Terminating HTTPS on Amazon EC2 instances running .NET

The following configuration file creates and runs a Windows PowerShell script that performs the following tasks:

• Checks for an existing HTTPS certificate binding to port 443

• Gets the PFX certificate and password from an Amazon S3 bucket

  Note

  Add an AmazonS3ReadOnlyAccess policy to the aws-elasticbeanstalk-ec2-role to access the SSL certificate and password files in the Amazon S3 bucket.

• Installs the certificate

• Binds the certificate to port 443

  Note

  To remove the HTTP endpoint (port 80), include the Remove-WebBinding command under the Remove the HTTP binding section of the example.

Example .ebextensions/https-instance-dotnet.config

files:
  "C:\\certs\\install-cert.ps1":
    content: |
      import-module webadministration
      ## Settings - replace the following values with your own
      $bucket = "DOC-EXAMPLE-BUCKET"        ## S3 bucket name
      $certkey = "example.com.pfx" ## S3 object key for your PFX certificate
      $pwdkey = "password.txt"     ## S3 object key for a text file containing the certificate's password
      ##

      # Set variables
      $certfile = "C:\cert.pfx"
      $pwdfile = "C:\certs\pwdcontent"
      Read-S3Object -BucketName $bucket -Key $pwdkey -File $pwdfile
      $pwd = Get-Content $pwdfile -Raw

      # Clean up existing binding
      if ( Get-WebBinding "Default Web Site" -Port 443 ) {
        Echo "Removing WebBinding"
        Remove-WebBinding -Name "Default Web Site" -BindingInformation *:443:
      }
      if ( Get-Item -path IIS:\SslBindings\0.0.0.0!443 ) {
        Echo "Deregistering WebBinding from IIS"
        Remove-Item -path IIS:\SslBindings\0.0.0.0!443
      }

      # Download certificate from S3
      Read-S3Object -BucketName $bucket -Key $certkey -File $certfile
      
      # Install certificate
      Echo "Installing cert..."
      $securepwd = ConvertTo-SecureString -String $pwd -Force -AsPlainText
      $cert = Import-PfxCertificate -FilePath $certfile cert:\localMachine\my -Password $securepwd
      
      # Create site binding
      Echo "Creating and registering WebBinding"
      New-WebBinding -Name "Default Web Site" -IP "*" -Port 443 -Protocol https
      New-Item -path IIS:\SslBindings\0.0.0.0!443 -value $cert -Force
      
      ## Remove the HTTP binding
      ## (optional) Uncomment the following line to unbind port 80
      # Remove-WebBinding -Name "Default Web Site" -BindingInformation *:80:
      ##
      
      # Update firewall
      netsh advfirewall firewall add rule name="Open port 443" protocol=TCP localport=443 action=allow dir=OUT

commands:
  00_install_ssl:
    command: powershell -NoProfile -ExecutionPolicy Bypass -file C:\\certs\\install-cert.ps1

In a single instance environment, you must also modify the instance's security group to allow traffic on port 443. The following configuration file retrieves the security group's ID using an AWS CloudFormation function and adds a rule to it.

Example .ebextensions/https-instance-single.config

Resources:
  sslSecurityGroupIngress: 
    Type: AWS::EC2::SecurityGroupIngress
    Properties:
      GroupId: {"Fn::GetAtt" : ["AWSEBSecurityGroup", "GroupId"]}
      IpProtocol: tcp
      ToPort: 443
      FromPort: 443
      CidrIp: 0.0.0.0/0

For a load-balanced environment, you configure the load balancer to either pass secure traffic through untouched, or decrypt and re-encrypt for end-to-end encryption.