HowTo: Grant IAM role to Cognito authenticated user

permissionPolicy.json

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "s3:GetObject",
        "s3:PutObject",
        "s3:DeleteObject"
      ],
      "Resource": [
        "arn:aws:s3:::<S3 bucket>/${cognito-identity.amazonaws.com:sub}",
        "arn:aws:s3:::<S3 bucket>/${cognito-identity.amazonaws.com:sub}/*"
      ]
    }
  ]
}