Security exit overview

Security exits normally work in pairs. They are called before messages flow and their purpose is to allow an MCA to authenticate its partner.

Security exits normally work in pairs; one at each end of a channel. They are called immediately after the initial data negotiation has completed on channel startup, but before any messages start to flow. The primary purpose of the security exit is to enable the MCA at each end of a channel to authenticate its partner. However, there is nothing to prevent a security exit from performing other function, even function that has nothing to do with security.

Security exits can communicate with each other by sending security messages. The format of a security message is not defined and is determined by the user. One possible outcome of the exchange of security messages is that one of the security exits might decide not to proceed any further. In that case, the channel is closed and messages do not flow. If there is a security exit at only one end of a channel, the exit is still called and can elect whether to continue or to close the channel.

Security exits can be called on both message and MQI channels. The name of a security exit is specified as a parameter in the channel definition at each end of a channel.

For more information about security exits, see Link level security using a security exit.

Parent topic: Channel exit programs