listcerts.com

The idea for this website came from the fact that there isn't a good place online (or I couldn't easily find one), where one can see the SSL certificates used by a website in an HTTPS connection.

Chrome, Firefox, and Edge all provide ways for everyone to view the SSL certificates in the browser, but each of them displays the certificates differently. I believe that for most people certificate information is difficult to read, and when that is paired with a complex presentation, it becomes nearly impossible to comprehend it. Which is why it's important to have a clean design. In my opinion, Firefox does this best in their browser, and this project is largely inspired by that.

How to start this project locally

The front end of this project is built with React and bundled with Webpack. If you have Node installed locally, you can run this app by first installing all dependencies npm i and then starting the project with npm start in the terminal. You can access http://localhost:3000 to view it in the browser.

The page will reload if you make edits, and you will also see any lint errors in the console.

Technologies

Front end

• I use React for the front end. The code is strongly typed with Typescript.
• The UI is built with React Bootstrap components.
• The code is bundled with Webpack and follows ES6.

Back end

• The back end is written in Go. It is executed by an AWS Lambda function.
• To build it, run GOARCH=arm64 GOOS=linux go build -tags lambda.norpc -o bootstrap . This builds the binary for the new Graviton2 CPUs and removes the RPC calls from binary (the RPC calls are not present in the new provided.al2 runtime): https://aws.amazon.com/blogs/compute/migrating-aws-lambda-functions-from-the-go1-x-runtime-to-the-custom-runtime-on-amazon-linux-2/
• To upload it to AWS Lambda, compress the bootstrap file to a .zip archive and upload it.

Hosting

• The front end is hosted on AWS S3 as static content.
• The back end consists of an API endpoint provided by AWS API Gateway, which is linked to an AWS Lambda function, and executes it on each request.
• The domains and the DNS records are managed by AWS Route53.
• The SSL certificates for HTTPS are provided by AWS Certificate Manager.
• An AWS CloudFront distribution is the link between the Route53 DNS records, the SSL certificate, and the S3 bucket.

Resources

If you'd like to learn how to host a static website yourself on AWS S3 with all of the tooling above, I highly recommend this blog post, which helped me a lot in the hosting process: https://towardsdatascience.com/static-hosting-with-ssl-on-s3-a4b66fb7cd00