title: How does S3 get permission from Lambda trigger?
body: <p>I'm working out the security details for working with Lambda. One thing I can't find out is how S3 gets permission to push to Lambda when you add a trigger from the Lambda console or via S3 - Properties - Events. I know how it works using the CLI and I know you could do it via the SDK but I also noticed it isn't always necessary. Mostly the trigger just 'works' without me adding any permissions. Does anybody know why?</p>
  
  <p>And is there a way to find out what Permissions S3/an S3 bucket has? I know there's a tab 'Permissions' but that's not giving me any information. I also know about Truster Advisor but that's just telling me there's no explicit problem with the permissions. I'm wondering if I can get a list of permissions though? </p>
  
  <p>I hope someone can help me out, thanks in advance!</p>