presigned_cookie.js

const AWS = require("aws-sdk")

const keyPairId = "キーペアID"
const privateKey = "秘密鍵pem"

module.exports.handler = async () => {
  const signer = new AWS.CloudFront.Signer(
    keyPairId,
    privateKey
  )

  const signedCookie = signer.getSignedCookie({
    policy: JSON.stringify({
      Statement: [
        {
          Resource: `https://CloudFrontのドメイン(or独自ドメイン)/*`,
          Condition: {
            DateLessThan: {
              'AWS:EpochTime': Math.floor(Date.now() / 1000) + 3600
            }
          }
        }
      ]
    })
  })
  const domain = 'ドメイン(or独自ドメイン)'
  return {
    statusCode: 200,
    cookies: [
      `CloudFront-Policy=${signedCookie["CloudFront-Policy"]};Domain=${domain};path=/;Secure;HttpOnly;`,
      `CloudFront-Signature=${signedCookie["CloudFront-Signature"]};Domain=${domain};path=/;Secure;`,
      `CloudFront-Key-Pair-Id=${signedCookie["CloudFront-Key-Pair-Id"]};Domain=${domain};path=/;Secure;`
    ],
    body: JSON.stringify(userResponse)
  }
}