SSL Error: Hostname/IP does not match certificate's altnames

Question

I have a ReactJs front-end app deployed in Netlify and  Rails back-end app deployed on AWS using Elastic Beanstalk. When I test my app with Postman making requests to my API via HTTP, I get results back, but fetching to it via HTTPS gives me the following error:

"SSL Error: Hostname/IP does not match certificate's altnames"

I acquired a domain from GoDaddy, and added the certificate to the AWS load balancer by adding a listener on PORT 443. Even after that, I can't seem to fetch from any source who's URL starts with https.

If anyone could briefly meet over a zoom call and shed some light on this issue, I would highly appreciate it. This is my only obstacle before having a fully functional full-stack application.

Please feel free to contact me through linkedIn at: https://www.linkedin.com/in/albertogonzalez1091/

Thank you!
Alberto Gonzalez

Answer

Next a few things you can check to ensure that you configured your certificate correctly:

Certificate Validation: Verify that the certificate's CN or SAN includes your domain (e.g., example.com, and/or *.example.com, or subdomain.example.com).
DNS Settings: Ensure your domain points to the AWS load balancer.
Load Balancer Listener: Double-check that your load balancer's listener for port 443 uses the correct SSL certificate.
Application Routing: Ensure ReactJS makes HTTPS requests to the correct AWS domain (e.g., https://example.com/api).
HTTPS Redirect: Set up an HTTP to HTTPS redirect in your load balancer settings.

SSL Error: Hostname/IP does not match certificate's altnames

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