Enable multi-factor authentication for AWS Managed Microsoft AD

You can enable multi-factor authentication (MFA) for your AWS Managed Microsoft AD directory to increase security when your users specify their AD credentials to access Supported Amazon Enterprise applications. When you enable MFA, your users enter their username and password (first factor) as usual, and they must also enter an authentication code (the second factor) they obtain from your virtual or hardware MFA solution. These factors together provide additional security by preventing access to your Amazon Enterprise applications, unless users supply valid user credentials and a valid MFA code.

To enable MFA, you must have an MFA solution that is a Remote authentication dial-in user service (RADIUS) server, or you must have an MFA plugin to a RADIUS server already implemented in your on-premises infrastructure. Your MFA solution should implement One Time Passcodes (OTP) that users obtain from a hardware device or from software running on a device such as a cell phone.

RADIUS is an industry-standard client/server protocol that provides authentication, authorization, and accounting management to enable users to connect to network services. AWS Managed Microsoft AD includes a RADIUS client that connects to the RADIUS server upon which you have implemented your MFA solution. Your RADIUS server validates the username and OTP code. If your RADIUS server successfully validates the user, AWS Managed Microsoft AD then authenticates the user against Active Directory. Upon successful Active Directory authentication, users can then access the AWS application. Communication between the AWS Managed Microsoft AD RADIUS client and your RADIUS server require you to configure AWS security groups that enable communication over port 1812.

You can enable multi-factor authentication for your AWS Managed Microsoft AD directory by performing the following procedure. For more information about how to configure your RADIUS server to work with AWS Directory Service and MFA, see Multi-factor authentication prerequisites.

Considerations

The following are some considerations for multi-factor authentication for your AWS Managed Microsoft AD:

• Multi-factor authentication is not available for Simple AD. However, MFA can be enabled for your AD Connector directory. For more information, see Enable multi-factor authentication for AD Connector.

• MFA is a Regional feature of AWS Managed Microsoft AD. If you are using Multi-Region replication, the following procedures must be applied separately in each Region. For more information, see Global vs Regional features.

• If you intend to use AWS Managed Microsoft AD for external communications, we recommend you configure a Network Address Translation (NAT) Internet Gateway or Internet Gateway outside of the AWS network for these communications.

  • If you wish to support external communications between your AWS Managed Microsoft AD and your RADIUS server hosted on the AWS network, please contact AWS Support.

Enable multi-factor authentication for AWS Managed Microsoft AD

The following procedure shows you how to enable multi-factor authentication for AWS Managed Microsoft AD.

1. Identify the IP address of your RADIUS MFA server and your AWS Managed Microsoft AD directory.

2. Edit your Virtual Private Cloud (VPC) security groups to enable communications over port 1812 between your AWS Managed Microsoft AD IP end points and your RADIUS MFA server.

3. In the AWS Directory Service console navigation pane, select Directories.

4. Choose the directory ID link for your AWS Managed Microsoft AD directory.

5. On the Directory details page, do one of the following:

   • If you have multiple Regions showing under Multi-Region replication, select the Region where you want to enable MFA, and then choose the Networking & security tab. For more information, see Primary vs additional Regions.

   • If you do not have any Regions showing under Multi-Region replication, choose the Networking & security tab.

6. In the Multi-factor authentication section, choose Actions, and then choose Enable.

7. On the Enable multi-factor authentication (MFA) page, provide the following values:

   Display label

   Provide a label name.

   RADIUS server DNS name or IP addresses

   The IP addresses of your RADIUS server endpoints, or the IP address of your RADIUS server load balancer. You can enter multiple IP addresses by separating them with a comma (e.g., 192.0.0.0,192.0.0.12).

   Note

   RADIUS MFA is applicable only to authenticate access to the AWS Management Console, or to Amazon Enterprise applications and services such as WorkSpaces, Amazon QuickSight, or Amazon Chime. It does not provide MFA to Windows workloads running on EC2 instances, or for signing into an EC2 instance. AWS Directory Service does not support RADIUS Challenge/Response authentication.

   Users must have their MFA code at the time they enter their user name and password. Alternatively, you must use a solution that performs MFA out-of-band such as SMS text verification for the user. In out-of-band MFA solutions, you must make sure you set the RADIUS time-out value appropriately for your solution. When using an out-of-band MFA solution, the sign-in page will prompt the user for an MFA code. In this case, users must enter their password in both the password field and the MFA field.

   Port

   The port that your RADIUS server is using for communications. Your on-premises network must allow inbound traffic over the default RADIUS server port (UDP:1812) from the AWS Directory Service servers.

   Shared secret code

   The shared secret code that was specified when your RADIUS endpoints were created.

   Confirm shared secret code

   Confirm the shared secret code for your RADIUS endpoints.

   Protocol

   Select the protocol that was specified when your RADIUS endpoints were created.

   Server timeout (in seconds)

   The amount of time, in seconds, to wait for the RADIUS server to respond. This must be a value between 1 and 50.

   Note

   We recommend configuring your RADIUS server timeout to 20 seconds or less. If the timeout exceeds 20 seconds, the system cannot retry with another RADIUS server and may result in a timeout failure.

   Max RADIUS request retries

   The number of times that communication with the RADIUS server is attempted. This must be a value between 0 and 10.

   Multi-factor authentication is available when the RADIUS Status changes to Enabled.

8. Choose Enable.

Supported Amazon Enterprise applications

All Amazon Enterprise IT applications including WorkSpaces, Amazon WorkDocs, Amazon WorkMail, Amazon QuickSight, and access to AWS IAM Identity Center and AWS Management Console are supported when using AWS Managed Microsoft AD and AD Connector with MFA.

For information about how to configure basic user access to Amazon Enterprise applications, AWS Single Sign-On and the AWS Management Console using AWS Directory Service, see Enable access to AWS applications and services and Enable access to the AWS Management Console with AD credentials.

Related AWS Security blog article

• How to enable multi-factor authentication for AWS services by using AWS Managed Microsoft AD and on-premises credentials