AWS Certificate Manager (ACM) is a service that simplifies the process of provisioning, managing, and deploying Secure Sockets Layer/Transport Layer Security (SSL/TLS) certificates for use with AWS services and internal connected resources. With ACM, you can request and manage public and private certificates seamlessly, enabling secure communications over the internet and within your organization. This knowledge base provides a comprehensive guide to setting up AWS Certificate Manager, including certificate provisioning, validation methods, deployment options, and best practices.

Understanding AWS Certificate Manager

What is SSL/TLS?

Secure Sockets Layer (SSL) and its successor, Transport Layer Security (TLS), are cryptographic protocols that provide secure communication over a computer network. When a user accesses a website that uses HTTPS, SSL/TLS encrypts the data transmitted between the user's browser and the web server, ensuring data integrity and privacy.

Benefits of Using AWS Certificate Manager

1. Simplified Management: ACM automates the process of renewing and deploying SSL/TLS certificates, reducing manual intervention.
2. Free Public Certificates: ACM provides free public certificates, eliminating the need for a third-party certificate authority (CA).
3. Integration with AWS Services: ACM integrates with various AWS services such as Elastic Load Balancing, Amazon CloudFront, and Amazon API Gateway, making it easy to secure web applications.
4. Private Certificates: With ACM Private Certificate Authority (CA), you can create and manage private certificates for internal resources.

Setting Up AWS Certificate Manager

Setting up AWS Certificate Manager involves several steps, including requesting a certificate, validating domain ownership, and deploying the certificate. This section outlines the process in detail.

Accessing AWS Certificate Manager

1. Log in to the AWS Management Console.
2. Navigate to the AWS Certificate Manager service by searching for ACM in the search bar.

Requesting a Certificate

Once you're in the ACM console, you can request a new certificate.

1. Click on the Request a certificate button.

2. Choose between a Public certificate and a Private certificate:

   • Public certificate: For securing your website or applications accessible over the internet.
   • Private certificate: For securing internal applications and services.

3. Click on Next after selecting the certificate type.

Domain Validation

ACM requires you to validate that you own or control the domain for which you are requesting the certificate. There are two primary methods for domain validation:

 Email Validation

1. ACM sends an email to the registered contact addresses for the domain.
2. Choose one or more email addresses (e.g., admin@yourdomain.com) to receive the validation email.
3. Click Next after selecting your email addresses.

 DNS Validation

1. ACM provides a CNAME record that you need to add to your domain’s DNS settings.
2. Choose this option and copy the provided CNAME record.
3. Log in to your DNS provider and create a new CNAME record with the values provided by ACM.
4. After adding the record, return to the ACM console and click Next.

Adding Tags (Optional)

You can optionally add tags to the certificate request to help organize your resources.

1. Click Next after adding any tags you wish to use.

Review and Request

1. Review your certificate details, including the domain name and validation method.
2. Click on Confirm and request to submit your certificate request.

Validation Process

• Email Validation: If you chose email validation, check the selected email inbox for the validation email and follow the instructions within to confirm domain ownership.
• DNS Validation: The status of your certificate will change to Pending validation while ACM checks for the CNAME record. This can take a few minutes. Once ACM detects the record, the status will change to Issued.

Deploying the Certificate

Once your certificate is issued, you can deploy it to various AWS services.

Choose a Deployment Option

ACM allows you to deploy certificates to different AWS services, including:

• Elastic Load Balancing: Use the certificate to secure connections to your load balancer.
• Amazon CloudFront: Secure your CloudFront distributions with SSL/TLS.
• Amazon API Gateway: Protect your APIs with SSL/TLS.

Deploy to Elastic Load Balancer (ELB)

1. Navigate to the EC2 dashboard and select Load Balancers.
2. Choose the load balancer where you want to deploy the certificate.
3. Go to the Listeners tab and click on View/edit rules for the HTTPS listener.
4. Select Change certificate and then select the certificate you requested from ACM.
5. Click Update to save your changes.

Deploy to Amazon CloudFront

1. Go to the CloudFront console.
2. Select the distribution where you want to use the certificate.
3. Choose the General tab and select Edit.
4. Under SSL Certificate, select Custom SSL Certificate (example.com) and choose your ACM certificate.
5. Click Yes, Edit to apply the changes.

Deploy to API Gateway

1. Navigate to the API Gateway console.
2. Select your API and go to the Custom Domain Names section.
3. Choose Create and enter your custom domain name.
4. Select ACM Certificate and choose the certificate from the dropdown.
5. Configure your API mapping and click Create to finish.

Managing Certificates

Renewing Certificates

ACM automatically handles renewals for public certificates issued by ACM. However, you should monitor the expiration dates for private certificates.

1. Navigate to the ACM console.
2. Select the certificate and view its expiration date.
3. If a certificate is nearing its expiration, ACM will notify you. You can manually renew it by following the same process used to request a new certificate.

Deleting Certificates

To delete an ACM certificate:

1. Go to the ACM console.
2. Select the certificate you want to delete.
3. Click on the Delete button and confirm your action.

Viewing Certificate Details

You can view details such as the certificate status, domain names, and validation method from the ACM console.

1. Select the certificate from the list.
2. Review the details in the lower pane of the console.

Best Practices for Using AWS Certificate Manager

1. Choose the Right Validation Method: If you frequently change DNS records, consider using DNS validation for easier management.
2. Monitor Certificate Status: Regularly check the status of your certificates to ensure they are issued and not nearing expiration.
3. Use Tags: Utilize tags to organize and identify your certificates, making it easier to manage them over time.
4. Automate Renewal Notifications: Set up CloudWatch alarms to notify you of upcoming certificate expirations, especially for private certificates that require manual renewal.
5. Secure Private Keys: When using ACM Private CA, ensure that the private keys are stored securely and access is restricted to authorized personnel.

Troubleshooting Common Issues

Certificate Not Issued

1. Validation Issues: Check your domain validation status. If using DNS validation, confirm that the CNAME record is correctly configured.
2. Email Validation: Ensure that the email address you chose is monitored and check your spam folder for the validation email.

Deployment Failures

1. Mismatch Errors: Ensure that the certificate is correctly attached to the intended AWS resource (e.g., load balancer, CloudFront distribution).
2. Propagation Delays: Sometimes changes can take a few minutes to propagate. Wait for a few moments and try again.

Certificate Expiration Alerts

1. Enable CloudWatch Alarms: Set up CloudWatch alarms to notify you of certificate expiration so you can take action before they expire.
2. Regular Audits: Regularly audit your certificates and their expiration dates to ensure timely renewals.

AWS Certificate Manager simplifies the management of SSL/TLS certificates, enabling secure communications across AWS resources. By following the steps outlined in this knowledge base, you can effectively set up and manage your certificates within ACM.

With its integration into various AWS services and the automation of certificate renewals, ACM is an essential tool for maintaining security and compliance in your cloud infrastructure. Understanding best practices and troubleshooting common issues can enhance your experience with AWS Certificate Manager, ensuring your applications remain secure and reliable.