Self-Study: Permissions and Policies in AWS (2.6)

 

Brief

This self-study module covers the foundational concepts of Permissions and Policies in AWS Identity and Access Management (IAM). It includes types of policies, best practices, and hands-on activities to create, manage, and evaluate IAM permissions and policies.

Videos

1. Introduction to IAM Permissions and Policies
2. Understand the basics of AWS IAM, including how permissions and policies work together to control access.
3. Watch the video: https://www.youtube.com/watch?v=SXSqhTn2DuE
4. IAM Policy Types and Examples
5. Learn about Identity-Based Policies, Resource-Based Policies, and other advanced IAM features.
6. Watch the video: https://www.youtube.com/watch?v=BmkVTOsUadE&ab_channel=StephaneMaarek
7. Best Practices for IAM in AWS
8. Explore practical tips for securing IAM user credentials and policies in AWS.
9. Watch the video: https://www.youtube.com/watch?v=TKmf3VKh-Sc&ab_channel=Pythoholic

Readings

1. AWS IAM Overview
2. Learn the fundamental components of IAM, including users, groups, roles, and policies.
3. Read more: https://aws.amazon.com/iam/
4. IAM Policy Types
5. Understand the different types of IAM policies, such as Identity-Based Policies, Resource-Based Policies, and Permissions Boundaries.
6. Read more: https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies.html
7. Identity-Based Policies
8. Dive deeper into managed and inline policies and how to assign them to users, groups, and roles.
9. Read more: https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies_identity-vs-resource.html
10. IAM Best Practices
11. Follow AWS’s recommended best practices for managing IAM permissions and policies securely.
12. Read more: https://aws.amazon.com/iam/resources/best-practices/
13. Policy Evaluation Logic
14. Explore how AWS evaluates permissions and policies to determine access.
15. Read more: https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_evaluation-logic.html

Hands-On Practice

1. Create an IAM User and Assign Permissions

• Create a new IAM user in AWS Management Console.
• Attach the ReadOnlyAccess managed policy to the user.
• Test the user’s permissions by accessing an S3 bucket and verifying that only read operations are allowed.

1. Create a Custom Identity-Based Policy

• Write a custom policy in JSON format to allow specific actions (e.g., S3 List and GetObject).
• Attach the policy to an IAM role and validate its permissions.

1. Resource-Based Policy for Cross-Account Access

• Create an S3 bucket policy that allows access from another AWS account.
• Test cross-account access by switching between accounts.

1. Implement and Test Permissions Boundaries

• Set up a permissions boundary for an IAM role to restrict maximum permissions.
• Test how permissions boundaries interact with identity-based policies.

1. Use Session Policies

• Create a temporary session for a role using the AWS CLI with a session policy.
• Test the session’s limited permissions and observe how they differ from the role’s full permissions.

Key Concepts

1. IAM Core Components

• Users: Represent human individuals requiring AWS access.
• Groups: Collections of users sharing the same permissions.
• Roles: Permissions assigned to AWS services or cross-account access.
• Policies: JSON documents defining permissions.

1. Types of Policies

• Identity-Based Policies: Attach to users, groups, or roles.
• Resource-Based Policies: Attach to resources like S3 buckets.
• Permissions Boundaries: Set maximum permissions for identity-based policies.
• Session Policies: Limit permissions for temporary sessions.

1. Best Practices

• Rotate access keys regularly.
• Require Multi-Factor Authentication (MFA).
• Follow the principle of least privilege.
• Avoid using root credentials for everyday tasks.

1. Policy Evaluation Logic

• Explicit DENY takes precedence over ALLOW.
• The final permissions result is the intersection of all applicable policies.

1. Policy Syntax

• Effect: Allow or Deny.
• Action: Specifies the AWS actions (e.g., s3:GetObject).
• Resource: Defines the resources to which the policy applies.

Helpful Links (References)

1. AWS IAM User Guide
2. Comprehensive documentation for all IAM features and use cases.
3. Visit: https://docs.aws.amazon.com/IAM/latest/UserGuide/
4. IAM JSON Policy Elements
5. Learn about the structure and elements of IAM policy JSON documents.
6. Visit: https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_elements.html
7. IAM Policy Simulator
8. Test and validate IAM policies using AWS’s policy simulator.
9. Visit: https://policysim.aws.amazon.com/
10. Cross-Account Access in AWS
11. Guide to setting up secure cross-account access using IAM roles and policies.
12. Visit: https://docs.aws.amazon.com/IAM/latest/UserGuide/tutorial_cross-account-with-roles.html