The principals indicate the users bucket policies apply to. These users can be accounts, federated users or federated user groups, and IAM users. Target users can be specified in either of the following ways:
With Principal set to Current account, you can select one or more IAM users under this account, so the bucket policy applies to the selected IAM users.
When the Principal is set to Other account, you can enter the ID of other accounts. If you want to apply the bucket policy to IAM users under that account, you need to enter the user IDs, and use commas (,) to separate one from another.
An authorized user can go to the My Credential page to obtain the domain ID and user ID after login.
For Account ID, enter the Domain ID that can be found on the My Credential page.
To grant the bucket access permission to anyone, set the Principal to Other account and enter an asterisk (*) as the account ID.
Exercise caution when granting the bucket access permissions to anonymous users. If you grant the bucket access permission to anonymous users, anyone can access your bucket, and the traffic and storage fees generated will be borne by the bucket owner (cloud service account). You are advised to set restrictions on access requests. For example, you can allow the access requests from only one IP address.
The Principal of a bucket policy can also be a federated user or a federated user group.