AWS CloudFront提供了一种解决方法来降低SSL握手的出口成本。这种方法称为SNI扩展并利用基于主机的路由解决方法，可以在单个IP地址上托管和服务多个SSL/TLS证书。这意味着您可以使用SNI扩展将多个域名绑定到同一IP地址，并减少SSL握手所需的出口数据传输成本。

使用下面的CloudFormation模板创建CloudFront分布式API，并启用SNI扩展：

AWSTemplateFormatVersion: '2010-09-09'
Resources:
  CloudFrontDistribution:
    Type: 'AWS::CloudFront::Distribution'
    Properties:
      DistributionConfig:
        CallerReference: !Ref 'AWS::Region'
        DefaultCacheBehavior:
          AllowedMethods:
            - GET
            - HEAD
            - OPTIONS
          Compress: true
          DefaultTTL: 3600
          ForwardedValues:
            Cookies:
              Forward: none
            Headers:
              - Host
            QueryString: false
          MaxTTL: 86400
          MinTTL: 0
          TargetOriginId: !Ref 'apiOrigin'
          ViewerProtocolPolicy: redirect-to-https
        DefaultRootObject: index.html
        Enabled: true
        ViewerCertificate:
          CloudFrontDefaultCertificate: true
        Origins:
          - DomainName: !Sub '${apiId}.execute-api.${AWS::Region}.amazonaws.com'
            Id: !Ref 'apiOrigin'
            CustomOriginConfig:
              HTTPPort: 80
              HTTPSPort: 443
              OriginProtocolPolicy: https-only
        PriceClass: PriceClass_100
        # SNI扩展
        Aliases:
          - example.com
        ViewerCertificate:
          AcmCertificateArn:
            - arn:aws:acm:us-east-1:GOOGLE:certificate/GOOGLE
          MinimumProtocolVersion: TLSv1.2_2018
          SslSupportMethod: sni-only

注意：这是一个简