Amazon Private CA VPC endpoints (Amazon PrivateLink)

You can create a private connection between your VPC and Amazon Private CA by configuring an interface VPC endpoint. Interface endpoints are powered by Amazon PrivateLink, a technology for privately accessing Amazon Private CA API operations. Amazon PrivateLink routes all network traffic between your VPC and Amazon Private CA through the Amazon network, avoiding exposure on the open internet. Each VPC endpoint is represented by one or more elastic network interfaces with private IP addresses in your VPC subnets.

The interface VPC endpoint connects your VPC directly to Amazon Private CA without an internet gateway, NAT device, VPN connection, or Amazon Direct Connect connection. The instances in your VPC don't need public IP addresses to communicate with the Amazon Private CA API.

To use Amazon Private CA through your VPC, you must connect from an instance that is inside the VPC. Alternatively, you can connect your private network to your VPC by using an Amazon Virtual Private Network (Amazon VPN) or Amazon Direct Connect. For information about Amazon VPN, see VPN Connections in the Amazon VPC User Guide. For information about Amazon Direct Connect, see Creating a Connection in the Amazon Direct Connect User Guide.

Amazon Private CA does not require the use of Amazon PrivateLink, but we recommend it as an additional layer of security. For more information about Amazon PrivateLink and VPC endpoints, see Accessing Services Through Amazon PrivateLink.

Considerations for Amazon Private CA VPC endpoints

Before you set up interface VPC endpoints for Amazon Private CA, be aware of the following considerations:

Amazon Private CA API currently supports VPC endpoints in the following Amazon Web Services Regions:

Creating the VPC endpoints for Amazon Private CA

You can create a VPC endpoint for the Amazon Private CA service using either the VPC console at https://console.amazonaws.cn/vpc/ or the Amazon Command Line Interface. For more information, see the Creating an Interface Endpoint procedure in the Amazon VPC User Guide. Amazon Private CA supports making calls to all of its API operations inside your VPC.

If you have enabled private DNS host names for the endpoint, then the default Amazon Private CA endpoint now resolves to your VPC endpoint. For a comprehensive list of default service endpoints, see Service Endpoints and Quotas.

If you have not enabled private DNS host names, Amazon VPC provides a DNS endpoint name that you can use in the following format:

vpc-endpoint-id.acm-pca.region.vpce.amazonaws.com

For more information, see Amazon Private CA VPC endpoints (Amazon PrivateLink) in the Amazon VPC User Guide.

Create a VPC endpoint policy for Amazon Private CA

You can create a policy for Amazon VPC endpoints for Amazon Private CA to specify the following:

For more information, see Controlling Access to Services with VPC Endpoints in the Amazon VPC User Guide.

Example – VPC endpoint policy for Amazon Private CA actions

When attached to an endpoint, the following policy grants access for all principals to the Amazon Private CA actions IssueCertificate, DescribeCertificateAuthority, GetCertificate, GetCertificateAuthorityCertificate, ListPermissions, and ListTags. The resource in each stanza is a private CA. The first stanza authorizes the creation of end-entity certificates using the specified private CA and certificate template. If you don't want to control the template being used, the Condition section is not needed. However, removing this allows all principals to create CA certificates as well as end-entity certificates.

{
      "Statement":[
         {
            "Principal":"*",
            "Effect":"Allow",
            "Action":[
               "acm-pca:IssueCertificate"
            ],
            "Resource":[
               "arn:aws:acm-pca:us-east-1:111122223333:certificate-authority/11223344-1234-1122-2233-112233445566"
            ],
            "Condition":{
               "StringEquals":{
                  "acm-pca:TemplateArn":"arn:aws:acm-pca:::template/EndEntityCertificate/V1"
               }
            }
         },
         {
            "Principal":"*",
            "Effect":"Allow",
            "Action":[
               "acm-pca:DescribeCertificateAuthority",
               "acm-pca:GetCertificate",
               "acm-pca:GetCertificateAuthorityCertificate",
               "acm-pca:ListPermissions",
               "acm-pca:ListTags"
            ],
            "Resource":[
               "arn:aws:acm-pca:us-east-1:111122223333:certificate-authority/11223344-1234-1122-2233-112233445566"
            ]
         }
      ]
   }