Principals

The Principal element specifies the user, account, service, or other entity that is allowed or denied access to a resource. For more information, see Principal in the IAM User Guide.

Grant permissions to an AWS account

To grant permissions to an AWS account, identify the account using the following format.

"AWS":"account-ARN"

The following are examples.

"Principal":{"AWS":"arn:aws:iam::AccountIDWithoutHyphens:root"}

"Principal":{"AWS":["arn:aws:iam::AccountID1WithoutHyphens:root","arn:aws:iam::AccountID2WithoutHyphens:root"]}

Grant permissions to an IAM user

To grant permission to an IAM user within your account, you must provide an "AWS":"user-ARN" name-value pair.

"Principal":{"AWS":"arn:aws:iam::account-number-without-hyphens:user/username"}

Note

If an IAM identity is deleted after you update your resource policy, the resource policy will show a unique identifier in the principal element instead of an ARN. These unique IDs are never reused, so you can safely remove principals with unique identifiers from all of your policy statements. For more information about unique identifiers, see IAM identifiers in the IAM User Guide.

Grant anonymous permissions

To grant permission to everyone, also referred as anonymous access, you set the wildcard ("*") as the Principal value. For example, if you want to use clients with no AWS authorization to their origin endpoints.

"Principal":"*"

"Principal":{"AWS":"*"}

Using "Principal": "*" with an Allow effect in a resource-based policy allows anyone, even if they’re not signed in to AWS, to access your resource.

Using "Principal" : { "AWS" : "*" } with an Allow effect in a resource-based policy allows any root user, IAM user, assumed-role session, or federated user in any account in the same partition to access your resource.

For anonymous users, these two methods are equivalent. For more information, see All principals in the IAM User Guide.

You cannot use a wildcard to match part of a principal name or ARN.

Important

Because anyone can create an AWS account, the security level of these two methods is equivalent, even though they function differently.

Warning

Use caution when granting anonymous access to your MediaPackage origin endpoints. When you grant anonymous access, anyone in the world can access your bucket. We highly recommend that you never grant any kind of anonymous write access to your origin endpoints.