Amazon Cognito is a service designed to add user sign-up, sign-in, and access control to web and mobile applications. It directly supports the requirements by providing two main components: User Pools and Identity Pools. A User Pool is a user directory that provides sign-up and sign-in options for app users, including direct sign-in with a user name and password. Identity Pools enable granting users access to other AWS services and support federation with third-party identity providers, such as social providers (like Google, Facebook) and enterprise providers (via SAML 2.0).

A. AWS IAM Identity Center is used to manage single sign-on access for an organization's workforce to AWS accounts and business applications, not for authenticating an application's end-users.
B. AWS Signer is a code-signing service that ensures the trust and integrity of your code; it is not used for user authentication.
D. AWS Directory Service provides managed directories, such as Microsoft Active Directory, primarily for enterprise IT and workforce identity management, not for consumer-facing application authentication with social providers.

1. Amazon Cognito Developer Guide: "Amazon Cognito provides authentication

authorization

and user management for your web and mobile apps. Your users can sign in directly with a user name and password

or through a third party such as Facebook

Amazon

Google or Apple."

Source: AWS Documentation

What Is Amazon Cognito?

Introduction.

2. AWS IAM Identity Center (AWS Single Sign-On) User Guide: "AWS IAM Identity Center (AWS Single Sign-On) is a cloud-based service that makes it easy to centrally manage single sign-on (SSO) access to all of your AWS accounts and cloud applications... IAM Identity Center is for the administrators and users in your workforce."

Source: AWS Documentation

What Is AWS IAM Identity Center?

Introduction.

3. AWS Signer Developer Guide: "AWS Signer is a fully managed code-signing service to ensure the trust and integrity of your code. Organizations use Signer to validate code against a digital signature to confirm that the code is unaltered and from a trusted publisher."

Source: AWS Documentation

What Is AWS Signer?

Introduction.

4. AWS Directory Service Administration Guide: "AWS Directory Service for Microsoft Active Directory

also known as AWS Managed Microsoft AD

enables your directory-aware workloads and AWS resources to use managed Active Directory in the AWS Cloud."

Source: AWS Documentation

AWS Directory Service Administration Guide

"What is AWS Managed Microsoft AD?".