Tag / security

by Shawn McKinney

What Are Temporal Constraints?

Defined

Ability to control when an entity activation occurs based on time and date criteria.  Temporal constraints are typically applied during User and Role activation as part of an authentication or authorization check.

What Are They For?

Can be used to limit when a User may log onto or activate a particular Role within a security domain.  Follows the principle of least privilege as it ensures access rights are only granted when appropriate.

How Do They Work?

There may be policies to control what dates, times, and days of week a User may access a particular area of the system and in what Role.  Can also be used to enforce a lockout period when the User is inactive or otherwise away for an extended period of time.

Apache Fortress Temporal Constraints

Fortress allows constraints to be applied onto both User and Role entities.  There are rules that fire during an activation event (any policy enforcement API call):

  1. Can the entity be active on this Date?
  2. Is the entity within a lockout period?
  3. Has the entity exceeded a particular inactive period?
  4. Can the entity be used at this time?
  5. Can the entity be used on this day?
  6. Are there mutual exclusion constraints that prevent activating this entity?  (Roles Only)

These temporal constraint rules are pluggable and may be added, overridden or removed.

by Shawn McKinney

What are Password Policies?

Defined

A set of rules surrounding the content, quality and lifecycle of a password.

What Are They For?

Helps to safeguard the integrity of password values within a particular security domain.  With moves toward Multi-Factor Authentication (MFA) and other biometric authentication measures one can make the argument that the password’s days are numbered.  Nevertheless they remain in use widely today and will continue for the foreseeable future.

How Do They Work?

Define a set of rules to be enforced during a password lifecycle event.  An example of a lifecycle event is authentication, password change and password expiration.  There are a few standards that govern how systems should behave in this area.

IETF Password Policies

Apache Fortress adheres to IETF Password Policy Draft.  While this draft was never formally adopted it has traction within the various directory implementations and remains the de facto standard today.

Password Policy Enforcement

Password enforcement options include:

  1. A configurable limit on failed authentication attempts.
  2. A counter to track the number of failed authentication attempts.
  3. A time frame in which the limit of consecutive failed authentication attempts must happen before action is taken.
  4. The action to be taken when the limit is reached. The action will either be nothing, or the account will be locked.
  5. An amount of time the account is locked (if it is to be locked) This can be indefinite.
  6. Password expiration.
  7. Expiration warning
  8. Grace authentications
  9. Password history
  10. Password minimum age
  11. Password minimum length
  12. Password Change after Reset
  13. Safe Modification of Password
  14. Password Policy for LDAP Directories
by Shawn McKinney

What is Delegated Administration?

Defined

The ability to control access on the security system itself.  This control is exercised inside the policy administration programs.

In addition to what functions may be executed, we must control which entities to operate on.  A common use case is to allow User X the ability to reset and unlock passwords only for Users within Organization Y.  Another is the administrator may only assign a specific subset of Roles to Users who reside inside their Organization.  Additionally we must also be able to limit an Administrator to a specific subset of Roles in which to Grant to a subset of Permissions.  Indeed every API that changes state inside the back-end security repository must be governed via a well understood delegated administration policy.

Administrative Role-Based Access Control (ARBAC)

Apache Fortress has implemented ARBAC02. [link to paper].  This is a formal model for Delegated Administration and builds on the ANSI RBAC specification.  The control is marshaled into three interfaces:

  1. Delegated Admin Manager – Provides CRUD for related entities like Administrative Roles and Permissions.
  2. Delegated Review Manager – Interrogation of Delegated Admin policy objects.
  3. Delegated Access Manager – Enforcement of Delegated Administration Policies.

1 & 2 are for management of the Delegated Admin policies themselves.  3 is for enforcement of Delegated Admin policies at runtime.

Delegated Admin Policy Enforcement

There are two types of controls:

  1. Ensure that the caller has the permission to call the security administrative method (e.g. addUser, addRole, addPermission,…)
  2. Ensure the caller is entitled to perform the function for a given organization (e.g. which Users and Permissions to grant access rights).

With Fortress, the Delegated Administration control is baked into its APIs.  The enforcement occurs during API invocation which means it can’t be circumvented by poorly implemented administrative programs.

In addition to control, every API invocation leaves an audit trail so you may determine what policies changed, by whom, when and where.

by Shawn McKinney

How Much is One Millisecond Worth To You?

For those who don’t keep these kinds of details in their heads a millisecond is 1/1000th of a second.

With respect to security processing what can be done in that time increment – can you perform a fine-grained permission check over the network?  How about logging results into a remote database?

Would you believe me if I told you we can perform both operations within that allotment of time on a modest hardware configuration?  What if I also tried to tell you that over eleven thousand of these requests may be performed a second with the same response time?

Such were the results as documented in this series of benchmarks:

fortress-rbac-accelerator-pdp-benchmark-report

Read more about the accelerator rationale here:

the-case-for-a-policy-decision-point-inside-the-ldap-server

by Shawn McKinney

Fortress RBAC Accelerator PDP Benchmark Report

Benchmark Overview

This post provides a summary of a recent benchmark effort for the Fortress RBAC Accelerator.  The RBAC accelerator uses LDAPv3 extended operations to perform the following access control functions:

  1. Create Session – attempts to authenticate client; if successful, initiates an RBAC session by activating one or more user roles
  2. Check Access – determines if user has access rights for a given resource
  3. Add Active Role – attempts activation for a given role into user’s RBAC session
  4. Drop Active Role – deactivates a given role from user’s RBAC session
  5. Delete Session – deletes the given RBAC session from the server
  6. Session Roles – Returns the active roles associated with current session

The result of each of the above functions are persisted to LMDB for audit trail.

Benchmarks performed using a Jmeter test client to drive load for CheckAccess (#2).  The server hosts the OpenLDAP daemon which has the RBAC accelerator overlay.

Client Machine

  • operating system: ubuntu 13.04
  • kernel: 3.8.0-32-generic
  • processor: Intel® Core™ i7-4702MQ CPU @ 2.20GHz × 8
  • memory: 16GB (doesn’t use anywhere close to that)
  • Java version 7

Server Machine

  • operating system: ubuntu 14.04
  • kernel: 3.13.0-32-generic
  • processor: Intel® Core™ i7-4980HQ CPU @ 2.80GHz × 4
  • memory: 8GB
  • OpenLDAP version: 2.4.39

Test Details

  • 25 threads running on client
  • each thread runs checkAccess 50,000 times
  • 1,250,000 total
  • Client CPU load: approximately 50%

Test Results

  • Response time: 1 millisecond
  • Throughput: 11,533 transactions per second
  • Server CPU load: approximately 85%
by Shawn McKinney

The Case for a Policy Decision Point inside the LDAP Server

Feature image from: http://kb.linuxvirtualserver.org/wiki/Building_Scalable_Network_Services

Why on earth would you do that?

We all understand that runtime characteristics change as processes get moved around the network.  Having problems with network io?  Move the database daemon to the same tier as the client process.  Worried about file io?  Store the data in memory as opposed to disk.  etc…

These same notions apply for system architecture with respect to security.  Location of policy enforcement, decision, and database processes hugely impact the overall welfare of your organization’s computational systems.

With these kinds of thoughts, let’s move the security processes around and see what happens.

But first, we’ll define them:

1. Policy Enforcement Point (PEP)

Invoked by client programs for security policy enforcement.  These gatekeepers are embedded directly into their host thus require platform specific bindings.  The less impact to their host, the better.

2. Database (DB)

Invoked by PDPs to store security credentials, attributes and activity logs.  An important concern is speed; to be used correctly, it’s used often.  Another important concern is reliability; the integrity of its data is mission critical.

3. Policy Decision Point (PDP)

Invoked by PEPs and dependent on a DB.  Responsible for computing:

  • authentication – with passwords or keys
  • authorization – with attributes or permissions
  • audit trail – identify subjects, decisions, time/date/locations, and resources

Three types of PDPs

  • Type 1 – runs in-process to PEP, with out-of-process DB
  • Type 2 – runs out-of-process to PEP, with out-of-process DB
  • Type 3 – runs out-of-process to PEP, with in-process DB

PDP Type 1 (runs in-process to PEP)

The Tomcat JDBC Realm is a Type 1 PDP.  It functions both as PEP and PDP.  Other Type 1’s include Apache Fortress, Shiro and Spring Security.  Most of the open-source security frameworks are this type.  The policy decisions happen synchronously inside the client process.

Type 1 PDP interaction between processes

The PEP and PDP process reside on one tier; the DB process on another.

The PEP and PDP process reside on one tier; the DB process on another.

Benefits of Type 1 PDP

Type 1 PDP advantages
  • simple – only security framework and DB required
  • widely available
  • works well for single deployments of stand-alone apps
Type 1 PDP disadvantages
  • more code exposed to the client (making deployment harder)
  • more load on the client
  • more memory consumed on the client
  • more network io traffic on the client
  • fewer platforms supported (can it run on Java, NET, PHP, Python, and all the others?)

PDP Type 2 (runs out-of-process to PEP and DB)

Here the PDP and DB both run out-of-process to the PEP.  These types of PDPs are more complicated and usually obtained as separate COTS or OSS products.  For example, CA Siteminder, Tivoli Access Manager, Oracle Access Manager, Shibboleth, CAS and many others.

Type 2 PDP interaction between processes

The PEP, PDP and DB processes reside on separate tiers from one another.

The PEP, PDP and DB processes reside on separate tiers from one another.

Benefits of Type 2 PDP

Type 2 PDP advantages
  • less network traffic on client
  • less cpu consumed on client
  • less memory consumed on client
  • less code exposed to client (making deployment simpler)
  • more platforms supported (simple to code PEP ‘shims’ to communicate with centralized PDPs)
Type 2 PDP disadvantages
  • more security processes to maintain due to PEP, PDP and DB all running separately (increasing management burden)
  • poor response time due to extra network hops
  • poor throughput due to PDP reliance on heavyweight communication protocols (xml/json/http)

PDP Type 3 (runs out-of-process to PEP and in-process to DB)

The PDP and DB run in-process and the PEP is out-of-process.  The advantage here is offloading computations from the PEP reducing load and traffic from the client.  It gains speed over the Type 2 because of the embedded database.

Type 3 PDP interaction between processes

The PEP process resides on one tier; the PDP and DB process on another.

The PEP process resides on one tier; the PDP and DB process on another.

Benefits of Type 3 PDP

Type 3 PDP advantages
  • all of Type 2
  • embedded database speed gain
  • embedded database reliability gain
Type 3 PDP disadvantages
  • poor throughput due to reliance on heavyweight communication protocols (xml/json/http)

The Case for a PDP in OpenLDAP

The OpenLDAP RBAC Accelerator is a Type 3 PDP.  It has all the advantages of its type without the disadvantage because using extended LDAP protocols is very efficient.  It runs inside of the OpenLDAP slapd daemon and uses LMDB, which is the fastest embedded, key-value database available, giving a nice turbo boost to read/write speeds.

Now let’s return to the original question:  Why on earth would you do that?

To enable authentication, fine-grained authorization, and audit trail on every platform.  To ease concerns for high cpu, memory, network, and file io consumption.  And to use well understood technologies that can be widely distributed.

by Shawn McKinney

Why another open source iam product?

A question that has been lingering.  It’s fair game, but before I get around to actually answering, let’s remember how we got here.

Late 90’s

Before the first open source iam product existed we had standard policy enforcement protocols in use.  Examples include Java’s ee security & jaas. Unix had PAM, sudo and kerberos.  Windows, NTLM and SPNEGO.  There were web-based protocols like HTTP basic auth and ISAPI.

IAM Complete Solution Defined

Those policy enforcement mechanisms didn’t meet the wider requirements of a complete solution:

  • extensible and pluggable policy enforcement services
  • centralized policy decision point services
  • common policy administration services
  • common policy information services
  • audit and review capabilities

The gaps made us scramble to meet the need.

Early to Mid 2000’s

Commercial vendors ruled.  Several more policy enforcement protocols appeared including liberty, saml, ws-*, xmlsecurity and xacml.  Those in need either built or bought because open source iam solutions were barely in existence.

There were many open source projects that provided the legos to build with.

2008

The era of opportunity for open source innovation.  Most of the technical problems were solved.  All one had to do was assemble a solution using the building blocks available in the public domain.

But not another access control framework.  Needed a complete solution.

2009

As code construction commenced on fortress, many open source policy enforcement frameworks became widely used, such as spring security and opensso, but still no complete solution.

2011

Around the the time of the first fortress release the situation changed.  Sun’s merger with Oracle foretold the end of the commercial vendor stranglehold creating a void in which companies like Symas, Linagora, Evolveum, and Tirasa sprung complete solutions.

Today

Now that we have several complete open source iam solutions on the market, the industry continues to focus on policy enforcement standards, the latest being oauth, uma and open id connect.

But we continue to struggle because uniform policy enforcement is the tip of iceberg.  More benefit comes through shared policy decision and admin services.  This promotes reuse of infrastructure and data across organizational, vendor and platform boundaries.

Tomorrow

Policy enforcement protocols will continue to be volatile and ill-equipped.

Standards-based policy decision and admin services will continue to be needed.

So that Vendor A’s PEP can plug into Vendor B’s PDP, and Vendor C’s PAP can plug in Vendor D’s PIP.

Why Fortress

Based on ansi incits 359, our best hope for standardizing the complete iam solution.

by Shawn McKinney

ABAC – Where are the Functional Specs?

As a security architect I have long-awaited the means to express authorization policies using dynamic constraints – in a standard way. Over the years there have not been many models to choose from.

First came A Resource Access Decision Service, which had promise, but departed with CORBA.

Next came eXtensible Access Control Markup Language (XACML).  Some believe it dead, and there are those who continue to promote.  The jury is out.

What do you think about XACML?

Now the buzz is Attribute-Based Access Control (ABAC).

Blurring the lines, supposedly XACML implements ABAC, because attributes combine with decisions.

There are commonalities across the three models:

  1. Grammar to express very fine-grained access control policies.
  2. Rules containing variables captured from subjects and resources.  Facts such as location, time and date included.
  3. Adjudication when rules combine or clash.
  4. Separation into multiple components, e.g. Policy Enforcement Point (PEP), Policy Decision Point (PDP), Policy Information Point (PIP).

The promise is reuse.

So where are the functional specs?  I must understand and share.

“Despite the clear guidance to implement contextual (risk adaptive) role or attribute based access control ABAC, to date there has not been a comprehensive effort to formally define or guide the implementation of ABAC”
NIST – ATTRIBUTE BASED ACCESS CONTROL (ABAC)

Ruh roh.

Until formal specifications are drafted, ABAC is useless because it’s non-standard and/or proprietary.

Back to square one – awaiting an industry standard dynamic authorization model.