Example S3 Bucket Policies

Limiting Access to Specific IP Addresses

• This statement identifies the 54.240.143.0/24 as the range of allowed IPv4 IP addresses.

{
  "Version": "2012-10-17",
  "Id": "S3PolicyId1",
  "Statement": [
    {
      "Sid": "IPAllow",
      "Effect": "Deny",
      "Principal": "*",
      "Action": "s3:*",
      "Resource": [
	       "arn:aws:s3:::DOC-EXAMPLE-BUCKET",
         "arn:aws:s3:::DOC-EXAMPLE-BUCKET/*"
      ],
      "Condition": {
	 "NotIpAddress": {"aws:SourceIp": "54.240.143.0/24"}
      }
    }
  ]
}

Adding a Bucket Policy to Require MFA

• S3 supports MFA-protected API access, a feature that can enforce MFA for access to your S3 resources.

{
    "Version": "2012-10-17",
    "Id": "123",
    "Statement": [
      {
        "Sid": "",
        "Effect": "Deny",
        "Principal": "*",
        "Action": "s3:*",
        "Resource": "arn:aws:s3:::DOC-EXAMPLE-BUCKET/taxdocuments/*",
        "Condition": { "Null": { "aws:MultiFactorAuthAge": true }}
      }
    ]
 }

Granting Read-Only Permission to an Anonymous User

• The following example policy grants the s3:GetObject permission to any public anonymous users.

{
  "Version":"2012-10-17",
  "Statement":[
    {
      "Sid":"PublicRead",
      "Effect":"Allow",
      "Principal": "*",
      "Action":["s3:GetObject","s3:GetObjectVersion"],
      "Resource":["arn:aws:s3:::DOC-EXAMPLE-BUCKET/*"]
    }
  ]
}