Q:

Find S3 Bucket Owner

If there is a bucket that I have read/write access on from my AWS account, is there any way to get the CanonicalUser id of the owner?
Reading the ACL Policy seems to be impossible unless you are the owner : /.

A:

Use get-bucket-acl, if you have read permission of the bucket. It would give output like this
{
    "Owner": {
        "DisplayName": "my-username",
        "ID": "7009a8971cd538e11f6b6606438875e7c86c5b672f46db45460ddcd087d36c32"
    },
    "Grants": [
        {
            "Grantee": {
                "DisplayName": "my-username",
                "ID": "7009a8971cd538e11f6b6606438875e7c86c5b672f46db45460ddcd087d36c32"
            },
            "Permission": "FULL_CONTROL"
        }
    ]
}

