NET::ERR_CERT_INVALID: Details

• Cert completely malformed (non-DER/PEM)
• Cert issued for wrong key type
• Chain cycle (A signs B, B signs A)
• Legacy cert SHA-1 signature (deprecated)
• Multiple concurrent issues

1. openssl x509 -in cert.pem -text -noout — parse cert
2. openssl s_client -connect host:443 -servername host — live handshake
3. Enterno SSL Checker — automatic analysis
4. chrome://net-export/ — save network log for analysis
5. Reissue via Let's Encrypt — fresh start

Check SSL Certificate →

• ERR_SSL_PROTOCOL_ERROR
• NET::ERR_CERT_AUTHORITY_INVALID
• SSL Handshake Failed
• All SSL errors

The NET::ERR_CERT_INVALID error in Chrome can be attributed to various underlying causes related to SSL certificate validation. Understanding these causes is crucial for effective troubleshooting.

Here are some common reasons for this error:

• AUTHORITY_INVALID: This occurs when the certificate is not issued by a trusted certificate authority (CA). Ensure that the CA is recognized by major browsers.
• DATE_INVALID: This error indicates that the SSL certificate is either expired or not yet valid. Check the certificate’s validity period to ensure it is current.
• COMMON_NAME_INVALID: This happens when the domain name in the SSL certificate does not match the domain being accessed. Verify that the certificate is issued for the correct domain.

Each of these causes requires a different approach for resolution, and identifying the specific reason is the first step towards fixing the NET::ERR_CERT_INVALID error.

Using command line tools can provide deeper insights into SSL certificate issues that lead to the NET::ERR_CERT_INVALID error. Here are two powerful tools: nslookup and openssl.

1. **nslookup**: This command helps verify the DNS resolution for the domain. Open your terminal and run:

Check if the returned IP matches your server's IP address. If not, you may have a DNS issue.

2. **openssl s_client**: This command allows you to connect to the server and retrieve the SSL certificate details. Use the following command:

This will display the certificate chain, validity dates, and any errors. Look for messages that indicate issues like 'unable to verify the first certificate' or 'certificate has expired'.

By utilizing these tools, you can diagnose the SSL certificate problems more effectively and implement the necessary fixes.

Resolving the NET::ERR_CERT_INVALID error typically involves a series of checks and potential fixes. Below are some common strategies to address the issue:

• Update Your SSL Certificate: If the certificate is expired or about to expire, renew it with your certificate authority. Ensure that the new certificate is correctly installed on your server.
• Check Certificate Chain: Ensure that your server is sending the complete certificate chain. Use openssl s_client to verify that intermediate certificates are included.
• Verify Domain Name: Ensure that the SSL certificate's common name matches the domain name. If it does not, you may need to reissue the certificate with the correct domain.
• Clear Browser Cache: Sometimes, the error may persist due to cached data. Clear your browser's cache and try accessing the site again.
• Adjust Server Configuration: Ensure that your web server is configured correctly to serve the SSL certificate. Check your server's configuration files for any misconfigurations.

By systematically applying these fixes, you can resolve the NET::ERR_CERT_INVALID error and restore secure access to your website.