AWS CloudFront access denied to S3 bucket

I am trying to setup CloudFront to serve static files hosted in my S3 bucket. I have setup distribution but I get AccessDenied when trying to browse to the CSS (/CSS/stlyle.css) file inside S3 bucket:

<Error>
    <Code>AccessDenied</Code>
    <Message>Access Denied</Message>
    <RequestId>E193C9CDF4319589</RequestId>
    <HostId>
xbU85maj87/jukYihXnADjXoa4j2AMLFx7t08vtWZ9SRVmU1Ijq6ry2RDAh4G1IGPIeZG9IbFZg=
    </HostId>
</Error>

I have set my CloudFront distribution to my S3 bucket and created new Origin Access Identity policy which was added automatically to the S3 bucket:

{
    "Version": "2008-10-17",
    "Id": "PolicyForCloudFrontPrivateContent",
    "Statement": [
        {
            "Sid": "1",
            "Effect": "Allow",
            "Principal": {
                "AWS": "arn:aws:iam::cloudfront:user/CloudFront Origin Access Identity E21XQ8NAGWMBQQ"
            },
            "Action": "s3:GetObject",
            "Resource": "arn:aws:s3:::myhost.com.cdn/*"
        }
    ]
}

Did I miss something?

I want all my files in this S3 bucket be served via CloudFront...

*** UPDATE ***

This cloud front guide says:

By default, your Amazon S3 bucket and all of the objects in it are private—only the AWS account that created the bucket has permission to read or write the objects in it. If you want to allow anyone to access the objects in your Amazon S3 bucket using CloudFront URLs, you must grant public read permissions to the objects. (This is one of the most common mistakes when working with CloudFront and Amazon S3. You must explicitly grant privileges to each object in an Amazon S3 bucket.)

So based on this I have added new permissions to all objects inside S3 bucket to Everyone Read/Download. Now I can access files.

But now when I access the file like https://d3u61axijg36on.cloudfront.net/css/style.css this is being redirected to S3 URI and HTTP. How do I disable this?

To assist with your question, I recreated the situation via:

• Created an Amazon S3 bucket with no Bucket Policy
• Uploaded public.jpg and make it public via "Make Public"
• Uploaded private.jpg and kept it private
• Created an Amazon CloudFront web distribution:
  • Origin Domain Name: Selected my S3 bucket from the list
  • Restrict Bucket Access: Yes
  • Origin Access Identity: Create a New Identity
  • Grant Read Permissions on Bucket: Yes, Update Bucket Policy

I checked the bucket, and CloudFront had added a Bucket Policy similar to yours.

The distribution was marked as In Progress for a while. Once it said Enabled, I accessed the files via the xxx.cloudfront.net URL:

• xxx.cloudfront.net/public.jpg redirected me to the S3 URL http://bucketname.s3.amazonaws.com/public.jpg. Yes, I could see the file, but it should not use a redirect.
• xxx.cloudfront.net/private.jpg redirected me also, but I then received Access Denied because it is a private file in S3.

I then did some research and found that this is quite a common occurrence. Some people use a workaround by pointing their CloudFront distribution to the static hosted website URL, but this has the disadvantage that it will not work with the Origin Access Identity and I also suspect it won't receive the 'free S3 traffic to the edge' discount.

So, I waited overnight, tested it this morning and everything is working fine.

Bottom line: Even if it says ENABLED, things might take several hours (eg overnight) to get themselves right. It will then work as documented.