CODEWITHSUNDEEP
amazon-web-servicesamazon-s3policybucket
Wondering Coder
Wondering Coder

Reputation: 1702

Access Denied upload to s3

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/[email protected] 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
  [email protected] //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?

Upvotes: 21

Views: 58297

Answers (4)

Nitish Kumar
Nitish Kumar

Reputation: 111

if you are using programmatic access using credential or aws-sdk with any server then try to comment ACL:public-read then everything works fine without any changes if IAM has already permission to (crud) itself

enjoy ! no more google

Upvotes: 1

Sebastien Horin
Sebastien Horin

Reputation: 11067

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)

enter image description here

  • 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())
        }
    })
})

Upvotes: 26

kenorb
kenorb

Reputation: 166389

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

Related:

Upvotes: 12

prestomation
prestomation

Reputation: 7440

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/[email protected]"                  
                ]
            },
            "Action": [
                "s3:List*",
                "s3:Get*"
            ],
            "Resource": [
                "arn:aws:s3:::my.bucket",
                "arn:aws:s3:::my.bucket/*"
            ]
        }
    ]
}

to grant the federated user [email protected] 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.

Upvotes: 7

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