Amazon s3 – 403 Forbidden with Correct Bucket Policy

Question

I'm trying to make all of the images I've stored in my s3 bucket publicly readable, using the following bucket policy.

{
"Id": "Policy1380877762691",
"Statement": [
    {
        "Sid": "Stmt1380877761162",
        "Action": [
            "s3:GetObject"
        ],
        "Effect": "Allow",
        "Resource": "arn:aws:s3:::<bucket-name>/*",
        "Principal": {
            "AWS": [
                "*"
            ]
        }
    }
]

}

I have 4 other similar s3 buckets with the same bucket policy, but I keep getting 403 errors.

The images in this bucket were transferred using s3cmd sync as I'm trying to migrate the contents of the bucket to a new account.

The only difference that I can see is that

1. i'm using an IAM user with admin access, instead of the root user
2. the files dont have a "grantee : everyone open/download file" permission on each of the files, something the files had in the old bucket

Answer 1

If you want everyone to access your S3 objects in the bucket, the principal should be "*", i.e., like this:

{
"Id": "Policy1380877762691",
"Statement": [
    {
        "Sid": "Stmt1380877761162",
        "Action": [
            "s3:GetObject"
        ],
        "Effect": "Allow",
        "Resource": "arn:aws:s3:::<bucket-name>/*",
        "Principal": "*"
        }
    }
]

}

Source: http://docs.aws.amazon.com/IAM/latest/UserGuide/AccessPolicyLanguage_ElementDescriptions.html#Principal