AMS interception on server-to-server message channels

Server-to-server message channel interception provides a means to control if messages should have any applicable Advanced Message Security (AMS) policies applied to them, when sender type message channel agents get messages from transmission queues, and receiver type message channel agents put messages to target queues.

This allows AMS protection to be enabled on a queue manager when communicating, using server-to-server message channels of type sender, server, receiver, and requester, with a queue manager that does not have AMS enabled.

That is, AMS protected messages in AMS enabled queue managers can be unprotected prior to being sent to non-AMS enabled queue managers, and unprotected messages received from non-AMS enabled queue managers can be protected, by applicable AMS policies, on AMS enabled queue managers.

Configure server-to-server message channel interception

PASSTHRU

Pass through, unchanged, any messages sent or received by the message channel agent for this channel.

This value is valid for channels with a channel type (CHLTYPE) of SDR, SVR, RCVR, or RQSTR, and is the default value.

REMOVE

Remove any AMS protection from messages retrieved from the transmission queue by the message channel agent, and send the messages to the partner.

When the message channel agent gets a message from the transmission queue, if an AMS policy is defined for the transmission queue, it is applied to remove any AMS protection from the message prior to sending the message across the channel. If an AMS policy is not defined for the transmission queue, the message is sent as is.

This value is valid only for channels with a channel type of SDR or SVR.

ASPOLICY

Based on the policy defined for the target queue, apply AMS protection to inbound messages prior to putting them on to the target queue.

When the message channel agent receives an inbound message, if an AMS policy is defined for the target queue, AMS protection is applied to the message prior to the message being put to the target queue. If an AMS policy is not defined for the target queue, the message is put to the target queue as is.

This value is valid only for channels with a channel type of RCVR or RQSTR.

User ID for message channel interception

The requirement for user IDs used with server-to-server message channel interception are the same as those for existing AMS enabled applications. For a running channel, the sending message channel agent gets messages from a transmission queue and the receiving message channel agent puts messages to target queues. The message channel agent user ID (MCAUSER) field, set on server to server channels, defines the user ID under which message channel agents perform put and get requests.

With server-to-server message channel interception, AMS functions are performed during get and put requests, as with other AMS enabled applications. Therefore, message channel agent user Ids have the same requirements as those for AMS application user IDs.

The MCAUSER used to perform the put and get is configurable, and dependent on whether it is an outbound or inbound channel. See MCAUSER for details of how the chosen user ID performs actions on the message channel agent. As such, the user ID that the channel initiator is running under is the user ID that is to be used for AMS functions performed during server-to-server message channel interception. Therefore, these user IDs have the same requirements as those for AMS application user IDs.

Message size and MAXMSGL

Due to AMS protection, the message size of protected messages will be larger than the original message size.

Protected messages are larger than unprotected messages. Therefore, the value of the MAXMSGL attribute, on both queues and channels, might need to be altered to take into account the size of protected messages.

Related information

• Server-to-server message channel interception example configurations