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Event Information

  • The ResendValidationEmail event in AWS Certificate Manager refers to the action of resending the validation email for a certificate request.
  • This event is triggered when the initial validation email fails to be delivered or when the recipient does not respond within the specified time frame.
  • Resending the validation email allows the certificate requester to complete the validation process and obtain a valid certificate for their domain.

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Examples

  1. Insecure email communication: Resending the validation email for Certificate Manager may involve sending sensitive information, such as validation tokens or private keys, via email. This can potentially expose the information to interception or unauthorized access, compromising the security of the certificate issuance process.

  2. Email spoofing and phishing attacks: Resending validation emails can increase the risk of email spoofing and phishing attacks. Attackers may attempt to impersonate the Certificate Manager service or the certificate authority, tricking users into providing sensitive information or clicking on malicious links.

  3. Lack of email security controls: Resending validation emails may bypass certain email security controls, such as spam filters or email encryption mechanisms. This can result in the delivery of validation emails to insecure or compromised email accounts, further increasing the risk of unauthorized access to the validation tokens or private keys.

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Remediation

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Using Console

  1. Identify the issue: Use the AWS Certificate Manager console to check the status of your certificates. Look for any certificates that are expired or nearing expiration.

  2. Renew or replace the certificate: If you have a certificate that is expired or nearing expiration, you can renew it or replace it with a new certificate. To do this, follow these steps:

    • Go to the AWS Certificate Manager console.
    • Select the certificate that needs to be renewed or replaced.
    • Click on the “Actions” button and choose either “Renew” or “Replace” depending on your requirements.
    • Follow the on-screen instructions to complete the renewal or replacement process.

  3. Update the certificate in your application or service: After renewing or replacing the certificate, you need to update it in your application or service to ensure that it is being used. The steps to update the certificate will depend on the specific application or service you are using. Generally, you will need to update the certificate in the configuration settings or SSL/TLS settings of your application or service.

Note: It is recommended to set up automated certificate renewal to avoid expiration issues in the future. You can do this by enabling the “Auto Renew” option for your certificates in the AWS Certificate Manager console.

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Using CLI

To remediate issues related to AWS Certificate Manager using AWS CLI, you can follow these steps:

  1. Renew a certificate:

    • Use the aws acm renew-certificate command to renew a certificate.
    • Specify the ARN of the certificate using the --certificate-arn parameter.
    • Optionally, you can provide a new private key using the --private-key parameter.
    • Example command: aws acm renew-certificate --certificate-arn <certificate_arn>

  2. Delete an expired certificate:

    • Use the aws acm delete-certificate command to delete an expired certificate.
    • Specify the ARN of the certificate using the --certificate-arn parameter.
    • Example command: aws acm delete-certificate --certificate-arn <certificate_arn>

  3. Enable automatic renewal for a certificate:

    • Use the aws acm update-certificate-options command to enable automatic renewal for a certificate.
    • Specify the ARN of the certificate using the --certificate-arn parameter.
    • Set the RenewalEligibility parameter to ENABLED to enable automatic renewal.
    • Example command: aws acm update-certificate-options --certificate-arn <certificate_arn> --options RenewalEligibility=ENABLED

Please note that you need to replace <certificate_arn> with the actual ARN of the certificate you want to remediate.

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Using Python

To remediate issues related to AWS Certificate Manager using Python, you can use the AWS SDK for Python (Boto3) to interact with the AWS Certificate Manager API. Here are three examples of how you can remediate common issues:

  1. Renewing an expiring certificate:

    • Use the boto3.client('acm') method to create a client object for AWS Certificate Manager.
    • Use the list_certificates() method to retrieve a list of all certificates.
    • Iterate through the list and identify the expiring certificate based on the NotAfter attribute.
    • Use the renew_certificate() method to renew the expiring certificate.
    import boto3

client = boto3.client('acm')

def renew_certificate():
    certificates = client.list_certificates()['CertificateSummaryList']
    for certificate in certificates:
        if certificate['NotAfter'] < datetime.datetime.now():
            response = client.renew_certificate(
                CertificateArn=certificate['CertificateArn']
            )
            print(f"Renewed certificate: {response['CertificateArn']}")

renew_certificate()

  2. Deleting an unused certificate:

    • Use the list_certificates() method to retrieve a list of all certificates.
    • Iterate through the list and identify the unused certificate based on your criteria (e.g., no associated resources).
    • Use the delete_certificate() method to delete the unused certificate.
    import boto3

client = boto3.client('acm')

def delete_unused_certificate():
    certificates = client.list_certificates()['CertificateSummaryList']
    for certificate in certificates:
        if not certificate['InUseBy']:
            response = client.delete_certificate(
                CertificateArn=certificate['CertificateArn']
            )
            print(f"Deleted certificate: {response['CertificateArn']}")

delete_unused_certificate()

  3. Importing a certificate from an external source:

    • Use the import_certificate() method to import a certificate from an external source.
    • Provide the necessary parameters such as the certificate’s private key, public key, and certificate chain.
    • Optionally, specify the certificate’s domain name and tags.
    import boto3

client = boto3.client('acm')

def import_certificate():
    response = client.import_certificate(
        CertificateArn='arn:aws:acm:us-east-1:123456789012:certificate/abcdefg-1234-5678-90ab-cdef12345678',
        Certificate='-----BEGIN CERTIFICATE-----\n...',
        PrivateKey='-----BEGIN PRIVATE KEY-----\n...',
        CertificateChain='-----BEGIN CERTIFICATE-----\n...',
        Tags=[
            {
                'Key': 'Environment',
                'Value': 'Production'
            }
        ]
    )
    print(f"Imported certificate: {response['CertificateArn']}")

import_certificate()

Please note that you need to have the necessary permissions and configure your AWS credentials before running these scripts.