AWS IAM Basics: Identity and Access Management

AWS Identity and Access Management (IAM) is a service that enables you to manage users and user permissions for your AWS account. With IAM, you can create and manage users, groups, and policies that control access to Amazon EC2 instances, Amazon S3 buckets, and other AWS resources.

This article will discuss the basics of AWS IAM: what it is, how it works, and how you can use it to secure your AWS account.

What Is IAM Used For?

IAM is used to manage the security of user access to AWS resources. It is basically responsible for managing user life cycles, meaning creating accounts, assigning roles, granting access, deleting accounts, enforcing policy, and more. With IAM solutions in place, organizations can enable secure access and authentication of user accounts while minimizing the risk of unauthorized access.

You can manage users and groups, assign permissions, and control user access to your AWS resources. For example, you could create a group of users with permission to view Amazon S3 buckets but not modify them or create a user that only has permission to manage EC2 instances.

How Does IAM Work?

AWS IAM provides access control through the use of policies. Policies are documents that define who has access to what resources and what actions they can take on those resources. For example, you could create a policy that allows only certain users to view S3 buckets or modify EC2 instances.

Once you've created your policies, you assign them to users or groups of users. Then, when an AWS user attempts to access a resource, IAM evaluates the user's permissions against the policy assigned to them and either grants or denies access accordingly.

AWS IAM Components

AWS IAM consists of four core components: users, groups, roles, and policies.

Users

Users are individual AWS accounts that can be granted access to your AWS resources. You can assign users specific permissions with policies or assign them to groups so they inherit the group's permissions. This means you can give different levels of access to certain services and control what types of actions each user is able to perform. 

Groups

Groups are collections of users that share the same set of permissions. When you assign a policy to a group, all members of the group will receive those same permissions. AWS IAM groups provide a secure and consistent way for teams with varying needs and roles to access cloud resources without needing multiple administrative logins.

Policies

Policies define what actions a user or service may take on AWS resources. They are written using JSON and contain one or more statements that control who has access, what actions they may take, and which resources they can access. Policies are assigned to users or groups and govern how they interact with AWS resources, such as Amazon S3 buckets and EC2 instances. 

Below you can find an example of JSON policy syntax from the IAM documentation:

{

  "Version": "2012-10-17",

  "Statement": {

    "Effect": "Allow",

    "Action": "s3:ListBucket",

    "Resource": "arn:aws:s3:::example_bucket"

  }

}

Roles

Roles are similar to groups. They also have associated policies, but roles are not tied to a particular user or group. They can be used to grant limited access to applications and users, allowing for greater security and control over resources. For example, an IAM Role can be assigned to an IAM user, and this role will determine what part of the AWS environment they have access to, such as EC2 instances or S3 buckets. Each IAM Role also includes a set of permissions rules which further limit what user activities can be performed within that role's scope. 

Using AWS IAM

The AWS IAM console is the main interface for managing users, groups, and policies. From here, you can create new users and groups, assign policies to them, manage existing user permissions, and view access logs.

You can also use the AWS CLI or APIs to manage your IAM resources from the command line or programmatically. This allows you to integrate IAM into automated processes, such as setting up EC2 instances or deploying applications.

The console provides a graphical user interface for managing IAM components, while the CLI is used for more complex tasks like creating custom policies.

Features of the Identity Access Management

AWS IAM provides a number of features to help you manage your users and resources. Here are some of the key features:

• Multi-factor authentication (MFA): MFA can be used to increase security by requiring users to provide additional forms of identification, such as FIDO security keys, TOTP hardware tokens, or time-based one-time passwords generated from a virtual authenticator app.

• Access control lists (ACLs): ACLs can be used to restrict access to specific resources or actions on those resources. For example, you can create an ACL that only allows certain users to view S3 buckets but not modify them.

• Identity federation: Identity federation enables users from other systems, such as Active Directory, to log in with their existing credentials. This can be used to simplify user management and reduce the burden of maintaining separate accounts for each system.

• Identity and access auditing: IAM provides audit logs that track user activities such as login attempts, policy changes, and resource accesses. These logs can be used to monitor user activity and detect potential security issues.

AWS IAM is an essential part of any AWS account. It provides a secure way to manage users and resources and control who has access to what resources. With IAM, you can create policies that define user permissions, assign them to users or groups, and use MFA and ACLs for additional security.

The audit logging features allow you to monitor user activity and detect potential issues. In addition, AWS IAM is an important tool for ensuring your AWS account remains secure and compliant with industry standards.

Conclusion

This article has provided an overview of the basics of AWS IAM, what it is, how it works, and how you can use it to secure your AWS account.

To learn more about IAM, including creating users and groups, assigning permissions with policies, and managing user access logs, be sure to check out the official Amazon documentation on Identity Access Management.