In Qpid, Access Control Lists (ACLs) specify which actions can be performed by each authenticated user. To enable, the <acl/> element is used within the <security/> element of the configuration XML. In the Java Broker, the ACL may be imposed broker wide or applied to individual virtual hosts. The <acl/> configuration references a text file containing the ACL rules. By convention, this file should have a .acl extension.

To apply an ACL broker-wide, add the following to the config.xml (assuming that conf has been set to a suitable location such as ${QPID_HOME}/etc): <broker> ... <security> ... <acl>${conf}/broker.acl</acl> </security> </broker> To apply an ACL on a single virtualhost named test, add the following to the config.xml: <virtualhost> ... <name>test</name> <test> ... <security> <acl>${conf}/vhost_test.acl</acl> </security> </test> </virtualhost>

The ACL file consists of a series of rules associating behaviour for a user or group. Use of groups can serve to make the ACL file more concise. See Configuring Group Providers for more information on defining groups. Each ACL rule grants or denies a particular action on an object to a user/group. The rule may be augmented with one or more properties, restricting the rule's applicability. ACL ALLOW alice CREATE QUEUE # Grants alice permission to create all queues. ACL DENY bob CREATE QUEUE name="myqueue" # Denies bob permission to create a queue called "myqueue" The ACL is considered in strict line order with the first matching rule taking precedence over all those that follow. In the following example, if the user bob tries to create an exchange "myexch", the operation will be allowed by the first rule. The second rule will never be considered. ACL ALLOW bob ALL EXCHANGE ACL DENY bob CREATE EXCHANGE name="myexch" # Dead rule If the desire is to allow bob to create all exchanges except "myexch", order of the rules must be reversed: ACL DENY bob CREATE EXCHANGE name="myexch" ACL ALLOW bob ALL EXCHANGE All ACL files end with an implict rule denying all operations to all users. It is as if each file ends with ACL DENY ALL ALL If instead you wish to allow all operations other than those controlled by earlier rules, add ACL ALLOW ALL ALL to the bottom of the ACL file. When writing a new ACL, a good approach is to begin with an .acl file containing only ACL DENY-LOG ALL ALL which will cause the Broker to deny all operations with details of the denial logged to the Qpid log file. Build up the ACL rule by rule, gradually working through the use-cases of your system. Once the ACL is complete, consider switching the DENY-LOG actions to DENY to improve performamce and reduce log noise. ACL rules are very powerful: it is possible to write very granular rules specifying many broker objects and their properties. Most projects probably won't need this degree of flexibility. A reasonable approach is to choose to apply permissions at a certain level of abstraction (e.g. QUEUE) and apply them consistently across the whole system.

ACL rules follow this syntax: ACL {permission} {<group-name>|<user-name>>|ALL} {action|ALL} [object|ALL] [property="<property-value>"] Comments may be introduced with the hash (#) character and are ignored. Long lines can be broken with the slash (\) character. # A comment ACL ALLOW admin CREATE ALL # Also a comment ACL DENY guest \ ALL ALL # A broken line

ALLOW Allow the action ALLOW-LOG Allow the action and log the action in the log DENY Deny the action DENY-LOG Deny the action and log the action in the log CONSUME Applied when subscriptions are created PUBLISH Applied on a per message basis on publish message transfers CREATE Applied when an object is created, such as bindings, queues, exchanges ACCESS Applied when an object is read or accessed BIND Applied when queues are bound to exchanges UNBIND Applied when queues are unbound from exchanges DELETE Applied when objects are deleted PURGE Applied when purge the contents of a queue UPDATE Applied when an object is updated VIRTUALHOST A virtualhost (Java Broker only) MANAGEMENT Management - for web and JMX (Java Broker only) QUEUE A queue EXCHANGE An exchange USER A user (Java Broker only) GROUP A group (Java Broker only) METHOD Management or agent or broker method (Java Broker only) LINK A federation or inter-broker link (not currently used in Java Broker) BROKER The broker (not currently used in Java Broker) name String. Object name, such as a queue name, exchange name or JMX method name. durable Boolean. Indicates the object is durable routingkey String. Specifies routing key passive Boolean. Indicates the presence of a passive flag autodelete Boolean. Indicates whether or not the object gets deleted when the connection is closed exclusive Boolean. Indicates the presence of an exclusive flag temporary Boolean. Indicates the presence of an temporary flag type String. Type of object, such as topic, fanout, or xml alternate String. Name of the alternate exchange queuename String. Name of the queue (used only when the object is something other than queue component String. JMX component name (Java Broker only) schemapackage String. QMF schema package name (Not used in Java Broker) schemaclass String. QMF schema class name (Not used in Java Broker) from_network Comma-separated strings representing IPv4 address ranges. Intended for use in ACCESS VIRTUALHOST rules to apply firewall-like restrictions. The rule matches if any of the address ranges match the IPv4 address of the messaging client. The address ranges are specified using either Classless Inter-Domain Routing notation (e.g. 192.168.1.0/24; see RFC 4632) or wildcards (e.g. 192.169.1.*). Java Broker only. from_hostname Comma-separated strings representing hostnames, specified using Perl-style regular expressions, e.g. .*\.example\.company\.com Intended for use in ACCESS VIRTUALHOST rules to apply firewall-like restrictions. The rule matches if any of the patterns match the hostname of the messaging client. To look up the client's hostname, Qpid uses Java's DNS support, which internally caches its results. You can modify the time-to-live of cached results using the *.ttl properties described on the Java Networking Properties page. For example, you can either set system property sun.net.inetaddr.ttl from the command line (e.g. export QPID_OPTS="-Dsun.net.inetaddr.ttl=0") or networkaddress.cache.ttl in $JAVA_HOME/lib/security/java.security. The latter is preferred because it is JVM vendor-independent. Java Broker only. UserManagement User maintainance; create/delete/view users, change passwords etc permissionable at broker level only ConfigurationManagement Dynammically reload configuration from disk. permissionable at broker level only LoggingManagement Dynammically control Qpid logging level permissionable at broker level only ServerInformation Read-only information regarding the Qpid: version number etc permissionable at broker level only VirtualHost.Queue Queue maintainance; copy/move/purge/view etc VirtualHost.Exchange Exchange maintenance; bind/unbind queues to exchanges VirtualHost.VirtualHost Virtual host maintainace; create/delete exchanges, queues etc

Here are some example ACLs illustrating common use cases. In addition, note that the Java broker provides a complete example ACL file, located at etc/broker_example.acl.

Suppose you wish to permission two users: a user 'operator' must be able to perform all Management operations, and a user 'readonly' must be enable to perform only read-only functions. Neither 'operator' nor 'readonly' should be allowed to connect clients for messaging. # Deny (loggged) operator/readonly permission to connect messaging clients. ACL DENY-LOG operator ACCESS VIRTUALHOST ACL DENY-LOG readonly ACCESS VIRTUALHOST # Give operator permission to perfom all other actions ACL ALLOW operator ALL ALL # Give readonly permission to execute only read-only actions ACL ALLOW readonly ACCESS ALL ... ... rules for other users ... # Explicitly deny all (log) to eveyone ACL DENY-LOG ALL ALL

Suppose you wish to restrict User Management operations to users belonging to a group 'usermaint'. No other user is allowed to perform user maintainence This example illustrates the permissioning of an individual component. # Give usermaint access to management and permission to execute all JMX Methods on the # UserManagement MBean and perform all actions for USER objects ACL ALLOW usermaint ACCESS MANAGEMENT ACL ALLOW usermaint ALL METHOD component="UserManagement" ACL ALLOW usermaint ALL USER ACL DENY ALL ALL METHOD component="UserManagement" ACL DENY ALL ALL USER ... ... rules for other users ... ACL DENY-LOG ALL ALL

Suppose you wish to permission a system using a request/response paradigm. Two users: 'client' publishes requests; 'server' consumes the requests and generates a response. This example illustrates the permissioning of AMQP exchanges and queues. # Allow client and server to connect to the virtual host. ACL ALLOW client ACCESS VIRTUALHOST ACL ALLOW server ACCESS VIRTUALHOST # Client side # Allow the 'client' user to publish requests to the request queue. As is the norm for the request/response paradigm, the client # is required to create a temporary queue on which the server will respond. Consequently, there are rules to allow the creation # of the temporary queues and consumption of messages from it. ACL ALLOW client CREATE QUEUE temporary="true" ACL ALLOW client CONSUME QUEUE temporary="true" ACL ALLOW client DELETE QUEUE temporary="true" ACL ALLOW client BIND EXCHANGE name="amq.direct" temporary="true" ACL ALLOW client UNBIND EXCHANGE name="amq.direct" temporary="true" ACL ALLOW client PUBLISH EXCHANGE name="amq.direct" routingKey="example.RequestQueue" # Server side # Allow the 'server' user to consume from the request queue and publish a response to the temporary response queue created by # client. We also allow the server to create the request queue. ACL ALLOW server CREATE QUEUE name="example.RequestQueue" ACL ALLOW server CONSUME QUEUE name="example.RequestQueue" ACL ALLOW server BIND EXCHANGE ACL ALLOW server PUBLISH EXCHANGE name="amq.direct" routingKey="TempQueue*" ACL DENY-LOG all all

This example illustrates how to set up an ACL that restricts the IP addresses and hostnames of messaging clients that can access a virtual host. ################ # Hostname rules ################ # Allow messaging clients from company1.com and company1.co.uk to connect ACL ALLOW all ACCESS VIRTUALHOST from_hostname=".*\.company1\.com,.*\.company1\.co\.uk" # Deny messaging clients from hosts within the dev subdomain ACL DENY-LOG all ACCESS VIRTUALHOST from_hostname=".*\.dev\.company1\.com" ################## # IP address rules ################## # Deny access to all users in the IP ranges 192.168.1.0-192.168.1.255 and 192.168.2.0-192.168.2.255, # using the notation specified in RFC 4632, "Classless Inter-domain Routing (CIDR)" ACL DENY-LOG messaging-users ACCESS VIRTUALHOST \ from_network="192.168.1.0/24,192.168.2.0/24" # Deny access to all users in the IP ranges 192.169.1.0-192.169.1.255 and 192.169.2.0-192.169.2.255, # using wildcard notation. ACL DENY-LOG messaging-users ACCESS VIRTUALHOST \ from_network="192.169.1.*,192.169.2.*" ACL DENY-LOG all all