The Impact of Conditional IAM Policy on User A

Correct Answer: D.

Conditions within an IAM policy can be used to specify conditions when a policy is in effect.

Multiple key-value pairs can be combined in a condition statement of IAM policy.

For a condition statement with ForAnyValue qualifier, if any of the attributes match in the request, then action in the “Effect” element results.

In the above IAM policy, Effect is denied, and ForAnyValue qualifier matching any request from user A with a user ID or Tags attribute will result in denying action.

Since the Username attribute is not part of the condition, User A with username attribute trying to perform PutItem action on DynamoDB table will not be denied by this IAM policy.

Option A is incorrect.

Since the effect is Deny, any attribute with a user ID or Tags used to perform PutItem action on the DynamoDB table will be denied.

Option B is incorrect.

Since the condition is ForAnyValue, any attribute matching in the request ID or tag is matched and is denied from performing PutItem action on the DynamoDB table.

Option C is incorrect.

Since the condition is ForAnyValue, any attribute matching in the request ID or tag is matched and is denied from performing PutItem action on the DynamoDB table.

For more information on Conditions with AWS IAM policies, refer to the following URL,

https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_multi-value-conditions.html

The IAM policy given in the question is a conditional policy, which means that it only applies when certain conditions are met. In this case, the condition is that the attributes being written to the table must be either "ID" or "Tags" for the policy to apply.

The policy has an "Effect" of "Deny", which means that if the condition is met, the request will be denied. The "Action" specified in the policy is "dynamodb:PutItem", which is the action that User A is trying to perform.

The "Resource" specified in the policy is "arn:aws:dynamodb:::table/Thread", which means that the policy applies to the "Thread" table in DynamoDB in all regions.

Now, let's look at the answer choices:

A. User A request is not denied by the policy when he tries to perform PutItem action in DynamoDB with either user ID or Tags attribute.

This answer is incorrect because the policy only allows the "ID" and "Tags" attributes to be written to the table. If any other attribute is included in the PutItem request, the policy will deny the request.

B. User A request is not denied by the policy when he tries to perform PutItem action in DynamoDB with just the Tags attribute.

This answer is incorrect because the policy only allows the "ID" and "Tags" attributes to be written to the table. If only the "Tags" attribute is included in the PutItem request, the policy will still deny the request because the condition is not met.

C. User A request is not denied by the policy when he tries to perform PutItem action in DynamoDB with just the user ID attribute.

This answer is incorrect because the policy only allows the "ID" and "Tags" attributes to be written to the table. If only the "ID" attribute is included in the PutItem request, the policy will still deny the request because the condition is not met.

D. User A request is not denied by the policy when he tries to perform the PutItem action in DynamoDB with just the Username attribute.

This answer is correct because the policy only applies to the "ID" and "Tags" attributes. If the request only includes the "Username" attribute, the policy will not apply and the request will be allowed.

Therefore, the correct answer is D.