Wednesday, April 22, 2015

Renew expiring GeoTrust HTTPS/SSL certificate in Amazon AWS for S3 and CloudFront

Key Insight

AWS doesn't let you modify the key for server-credentials, forcing you to create new ones and then update CloudFront(CF) and Elastic Load Balancer(ELB) configurations to use the new cert.

My corporate https/ssl certificate is expiring. I need to renew it and get it pushed to AWS IAM for use in S3 and CloudFront. If you're in the same boat, I hope these instructions help you out.

PS. Hi Future me, I'll see you in about a year when this round of certs expires.

Materials Needed:

  1. CSR and private key file.
    1. The current set is preferred.
    2. If you don't have the original files, you can create a new pair.
    3. If you are changing the CSR, your certificate authority may need to spend time re-validating you.
  2. account & password to your certificate authority.
  3. aws credentials and access to modify IAM certificates
  4. aws command line tools installed.

Basic Steps:

  1. Renew the certificate:
    1. Connect to certificate authority.  For me this is GeoTrust
    2. Click the big [renew]  button by your current certificate.  
      1. pick the new certificate term,  
      2. confirm admin and billing contacts
      3. update the CSR for confirmation
      4. pay.
      5. wait for confirmation
  2. Download and prep the certificate files:
    1. Download the certificate bundle.  Choose type "other" which will provide a zipped bundle of files. Unzip and enter the directory.
    2. crossRootCA.cer
    3. Create a certificate bundle from the root and intermediate file:
    4. cat IntermediateCA.cer crossRootCA.cer > geotrust-chain.pem
    5. Copy the original secure key to the local dir.  For me this is company.rsa.key.  This must be a RSA key in x509 format.
    6. cp secret_files/company.rsa.key ./
  3. Create a new AWS IAM server-certificate.
    1. AWS doesn't support modifying the keyfile in existing server-certificates, we need to create new ones.
    2. CloudFront requires a separate server-certificate with a path starting with 'cloudfront/', so we'll upload the key twice to create two server-c
    3. aws iam upload-server-certificate \
      --server-certificate-name company-test \
      --certificate-body file://ssl_certificate.cer \
      --private-key file://company.rsa.key \
      --certificate-chain file://geotrust-chain.pem \
      --path /
      aws iam upload-server-certificate \
      --server-certificate-name company-test-cf \
      --certificate-body file://ssl_certificate.cer \
      --private-key file://company.rsa.key \
      --certificate-chain file://geotrust-chain.pem \
      --path /cloudfront/
  4. Update AWS to use the new server-certificates
    1. Cloudfront:
      1. For each CloudFront distribution using the expiring server-certificate: 
        1. In the console: Console -> CloudFront -> Distribution Name -> [General] -> [Edit] 
        2. Then choose the new certificate from the drop-down.
    2. ELB:
      1. Console -> EC2 -> (pick region) -> Load Balancers
      2. For each load balancer that uses HTTPS with the old cert:
        1. right-click -> 'edit listeners'
        2. Use the "change" link in the SSL Certificate column.
          1. Certificate Type: Choose an existing certificate
          2. Certificate Name: choose new certiicate from the drop-down
Today I learned about and used the aws iam *-server-certificate* commands. Next steps would be bypassing the console and automating detection and updates of ELB and CF entries.


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