AWS Certified Solutions Architect – Associate (SAA-C03) — Question 120

A company is developing a file-sharing application that will use an Amazon S3 bucket for storage. The company wants to serve all the files through an Amazon CloudFront distribution. The company does not want the files to be accessible through direct navigation to the S3 URL.
What should a solutions architect do to meet these requirements?

Answer options

• A. Write individual policies for each S3 bucket to grant read permission for only CloudFront access.
• B. Create an IAM user. Grant the user read permission to objects in the S3 bucket. Assign the user to CloudFront.
• C. Write an S3 bucket policy that assigns the CloudFront distribution ID as the Principal and assigns the target S3 bucket as the Amazon Resource Name (ARN).
• D. Create an origin access identity (OAI). Assign the OAI to the CloudFront distribution. Configure the S3 bucket permissions so that only the OAI has read permission.

Correct answer: D

Explanation

The correct answer is D because creating an origin access identity (OAI) allows CloudFront to securely access the S3 bucket without exposing it directly. This ensures that only the OAI can read the files, while the other options either do not restrict access properly or involve incorrect configurations that do not meet the requirement of preventing direct S3 URL access.