AWS WAF对CloudFront后面的API Gateway没有直接影响。但是，您可以通过将API Gateway与CloudFront结合使用，并使用AWS WAF来增加安全性。下面是一个使用CloudFormation的示例代码，将CloudFront与API Gateway和AWS WAF结合使用：

Resources:
  MyApiGateway:
    Type: AWS::ApiGateway::RestApi
    Properties:
      Name: MyApiGateway

  MyApiGatewayDeployment:
    Type: AWS::ApiGateway::Deployment
    Properties:
      RestApiId: !Ref MyApiGateway

  MyApiGatewayStage:
    Type: AWS::ApiGateway::Stage
    Properties:
      RestApiId: !Ref MyApiGateway
      StageName: prod
      DeploymentId: !Ref MyApiGatewayDeployment

  MyCloudFrontDistribution:
    Type: AWS::CloudFront::Distribution
    Properties:
      DistributionConfig:
        Origins:
          - DomainName: !Ref MyApiGatewayStage
            Id: MyApiGatewayOrigin
            CustomOriginConfig:
              HTTPPort: 80
              HTTPSPort: 443
              OriginProtocolPolicy: http-only
        Enabled: true
        DefaultCacheBehavior:
          TargetOriginId: MyApiGatewayOrigin
          ForwardedValues:
            QueryString: true
          ViewerProtocolPolicy: redirect-to-https
        DefaultRootObject: index.html
        Aliases:
          - example.com
        WebACLId: !Ref MyWafWebACL

  MyWafWebACL:
    Type: AWS::WAFv2::WebACL
    Properties:
      Name: MyWafWebACL
      Scope: REGIONAL
      DefaultAction:
        Allow: {}
      VisibilityConfig:
        CloudWatchMetricsEnabled: true
        MetricName: MyWafWebACL
        SampledRequestsEnabled: true
      Rules:
        - Name: AllowAllRule
          Priority: 0
          Statement:
            RateBasedStatement:
              Limit: 1000
              AggregateKeyType: IP
            RuleAction:
              Allow: {}

上述代码创建了一个包含API Gateway、CloudFront Distribution和WAF WebACL的 CloudFormation stack。在给定的示例中，将API Gateway作为CloudFront的一个源origin，并将WAF WebACL关联到CloudFront Distribution上。

请注意，这只是一个示例，您可能需要根据自己的需求进行修改和适应。