IAM Roles, Security Tools, and Monitoring

In this lesson, we’ll explore how AWS enables secure and temporary access to resources using IAM roles, and how developers can monitor and secure that access using AWS security services and observability tools. We’ll start with the problem IAM roles solve, examine how temporary credentials work, and conclude how services like CloudTrail, IAM Access Analyzer, and GuardDuty enhance visibility and governance.

IAM roles

IAM roles are identities that AWS services or applications can assume to perform actions on AWS resources. IAM roles provide secure, temporary access to AWS resources without long-term credentials, supporting scalable and secure application development.

They are used whenever an AWS service or external user needs to perform actions without using static credentials, such as a Lambda function accessing an S3 bucket. Roles are created with permissions and can be assumed by trusted entities. Multiple policies associated with an IAM role dictate the scope of permissions of the role and the entities that are allowed to use the role. These policies are as follows:

• Trust policy: This resource-based policy specifies the entities allowed to assume an IAM role.

• Permissions policy: This identity-based policy specifies the role’s permissions.

An IAM role can have multiple permission policies attached to it, but only one trust policy. Also, we can create an IAM role without a permission policy, but specifying a trust policy is required during the creation of an IAM role. Upon assuming a role, AWS issues temporary credentials enabling secure access within the permission boundaries defined by the role.

Using MFA for secure role assumptions

To enhance IAM role security, AWS allows roles to require multi-factor authentication (MFA) during the AssumeRole process. This is enforced in the trust policy using a condition like "aws:MultiFactorAuthPresent": "true".

This ensures that even if access keys are compromised, attackers can't assume roles without an MFA token. It's particularly useful for roles with administrative privileges or those used in cross-account access.

Understanding the basic idea of IAM roles provides the foundation for understanding how AWS applies them in a broader security model known as role-based access control (RBAC).

Role-based access control (RBAC) with IAM roles

AWS Identity and Access Management (IAM) roles implement role-based access control (RBAC) principles. RBAC allows centralized management of permissions, simplifying security administration and enforcing the principle of least privilege. It is used when multiple users, services, or applications need standardized access to resources based on their roles rather than individual identity management. Permissions are attached to roles, not users. ...