前提

受信確認まで終わってること
- 【AWS SDK for PHP】AWS SNSでHTTPエンドポイントへの受信確認するまでの簡単なメモ - Qiita https://qiita.com/kure/items/b286b003050c326a1843

メモ

{
  "Type" : "Notification",
  "MessageId" : "xxxxxxxxxx",
  "TopicArn" : "arn:aws:sns:ap-northeast-1:xxxxxx:http-test",
  "Subject" : "kenmei",
  "Message" : "message",
  "Timestamp" : "2018-11-29T10:00:51.206Z",
  "SignatureVersion" : "1",
  "Signature" : "xx+xxxxxxx==",
  "SigningCertURL" : "https://sns.ap-northeast-1.amazonaws.com/SimpleNotificationService-xxxxxxx.pem",
  "UnsubscribeURL" : "https://sns.ap-northeast-1.amazonaws.com/?Action=Unsubscribe&SubscriptionArn=arn:aws:sns:ap-northeast-1:xxxxxx:http-test:xxxxxxx"
}