Local operating system registries
With the registry implementation for the local operating system, the WebSphere® Application Server authentication mechanism can use the user accounts database of the local operating system.
Lightweight Directory Access Protocol (LDAP) is a centralized registry. Most local operating system registries are not centralized registries.
WebSphere Application Server provides implementations for the Windows local accounts registry and domain registry, as well as implementations for the Linux®, Solaris, and AIX® user accounts registries. Windows Active Directory is supported through the LDAP user registry implementation discussed later.
Do not use a local operating system registry in a WebSphere Application Server environment where application servers are dispersed across more than one machine because each machine has its own user registry.
The Windows domain registry and Network Information Services (NIS) are exceptions. Both the Windows domain registry and Network Information Services (NIS) are centralized registries. The Windows domain registry is supported by WebSphere Application Server; however, NIS is not supported.
As mentioned previously, the access IDs taken from the user registry are used during authorization checks. Because these IDs are typically unique identifiers, they vary from machine to machine, even if the exact users and passwords exist on each machine.
Web client certificate authentication is not currently supported when using the local operating system user registry. However, Java™ client certificate authentication does function with a local operating user registry. Java client certificate authentication maps the first attribute of the certificate domain name to the user ID in the user registry.
Even though Java client certificates function correctly, the following error displays in the SystemOut.log file:
Required privileges
The user that is running the WebSphere Application Server process requires enough operating system privilege to call the Windows systems application programming interface (API) for authenticating and obtaining user and group information from the Windows operating system. This user logs into the machine, or if running as a service, is the Log On As user. Depending on the machine and whether the machine is a stand-alone machine or a machine that is part of a domain or is the domain controller, the access requirements vary.
- For a stand-alone machine, the user:
- Is a member of the administrative group.
- Has the Act as part of the operating system privilege.
- Has the Log on as a service privilege, if the server is run as a service.
- For a machine that is a member of a domain, only a domain user can start the server process
and:
- Is a member of the domain administrative groups in the domain controller.
- Has the Act as part of the operating system privilege in the Local security policy on the local machine.
- Has the Log on as a service privilege on the local machine, if the server is run as a
service.
The user is a domain user and not a local user, which implies that when a machine is part of a domain, only a domain user can start the server.
- For a domain controller machine, the user:
- Is a member of the domain administrative groups in the domain controller.
- Has the Log on as a service privilege on the domain controller, if the server is run as a service.
- A required privilege is not held by the client.
- Access is denied.
Domain and local user registries
When WebSphere Application Server is started, the security run-time initialization process dynamically attempts to determine if the local machine is a member of a Windows domain. If the machine is part of a domain then by default both the local registry users or groups and the domain registry users or groups can be used for authentication and authorization purposes with the domain registry taking precedence. The list of users and groups that is presented during the security role mapping includes users and groups from both the local user registry and the domain user registry. The users and groups can be distinguished by the associated host names.
WebSphere Application Server does not support trusted domains.
If the machine is not a member of a Windows system domain, the user registry local to that machine is used.
Using both the domain user registry and the local operating system registry
- Best practices
- In general, if the local and the domain registries do not contain common users or groups, it is simpler to administer and it eliminates unfavorable side effects. If possible, give users and groups access to unique security roles, including the server ID and administrative roles. In this situation, select the users and groups from either the local user registry or the domain user registry to map to the roles.
- In cases where the same users or groups exist in both the local user registry and the domain user registry, it is recommended that at least the server ID and the users and groups that are mapped to the administrative roles be unique in the registries and exist only in the domain.
- If a common set of users exists, set a different password to make sure that the appropriate user is authenticated.
- How it works
- When a machine is part of a domain, the domain user registry takes precedence over the local user registry. For example, when a user logs into the system, the domain user registry tries to authenticate the user first. If authentication fails, the local user registry is used. When a user or a group is mapped to a role, the user and group information is first obtained from the domain user registry. In case of failure, the local user registry is tried.
- However, when a fully qualified user or a group name, one with
an attached domain or host name, is mapped to a role, only that user
registry is used to get the information. Use the administrative console
or scripts to get the fully qualified user and group names, which
is the recommended way to map users and groups to roles.Tip: A user, Bob, on one machine in the local OS user registry, for example, is not the same as the user Bob on another machine in the domain user registry, for example, because the unique ID of Bob, which is the security identifier [SID] in this case, is different in different user registries.
- ExamplesThe
MyMachine
machine is part of theMyDomain
domain. TheMyMachine
machine contains the following users and groups:- MyMachine\user2
- MyMachine\user3
- MyMachine\group2
MyDomain
domain contains the following users and groups:- MyDomain\user1
- MyDomain\user2
- MyDomain\group1
- MyDomain\group2
Here are some scenarios that assume the previous set of users and groups:- When user2 logs into the system, the domain user registry is used for authentication. If the authentication fails because the password is different, for example, the local user registry is used.
- If the MyMachine\user2 user is mapped to a role, only the user2 user in MyMachine machine has access. Thus, if the user2 password is the same on both the local and the domain user registries, the user2 user cannot access the resource because the user2 user is always authenticated using the domain user registry. If both user registries have common users, it is recommended that you have different passwords.
- If the group2 group is mapped to a role, only the users who are members of the MyDomain\group2 group can access the resource because group2 information is first obtained from the domain user registry.
- If the MyMachine\group2 group is mapped to a role, only the users who are members of the MyMachine\group2 group can access the resource. A specific group is mapped to the role (MyMachine\group2 instead of just group2).
- Use either the user3 user or the MyMachine\user3 user to map to a role because the user3 user is unique as it exists in one user registry only.
Authorizing with the domain user registry first can cause problems if a user exists in both the domain and local user registries with the same password. Role-based authorization can fail in this situation because the user is first authenticated within the domain user registry. This authentication produces a unique domain security ID that is used in WebSphere Application Server during the authorization check. However, the local user registry is used for role assignment. The domain security ID does not match the unique security ID that is associated with the role. To avoid this problem, map security roles to domain users instead of local users.
Using either the local or the domain user registry
If you want to access users and groups from either the local or the domain user registry, instead of both, set the com.ibm.websphere.registry.UseRegistry property. This property can be set to either local or domain. When this property is set to local (case insensitive) only the local user registry is used. When this property is set to domain, (case insensitive) only the domain user registry is used.
- Click
- Under User account repository, click the Available realm definitions drop-down list, select Local operating system, and click Configure.
- Under Additional properties, click Custom properties.
Using system user registries
- When using system user registries, the process ID that runs the WebSphere Application Server process needs the root authority to call the local operating system APIs for authentication and for obtaining user or group information.
- Only the local machine user registry is used. Network Information Service (NIS) (Yellow Pages) is not supported.
- If you are using the local operating system user registry, HP-UX must be configured in untrusted mode. Trusted mode is not supported if using the local operating system user registry.
For WebSphere Application Server local operating system registry to work on the Linux and Solaris platforms, a shadow password file must exist. The shadow password file is named shadow and is located in the /etc directory. If the shadow password file does not exist, an error occurs after enabling administrative security and configuring the registry as local operating system.
To create the shadow file, run the pwconv command (with no parameters). This command creates an /etc/shadow file from the /etc/passwd file. After creating the shadow file, you can enable local operating system security successfully.