DBMS_DISTRIBUTED_TRUST_ADMIN
procedures maintain the Trusted Servers List. Use these procedures to define whether a server is trusted. If a database is not trusted, Oracle refuses current user database links from the database.
This chapter contains the following topics:
Using DBMS_DISTRIBUTED_TRUST_ADMIN
Overview
Security Model
Examples
Oracle uses local Trusted Servers Lists, along with enterprise domain membership lists stored in the enterprise LDAP directory service, to determine if another database is trusted. The LDAP directory service entries are managed with the Enterprise Security Manager Tool in Oracle Enterprise Manager.
Oracle considers another database to be "trusted" if it meets the following criteria:
It is in the same enterprise domain in the directory service as the local database.
The enterprise domain is marked as trusted in the directory service.
It is not listed as untrusted in the local Trusted Servers List. Current user database links will only be accepted from another database if both databases involved trust each other.
You can list a database server locally in the Trusted Servers List regardless of what is listed in the directory service. However, if you list a database that is not in the same domain as the local database, or if that domain is untrusted, the entry will have no effect.
This functionality is part of the Enterprise User Security feature of the Oracle Advanced Security Option.
To execute DBMS_DISTRIBUTED_TRUST_ADMIN
, the EXECUTE_CATALOG_ROLE
role must be granted to the DBA. To select from the view TRUSTED_SERVERS
, the SELECT_CATALOG_ROLE
role must be granted to the DBA.
It is important to know whether all servers are trusted or not trusted. Trusting a particular server with the ALLOW_SERVER
procedure does not have any effect if the database already trusts all databases, or if that database is already trusted. Similarly, denying a particular server with the DENY_SERVER
procedure does not have any effect if the database already does not trust any database or if that database is already untrusted.
The procedures DENY_ALL
and ALLOW_ALL
delete all entries (in other words, server names) that are explicitly allowed or denied using the ALLOW_SERVER
procedure or DENY_SERVER
procedure respectively.
If you have not yet used the package DBMS_DISTRIBUTED_TRUST_ADMIN
to change the trust listing, by default you trust all databases in the same enterprise domain if that domain it listed as trusted in the directory service:
SELECT * FROM TRUSTED_SERVERS; TRUST NAME --------- --------------------- Trusted All
Because all servers are currently trusted, you can execute the DENY_SERVER Procedure and specify that a particular server is not trusted:
EXECUTE DBMS_DISTRIBUTED_TRUST_ADMIN.DENY_SERVER ('SALES.US.AMERICAS.ACME_AUTO.COM'); PL/SQL procedure successfully completed. SELECT * FROM TRUSTED_SERVERS; TRUST NAME --------- ----------------------------------------------- Untrusted SALES.US.AMERICAS.ACME_AUTO.COM
By executing the DENY_ALL Procedure, you can choose to not trust any database server:
EXECUTE DBMS_DISTRIBUTED_TRUST_ADMIN.DENY_ALL; PL/SQL procedure successfully completed. SELECT * FROM TRUSTED_SERVERS; TRUST NAME --------- ----------------------------------------------- Untrusted All
The ALLOW_SERVER Procedure can be used to specify that one particular database is to be trusted:
EXECUTE DBMS_DISTRIBUTED_TRUST_ADMIN.ALLOW_SERVER ('SALES.US.AMERICAS.ACME_AUTO.COM'); PL/SQL procedure successfully completed. SELECT * FROM TRUSTED_SERVERS; TRUST NAME --------- ------------------------------------------------ Trusted SALES.US.AMERICAS.ACME_AUTO.COM
Table 36-1 DBMS_DISTRIBUTED_TRUST_ADMIN Package Subprograms
Subprogram | Description |
---|---|
Empties the list and inserts a row indicating that all servers should be trusted |
|
Enables a specific server to be allowed access even though |
|
Empties the list and inserts a row indicating that all servers should be untrusted |
|
Enables a specific server to be denied access even though allow all is indicated in the list |
This procedure empties the Trusted Servers List and specifies that all servers that are members of a trusted domain in an enterprise directory service and that are in the same domain are allowed access.
The view TRUSTED_SERVERS
will show "TRUSTED
ALL
" indicating that the database trusts all servers that are currently trusted by the enterprise directory service.
DBMS_DISTRIBUTED_TRUST_ADMIN.ALLOW_ALL;
ALLOW_ALL
only applies to servers listed as trusted in the enterprise directory service and in the same enterprise domain.
This procedure ensures that the specified server is considered trusted (even if you have previously specified "deny
all
").
DBMS_DISTRIBUTED_TRUST_ADMIN.ALLOW_SERVER ( server IN VARCHAR2);
Table 36-2 ALLOW_SERVER Procedure Parameters
Parameter | Description |
---|---|
|
Unique, fully-qualified name of the server to be trusted. |
If the Trusted Servers List contains the entry "deny
all
", then this procedure adds a specification indicating that a specific database (for example, DBx
) is to be trusted.
If the Trusted Servers List contains the entry "allow
all
", and if there is no "deny
DBx
" entry in the list, then executing this procedure causes no change.
If the Trusted Servers List contains the entry "allow
all
", and if there is a "deny
DBx
" entry in the list, then that entry is deleted.
This procedure empties the Trusted Servers List and specifies that all servers are denied access.
The view TRUSTED_SERVERS
will show "UNTRUSTED
ALL
" indicating that no servers are currently trusted.
DBMS_DISTRIBUTED_TRUST_ADMIN.DENY_ALL;
This procedure ensures that the specified server is considered untrusted (even if you have previously specified allow all
).
DBMS_DISTRIBUTED_TRUST_ADMIN.DENY_SERVER ( server IN VARCHAR2);
Table 36-3 DENY_SERVER Procedure Parameters
Parameter | Description |
---|---|
|
Unique, fully-qualified name of the server to be untrusted. |
If the Trusted Servers List contains the entry allow
all
, then this procedure adds an entry indicating that the specified database (for example, DBx
) is not to be trusted.
If the Trusted Servers List contains the entry "deny
all
", and if there is no "allow
DBx
" entry in the list, then this procedure causes no change.
If the Trusted Servers List contains the entry "deny
all
", and if there is an "allow
DBx
" entry, then this procedure causes that entry to be deleted.