title: Denying a Sign-up request in Cognito User Pools
body: <p>The description of a Cognito User Pools Pre Sign-up Lambda Trigger is: </p>
  
  <blockquote>
    <p>This trigger is invoked when a user submits their information to sign up, allowing you to perform custom validation to accept or deny the sign up request.</p>
  </blockquote>
  
  <p>I want to deny a sign-up request based on a certain condition in my Lambda. The trigger parameters (reproduced from the docs below) seem to only support auto-verification and auto-confirmation: </p>
  
  <pre><code>{
      "request": {
          "userAttributes": {
              "string": "string",
              ....
          },
          "validationData": {
              "string": "string",
              "string": "string",
               ....
          }
      },
  
      "response": {
          "autoConfirmUser": "boolean",
          "autoVerifyPhone": "boolean",
          "autoVerifyEmail": "boolean"
      }
  }
  </code></pre>
  
  <p>How can I accept or deny a sign-up request based on the outcome of the Pre Sign-up Lambda Trigger?</p>