By Andrew Cameron and Graham Williamson
© 2021 Andrew Cameron, Graham Williamson, IDPro
Note: IDPro® does not endorse a particular architecture framework. IAM practitioners will face many different approaches and must adopt the model that best suits their organizations.
Identity and Access Management (IAM) touches all aspects of an organization’s IT environment. Whether it is the human resources (HR) system, email system, phone system, or corporate applications, each system needs to interface to the IAM environment. IAM will always play a role in making IT operations efficient and secure, by supporting the enforcement of user provisioning rules, as an example, or validating the access of non-corporate users. An architectural approach to developing IAM systems will heighten the organization’s probability of achieving a consistent and comprehensive IAM solution.
If the organization maintains an enterprise architecture (EA), any IAM solution they deploy must adhere to the enterprise models and be reflected in the organization’s EA artifacts. This article provides a basic approach for IAM professionals to consider whether or not there is an EA in place.
Access Management: the use of identity information to provide access control to protected resources such as computer systems, databases, or physical spaces.
Architecture: a framework for the design, deployment, and operation of an information technology infrastructure. It provides a structure whereby an organization can standardize its technology and align its IT infrastructure with digital transformation policy, IT development plans, and business goals.
Architecture Overview: describes the architecture components required for supporting IAM across the enterprise.
Architecture Patterns: identifies the essential patterns that categorize the IT infrastructure architecture in an organization and will guide the deployment choices for IAM solutions.
Enterprise Architecture: an architecture covering all components of the information technology (IT) environment
Identity Governance and Administration (IGA): includes the collection and use of identity information as well as the governance processes that ensure the right person has the right access to the right systems at the right time.
AP – Application Portfolio
BPMn – Business Process Mapping notation
BSA – Business System Architecture
EA – Enterprise Architecture
HTTP – HyperText Transfer Protocol
IA – Information Architecture
IAM – Identity and Access Management
IDaaS – Identity-as-a-Service
IGA – Identity Governance and Administration
JSON – file structure for the communication of data attributes
MFA – Multi-factor Authentication
PABX – Private Automatic Branch Exchange
PAP – Policy Administration Point
PDP – Policy Decision Point
PEP – Policy Enforcement Point
PIP – Policy Information Point
RBAC – Role-based Access Control
RESTful API - architecture for a programming interface defining how HTTP methods are to be used
SAML – Security Assertion Markup Language
SCIM – System for Cross-domain Identity Management
SSO – Single Sign-On
TA – Technical Architecure
XML – eXtensible Markup Language - a file structure for the communication of data attributes
IAM Architecture Overview
IAM professionals must have a vision for the IAM environment that satisfies corporate requirements. Each IAM project must build towards the desired target state. An architectural approach will enable the IAM professional to plan, design, and deploy IAM solutions that are both coordinated and integrated; and combine to form a comprehensive IAM environment that meets corporate stakeholders' current and projected needs.
Identity management within an enterprise touches virtually all systems in use within the organization. Systems, in this context, comprise computer systems that staff and business partners use in the performance of their job responsibilities and physical access systems, such as a requirement to show an identity pass to gain access to a restricted area. Staff includes contractors; they are typically managed through a different system (many HR systems only accommodate employees) but need access to many of the same corporate systems as employees. Including non-human accounts should also be considered; most organizations have service accounts for machine access to systems. As more automation is incorporated into company operations, access control for sensors or bots should be incorporated in the IAM environment. Including non-human entities in the architecture allows the enterprise to manage their access control in a manner consistent with all other accounts; IAM professionals should consider these entities during the system development planning process.
It is the task of an IAM practitioner to ensure that, wherever and whenever identity information is used within an enterprise, the information is collected and used in a properly designed environment that ensures efficiency, protects privacy, and safeguards integrity. Applying an architectural approach, i.e., developing project requirements within a structured framework, will significantly raise the likelihood that an IAM project will be completed consistently and comprehensively with a controlled impact on stakeholders.
There are four levels that the IAM practitioner should consider when developing a solution architecture:
Figure 1: Generic Enterprise Architecture Framework
Business System Architecture (BSA)
Mapping business processes for the collection, usage, and eventual deletion of identity data will greatly assist in understanding the breadth of the IAM task. While BPMn is typically used for business process mapping, the IAM practitioner should adopt whatever tool is typically used in their company.
Considering IT architecture at the business level will facilitate a more holistic approach that considers the identity requirements of all connected systems and ensures consistency in naming conventions. It will also reduce the probability of an IAM project running over budget or over time (a common occurrence when a system owner who has not previously been consulted hears about an IAM project and adds unanticipated requirements).
It is important to map the identity data elements required by the various applications to the IAM collection, management, and governance systems. This mapping will ensure no application is ‘left behind’ when the IAM systems are re-developed. A useful tool is an ‘entity-relationship diagram’ that maps each attribute collected to each system that requires it. The Information Architecture (IA) should drive consistency between connected systems (e.g., should Firstname, Middle Initial, and Lastname be used, or should Common name, Lastname be used). It should also help define roles (e.g., is this role for a Payroll Clerk or a Financial Officer). The IA should nominate attribute authority (e.g., which system is the authority for phone numbers). Best practice is for the IAM system to be the ‘source of truth’ for identity information in the company (sometimes called the ‘book of record’) because it is typically bad practice for source systems (HR, PABX, etc.) to be queried for data attribute lookups.
The IA becomes the vehicle for ‘identity data orchestration.’ It is the master plan for the collection and use of identity data within an enterprise.
An inventory of applications to be included in the IAM project should be conducted.1 How current are they? Are any of the included applications under development? Will the IAM project materially change how each application interacts with the IAM environment? For instance, if an API gateway is being deployed for access to IAM attributes, any application redevelopment should migrate from existing authentication mechanisms to the gateway operation.
A company’s Application Portfolio (AP) becomes an inventory of corporate applications. The record for each application should identify the system owner, type of application (web app, client-server, mainframe, etc.), and its reliance on the IAM environment. Some applications will expect the IAM system to pass authenticated sessions to it. In contrast, others will require user attributes so that it can determine the authorization that a user has to application functionality. The AP should identify the level of integration between each relying application and the IAM system. Web applications will likely pass user requests and responses via HTTP headers. In other scenarios, client-server applications may use an API, while cloud applications may use a SAML request or, if it maintains its own data repository, the SCIM protocol.2
The AP becomes an important record for an organization because it facilitates the planning required as applications are updated.
The Technical Architecture (TA) describes, among other things, the technical environment to be supported by the IAM environment. This description will involve understanding the patterns used within the company. Most organizations will have “n-tier” web services and hybrid cloud patterns, but there might still be client-server patterns and potentially mainframe hub-and-spoke patterns. Each additional pattern to be supported will increase the complexity and cost of the project. Often IAM environments with older infrastructure leave out support for legacy technology due to cost considerations, but this fragments the IAM task. Properly constituted, a cost/benefit analysis for deploying legacy connectors will typically be successful.
The TA impacts the IAM environment because different solutions are required for different patterns. For example, a web services pattern will mandate a single sign-on (SSO) environment capable of supporting RESTful APIs and SAML assertions and passing identity attributes in JSON arrays or XML files. An on-premise Windows environment, as another example, will typically use the Kerberos authentication protocol from an AD infrastructure or an LDAP directory. A cloud environment will often require a SAML operation or an Identity-as-a-Service (IDaaS) offering, whereas an older directory should be supported via a connector from the IAM infrastructure.
Additionally, corporate security policy may create requirements that require certain technical decisions. For instance, a requirement to maintain full control and authority over the data and infrastructure may require hosting the entire identity management stack on premises.
It is an unfortunate fact that many IAM (identity and access management) projects exceed their scheduled time and budget. The usual reason for this is a misunderstanding of the extent of the project and the systems impacted. The project team tends to focus just on the task at hand, e.g., installing the IAM software package, without realizing that IAM systems within an enterprise touch virtually all other systems in use within the organization. These other systems might include a birthright system such as email, an administrative system such as the Financial Management system, or an operational system such as an Enterprise Resource Management system.
In some circumstances, the change caused by an IAM project will be minimal, with a limited impact on resources. In other cases, the change will be significant, impacting both infrastructure and personnel across the organization. An architectural approach will ensure that a solution architecture is developed for each IAM project to understand the extent of the work required and effectively plan for the change it will generate.
An IAM practitioner's task is to ensure that, wherever and whenever identity information is used within an enterprise, the information is collected and used in a properly designed environment that ensures efficiency, protects privacy, and safeguards integrity.
For organizations with an EA, understanding how information is collected and used should be quite easy, as it is fundamentally a part of how the systems are deployed. For other organizations, the environment will be a “greenfield,” allowing the IAM practitioner to develop their own architectural approach.
At the Technical Architecture level, a “pattern” approach is useful to understand the supported technology within an organization. For instance: what is the predominant server infrastructure – is it Linux or Windows or both? What server operating system versions are supported? Are VMs used? What is the support for cloud infrastructure – public, private, hybrid? Is AWS, Azure, or Google Cloud supported? Can the scale required for customer IAM be accommodated? For IoT devices – how does the IoT platform integrate with the corporate environment?
The TA will define the computer system “patterns” to be supported by the IAM environment within an organization. For young companies, this will be web-based patterns, either “2-tier” or “n-tier.” Increasingly managed cloud environments are being engaged, potentially with a micro-services approach. But for mature organizations, there will typically be legacy applications with a client-server pattern, or even a mainframe ‘hub and spoke’ pattern, with PCs running terminal emulator software.
The IAM environment must support the selected patterns and ensure a managed approach that adheres to the organization’s governance and cybersecurity policy.
There are few mainframe systems left in service, with notable exceptions in the banking industry and some government installations. The IAM environment will often be required to synchronize to an older data store to support a mainframe system.
Figure 2: Mainframe application accessed from a monitor
Client-server environments can present a complex support requirement since many such systems maintain their own identity database to provide fine-grained access control to system functionality. Redevelopment of a client-server application to externalize access control decisions to an authentic authorization server can be a way to harmonize access policies across an organization.
Figure 3: Client application access a backend server
The most common on-premise application environment these days is an “n-tier” web services infrastructure. While there are many variants, a user accessing the front-end web server will be redirected to an authentication service, usually supporting SSO, with an authentication token passed back to the application in an HTTP header. If the application requires user authentication, the IAM system should set user entitlements as part of the initial provisioning activity when a user joins the organization.
Figure 4: Common web-services model
Hub & Spoke
Hub and spoke systems are typically only in large transaction processing systems. Often the only IAM touchpoint is access control for DevOps staff via a privileged access management system.
Figure 5: Common data service configuration
Increasingly remote access to corporate systems must be supported. The authentication server must accommodate the required access control mechanisms, from basic LDAP lookups for password accounts to sophisticated MFA environments capable of elevating authentication levels to suit application security requirements. The provisioning task in such environments requires maintaining one or more identity provider services within the enterprise.
Figure 6: Typical enterprise network access model
Hybrid Cloud Identity
A key indicator of effectiveness in an IAM Architecture is how complexity is managed across the IAM components in the environment. Today, most organizations are leveraging cloud infrastructure platforms in some capacity, either private clouds provided by their technology partners or public clouds such as AWS, Azure, or Google. This raises the issue of how to establish identity as a common control plane between the on-premises environment and the cloud infrastructure. IAM is a critical component of a hybrid IT architecture. Hybrid IAM allows organizations to establish a common credential that can be enabled for access to resources in either on-premises or cloud environments.
The hybrid cloud example assumes an existing ‘source of truth’ to which all enterprise users authenticate; this is typically Active Directory. With the Hybrid IAM pattern, authenticated on-premise users will have access to on-premise, public cloud, or other external services that support common identity standards such as OpenID Connect or OAuth.
Figure 7: Hybrid Cloud Identity Architecture model
Table 1: Hybrid IAM Architecture components
|On-Premise (Corporate) Directory||Directory service that enables authentication to access enterprise resources (e.g., Active Directory). Typically contains directory objects (accounts) that represent a human (user account) or non-human identity (service account).|
|On-Premise Federation Service||Identity service that implements common access management capabilities (authentication and authorization) for enterprise applications. Typically supports identity standards like SAML or OpenID Connect to enable access to internal or external resources.|
|Identity Sync Service||Infrastructure service that monitors directory objects in the enterprise directory for changes and synchronizes changes to a mapped cloud directory object. Sync direction can be one-way or two-way but is typically implemented in an Enterprise to Cloud direction to minimize risk and complexity. Standards such as SCIM can be used for this data transfer.|
|Cloud IAM Service||Platform service in a public cloud that implements core IAM capabilities (Authentication, Federation, Access Management) and can be leveraged to access on-premise resources as well.|
Important considerations for Hybrid IAM:
User Provisioning: User objects can be configured to synchronize when added to either the cloud or the on-premises environment. The best practice is to restrict user provisioning to one environment and sync account and profile data to the other environment (typically from enterprise to the cloud).
Profile Data: Manually maintaining identities in more than one environment can add unnecessary complexity and risk to your security posture. Cloud identity objects may not need the entire set of user profile data available for an on-premises user; the IAM practitioner should take care (e.g., understand the business requirements for authentication) when deciding how much user profile data should be stored on a cloud user object. A principle of “least privilege” should be applied to avoid data spillage.
Single Sign-On: Cloud IAM environments can enable SSO to on-premises applications or services. For SSO to be successful, the user object must have been provisioned and enabled for sign-in. It is critical to understand the authentication scenarios available from the cloud IAM platform (e.g., pass-through authentication or federation) and ensure that there is a fit with the enterprise requirements.
As enterprises place increasing importance on “time to value”, a hybrid IAM architecture will be critical to support infrastructure expansion beyond the enterprise perimeter and leverage cloud-enabled benefits (e.g., agility, scalability, reliability). The IAM professional will find use-cases where IDaaS solutions offer rapid deployment and appealing software update methods, when compared as an alternative to on-premises solutions. However, hybrid scenarios may require both types of deployments, cloud and on-premise, to working together. In some cases, the cloud identity service will be the ‘source of truth’ for identity data within the organization. Such an IDaaS approach can reduce the overhead of managing on-premise infrastructure for an enterprise, an activity that can be costly and inflexible.
Applying an Architectural Approach
An architectural approach can be taken to an IAM project regardless of whether it is in the collection and management of identity information or access management, using identity information for access control to protected resources.
Identity Governance and Administration
Identity Governance and Administration (IGA) covers the identity management side of IAM, e.g., the ‘admin-time’ events that establish user entitlements, as opposed to ‘real-time’ events that occur when users request access to protected resources. IGA combines administration and governance over the collection, use, and disposal of identity information. It requires a governance facility that enables managers to certify the entitlements that their staff have been granted. In addition, IGA typically includes monitoring and reporting functions for identity services that, in turn, support corporate requirements.
IGA systems support:
Administering accounts and credentials
Identity and account provisioning
Segregation of duties
Analytics and reporting
IGA systems provide additional functionality beyond standard IAM systems. In particular, they help organizations meet compliance requirements and enable them to audit access for compliance reporting. They also automate workflows for tasks such as access approvals and provisioning/deprovisioning.
The business rules that tie these elements together are generally referred to as the identity lifecycle.3 In the identity lifecycle, an identity is created that defines who or what (human or non-human) needs access to a protected resource. Every stage of the identity lifecycle sees the activities of the identity managed to ensure business rules are enforced according to the identity and security rules of the enterprise.
Figure 8: Identity Lifecycle Categories
IGA System Components
Identity governance and administration tools help facilitate identity lifecycle management.
IGA systems generally include the following components for identity administration:
Password management: using tools like password vaults or, more often, SSO, IGAs ensure users don’t have to remember many different passwords to access applications.
Integration connectors: used to integrate with directories and other systems that contain information about users and the applications and systems they have access to, as well as their authorization in those systems.
Access request approval workflows: support the automation of a user’s request for access to applications and systems and ensures all access is properly authorized.
Automated de-provisioning: supports the removal of a user’s entitlement to access an application when the user is no longer authorized to access a system.
Attestation reporting: used to periodically verify user entitlements in various applications (such as add, edit, view, or delete data) and is usually sent to a user’s manager.
Recertification of user entitlements: often a response to an attestation report, recertification of user entitlements involves recording a manager’s approval of their staff’s system access. If access is no longer required, this shifts to automatic de-provisioning.
Segregation of duties: rules that prevent risky sets of access from being granted to a person. For example, if a person has the ability to both view a corporate bank account and transfer funds to outside accounts, this might enable a user to transfer money to a personal account.
Access reviews: reviews include tools that streamline the review and verification (or revocation) of a user’s access to different apps and resources. Some IGA tools also provide discovery features that help identify entitlements that have been granted.
Role-based management: also known as Role-based Access Control (RBAC), this includes defining and managing access through user roles.
Analytics and reporting: include tools that log activities, generate reports (including for compliance), and provide analytics to identify issues and optimizations.
IGA Solution Architecture
An example of how an IGA solution could support an authentication service is shown in Figure 9 (access management shown for context):
Figure 9: IAM Architecture Components
This architecture supports the following IAM Processes:
Table 2: IAM Processes
|Identity Provisioning||Creates identity records based on initiation from trusted identity sources (e.g., the HR System)|
|Account Provisioning||Creates accounts in Enterprise Directories based on birthright provisioning rules. Also supports the creation of application accounts based on request / approval workflows.|
|Entitlement Management||Supports the workflow and administration requirements of enabling user-to-group/role mappings that enable access management rule creation.|
Access Management is the ‘real-time’ component of IAM. It encompasses the processes that are critical in protecting corporate resources and securing the digital business. Whether it is giving access to customers to enable e-commerce or securing resources for partners to conduct business securely, the Access Management architecture will control the planning, design, and development of the enabling technology.
Access Management Overview
An access management architecture will have components that enable only those accounts that are authorized to perform an action on a protected enterprise resource.
The key functions supported in an Access Management Architecture are:
User Authentication (staff, contractors, business partners)
Access Policy Management
Access Policy Decision making and enforcement
Authorization Control (Coarse / Fine-Grained)
Adaptive Access controls
Single Sign-On (SSO)
Authenticated Session Management
Security Token Services
Access Event Logging
User Behavior Analytics
Access Management Solution Architecture
The two most common Access Management services supported in most scenarios are:
Authentication – logging into a computer system - typically role-based
Authorization – accessing computer system functionality – typically attribute-based
Policy-based authorization is increasingly being deployed. It provides access control to corporate resources in accordance with centrally managed corporate policy rather than entitlements established on a system-by-system basis.
An example of a fine-grained authorization environment is shown in Figure 10. The components of the solution combine to control access to corporate resources based on the policies in the Decision Point.
Figure 10: Typical Components of an Authorization Service
The architecture of an authorization service will typically contain the key elements that are involved in the flow from an actor (person or system) on a device (mobile or desktop) that accesses an application or service (typically over the internet) that resides within an enterprise boundary (behind network firewalls).
Table 3: Policy Control Points
|Policy Control Point||Definition|
|Policy Administration Point (PAP)||responsible for creating policy statements that tie the user to a role or group and defines the type of access to a resource|
|Policy Enforcement Point (PEP)||responsible for protecting the resource; intercepts traffic to the resource, and validates access with the PDP|
|Policy Decision Point (PDP)||determines access to a resource, uses policy to determine if a subject (user) has access to a resource, usually via an attribute value or role or group membership.|
|Policy Information Point (PIP)||typically a user or attribute store that provide information about managed users (e.g., Active Directory or LDAP directory)|
Access Management Patterns
A well-crafted IAM architecture is able to both improve user experience and increase security by combining the flow between architecture components in a connected, orchestrated framework. Historically, organizations have seen security and ease of use as tradeoffs, but with the new identity technologies available today, it is possible to have both.
When combining these key components in a deployment blueprint (solution configuration), an architecture pattern evolves to support most, if not all, access management needs across the organization.
Figure 11: Access Management Patterns
Table 4: Access Management Pattern descriptions
|Browser to Web Application||A user needs to sign in to a web application that is secured by an Authentication Service|
|Native App (also Single Page App) to Web API||A native application needs to authenticate a user to access resources from a web API that is secured by an Authentication Service|
|Server App to Web API||A server application with no web user interface needs to get resources from a web API secured by an Authentication Service|
No IAM solution architecture is complete without addressing the applicable standards. Because IAM touches virtually all corporate systems, interfaces need to adhere to standards in order to minimize the amount of customization that would otherwise be required. An IAM Architecture should support a “pluggable” approach that facilitates interconnection and ties together key security enablers that are built on industry standards. There are several industry organizations (standards bodies) like IETF, OASIS, Kantara Initiative, and the OpenID Foundation.
The key standards that support modern identity and access management today are OIDC, OAuth2, and SAML.4
Figure 12: Logos for OIDC, OAuth2 , SAML
IAM practitioners should adopt the enterprise architecture approach used within the organization in which they are working. In the absence of a corporate approach to architecture, IAM practitioners should develop an architectural approach that ensures their IAM projects consider all the business systems that might be affected, the types of applications to be supported, and the infrastructure on which IAM solutions are to be deployed.
An IAM project that takes such an approach will have a significantly better chance of being completed within schedule and budget constraints. It will also be much more likely to satisfy users.
Andrew Cameron is the Enterprise Architect for Identity and Access Management at General Motors. His responsibilities include Defining the Strategy and Implementation Roadmaps of their IAM technology platform and ensuring the architectural quality of the many initiatives driving the GM digital business.
Graham Williamson is an IAM consultant working with commercial and government organizations for over 20 years with expertise in identity management and access control, enterprise architecture and service-oriented architecture, electronic commerce, and public key infrastructure, as well as ICT strategy development and project management. Graham has undertaken major projects for commercial organizations such as Cathay Pacific in Hong Kong and Sensis in Melbourne, academic institutions in Australia such as Monash University and Griffith University, and government agencies such as Queensland Government CIO’s office and the Northern Territory Government in Australia and the Ministry of Home Affairs in Singapore.
|2021-09-30||Additional information added regarding hybrid cloud infrastructures; removed specific mention of RACF; minor editorial updates|
Readers may find the IDPro BoK article “Introduction to Project Management for IAM Projects” of interest. See Williamson, Graham, and Corey Scholefield, “Introduction to Project Management for IAM Projects,” IDPro Body of Knowledge, vol 1, issue 1, March 2020, https://bok.idpro.org/article/id/25/.↩︎
OpenID Connect, website, OpenID Foundation, https://openid.net/connect/; OAuth2, website, https://oauth.net/2/ ; “Security Assertion Markup Language (SAML) V2.0 Technical Overview,” OASIS, http://docs.oasis-open.org/security/saml/Post2.0/sstc-saml-tech-overview-2.0.html↩︎