Difference between revisions of "Argus Installation"

Latest revision as of 18:18, 27 January 2014

Introduction

Argus Authorization Framework^[1] is an implementation of OASIS eXtended Access Control Markup Language (XACML) Standard^[2]. It is composed by a set of web services provided by three elements:

• Policy Administration Point (PAP), to store and manage XACML Policies
• Policy Decision Point (PDP), to take authorization decision basing on the policies and context attributes (e.g. date/hour)
• Policy Enforcement Point, Client (PEPC) and Daemon (PEPD), to enforce policy decisions

Further information on the architecture can be found on SOA3 Authorization Module.

SOA3 Authorization Module

The picture shows how Argus elements is integrated in SOA3 Authorization Module: in particular, SOA3 Policy Management Service manages the policies with Argus PAP, while the PEPC library is integrated in SOA3 Authorization Service and communicates with Argus PEPD.

In this section a step by step guide to configure Argus elements is provided: it is based on Argus 1.5.0, but other versions differs only for the path of the configuration files. The installation procedure has been tested on Centos 6.4 and Fedora 17, but it should be valid for any Red Hat based distribution and for any linux distribution supporting RPMs.

Argus v1.5.0 or above is recommended: an RPM can be found here.

Policy Administration Point

The file

  /etc/argus/pap/attribute-mappings.ini

contains the attributes recognized by argus. For IMarine it should contain at least roles:

id = role
role.xacml-id = urn:oasis:names:tc:xacml:2.0:subject:role
role.xacml-datatype = http://www.w3.org/2001/XMLSchema#string
role.xacml-target-element = subject
role.xacml-match-function = urn:oasis:names:tc:xacml:1.0:function:string-regexp-match

role.xacml-match-function establishes that the match must be performed using regexp: in this case rules based on roles defined by regular expressions are supported.

It is possible to add other subject attributes, e.g.:

id = subject
subject.xacml-id = urn:oasis:names:tc:xacml:1.0:subject:subject-id
subject.xacml-datatype = http://www.w3.org/2001/XMLSchema#string
subject.xacml-target-element = subject
subject.xacml-match-function = urn:oasis:names:tc:xacml:1.0:function:string-equal
 
id = tenant
tenant.xacml-id = urn:oasis:names:tc:xacml:2.0:subject:tenant
tenant.xacml-datatype = http://www.w3.org/2001/XMLSchema#string
tenant.xacml-target-element = subject
tenant.xacml-match-function = urn:oasis:names:tc:xacml:1.0:function:string-regexp-match

Action and resource attributes defined for IMarine are the following:

id = action
action.xacml-id = urn:oasis:names:tc:xacml:1.0:action:action-id
action.xacml-datatype = http://www.w3.org/2001/XMLSchema#string
action.xacml-target-element = action
action.xacml-match-function = urn:oasis:names:tc:xacml:1.0:function:string-regexp-match
 
id = resource
resource.xacml-id = urn:oasis:names:tc:xacml:1.0:resource:resource-id
resource.xacml-datatype = http://www.w3.org/2001/XMLSchema#string
resource.xacml-target-element = resource
resource.xacml-match-function = urn:oasis:names:tc:xacml:1.0:function:string-regexp-match

The file

  /etc/argus/pap/pap_configuration_ini

is the main configuration file for Argus PAP. The parameters to be modified are the following:

• hostname with the correct name (with dns suffix) of the host
• security section, in particular certificate and private_key with the path to the TLS certificate and key

Policy Decision Point

The configuration file is the following:

  /etc/argus/pdp/pdp.ini

and the parameters to be modified are:

• hostname and adminHost: hostname (with dns suffix) of the machine
• paps: the url(s) of the policy provisioning service(s) provided by the PAP(s). The pattern is https://<pap-hostname>:<pap-port>/pap/services/ProvisioningService: comma separated values are supported
• security section
  • enableSSL (true/false) to enable https protocol (recommended)
  • servicePrivateKey path of the private key
  • serviceCertificate path of the public key
  • trustInfoDir path of the directory containing the trusted CA for client authentication

Policy Enforcement Point Daemon

The configuration file is

  /etc/argus/pepd/pepd.ini

and the parameters to be modified are:

• hostname with the correct name (with dns suffix) of the host
• pips should be TIME_PIP to enable time based policies
• pdps: the url(s) of the policy decision service(s). The pattern is https://<pdp-hostname>:<pap-port>:8152/authz: comma separated values are supported
• security section
  • servicePrivateKey path of the private key
  • serviceCertificate path of the public key
  • trustInfoDir path of the directory containing the trusted CA for client authentication
  • enableSSL (true/false) to enable https protocol (recommended)
  • requireClientCertAuthentication (true/false) to enable client ssl authentication (recommended)

References

1. ↑ https://twiki.cern.ch/twiki/bin/view/EGEE/AuthorizationFramework
2. ↑ http://docs.oasis-open.org/xacml/2.0/access_control-xacml-2.0-core-spec-os.pdf