Local operating system user registries

With the local operating system, or Local OS, user registry implementation, the WAS authentication mechanism can use the user accounts database of the local operating system.

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 Lightweight Directory Access Protocol (LDAP) user registry implementation discussed later.

Note: For an Active Directory (domain controller), the three group scopes are Domain Local Group, Global Group, and Universal Group. For an Active Directory (Domain Controller), the two group types are Security and Distribution.

When a group is created, the default value is Global (and the default type is Security). With Windows NT domain registry support for Windows 2000 and 20003 domain controllers, WAS only supports Global groups that are the Security type. It is recommended that you use the Active Directory registry support (rather than an NT domain registry) if you use Windows 2000 and 2003 domain controllers because the Active Directory supports all group scopes and types. The Active Directory also supports a nested group that is not support by NT domain registry. The Active Directory is a centralized control registry.

WebSphere Application Server does not have to install the member of the domain because it can be installed on any machine on any platform. Note that the NT domain native call only returns the support group (with no error).

A Local OS user registry is not a centralized user registry like LDAP

Do not use a Local OS user registry in a WAS environment, where application servers are dispersed across more than one machine because each machine has its own user registry. Exceptions include a Windows domain registry, which is a centralized registry and Network Information Services (NIS), which is not supported by WebSphere Application Server.

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:

CWSCJ0337E: The mapCertificate method is not supported The error is intended for Web client certificates; however, it also displays for Java client certificates. Ignore this error for Java client certificates.

 

Using

Windows operating system registries

When enabling security on Windows operating systems, if the local operating system (LocalOS) is selected as the registry, consider the following points:

 

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 Domain security policy on 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 Act as part of the operating system privilege in the Domain security policy on the domain controller.

  • Has the Log on as a service privilege on the domain controller, if the server is run as a service.

To give a user the Act as part of the operating system or Log on as a service on Windows 2000 systems:

1. Click Start > Settings > Control Panel > Administrative Tools > Local Security Policy > Local Policies > User Rights Assignments > Act as part of the operating system (or Log on as a service) .

   Note: If the machine is a stand-alone machine and not a member of a domain, add a machineName\userID, where the userID is the owner of the process, such as WebSphere Application Server. If you run WebSphere Application Server as a service, one can log on with localsystem as the service.

   If the machine is a member of a domain, add domainName\userID, where the userID is the owner of process (such as WebSphere Application Server). Start WAS as a service with login ID domainName\userID. If WAS is already in service, go to the service and right-click IBM WAS > properties >Logon to change the logon ID and password to restart WebSphere Application Server.

2. Add the user name by clicking Add.

3. Restart the machine.

   Windows 2000 domain controller users: For a Windows 2000 domain controller, replace Local Security Policy with Domain Security Policy in the previous step.

   Note: In all of the previous configurations, the server can be run as a service using LocalSystem for the Log On As entry. The LocalSystem entry has the required privileges and there is no need to give special privileges to any user. However, because the LocalSystem entry has special privileges, make sure that it is appropriate to use in your environment.

If the user running the server does not have the required privilege, you might see one of the following exception messages in the log files:

• A required privilege is not held by the client.

• Access is denied.

 

Domain

and local registries

When WAS 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 registry and the local registry

When the machine that hosts the WAS process is a member of a domain, both the local and the domain registries are used by default. The following section describes more on this topic and recommends some best practices to avoid unfavorable consequences.

• 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 registry or the domain registry to map to the roles.

  In cases where the same users or groups exist in both the local registry and the domain 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 registry tries to authenticate the user first. If the authentication fails the local 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 registry. In case of failure, the local 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, then only that 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.

  Note: A user Bob on one machine (the local registry, for example) is not the same as the user Bob on another machine (say the domain registry) because the uniqueID of Bob (the security identifier [SID], in this case) is different in different registries.

• Examples

  The machine MyMachine is part of the domain MyDomain. MyMachine contains the following users and groups:

  • MyMachine\user2

  • MyMachine\user3

  • MyMachine\group2

  MyDomain 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.

  1. When user2 logs into the system, the domain registry is used for authentication. If the authentication fails (the password is different) the local registry is used.

  2. If the user MyMachine\user2 is mapped to a role, only the user2 in MyMachine has access. So if the user2 password is the same on both the local and the domain registries, user2 cannot access the resource, because user2 is always authenticated using the domain registry. Hence, if both registries have common users, it is recommended that the password be different.

  3. If the group2 is mapped to a role, only the users who are members of the MyDomain\group2 can access the resource because group2 information is first obtained from the domain registry.

  4. If the group MyMachine\group2 is mapped to a role, only the users who are members of the MyMachine\group2 can access the resource. A specific group is mapped to the role (MyMachine\group2 instead of just group2).

  5. Use either user3 or MyMachine\user3 to map to a role, because user3 is unique; it exists in one 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.

  Note: In a Network Deployment environment, only a centralized repository can be used if more than one node is involved. This usage implies that only the domain registry can be used because the user and group uniqueIDs (SIDs) differ on various nodes, as previously mentioned.

Using either the local or the domain registry. If you want to access users and groups from either the local registry or the domain registry, instead of both, set the com.ibm.websphere.registry.UseRegistry property. This property can be set to either localor domain. When this property is set to local(case insensitive) only the local registry is used. When this property is set to domain, (case insensitive) only the domain registry is used. Set this property by clicking Custom Properties in the Security > User Registries > Local OS panel in the administrative console or by using scripts. When the property is set, the privilege requirement for the user who is running the product process does not change. For example, if this property is set to local, the user that is running the process requires the same privilege, as if the property was not set.

 

Using

UNIX system registries

When using UNIX system registries, the process ID that runs the WAS process needs the root authority to call the local operating system APIs for authentication and for obtaining user or group information.

Note: In UNIX systems, only the local machine registry is used. Network Information Service (NIS) (Yellow Pages) is not supported.

 

Using

Linux and Solaris system registries

For WebSphere Application Server Local OS security 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 global security and configuring the user registry as Local OS.

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, one can enable local operating system security successfully.

 

Remote registries

By default, the registry is local to all of the product processes. The performance is higher, (no need for remote calls) and the registry also increases availability. Any process failing does not effect other processes.

When using LocalOS as the registry, every product process must run with privilege access (root in UNIX, Act as part of operating system in Windows systems).

If this process is not practical in some situations, use a remote registry from the node (or in very rare situations from the cell). Using a remote registry affects performance and creates a single point of failure. Use remote registries only in rare situations.

The node and the cell processes are meant for manipulating configuration information and for hosting the registry for all the application servers that create traffic and cause problems.

Use remote registries only when a very limited number of application servers exist in a Network Deployment environment.

a node agent (instead of the cell) to host the remote registry is preferable because the cell process is not designed to be highly available. Also, using a node to host the remote registry indicates that only the application servers in that node are using it. Because the node agent does not contain any application code, giving it the access required privilege is not a concern.

You can set up a remote registry by setting the WAS_UseRemoteRegistry property in the Global Security panel using the Custom Properties link at the bottom of the administrative console panel. Use either theCell or the Node(case insensitive) value. If the value is Cell, the cell registry is used by all of the product processes including the node agent and all of the application servers. If the cell process is down for any reason, restart all of the processes after the cell is restarted. If the node agent registry is used for the remote registry, set the WAS_UseRemoteRegistry value to node. In this case, all the application server processes use the node agent registry. In this case, if the node agent fails and does not start automatically, you might need to restart all the application servers after the node agent is started.

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See Also

Custom user registries

 

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