How does an CERT record work
When a device or application needs to verify the identity of a domain, it queries the DNS for a CERT record. If a CERT record exists, it provides the certificate or information about the certificate. The application can then use this data to establish a secure connection or verify an email’s authenticity.
The data stored in a CERT record is encoded, ensuring it is secure and efficient to distribute. This encoding ensures that sensitive certificate information is protected during transmission.
Understanding key components
CERT records contain several components that define their purpose and function.
- Domain Name: This is the domain or subdomain associated with the certificate. For example, “secure.mybusiness.com” or “email.mybusiness.com.”
- Certificate Type: This indicates the type of certificate stored in the record. Common types include X.509 for websites and PGP for email encryption.
- Key Tag: This is a unique identifier for the certificate, helping distinguish it from others in the DNS.
- Algorithm: This specifies the cryptographic algorithm used to generate the certificate. Examples include RSA and DSA.
- Certificate Data: This is the actual certificate or certificate-related information, encoded in a secure format.
Examples
CERT records can be used in various scenarios where secure communication or authentication is required.
- If you want to provide secure email communication for your domain, a CERT record can store a PGP certificate. This certificate allows users to send encrypted emails to addresses like “info@mybusiness.com,” ensuring that only the intended recipient can read them.
- Another example is for secure website connections. A CERT record can store an X.509 certificate used for SSL/TLS encryption. When users visit your website, their browsers can retrieve the certificate and verify that your site is authentic and secure.
- CERT records are also useful for distributing public keys in IoT (Internet of Things) systems, where secure communication between devices is critical.
How to check your CERT records
Checking your CERT records ensures that they are properly configured and accessible. To view your CERT records, log in to your domain registrar or DNS hosting provider. Navigate to the DNS management section, where all your domain’s DNS records are listed.
In the DNS settings, look for entries labeled as “CERT.” These will display the domain name, certificate type, and encoded certificate data. Verify that the records contain the correct certificate information provided by your certificate authority or encryption service.
Common problems and how to fix them
CERT records can encounter issues that affect the distribution and use of certificates. Understanding and addressing these problems is critical for maintaining secure communication.
- Missing CERT Records: If a required CERT record is missing, systems relying on it for encryption or authentication will fail. Add the correct record to your DNS settings based on your service provider’s instructions.
- Incorrect Certificate Data: Mistakes in the certificate data can cause validation errors. Double-check the encoded certificate information to ensure it matches the certificate provided by your certificate authority.
- Unsupported DNS Providers: Not all DNS providers support CERT records. If your provider does not support them, consider switching to a provider that does or explore alternative methods for distributing certificates.
- Propagation Delays: Changes to CERT records can take time to propagate across the internet. Plan updates carefully and verify the records after the propagation period.
- Expired Certificates: Certificates stored in CERT records have expiration dates. Ensure that you update the records with new certificates before the old ones expire to maintain uninterrupted security.
