# How AWS Outposts works with IAM
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Before you use IAM to manage access to AWS Outposts, learn what IAM features are available to use with AWS Outposts.


| IAM feature | AWS Outposts support | 
| --- | --- | 
|  [Identity-based policies](#security_iam_service-with-iam-id-based-policies)  |   Yes  | 
|  Resource-based policies  |   No   | 
|  [Policy actions](#security_iam_service-with-iam-id-based-policies-actions)  |   Yes  | 
|  [Policy resources](#security_iam_service-with-iam-id-based-policies-resources)  |   Yes  | 
|  [Policy condition keys (service-specific)](#security_iam_service-with-iam-id-based-policies-conditionkeys)  |   Yes  | 
|  ACLs  |   No   | 
|  [ABAC (tags in policies)](#security_iam_service-with-iam-tags)  |   Yes  | 
|  [Temporary credentials](#security_iam_service-with-iam-roles-tempcreds)  |   Yes  | 
|  [Principal permissions](#security_iam_service-with-iam-principal-permissions)  |   Yes  | 
|  Service roles  |   No   | 
|  [Service-linked roles](#security_iam_service-with-iam-roles-service-linked)  |   Yes  | 

## Identity-based policies for AWS Outposts
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**Supports identity-based policies:** Yes

Identity-based policies are JSON permissions policy documents that you can attach to an identity, such as an IAM user, group of users, or role. These policies control what actions users and roles can perform, on which resources, and under what conditions. To learn how to create an identity-based policy, see [Define custom IAM permissions with customer managed policies](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies_create.html) in the *IAM User Guide*.

With IAM identity-based policies, you can specify allowed or denied actions and resources as well as the conditions under which actions are allowed or denied. To learn about all of the elements that you can use in a JSON policy, see [IAM JSON policy elements reference](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_elements.html) in the *IAM User Guide*.

### Identity-based policy examples for AWS Outposts
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To view examples of AWS Outposts identity-based policies, see [AWS Outposts policy examples](security_iam_id-based-policy-examples.md).

## Policy actions for AWS Outposts
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**Supports policy actions:** Yes

Administrators can use AWS JSON policies to specify who has access to what. That is, which **principal** can perform **actions** on what **resources**, and under what **conditions**.

The `Action` element of a JSON policy describes the actions that you can use to allow or deny access in a policy. Include actions in a policy to grant permissions to perform the associated operation.

To see a list of AWS Outposts actions, see [Actions defined by AWS Outposts](https://docs.aws.amazon.com/service-authorization/latest/reference/list_awsoutposts.html#awsoutposts-actions-as-permissions) in the *Service Authorization Reference*.

Policy actions in AWS Outposts use the following prefix before the action:

```
outposts
```

To specify multiple actions in a single statement, separate them with commas.

```
"Action": [
    "outposts:action1",
    "outposts:action2"
]
```

You can specify multiple actions using wildcards (\$1). For example, to specify all actions that begin with the word `List`, include the following action:

```
"Action": "outposts:List*"
```

## Policy resources for AWS Outposts
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**Supports policy resources:** Yes

Administrators can use AWS JSON policies to specify who has access to what. That is, which **principal** can perform **actions** on what **resources**, and under what **conditions**.

The `Resource` JSON policy element specifies the object or objects to which the action applies. As a best practice, specify a resource using its [Amazon Resource Name (ARN)](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference-arns.html). For actions that don't support resource-level permissions, use a wildcard (\$1) to indicate that the statement applies to all resources.

```
"Resource": "*"
```

Some AWS Outposts API actions support multiple resources. To specify multiple resources in a single statement, separate the ARNs with commas.

```
"Resource": [
    "resource1",
    "resource2"
]
```

To see a list of AWS Outposts resource types and their ARNs, see [Resource types defined by AWS Outposts](https://docs.aws.amazon.com/service-authorization/latest/reference/list_awsoutposts.html#awsoutposts-resources-for-iam-policies) in the *Service Authorization Reference*. To learn with which actions you can specify the ARN of each resource, see [Actions defined by AWS Outposts](https://docs.aws.amazon.com/service-authorization/latest/reference/list_awsoutposts.html#awsoutposts-actions-as-permissions).

## Policy condition keys for AWS Outposts
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**Supports service-specific policy condition keys:** Yes

Administrators can use AWS JSON policies to specify who has access to what. That is, which **principal** can perform **actions** on what **resources**, and under what **conditions**.

The `Condition` element specifies when statements execute based on defined criteria. You can create conditional expressions that use [condition operators](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_elements_condition_operators.html), such as equals or less than, to match the condition in the policy with values in the request. To see all AWS global condition keys, see [AWS global condition context keys](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_condition-keys.html) in the *IAM User Guide*.

To see a list of AWS Outposts condition keys, see [Condition keys for AWS Outposts](https://docs.aws.amazon.com/service-authorization/latest/reference/list_awsoutposts.html#awsoutposts-policy-keys) in the *Service Authorization Reference*. To learn with which actions and resources you can use a condition key, see [Actions defined by AWS Outposts](https://docs.aws.amazon.com/service-authorization/latest/reference/list_awsoutposts.html#awsoutposts-actions-as-permissions).

To view examples of AWS Outposts identity-based policies, see [AWS Outposts policy examples](security_iam_id-based-policy-examples.md).

## ABAC with AWS Outposts
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**Supports ABAC (tags in policies):** Yes

Attribute-based access control (ABAC) is an authorization strategy that defines permissions based on attributes called tags. You can attach tags to IAM entities and AWS resources, then design ABAC policies to allow operations when the principal's tag matches the tag on the resource.

To control access based on tags, you provide tag information in the [condition element](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_elements_condition.html) of a policy using the `aws:ResourceTag/key-name`, `aws:RequestTag/key-name`, or `aws:TagKeys` condition keys.

If a service supports all three condition keys for every resource type, then the value is **Yes** for the service. If a service supports all three condition keys for only some resource types, then the value is **Partial**.

For more information about ABAC, see [Define permissions with ABAC authorization](https://docs.aws.amazon.com/IAM/latest/UserGuide/introduction_attribute-based-access-control.html) in the *IAM User Guide*. To view a tutorial with steps for setting up ABAC, see [Use attribute-based access control (ABAC)](https://docs.aws.amazon.com/IAM/latest/UserGuide/tutorial_attribute-based-access-control.html) in the *IAM User Guide*.

## Using temporary credentials with AWS Outposts
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**Supports temporary credentials:** Yes

Temporary credentials provide short-term access to AWS resources and are automatically created when you use federation or switch roles. AWS recommends that you dynamically generate temporary credentials instead of using long-term access keys. For more information, see [Temporary security credentials in IAM](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_credentials_temp.html) and [AWS services that work with IAM](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_aws-services-that-work-with-iam.html) in the *IAM User Guide*.

## Cross-service principal permissions for AWS Outposts
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**Supports forward access sessions (FAS):** Yes

 Forward access sessions (FAS) use the permissions of the principal calling an AWS service, combined with the requesting AWS service to make requests to downstream services. For policy details when making FAS requests, see [Forward access sessions](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_forward_access_sessions.html). 

## Service-linked roles for AWS Outposts
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**Supports service-linked roles:** Yes

 A service-linked role is a type of service role that is linked to an AWS service. The service can assume the role to perform an action on your behalf. Service-linked roles appear in your AWS account and are owned by the service. An IAM administrator can view, but not edit the permissions for service-linked roles. 

For details about creating or managing AWS Outposts service-linked roles, see [Service-linked roles for AWS Outposts](using-service-linked-roles.md).