within the /tmp
directory, except for your password file that exists in that directory, then you would grant permission for read and write to all files within /tmp
and limit read and write access to the password file.
If you want to specify an exception to the limitation, then you need to create an explicit grant permission to override the limitation permission. In the previously mentioned scenario, if you want the file owner to still be able to modify the password file, then you can grant a more explicit permission to allow access to one user, which will override the limitation. Oracle JVM security combines all rules to understand who really has access to the password file. This is demonstrated in the following diagram:
The explicit rule is as follows:
If the limitation permission implies the request, then for a grant permission to be effective, the limitation permission must also imply the grant.
The following code implements this example:
connect larry/larry REM Grant permission to all users (PUBLIC) to be able to read and write REM all files in /tmp. call dbms_java.grant_permission('PUBLIC', 'java.io.FilePermission', '/tmp/*', 'read,write'); REM Limit permission to all users (PUBLIC) from reading or writing the REM password file in /tmp. call dbms_java.restrict_permission('PUBLIC', 'java.io.FilePermission', '/tmp/password', 'read,write'); REM By providing a more specific rule that overrides the limitation, REM Larry can read and write /tmp/password. call dbms_java.grant_permission('LARRY', 'java.io.FilePermission', '/tmp/password', 'read,write'); commit;
The preceding code performs the following actions:
Grants everyone read and write permission to all files in /tmp
.
Limits everyone from reading or writing only the password
file in /tmp
.
Grants only Larry
explicit permission to read and write the password
file.
Acquiring Administrative Permission to Update Policy Table
All permissions are rows in PolicyTable
. Because it is a table in the database, you need appropriate permissions to modify it. Specifically, the PolicyTablePermission
object is required to modify the table. After initializing Oracle JVM, only a single role, JAVA_ADMIN
, is granted PolicyTablePermission
to modify PolicyTable
. The JAVA_ADMIN
role is immediately assigned to the database administrator (DBA). Therefore, if you are assigned to the DBA group, then you will automatically take on all JAVA_ADMIN
permissions.
If you need to add permissions as rows to this table, JAVA_ADMIN
must grant your schema update rights using PolicyTablePermission
. This permission defines that your schema can add rows to the table. Each PolicyTablePermission
is for a specific type of permission. For example, to add a permission that controls access to a file, you must have PolicyTablePermission
that lets you grant or limit a permission on FilePermission
. Once this occurs, you have administrative permission for FilePermission
.
An administrator can grant and limit PolicyTablePermission
in the same manner as other permissions, but the syntax is complicated. For ease of use, you can use the grant_policy_permission()
or grantPolicyPermission()
method to grant administrative permissions.
You can grant policy table administrative permission using DBMS_JAVA
, as follows:
procedure grant_policy_permission ( grantee varchar2, permission_schema varchar2, permission_type varchar2, permission_name varchar2 ) procedure grant_policy_permission ( grantee varchar2, permission_schema varchar2, permission_type varchar2, permission_name varchar2, key OUT number )
You can grant policy table administrative permission using Java, as follows:
long oracle.aurora.rdbms.security.PolicyTableManager.grantPolicyPermission ( java.lang.String grantee, java.lang.String permission_type, java.lang.String permission_name); void oracle.aurora.rdbms.security.PolicyTableManager.grantPolicyPermission ( java.lang.String grantee, java.lang.String permission_type, java.lang.String permission_name, long[] key);
Note:
When looking at the policy table, the name in thePolicyTablePermission
rows contains both the permission type and the permission name, which are separated by a #
. For example, to grant a user administrative rights for reading a file, the name in the row contains java.io.FilePermission#read
. The #
separates the Permission
class from the permission name.Example 10-3 shows how you can modify PolicyTable
.
Example 10-3 Granting PolicyTable Permission
This example shows SYS
, which has the JAVA_ADMIN
role assigned, giving Larry
permission to update PolicyTable
for FilePermission
. Once this permission is granted, Larry
can grant permissions to other users for reading, writing, and deleting files.
REM Connect as SYS, which is assigned JAVA_ADMIN role, to give Larry permission REM to modify the PolicyTable connect SYS/SYS as SYSDBA REM SYS grants Larry the right to administer permissions for REM FilePermission call dbms_java.grant_policy_permission('LARRY', 'SYS', 'java.io.FilePermission', '*');
You can create your own permission type by performing the following steps:
Create and load the user permission
Create your own permission by extending the java.security.Permission
class. Any user-defined permission must extend Permission
. The following example creates MyPermission
, which extends BasicPermission
, which, in turn, extends Permission
.
package test.larry; import java.security.Permission; import java.security.BasicPermission; public class MyPermission extends BasicPermission { public MyPermission(String name) { super(name); } public boolean implies(Permission p) { boolean result = super.implies(p); return result; } }
Grant administrative and action permissions to specified users
When you create a permission, you are designated as the owner of that permission. The owner is implicitly granted administrative permission. This means that the owner can be an administrator for this permission and can run grant_policy_permission()
. Administrative permission enable the user to update the policy table for the user-defined permission.
For example, if LARRY
creates a permission, MyPermission
, then only he can call grant_policy_permission()
for himself or another user. This method updates PolicyTable
on who can grant rights to MyPermission
. The following code demonstrates this:
REM Since Larry is the user that owns MyPermission, Larry connects to REW the database to assign permissions for MyPermission. connect larry/larry REM As the owner of MyPermission, Larry grants himself the right to REM administer permissions for test.larry.MyPermission within the JVM REM security PolicyTable. Only the owner of the user-defined permission REM can grant administrative rights. call dbms_java.grant_policy_permission ('LARRY', 'LARRY', 'test.larry.MyPermission', '*'); REM commit the changes to PolicyTable commit;
Once you have granted administrative rights, you can grant action permissions for the created permission. For example, the following SQL statements grant LARRY
the permission to run anything within MyPermission
and DAVE
the permission to run only actions that start with "act.
".
REM Since Larry is the user that creates MyPermission, Larry connects to REW the database to assign permissions for MyPermission. connect larry/larry REM Once able to modify PolicyTable for MyPermission, Larry grants himself REM full permission for MyPermission. Notice that the Permission is prepended REM with its owner schema. call dbms_java.grant_permission( 'LARRY', 'LARRY:test.larry.MyPermission', '*', null); REM Larry grants Dave permission to do any actions that start with 'act.*'. call dbms_java.grant_permission ('DAVE', 'LARRY:test.larry.MyPermission', 'act.*', null); REM commit the changes to PolicyTable commit;
Implement security checks using the permission
Once you have created, loaded, and assigned permissions for MyPermission
, you must implement the call to SecurityManager
to have the permission checked. There are four methods in the following example: sensitive()
, act()
, print()
, and hello()
. Because of the permissions granted using SQL in the preceding steps, the following users can run methods within the example class:
LARRY
can run any of the methods.
DAVE
is given permission to run only the act()
method.
Anyone can run the print()
and hello()
methods. The print()
method does not check any permissions. As a result, anyone can run it. The hello()
method runs AccessController.doPrivileged()
, which means that the method runs with the permissions assigned to LARRY
. This is referred to as the definer's rights.
package test.larry; import java.security.AccessController; import java.security.Permission; import java.security.PrivilegedAction; import java.sql.Connection; import java.sql.SQLException; /** * MyActions is a class with a variety of public methods that * have some security risks associated with them. We will rely * on the Java security mechanisms to ensure that they are * performed only by code that is authorized to do so. */ public class Larry { private static String secret = "Larry's secret"; MyPermission sensitivePermission = new MyPermission("sensitive"); /** * This is a security sensitive operation. That is it can * compromise our security if it is executed by a "bad guy". * Only larry has permission to execute sensitive. */ public void sensitive() { checkPermission(sensitivePermission); print(); } /** * Will print a message from Larry. We need to be * careful about who is allowed to do this * because messages from Larry may have extra impact. * Both larry and dave have permission to execute act. */ public void act(String message) { MyPermission p = new MyPermission("act." + message); checkPermission(p); System.out.println("Larry says: " + message); } /** * Print our secret key * No permission check is made; anyone can execute print. */ private void print() { System.out.println(secret); } /** * Print "Hello" * This method invokes doPrivileged, which makes the method run * under definer's rights. So, this method runs under Larry's * rights, so anyone can execute hello. Only Larry can execute hello */ public void hello() { AccessController.doPrivileged(new PrivilegedAction() { public Object run() { act("hello"); return null; } }); } /** * If a security manager is installed ask it to check permission * otherwise use the AccessController directly */ void checkPermission(Permission permission) { SecurityManager sm = System.getSecurityManager(); sm.checkPermission(permission); } }
Enabling or Disabling Permissions
Once you have created a row that defines a permission, you can disable it so that it no longer applies. However, if you decide that you want the row action again, then you can enable the row. You can delete the row from the table if you believe that it will never be used again. To delete, you must first disable the row. If you do not disable the row, then the deletion will not occur.
To disable rows, you can use either of the following methods:
revoke_permission()
This method accepts parameters similar to the grant()
and restrict()
methods. It searches the entire policy table for all rows that match the parameters provided.
disable_permission()
This method disables only a single row within the policy table. To do this, it accepts the policy table key as parameter. This key is also necessary to enable or delete a permission. To retrieve the permission key number, perform one of the following:
Save the key when it is returned on the grant or limit calls. If you do not foresee a need to ever enable or disable the permission, then you can use the grant and limit calls that do not return the permission number.
Look up DBA_JAVA_POLICY
or USER_JAVA_POLICY
for the appropriate permission key number.
You can disable permissions using DBMS_JAVA
, as follows:
procedure revoke_permission (permission_schema varchar2, permission_type varchar2, permission_name varchar2, permission_action varchar2) procedure disable_permission (key number)
You can disable permissions using Java, as follows:
void revoke (String schema, String type, String name, String action); void oracle.aurora.rdbms.security.PolicyTableManager.disable (long number);
You can enable permissions using DBMS_JAVA
, as follows:
procedure enable_permission (key number)
You can enable permissions using Java, as follows:
void oracle.aurora.rdbms.security.PolicyTableManager.enable (long number);
You can delete permissions using DBMS_JAVA
, as follows:
procedure delete_permission (key number)
You can delete permissions using Java, as follows:
void oracle.aurora.rdbms.security.PolicyTableManager.delete (long number);
Table 10-1 lists the installed permission types. Whenever you want to grant or limit a permission, you must provide the permission type. The permission types with which you control access are the following:
Java2 permission types
Oracle-specific permission types
User-defined permission types that extend java.security.Permission
Note:
SYS
is granted permission to load libraries that come with Oracle Database. However, Oracle JVM does not support other users loading libraries, because loading C libraries within the database is insecure. As a result, you are not allowed to grant RuntimePermission
for loadLibrary.*
.The Oracle-specific permissions are:
oracle.aurora.rdbms.security.PolicyTablePermission
This permission controls who can update the policy table. Once granted the right to update the policy table for a certain permission type, you can control the access to few resources.
After the initialization of Oracle JVM, only the JAVA_ADMIN
role can grant administrative rights for the policy table through PolicyTablePermission
. Once it grants this right to other users, these users can, in turn, update the policy table with their own grant and limitation permissions.
To grant policy table updates, you can use the grant_policy_permission()
method, which is in the DBMS_JAVA
package. Once you have updated the table, you can view either the DBA_JAVA_POLICY
or USER_JAVA_POLICY
view to see who has been granted permissions.
oracle.aurora.security.JServerPermission
This permission is used to grant and limit access to Oracle JVM resources. The JServerPermission
extends BasicPermission
. The following table lists the permission names for which JServerPermission
grants access:
Permission Name | Description |
---|---|
LoadClassInPackage. package_name |
Grants the ability to load a class within the specified package |
Verifier |
Grants the ability to turn the bytecode verifier on or off |
Debug |
Grants the ability for debuggers to connect to a session |
JRIExtensions |
Grants the use of MEMSTAT |
Memory.Call |
Grants rights to call certain methods in oracle.aurora.vm.OracleRuntime on call settings |
Memory.Stack |
Grants rights to call certain methods in oracle.aurora.vm.OracleRuntime on stack settings |
Memory.SGAIntern |
Grants rights to call certain methods in oracle.aurora.vm.OracleRuntime on SGA settings |
Memory.GC |
Grants rights to call certain methods in oracle.aurora.vm.OracleRuntime on garbage collector settings |
When you first initialize Oracle JVM, several roles are populated with certain permission grants. The following tables show these roles and their initial Permissions:
The JAVA_ADMIN
role is given access to modify the policy table for all permissions. All DBAs, including SYS
, are granted JAVA_ADMIN
. Full administrative rights to update the policy table are granted for the permissions listed in Table 10-1. In addition to the JAVA_ADMIN
permissions, SYS
is granted the permissions listed in Table 10-2. All users are initially granted the permissions defined in Table 10-3.
Table 10-2 SYS Initial Permissions
Permission Type | Permission Name | Action |
---|---|---|
|
Administrative rights to modify the policy table |
|
|
null |
|
|
null |
|
|
null |
|
|
write |
|
|
null |
|
|
null |
|
|
null |
|
|
null |
|
|
null |
Table 10-3 PUBLIC Default Permissions
Permission Type | Permission Name | Action |
---|---|---|
|
|
null |
|
|
read |
|
write |
|
|
|
null |
|
null |
|
|
null |
|
|
null |
|
|
null |
|
|
|
null |
Table 10-4 JAVAUSERPRIV Permissions
Permission Type | Permission Name | Action |
---|---|---|
|
connect, resolve |
|
|
read |
|
|
|
null |
Table 10-5 JAVASYSPRIV Permissions
Permission Type | Permission Name | Action |
---|---|---|
|
no applicable action |
|
|
read, write, execute, delete |
|
|
accept, connect, listen, resolve |
|
|
null |
|
|
null |
|
|
null |
|
|
null |
|
|
null |
|
|
null |
|
|
null |
|
|
null |
In Oracle8i Database release 8.1.5, the Oracle JVM security was controlled by granting the JAVASYSPRIV
, JAVAUSERPRIV
, or JAVADEBUGPRIV
role to schemas. In Oracle Database 10g, these roles still exist as permission groups. You can set up and define your own collection of permissions. Once defined, you can grant any collection of permissions to any user or role. That user will then have the same permissions that exist within the role. In addition, if you need additional permissions, then you can add individual permissions to either your specified user or role. Permissions defined within the policy table have a cumulative effect.
Note:
The ability to write to properties, granted through the write action onPropertyPermission
, is no longer granted to all users. Instead, you must have either JAVA_ADMIN
grant this permission to you or you can receive it by being granted the JAVASYSPRIV
role.The following example gives Larry and Dave the following permissions:
Larry receives JAVASYSPRIV
permissions.
Dave receives JAVADEBUGPRIV
permissions and the ability to read and write all files on the system.
REM Granting Larry the same permissions as those existing within JAVASYSPRIV grant javasyspriv to larry; REM Granting Dave the ability to debug grant javadebugpriv to dave; commit; REM I also want Dave to be able to read and write all files on the system call dbms_java.grant_permission('DAVE', 'SYS:java.io.FilePermission', '<<ALL FILES>>', 'read,write', null);
See Also:
"Fine-Grain Definition for Each Permission".A debug role, JAVADEBUGPRIV
, was created to grant permissions for running the debugger. The permissions assigned to this role are listed in Table 10-6. To receive permission to call the debug agent, the caller must have been granted JAVADEBUGPRIV
or the debug JServerPermission
as follows:
REM Granting Dave the ability to debug grant javadebugpriv to dave; REM Larry grants himself permission to start the debug agent. call dbms_java.grant_permission( 'LARRY', 'oracle.aurora.security.JServerPermission', 'Debug', null);
Although a debugger provides extensive access to both code and data on the server, its use should be limited to development environments.
See Also:
"Debugging Server Applications"To load classes, you must have the following permission:
JServerPermission("LoadClassInPackage." + class_name)
where, class_name
is the fully qualified name of the class that you are loading.
This excludes loading into system packages or replacing any system classes. Even if you are granted permission to load a system class, Oracle Database prevents you from performing the load. System classes are classes that are installed by Oracle Database using the CREATE JAVA SYSTEM
statement. The following error is thrown if you try to replace a system class:
ORA-01031 "Insufficient privileges"
The following describes what each user can do after database installation:
SYS
can load any class except for system classes.
Any user can load classes in its own schema that do not start with the following patterns: java.*
, oracle.aurora.*
, and oracle.jdbc.*
. If the user wants to load such classes into another schema, then it must be granted the JServerPermission(LoadClassInPackage.
class
)
permission.
The following example shows how to grant SCOTT
permission to load classes into the oracle.aurora.*
package:
dbms_java.grant_permission('SCOTT', 'SYS:oracle.aurora.tools.*', null)