Before implementing the security scheme, you must understand the existing security requirements and expectations in the environment. Because you are enabling application access to different databases on different systems, you must merge multiple security cultures. When developing your security scheme, the most stringent security requirements prevail. When you connect different systems into an operating whole, the system with the strictest security requirements generally dictates what the other systems can and cannot do.

Gateway security includes two main concerns:

• users and applications that are permitted access to a particular gateway instance and OLTP

• OLTP transactions that users and applications are able to execute

You can control access at several points in the gateway architecture. The primary options are discussed in the following sections. Control over remote transaction program (RTP) access is provided by each OLTP with native authorization mechanisms based on user ID. These facilities are described in the product documentation for your OLTP. Information in the following topics include how the gateway facilities determine the user ID that is in effect for a particular OLTP connection.

When the gateway is involved in an RPC request, security mechanisms are in effect for each system component encountered by the gateway. The first system component that is encountered is the application tool or 3GL program. The last system component that is encountered is the OLTP.

Each of the following sections identifies the component and the type of security processing that is available in that component. Each section offers a summary of key features and parameters. Refer to product-specific documentation for detailed information about the non-gateway components for Oracle and non-Oracle products.

An application must connect to an Oracle database before using that gateway. The type of logon authentication that you use determines the resulting Oracle user ID and can affect gateway operation.

Two basic types of authentication are available:

• Oracle authentication.

  With Oracle authentication, each Oracle user ID has an associated password that is known to Oracle. When an application connects to the server, it supplies a user ID and password. Oracle confirms that the user ID exists and that the password matches the one stored in the database.

• Operating system authentication

  With operating system authentication, the server's underlying operating system is responsible for authentication. An Oracle user ID that is created with the IDENTIFIED EXTERNALLY attribute (instead of a password) is accessed with operating system authentication. To log on to such a user ID, the application supplies a slash ( / ) for a user ID and does not supply a password.

  To perform operating system authentication, the server determines the requester's operating system user ID, optionally adds a fixed prefix to it, and uses the result as the Oracle user ID. The server confirms that the user ID exists and is identified externally, but no password checking is done. The underlying assumption is that users were authenticated when they logged on to the operating system.

  Operating system authentication is not available on all platforms and is not available in some Oracle Net (client-server) and multi-threaded server configurations. Refer to your Windows Oracle database documentation and Oracle Database Net Services Administrator's Guide to determine the availability of this feature in your configuration.

For more information about authenticating application logons, refer to the Oracle Database Administrator's Guide.

These topics discuss database links for users of the gateway employing either TCP/IP or SNA communications protocols.

• Link Accessibility

• Links and CONNECT Clauses

The information in this section applies only to the security needs of gateway users employing the SNA communications protocol. When an RPC request to start a remote transaction program is received by the gateway, the gateway attempts to start an APPC conversation with the OLTP. Before the conversation can begin, a session must start between Windows' Logical Unit (LU) and the OLTP LU.

APPC support for the Windows platform is provided by the SNA Server (Microsoft Host Integration Server or IBM Communication Server v6.1.1 or higher).

SNA and its various access method implementations, including VTAM and the SNA Server, provide security validation at session initiation time, allowing each LU to authenticate its partner. This validation is carried out entirely by network software before the gateway and OLTP application programs begin their conversation and process conversation-level security data. If session-level security is used, then correct password information must be established in Microsoft Windows' SNA profiles and in similar parameter structures in the OLTP to be accessed. Refer to the suitable communications software product documentation for detailed information about this subject.

The security information in this section applies only to users of the Oracle Database Gateway for APPC using the TCP/IP for IMS Connect feature. When an RPC request to start a RTP is received by the gateway, the gateway attempts to start the TCP/IP conversation with IMS Connect. IMS Connect would contact the OLTP (IMS) through OTMA and XCF. Refer to the IBM IMS Connect Guide and Reference for more information. The conversation between the gateway and IMS Connect occurs when the network uses the TCP/IP address or host name and port number to connect from the gateway to IMS Connect.

IMS Connect provides validation at session initiation time, allowing each connection to authenticate its partner. This validation is carried out entirely by network software before the gateway and OLTP application programs at IMS begin their conversation and process conversation-level security data. If session-level security is used, then correct password information must be established in Microsoft Windows and in similar parameter structures in the OLTP to be accessed.

Initialization parameters may contain sensitive information, such as user IDs or passwords. Initialization parameters are stored in plain text files and may be deemed insecure. An encryption feature has been added to Heterogenous Services making it possible to encrypt parameters values. This is done through the dg4pwd utility.