Grant access to a user to subscribe to a topic

This topic is the first one in a list of tasks that tells you how to grant access to topics by more than one user.

About this task

This task assumes that no administrative topic objects exist, nor have any profiles been defined for subscription or publication. The applications are creating new subscriptions, rather than resuming existing ones, and are doing so using the topic string only.

An application can make a subscription by providing a topic object, or a topic string, or a combination of both. Whichever way the application selects, the effect is to make a subscription at a certain point in the topic tree. If this point in the topic tree is represented by an administrative topic object, a security profile is checked based on the name of that topic object.

A diagrammatic representation of a topic object fruit, in a topic of price/fruit. — Figure 1. Topic object access example

Table 1. Example topic object access
Topic	Subscribe access required	Topic object
Price	No user	None
Price/Fruit	USER1	FRUIT

Define a new topic object as follows:

Procedure

Issue the MQSC command DEF TOPIC(FRUIT) TOPICSTR('Price/Fruit').
Grant access as follows:
- z/OS® :
  Grant access to USER1 to subscribe to topic Price/Fruit by granting the user access to the hlq.SUBSCRIBE.FRUIT profile. Do this, using the following RACF® commands:
```
RDEFINE MXTOPIC hlq.SUBSCRIBE.FRUIT UACC(NONE)
PERMIT hlq.SUBSCRIBE.FRUIT CLASS(MXTOPIC) ID(USER1) ACCESS(ALTER)
```
- Multiplatforms:
  Grant access to USER1 to subscribe to topic Price/Fruit by granting the user access to the FRUIT object. Do this, using the authorization command for the platform:
  AIX®, Linux®, and Windows systems
  setmqaut -t topic -n FRUIT -p USER1 +sub
  IBM® i
  GRTMQAUT OBJ(FRUIT) OBJTYPE(*TOPIC) USER(USER1) AUT(*SUB)

Results

When USER1 attempts to subscribe to topic Price/Fruit the result is success.

When USER2 attempts to subscribe to topic Price/Fruit the result is failure with an MQRC_NOT_AUTHORIZED message, together with:

On z/OS, the following messages seen on the console that show the full security path through the topic tree that has been attempted:
```
ICH408I USER(USER2   ) ...
  hlq.SUBSCRIBE.FRUIT ...

ICH408I USER(USER2   ) ...
  hlq.SUBSCRIBE.SYSTEM.BASE.TOPIC ...
```

On AIX, Linux, and Windows, the following authorization event:

MQRC_NOT_AUTHORIZED
ReasonQualifier	  MQRQ_SUB_NOT_AUTHORIZED
UserIdentifier	    USER2
AdminTopicNames	  FRUIT, SYSTEM.BASE.TOPIC
TopicString		   "Price/Fruit"

On IBMi, the following authorization event:

MQRC_NOT_AUTHORIZED
ReasonQualifier	  MQRQ_SUB_NOT_AUTHORIZED
UserIdentifier	    USER2
AdminTopicNames	  FRUIT, SYSTEM.BASE.TOPIC
TopicString		   "Price/Fruit"

Note that this is an illustration of what you see; not all the fields.