Identity and Access Management (IAM)¶
Introduction¶
AWS Identity and Access Management (IAM) is a global service that provides secure control over access to AWS resources. This guide outlines the core components and best practices for implementing IAM effectively in your AWS environment.
Users and Groups¶
IAM begins with the root account, which is created by default for every AWS account. However, the root account shouldn’t be used for daily operations or shared among users. Instead, organizations should create individual IAM users for people within their organization.
Users can be organized into groups for easier management. While groups can contain multiple users, they cannot contain other groups. It’s important to note that users have flexibility in group membership - they can belong to multiple groups or no group at all, depending on organizational needs.
IAM Permissions¶
Permission management in IAM is handled through JSON documents called policies. These policies define the specific permissions granted to users or groups. AWS emphasizes the principle of least privilege, meaning users should only receive permissions necessary for their tasks.
The policy structure consists of several key components. The Version field specifies the policy language version, typically “2012-10-17”. An optional Id field provides a policy identifier. The Statement section, which is required, contains one or more individual statements that define specific permissions.
Each statement includes several elements: - A Sid (Statement ID) for optional identification - An Effect that specifies whether to Allow or Deny access - A Principal that defines the account, user, or role affected - Action fields listing permitted or denied actions - Resource specifications indicating which AWS resources are affected - Optional Condition elements that define when the policy takes effect
Password Policy¶
IAM enables robust password security through customizable password policies. Organizations can establish requirements for password complexity, including minimum length and character type requirements such as uppercase letters, lowercase letters, numbers, and special characters. The system can enforce password expiration periods, prevent password reuse, and allow IAM users to manage their own passwords.
Multi-Factor Authentication (MFA)¶
Multi-Factor Authentication adds an essential security layer to AWS accounts. It combines something users know (their password) with something they own (an MFA device). This protection is crucial for both root accounts and IAM users, as it prevents unauthorized access even if passwords are compromised.
AWS supports several MFA device options. Virtual MFA devices include Google Authenticator and Authy for mobile devices. Physical security keys include Universal 2nd Factor (U2F) devices like YubiKey. Hardware key fob options are available from providers like Gemalto, with special versions for AWS GovCloud from SurePassID.
AWS Access Methods¶
Users can interact with AWS through three primary methods: the AWS Management Console, Command Line Interface (CLI), and Software Development Kit (SDK). The Console requires password and MFA protection, while CLI and SDK access is secured through access keys.
Access keys consist of an Access Key ID (similar to a username) and a Secret Access Key (similar to a password). These credentials must be carefully managed and never shared. Users are responsible for managing their own access keys through the AWS Console.
AWS CLI and SDK¶
The AWS Command Line Interface provides a tool for interacting with AWS services through command-line shells. It enables direct access to AWS service APIs and supports script development for resource management. The CLI is open-source and serves as an alternative to the AWS Management Console.
The AWS Software Development Kit provides language-specific APIs for programmatic AWS access. It supports multiple programming languages including JavaScript, Python, PHP, .NET, Ruby, Java, Go, Node.js, and C++. The SDK also includes support for mobile development (Android, iOS) and IoT devices (Embedded C, Arduino).
IAM Roles for Services¶
AWS services often need to perform actions on behalf of users. IAM Roles facilitate this by providing temporary credentials to AWS services. Common implementations include EC2 Instance Roles, Lambda Function Roles, and Roles for CloudFormation.
Security Tools¶
IAM provides two primary security assessment tools. The IAM Credentials Report offers account-level insights by listing all users and their credential status. The IAM Access Advisor provides user-level analysis of service permissions and their usage, helping administrators refine access policies.
Best Practices¶
AWS recommends several IAM best practices: - Reserve root account use for initial AWS account setup only - Create individual AWS users for each physical user - Manage permissions through groups rather than individual users - Implement and enforce strong password policies - Require MFA for all users - Use roles for AWS service permissions - Utilize access keys for programmatic access - Regular auditing using IAM security tools - Maintain strict control over IAM credentials
Shared Responsibility Model¶
The IAM service operates under AWS’s shared responsibility model. AWS maintains infrastructure security, performs configuration and vulnerability analysis, and ensures compliance validation. Customers are responsible for managing users, groups, roles, and policies, enabling MFA, rotating access keys, implementing appropriate permissions, and monitoring access patterns.
Through proper implementation of these IAM components and best practices, organizations can maintain secure and efficient access to their AWS resources while minimizing security risks.