Variable resource name in AWS IAM policy

Question

I am creating S3 buckets in a program using 'standard-prefix-{variable}'. In trying to create an IAM policy so a user can update, create, delete buckets in an account, but only if the bucket name contains the 'standard-prefix'. IE, I don't want to allow modifying other buckets in the account. I'm finding many ways to limit access to resources within a bucket, given a specific bucket name, but no way of limiting access when the bucket names are changing.

Something like (which doesn't seem to be working):

"Resource": "arn:aws:s3:::standard-prefix-*"

Examples from AWS Docs:

Dynamic name based on username is the closest I've found. But I need a wildcard for the variable part of the bucket name:

{
  "Version": "2012-10-17",
  "Statement": [{
    "Effect": "Allow",
    "Action": "sqs:*",
    "Resource": "arn:aws:sqs:us-west-2:*:${aws:username}-queue"
  }]
}

Items with in a specified bucket name:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Action": ["s3:ListBucket"],
      "Effect": "Allow",
      "Resource": ["arn:aws:s3:::mybucket"],
      "Condition": {"StringLike": {"s3:prefix": ["${aws:username}/*"]}}
    },
    {
      "Action": [
        "s3:GetObject",
        "s3:PutObject"
      ],
      "Effect": "Allow",
      "Resource": ["arn:aws:s3:::mybucket/${aws:username}/*"]
    }
  ]
}

voidnologo voidnologo · Accepted Answer · 2015-08-18T20:13:24

This is the policy that ended up working. When creating the buckets, they get a name such as standard_prefix-20150101, standard_prefix-20150515, etc. Users with this IAM policy can then do whatever on those buckets, but not modify other buckets in the account.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "One",
            "Effect": "Allow",
            "Action": [
                "*"
            ],
            "Resource": [
                "arn:aws:s3:::standard_prefix-*"
            ]
        },
                {
            "Sid": "Two",
            "Effect": "Allow",
            "Action": [
                "s3:List*"
            ],
            "Resource": [
                "arn:aws:s3:::*"
            ]
        }
    ]
}

Variable resource name in AWS IAM policy

1 Answers