Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
A company uses an Amazon S3 bucket to store sensitive documents. The security team requires that all objects uploaded to the bucket must be encrypted at rest using server-side encryption with a customer-managed KMS key (SSE-KMS). A developer needs to enforce this by denying any PutObject request that does not specify the required encryption. Which bucket policy condition should be used?
Answer choices
Why each option matters
Good practice is not just finding the correct option. The wrong answers often show the exact trap the exam wants you to fall into.
A
Best answer
"Condition": {"StringNotEquals": {"s3:x-amz-server-side-encryption-aws-kms-key-id": "arn:aws:kms:us-east-1:123456789012:key/abc123"}}
This condition key allows you to specify the exact KMS key ARN that must be used. A StringNotEquals condition will deny requests that do not use the correct key.
B
Distractor review
"Condition": {"StringNotEquals": {"s3:x-amz-server-side-encryption": "aws:kms"}}
This condition only checks that SSE-KMS is used, but does not enforce a specific key ID. Any KMS key would be accepted.
C
Distractor review
"Condition": {"Null": {"s3:x-amz-server-side-encryption-aws-kms-key-id": "true"}}
This condition denies requests if the key ID header is present, which is opposite of the requirement.
D
Distractor review
"Condition": {"ArnNotEquals": {"s3:x-amz-server-side-encryption-aws-kms-key-id": "arn:aws:kms:us-east-1:123456789012:key/abc123"}}
The condition key 's3:x-amz-server-side-encryption-aws-kms-key-id' does not support ArnNotEquals; it uses StringNotEquals. Also, the key ID in the condition should be the full ARN.
Common exam trap
Common exam trap: ACLs stop at the first match
ACLs are processed top to bottom. The first matching entry wins, and an implicit deny usually exists at the end.
Technical deep dive
How to think about this question
ACL questions test precision: source, destination, protocol, port and direction. A generally correct ACL can still fail if it is applied on the wrong interface or in the wrong direction.
KKey Concepts to Remember
- Standard ACLs match source addresses.
- Extended ACLs can match source, destination, protocol and ports.
- The first matching ACL entry is used.
- There is usually an implicit deny at the end.
TExam Day Tips
- Check inbound versus outbound direction.
- Read the ACL from top to bottom.
- Look for a broader permit or deny above the intended line.
Related practice questions
Related DVA-C02 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
More questions from this exam
Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.
Question 1
A developer is building a REST API using Amazon API Gateway that will serve static content from an Amazon S3 bucket. The API should cache responses for frequently accessed objects to reduce latency. Which API Gateway feature should the developer enable?
Question 2
A developer is running a web application on multiple Amazon EC2 instances behind an Application Load Balancer (ALB). The application needs to store user session state that must be available across all instances. The session data is small and temporary but must survive individual instance failures. Which AWS service should the developer use to store this session state?
Question 3
A developer has an AWS Lambda function that processes messages from an Amazon SQS standard queue. The function is idempotent and currently has a batch size of 10. The developer wants to increase throughput and increases the batch size to 100. After the change, CloudWatch metrics show a significant increase in throttles and the queue backlog is growing. The function's reserved concurrency is set to 10. What is the most effective action to resolve the throttling and improve throughput?
Question 4
A developer is managing an application running on Amazon EC2 instances behind an Application Load Balancer. Users report that the application becomes unresponsive after several hours, and restarting the instance temporarily fixes the issue. The developer suspects a memory leak but cannot add custom instrumentation. Which AWS service can collect memory utilization metrics and help identify the memory leak with minimal configuration?
Question 5
A developer is building a serverless web application using AWS Lambda and Amazon DynamoDB. The application needs to perform complex aggregations on data stored in DynamoDB. Which AWS service should the developer use to perform these aggregations efficiently without reading all the data into Lambda?
Question 6
A developer has an Amazon S3 bucket containing private user documents. The application must generate a time-limited URL for users to download their own documents without requiring the users to have AWS credentials. Which solution should the developer use?
FAQ
Questions learners often ask
What does this DVA-C02 question test?
Standard ACLs match source addresses.
What is the correct answer to this question?
The correct answer is: "Condition": {"StringNotEquals": {"s3:x-amz-server-side-encryption-aws-kms-key-id": "arn:aws:kms:us-east-1:123456789012:key/abc123"}} — To enforce SSE-KMS, you need a condition that checks for the 'x-amz-server-side-encryption-aws-kms-key-id' header or the 's3:x-amz-server-side-encryption' condition key. The correct condition key is 's3:x-amz-server-side-encryption-aws-kms-key-id' to require a specific KMS key. Using 's3:x-amz-server-side-encryption' only checks if encryption is specified but not the key ID.
What should I do if I get this DVA-C02 question wrong?
Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.
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