Access Denied upload to s3

问题

I tried uploading to s3 and when I see the logs from the s3 bucket logs this is what it says:

mybucket-me [17/Oct/2013:08:18:57 +0000] 120.28.112.39 
arn:aws:sts::778671367984:federated-user/dean@player.com BB3AA9C408C0D26F 
REST.POST.BUCKET avatars/dean%2540player.com/4.png "POST / HTTP/1.1" 403 
AccessDenied 231 - 132 - "http://localhost:8080/ajaxupload/test.html" "Mozilla/5.0 (X11; Linux i686) AppleWebKit/537.17 (KHTML, like Gecko) Chrome/24.0.1312.52 Safari/537.17" -

I got an access denied. From where it's pointing I think the only thing that I'm missing out is adding of bucket policy. So here goes.

Using my email I could log in to my app and upload an avatar. The bucket name where I want to put my avatar is mybucket-me and in that it has a sub bucket named avatars.

-mybucket-me
 -avatars
  -dean@player.com //dynamic based on who are logged in
   -myavatar.png //image uploaded

How do I add a bucket policy so I could grant a federated such as I to upload in s3 or what is the correct statement that I will add on my bucket policy so it could grant me a permission to upload into our bucket?

回答1:

You can attach the following policy to the bucket:

{
    "Version": "2008-10-17",
    "Id": "Policy1358656005371",
    "Statement": [
        {
            "Sid": "Stmt1354655992561",
            "Effect": "Allow",
            "Principal": {
                "AWS": [
                    "arn:aws:sts::778671367984:federated-user/dean@player.com"                  
                ]
            },
            "Action": [
                "s3:List*",
                "s3:Get*"
            ],
            "Resource": [
                "arn:aws:s3:::my.bucket",
                "arn:aws:s3:::my.bucket/*"
            ]
        }
    ]
}

to grant the federated user dean@player.com read-only permissions to 'my.bucket'.

This policy is not very maintainable because it names this user in particular. To give access to only certain federated users in a more scalable way, it would be better to do this when you call GetFederationToken. If you post your STS code I can help you assigning the policy there, but it is very similar to the above.

回答2:

2019+

You now either have to:

Set Block new public ACLs and uploading public objects to false if your items are public (top left policie in the picture)

Set acl: 'private' when uploading your image if your items are private

Example in Node.js:

const upload = multer({
    storage: multerS3({
        s3: s3,
        bucket: 'moodboard-img',
        acl: 'private',
        metadata: function (req, file, cb) {
            cb(null, {fieldName: file.fieldname});
        },
        key: function (req, file, cb) {
            cb(null, Date.now().toString())
        }
    })
})

回答3:

To upload to S3 bucket, you need to Add/Create IAM/Group Policy, for example:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": ["s3:ListBucket"],
      "Resource": ["arn:aws:s3:::test"]
    },
    {
      "Effect": "Allow",
      "Action": [
        "s3:PutObject",
        "s3:GetObject",
        "s3:DeleteObject"
      ],
      "Resource": ["arn:aws:s3:::test/*"]
    }
  ]
}

Where arn:aws:s3:::test is your Amazon Resource Name (ARN).

Source: Writing IAM Policies: How to Grant Access to an Amazon S3 Bucket