Bucket policy examples - Amazon Simple Storage Service

Bucket policy examples

With S3 on Outposts bucket policies, you can secure access to objects in your S3 on Outposts buckets, so that only users with the appropriate permissions can access them. You can even prevent authenticated users without the appropriate permissions from accessing your S3 on Outposts resources.

This section presents examples of typical use cases for S3 on Outposts bucket policies. To test these policies, replace the user input placeholders with your own information (such as your bucket name).

To grant or deny permissions to a set of objects, you can use wildcard characters (*) in Amazon Resource Names (ARNs) and other values. For example, you can control access to groups of objects that begin with a common prefix or end with a given extension, such as .html.

For more information about AWS Identity and Access Management (IAM) policy language, see Setting up IAM with S3 on Outposts.

Note

When testing s3outposts permissions by using the Amazon S3 console, you must grant additional permissions that the console requires, such as s3outposts:createendpoint, s3outposts:listendpoints, and so on.

Additional resources for creating bucket policies

Managing access to an Amazon S3 on Outposts bucket based on specific IP addresses

A bucket policy is a resource-based AWS Identity and Access Management (IAM) policy that you can use to grant access permissions to your bucket and the objects in it. Only the bucket owner can associate a policy with a bucket. The permissions attached to the bucket apply to all of the objects in the bucket that are owned by the bucket owner. Bucket policies are limited to 20 KB in size. For more information, see Bucket policy.

Restrict access to specific IP addresses

The following example denies all users from performing any S3 on Outposts operations on objects in the specified buckets unless the request originates from the specified range of IP addresses.

Note

When restricting access to a specific IP address, make sure that you also specify which VPC endpoints, VPC source IP addresses, or external IP addresses can access the S3 on Outposts bucket. Otherwise, you might lose access to the bucket if your policy denies all users from performing any s3outposts operations on objects in your S3 on Outposts bucket without the proper permissions already in place.

This policy's Condition statement identifies 192.0.2.0/24 as the range of allowed IP version 4 (IPv4) IP addresses.

The Condition block uses the NotIpAddress condition and the aws:SourceIp condition key, which is an AWS wide condition key. The aws:SourceIp condition key can only be used for public IP address ranges. For more information about these condition keys, see Actions, resources, and condition keys for S3 on Outposts. The aws:SourceIp IPv4 values use standard CIDR notation. For more information, see IAM JSON policy elements reference in the IAM User Guide.

Warning

Before using this S3 on Outposts policy, replace the 192.0.2.0/24 IP address range in this example with an appropriate value for your use case. Otherwise, you'll lose the ability to access your bucket.

{ "Version": "2012-10-17", "Id": "S3OutpostsPolicyId1", "Statement": [ { "Sid": "IPAllow", "Effect": "Deny", "Principal": "*", "Action": "s3outposts:*", "Resource": [ "arn:aws:s3-outposts:region:111122223333:outpost/OUTPOSTS-ID/accesspoint/EXAMPLE-ACCESS-POINT-NAME" "arn:aws:aws:s3-outposts:region:111122223333:outpost/OUTPOSTS-ID/bucket/DOC-EXAMPLE-BUCKET" ], "Condition": { "NotIpAddress": { "aws:SourceIp": "192.0.2.0/24" } } } ] }

Allow both IPv4 and IPv6 addresses

When you start using IPv6 addresses, we recommend that you update all of your organization's policies with your IPv6 address ranges in addition to your existing IPv4 ranges. Doing this will help to make sure that the policies continue to work as you make the transition to IPv6.

The following S3 on Outposts example bucket policy shows how to mix IPv4 and IPv6 address ranges to cover all of your organization's valid IP addresses. The example policy allows access to the example IP addresses 192.0.2.1 and 2001:DB8:1234:5678::1 and denies access to the addresses 203.0.113.1 and 2001:DB8:1234:5678:ABCD::1.

The aws:SourceIp condition key can only be used for public IP address ranges. The IPv6 values for aws:SourceIp must be in standard CIDR format. For IPv6, we support using :: to represent a range of 0s (for example, 2001:DB8:1234:5678::/64). For more information, see IP address condition operators in the IAM User Guide.

Warning

Replace the IP address ranges in this example with appropriate values for your use case before using this S3 on Outposts policy. Otherwise, you might lose the ability to access your bucket.

{ "Id": "S3OutpostsPolicyId2", "Version": "2012-10-17", "Statement": [ { "Sid": "AllowIPmix", "Effect": "Allow", "Principal": "*", "Action": "s3outposts:*", "Resource": [ "arn:aws:aws:s3-outposts:region:111122223333:outpost/OUTPOSTS-ID/bucket/DOC-EXAMPLE-BUCKET", "arn:aws:aws:s3-outposts:region:111122223333:outpost/OUTPOSTS-ID/bucket/DOC-EXAMPLE-BUCKET/*" ], "Condition": { "IpAddress": { "aws:SourceIp": [ "192.0.2.0/24", "2001:DB8:1234:5678::/64" ] }, "NotIpAddress": { "aws:SourceIp": [ "203.0.113.0/24", "2001:DB8:1234:5678:ABCD::/80" ] } } } ] }