Notes and anecdotes

Techstuff rambling

HTTPS for AWS CloudFront and AWS ELB

Wow, such easy, much free! A few simple steps on 1) How to obtain a certificate for your domain, and 2) how to use it on your CloudFront or Elastic Load Balancer.

(See 1.4 if it’s for a Load Balancer)

Quote CloudFront SSL Settings Page:

You can use certificates that you created in AWS Certificate Manager (ACM) in the US-East (N. Virginia) Region, or you can use certificates stored in the IAM certificate store.

1.1 Using AWS generated Certificate

If you don’t have a certificate (or if you do, but haven’t gotten too attached to it yet), this is the easy/recommended way – using AWS Certificate Manager:

  1. Go to AWS Certificate Manager in US East (North Virginia).
    • Request a certificate for your domain
  2. Wait… an email will arrive soon.
  3. Click the confirmation link in your e-mail and confirm that you know what’s happening
  4. Go to your CloudFront distribution > Select distribution > Distribution Settings > General > Edit
    • Make sure your domain name is in the “Alternate Domain Names (CNAMEs)” textbox.
    • Select “Custom SSL Certificate (example.com)”
    • Select the Certificate you got there.
  5. Wait… Changing a CloudFront distribution can take a while.
  6. Voilá! That’s it.

1.2 Using your own certificate

  1. Acquire a certificate (via e.g. Let’s Encrypt)
  2. Upload that via the aws cli upload-server-certificate (Important: region must be eu-east-1 (N. Virginia for CloudFront)
    aws iam upload-server-certificate
       --path /cloudfront/test/
       --server-certificate-name myFirstCertificate
       --certificate-body file://<my-pub-key-file>
       --private-key file://<my-private-key>
       --certificate-chain file://<my-certificate-chain>

    Note how the path must start with cloudfront (required for that service only).

  3. Go to step 4 in the section 1.1. Your uploaded certificate should be found there.

1.3 Troubleshooting

If your Cloudfront is in front of an s3 bucket (fishsticks) and points to its website url (fishsticks.s3-website.eu-central-1.amazonaws.com), you can run into trouble.

The S3 website url doesn’t support https out of the box. You can fix this by setting The Origin Protocol Policy to HTTP Only (CloudFront > Distribution Settings > Origin > Edit), which will make traffic between your CloudFront and S3 bucket be http. If you’re uncomfortable with this, you can points to its regular bucket url (https://fishsticks.s3.amazonaws.com/), which do support https. If you do, remember to set default root object on your CloudFront.

1.4 For Elastic Load balancer

If you’re using your own certificate, do steps 1.2 above. Else, do steps 1.1. In both cases, you must request/upload them to the same region as your ELB.

Then, add your certificate to your ELB by following the steps in Add an HTTPS Listener using the Console guide on AWS.


 

AWScertificate managercloudfrontelastic load balancerelbhttpsssl

tomfa • 2016-09-23


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