AWS - Unable to access S3 bucket object from EC2

Question

I am not sure if I am missing a step here or not.

I have an s3 bucket I need to be able to access from an AWS SDK PHP script I wrote running on my EC2. I created an IAM role to allow access.

IAM Allow_S3_Access_to_EC2

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "VisualEditor0",
            "Effect": "Allow",
            "Action": "s3:ListBucket",
            "Resource": "arn:aws:s3:::myinbox"
        },
        {
            "Sid": "VisualEditor1",
            "Effect": "Allow",
            "Action": "s3:GetObject",
            "Resource": "arn:aws:s3:::myinbox/*"
        },
        {
            "Sid": "VisualEditor2",
            "Effect": "Allow",
            "Action": "s3:ListAllMyBuckets",
            "Resource": "*"
        },
        {
            "Sid": "VisualEditor3",
            "Effect": "Allow",
            "Action": "s3:DeleteObject",
            "Resource": "arn:aws:s3:::myinbox/*"
        }
    ]
}

And my Trust Relationship for the IAM role is

Trust Relationship

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Principal": {
        "Service": "ec2.amazonaws.com"
      },
      "Action": "sts:AssumeRole"
    }
  ]
}

I then attached that IAM role to my EC2 instance. From what I have read this is all I have to do, but I think I need to do more.

In my Bucket Policy I have the following to allow access from my SES to be able to create the email object.

S3 Bucket Policy

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "AllowSESPuts",
            "Effect": "Allow",
            "Principal": {
                "Service": "ses.amazonaws.com"
            },
            "Action": "s3:PutObject",
            "Resource": "arn:aws:s3:::myinbox/*",
            "Condition": {
                "StringEquals": {
                    "aws:Referer": "************"
                }
            }
        },
        {
            "Effect": "Allow",
            "Principal": {
                "AWS": "arn:aws:iam::************:role/Allow_S3_Access_to_EC2"
            },
            "Action": "s3:*",
            "Resource": [
                "arn:aws:s3:::myinbox",
                "arn:aws:s3:::myinbox/*"
            ]
        }
    ]
}

My Bucket Policy has nothing in there for my EC2 or even my IAM role I have attached. Do I need to add something to my Bucket Policy as well? That is where I am confused.

What I am experiencing is when a new object is created and I try and access that object from my AWS SDK PHP I get a "403" Forbidden. If I make that object public in the S3 console I can then access it just fine. So even though I have set permissions for my EC2 to access my S3 unless I make the object public I can't access it.

I even tried using wget to the object on the actual server through the terminal and I still get the 403 unless I make the object public

When I run the IAM Policy Simulator on my role I get

Here is my PHP

PHP Script

require '../aws-ses/aws-autoloader.php';

use Aws\S3\S3Client;
use Aws\S3\Exception\S3Exception;

$bucketName = 'myinbox';

try {
// Instantiate the client.
    $s3 = new S3Client([
        'version' => 'latest',
        'region'  => 'us-west-2',
        'credentials' => array('key'=>'*********************',
                    'secret'=>'*******************************************')
    ]);
} catch (Exception $e) {
    // We use a die, so if this fails. It stops here. Typically this is a REST call so this would
    // return a json object.
    die("Error: " . $e->getMessage());
}
// Use the high-level iterators (returns ALL of your objects).
$objects = $s3->getIterator('ListObjects', array('Bucket' => $bucketName));

Answer 1

First, did you set up the trust relationship so that the EC2 service can assume that role?

Next, you don't associate IAM roles directly with EC2 instances; instead you need to use an Instance Profile. Did you set up an Instance Profile associated with that Role?

This document is a good start: https://docs.aws.amazon.com/codedeploy/latest/userguide/getting-started-create-iam-instance-profile.html