Great question — Amazon Cognito and AWS Identity and Access Management (IAM) are both identity and access management services in AWS, but they serve different purposes and user groups.
Let’s unpack this clearly 👇
🧠 Overview
| Service | Main Purpose |
|---|---|
| AWS IAM | Manage access to AWS resources for internal users, services, and roles (admins, developers, EC2, Lambda, etc.) |
| Amazon Cognito | Manage authentication and access for external users (app users, customers, website or mobile app users) |
🧩 Amazon Cognito
🧠 What It Is
Amazon Cognito is an identity and user authentication service designed for applications — especially web and mobile apps.
It helps you handle:
Sign-up / Sign-in
Password reset
User profile management
Social login (Google, Facebook, Apple)
Security (MFA, email verification)
You can think of it as the “login system for your application users.”
⚙️ Key Components
| Component | Description |
|---|---|
| User Pools | A secure user directory that stores user credentials and handles signup/signin. |
| Identity Pools (Federated Identities) | Provide AWS credentials (temporary IAM roles) to users after authentication. |
| Hosted UI | Ready-made login UI that supports username/password and social logins. |
📱 Example Use Case
You build a mobile app that allows users to log in via:
Google or Facebook
Or an email + password
After login, Cognito:
Authenticates the user
Issues a JWT token
Grants access to AWS resources (via an Identity Pool)
✅ Example: Upload profile pictures to S3
→ Cognito gives temporary IAM credentials to that user for S3 upload access only.
🧩 Key Features
User registration and authentication
MFA (Multi-Factor Authentication)
Account recovery
Federation (Google, Facebook, SAML, OIDC)
Temporary AWS credentials
Integration with API Gateway, Lambda, AppSync
🔐 AWS Identity and Access Management (IAM)
🧠 What It Is
AWS IAM is a core security service that manages who can access which AWS resources and what actions they can perform.
It’s mainly for administrators, developers, and AWS services — not for your app’s customers.
⚙️ Key Components
| Component | Description |
|---|---|
| Users | Individual accounts for people who manage AWS (admins, developers). |
| Groups | Collections of IAM users with shared permissions. |
| Roles | Assign permissions to AWS services or applications (e.g., EC2, Lambda). |
| Policies | JSON-based rules defining allowed/denied actions (e.g., “Allow S3:GetObject”). |
🧾 Example Use Case
Grant your developer permission to manage S3 buckets.
Allow EC2 instances to access a DynamoDB table.
Give Lambda function permission to invoke another service.
✅ IAM manages who in your AWS account can do what.
⚖️ Cognito vs. IAM — Key Differences
| Feature | Amazon Cognito | AWS IAM |
|---|---|---|
| Audience | App users (external) | AWS users, developers, services (internal) |
| Purpose | Authenticate & authorize end-users | Control access to AWS resources |
| Identity Type | Federated, social, or custom user accounts | AWS account users, roles, and policies |
| Credential Type | JWT tokens (ID, Access, Refresh) | Access keys, temporary STS tokens |
| Integration | Mobile apps, web apps, API Gateway | AWS console, SDKs, EC2, Lambda, S3, etc. |
| Federation | Supports Google, Facebook, Apple, SAML | Supports cross-account IAM roles and SAML (for enterprise login) |
| Primary Use Case | “Log in to my app” | “Grant service/user access to AWS resources” |
| Management Level | Application-level identity | Infrastructure-level identity |
| Access Granularity | Temporary AWS credentials per user | Fine-grained permissions for AWS entities |
🧠 Analogy
| Scenario | Explanation |
|---|---|
| Cognito | Like a login system for your app’s end-users (customers). |
| IAM | Like a security guard managing access between AWS services, admins, and developers. |
🧩 When They Work Together
Often, you use both:
Cognito authenticates a user (e.g., from a web app).
Then Cognito issues temporary IAM credentials (via an Identity Pool).
These credentials let the user securely access AWS services (like S3 or DynamoDB) without exposing your IAM keys.
🧭 Summary Table
| Aspect | Amazon Cognito | AWS IAM |
|---|---|---|
| Who logs in | End-users (app customers) | AWS users, admins, services |
| Manages | Authentication (who users are) | Authorization (what users can do) |
| Token Type | JWT tokens | AWS Access Keys / STS Tokens |
| Use Case | App login & federated access | Secure AWS infrastructure management |
| Access Scope | Temporary AWS credentials for app users | Full AWS resource access control |
✅ In short:
Cognito = Login and identity management for your app users.
IAM = Permission and access management for your AWS environment.
Would you like me to show a diagram of how Cognito + IAM work together (e.g., app user authenticates → Cognito issues token → IAM grants temporary AWS access)?
No comments:
Post a Comment