How to use the command 'aws acm-pca' (with examples)
AWS Certificate Manager Private Certificate Authority (ACM PCA) is a service that allows users to create and manage private certificate authorities (CAs), which are essential for encrypting and securing private networks. A private CA is instrumental in generating and distributing digital certificates within an organization, ensuring internal communications are secured. The aws acm-pca command provides several functionalities for creating, managing, and deleting private CAs and managing certificates issued by these authorities.
Use case 1: Create a private certificate authority
Code:
aws acm-pca create-certificate-authority --certificate-authority-configuration ca_config --idempotency-token token --permanent-deletion-time-in-days number
Motivation:
Creating a private certificate authority is the first step in managing an internal network’s encryption strategy. By setting up a CA, you can start issuing certificates that authenticate and secure internal services. This minimizes the reliance on public CAs for internal communications, offering more control and potentially reducing costs.
Explanation:
--certificate-authority-configuration ca_config: This parameter specifies the configuration settings for your CA, including the subject name of the root CA and its key configuration.--idempotency-token token: This acts as a unique identifier to ensure the command’s idempotency, ensuring that re-running the command doesn’t accidentally create duplicate resources.--permanent-deletion-time-in-days number: Defines the number of days after which the CA is permanently deleted if it has been disabled. This allows a grace period for any necessary recovery actions.
Example output:
{
"CertificateAuthorityArn": "arn:aws:acm-pca:region:account-id:certificate-authority/CA-ID"
}
Use case 2: Describe a private certificate authority
Code:
aws acm-pca describe-certificate-authority --certificate-authority-arn ca_arn
Motivation:
After creating a CA, you may want to retrieve detailed information about it, such as its current status, configuration settings, and more. This command helps ensure that the CA is correctly set up and properly functioning, which is crucial for the security of your internal network.
Explanation:
--certificate-authority-arn ca_arn: This specifies the Amazon Resource Name (ARN) of the CA you’d like to describe. The ARN uniquely identifies the CA in AWS.
Example output:
{
"CertificateAuthority": {
"Arn": "arn:aws:acm-pca:region:account-id:certificate-authority/CA-ID",
"Status": "ACTIVE",
"CertificateAuthorityConfiguration": {
...
},
...
}
}
Use case 3: List private certificate authorities
Code:
aws acm-pca list-certificate-authorities
Motivation:
Managing multiple CAs can become complex, so being able to list all CAs in your account is beneficial for oversight and management. This command provides a consolidated view of all your CAs, helping you monitor and manage your encryption infrastructure.
Explanation:
- No additional arguments are needed; the command in its bare form will list all available private CAs in your account.
Example output:
{
"CertificateAuthorities": [
{
"Arn": "arn:aws:acm-pca:region:account-id:certificate-authority/CA-ID-1",
"Status": "ACTIVE",
...
},
{
"Arn": "arn:aws:acm-pca:region:account-id:certificate-authority/CA-ID-2",
"Status": "PENDING_CERTIFICATE",
...
}
]
}
Use case 4: Update a certificate authority
Code:
aws acm-pca update-certificate-authority --certificate-authority-arn ca_arn --certificate-authority-configuration ca_config --status status
Motivation:
There may be occasions when you need to update a CA’s configuration or change its status. For example, you might update the configuration to reflect changes in the organizational unit or move the CA to active or disabled status based on your organization’s needs.
Explanation:
--certificate-authority-arn ca_arn: Identifies the CA to update.--certificate-authority-configuration ca_config: Specifies any updates to the CA’s configuration.--status status: Updates the status of the CA, which can be set to ACTIVE or DISABLED.
Example output:
{
"CertificateAuthorityArn": "arn:aws:acm-pca:region:account-id:certificate-authority/CA-ID"
}
Use case 5: Delete a private certificate authority
Code:
aws acm-pca delete-certificate-authority --certificate-authority-arn ca_arn
Motivation:
When a CA is no longer required, or you need to eliminate old CAs to maintain a tidy environment, safely deleting a CA becomes necessary. Removing unnecessary CAs helps reduce exposure to potential security risks and keeps your AWS environment organized.
Explanation:
--certificate-authority-arn ca_arn: Identifies the CA you wish to delete. This ensures that the correct CA is deleted without affecting others.
Example output:
{}
Use case 6: Issue a certificate
Code:
aws acm-pca issue-certificate --certificate-authority-arn ca_arn --certificate-signing-request cert_signing_request --signing-algorithm algorithm --validity validity
Motivation:
Once a CA is created, issuing certificates is one of its primary functions. Certificates are used to provide secure communications within your network. You can issue a certificate tailored to the needs of specific services or devices within your organization.
Explanation:
--certificate-authority-arn ca_arn: Identifies the CA that will issue the certificate.--certificate-signing-request cert_signing_request: The CSR contains the public key and other details needed for the certificate.--signing-algorithm algorithm: Specifies the signing algorithm (e.g., SHA256WITHRSA) used by the CA.--validity validity: Sets the validity period of the issued certificate.
Example output:
{
"CertificateArn": "arn:aws:acm-pca:region:account-id:certificate-authority/CA-ID/certificate/certificate-id"
}
Use case 7: Revoke a certificate
Code:
aws acm-pca revoke-certificate --certificate-authority-arn ca_arn --certificate-serial serial --reason reason
Motivation:
If a key associated with a certificate is compromised, or the certificate is no longer needed, revoking it is essential to maintain security. Revoked certificates are added to the Certificate Revocation List (CRL), informing clients that the certificate should not be trusted.
Explanation:
--certificate-authority-arn ca_arn: Identifies the issuing CA.--certificate-serial serial: The serial number of the certificate to be revoked.--reason reason: The reason for revocation, which could be compromise, cessation of operation, or unspecified.
Example output:
{}
Use case 8: Get certificate details
Code:
aws acm-pca get-certificate --certificate-authority-arn ca_arn --certificate-arn cert_arn
Motivation:
Understanding the intricacies of an issued certificate, such as its serial number, validity periods, or subject details, is vital for audits, troubleshooting, and ensuring compliance. This command fetches and displays detailed certificate information.
Explanation:
--certificate-authority-arn ca_arn: Identifies the CA that issued the certificate.--certificate-arn cert_arn: Specifies the ARN of the certificate to be fetched.
Example output:
{
"Certificate": "-----BEGIN CERTIFICATE----- ... -----END CERTIFICATE-----",
"CertificateChain": "-----BEGIN CERTIFICATE----- ... -----END CERTIFICATE-----"
}
Conclusion
The aws acm-pca command is a powerful tool for managing private certificate authorities and certificates within AWS. By utilizing the various options and commands available, organizations can secure internal communications effectively, manage certificates with agility, and ensure internal networks are protected against unauthorized access. Through these use cases, users gain an understanding of how to create, manage, and revoke certificates, as well as keep track of and describe certificate authorities essential for a secure digital infrastructure.
