SCS-C02 Exam Dumps : AWS Certified Security - Specialty

An Application Load Balancer (ALB) is a type of load balancer that operates at the application layer (layer 7) of the OSI model. It can distribute incoming traffic based on the content of the request, such as the host header, path, or query parameters. An ALB can also terminate TLS connections and decrypt requests from clients before sending them to the targets.

To implement TLS for incoming traffic to the application, the following steps are required:

Create a public ALB in a public subnet and register the EC2 instances as targets in a target group.

Create two listeners for the ALB, one on port 80 for HTTP traffic and one on port 443 for HTTPS traffic.

Create a rule for the listener on port 80 to redirect HTTP requests to HTTPS using the same host, path, and query parameters.

Provision a public TLS certificate in AWS Certificate Manager (ACM) for the domain name of the application. ACM is a service that lets you easily provision, manage, and deploy public and private SSL/TLS certificates for use with AWS services and your internal connected resources.

Attach the certificate to the listener on port 443 and configure the security policy to negotiate secure connections between clients and the ALB.

Configure the security groups for the ALB and the EC2 instances to allow inbound traffic on ports 80 and 443 from the internet and outbound traffic on any port to the EC2 instances.

This solution will meet the requirements of implementing TLS for incoming traffic without impacting performance or requiring end-to-end encryption. The ALB will handle the TLS termination and decryption, while forwarding unencrypted requests to the EC2 instances.

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The correct answer is B. Instruct users to run the aws sts get-session-token CLI command and pass the multi-factor authentication --serial-number and --token-code parameters. Use these resulting values to make API/CLI calls.

According to the AWS documentation1, the aws sts get-session-token CLI command returns a set of temporary credentials for an AWS account or IAM user. The credentials consist of an access key ID, a secret access key, and a security token. These credentials are valid for the specified duration only. The session duration for IAM users can be between 15 minutes and 36 hours, with a default of 12 hours.

You can use the --serial-number and --token-code parameters to provide the MFA device serial number and the MFA code from the device. The MFA device must be associated with the user who is making the get-session-token call. If you do not provide these parameters when your IAM user or role has a policy that requires MFA, you will receive an Access Denied error.

The temporary security credentials that are returned by the get-session-token command can then be used to make subsequent API or CLI calls that require MFA authentication. You can use environment variables or a profile in your AWS CLI configuration file to specify the temporary credentials.

Therefore, this solution will resolve the problem of users being unable to perform EC2 commands using the AWS CLI, while still enforcing MFA.

The other options are incorrect because:

A. Changing the value of aws:MultiFactorAuthPresent to true will not work, because this is a condition key that is evaluated by AWS when a request is made. You cannot set this value manually in your policy or request. You must provide valid MFA information to AWS for this condition key to be true.

C. Implementing federated API/CLI access using SAML 2.0 may work, but it requires more operational effort than using the get-session-token command. You would need to configure a SAML identity provider and trust relationship with AWS, and use a custom SAML client to request temporary credentials from AWS STS. This solution may also introduce additional security risks if the identity provider is compromised.

D. Creating a role and enforcing MFA in the role trust policy may work, but it also requires more operational effort than using the get-session-token command. You would need to create a role for each user or group that needs to perform EC2 commands, and specify a trust policy that requires MFA. You would also need to grant the users permission to assume the role, and instruct them to use the sts assume-role command instead of the get-session-token command.

To configure DNSSEC for a domain registered with Route 53, the most operationally efficient solution is to migrate the zone to Route 53 with DNSSEC signing enabled, create a key-signing key (KSK) that is based on an AWS Key Management Service (AWS KMS) customer managed key, and add a delegation signer (DS) record to the parent zone. This way, Route 53 handles the zone-signing key (ZSK) and the signing of the records in the hosted zone, and the customer only needs to manage the KSK in AWS KMS and provide the DS record to the domain registrar. Option A is incorrect because it does not involve migrating the zone to Route 53, which would simplify the DNSSEC configuration. Option B is incorrect because it creates both a ZSK and a KSK based on AWS KMS customer managed keys, which is unnecessary and less efficient than letting Route 53 manage the ZSK. Option C is incorrect because it does not involve migrating the zone to Route 53, and it requires running the dnssec-signzone command manually, which is less efficient than letting Route 53 sign the zone automatically.Verified References: