**Introducing a new console experience for Amazon WAF**

You can now use the updated experience to access Amazon WAF functionality anywhere in the console. For more details, see [Working with the console](https://docs.amazonaws.cn/waf/latest/developerguide/working-with-console.html). 

# Using IAM with Amazon Shield
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This section explains how to use IAM with Amazon Shield.



Amazon Identity and Access Management (IAM) is an Amazon Web Services service that helps an administrator securely control access to Amazon resources. IAM administrators control who can be *authenticated* (signed in) and *authorized* (have permissions) to use Shield resources. IAM is an Amazon Web Services service that you can use with no additional charge.

**Topics**
+ [Audience](#security_iam_audience)
+ [Authenticating with identities](#security_iam_authentication)
+ [Managing access using policies](#security_iam_access-manage)
+ [How Amazon Shield works with IAM](shd-security_iam_service-with-iam.md)
+ [Identity-based policy examples for Amazon Shield](shd-security_iam_id-based-policy-examples.md)
+ [Amazon managed policies for Amazon Shield](shd-security-iam-awsmanpol.md)
+ [Troubleshooting Amazon Shield identity and access](shd-security_iam_troubleshoot.md)
+ [Using service-linked roles for Shield Advanced](shd-using-service-linked-roles.md)

## Audience
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How you use Amazon Identity and Access Management (IAM) differs, depending on the work that you do in Shield.

**Service user** – If you use the Shield service to do your job, then your administrator provides you with the credentials and permissions that you need. As you use more Shield features to do your work, you might need additional permissions. Understanding how access is managed can help you request the right permissions from your administrator. If you cannot access a feature in Shield, see [Troubleshooting Amazon Shield identity and access](shd-security_iam_troubleshoot.md).

**Service administrator** – If you're in charge of Shield resources at your company, you probably have full access to Shield. It's your job to determine which Shield features and resources your service users should access. You must then submit requests to your IAM administrator to change the permissions of your service users. Review the information on this page to understand the basic concepts of IAM. To learn more about how your company can use IAM with Shield, see [How Amazon Shield works with IAM](shd-security_iam_service-with-iam.md).

**IAM administrator** – If you're an IAM administrator, you might want to learn details about how you can write policies to manage access to Shield. To view example Shield identity-based policies that you can use in IAM, see [Identity-based policy examples for Amazon Shield](shd-security_iam_id-based-policy-examples.md).

## Authenticating with identities
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Authentication is how you sign in to Amazon using your identity credentials. You must be authenticated as the Amazon Web Services account root user, an IAM user, or by assuming an IAM role.

For programmatic access, Amazon provides an SDK and CLI to cryptographically sign requests. For more information, see [Amazon Signature Version 4 for API requests](https://docs.amazonaws.cn/IAM/latest/UserGuide/reference_sigv.html) in the *IAM User Guide*.

### Amazon Web Services account root user
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 When you create an Amazon Web Services account, you begin with one sign-in identity called the Amazon Web Services account *root user* that has complete access to all Amazon Web Services services and resources. We strongly recommend that you don't use the root user for everyday tasks. For tasks that require root user credentials, see [Tasks that require root user credentials](https://docs.amazonaws.cn/IAM/latest/UserGuide/id_root-user.html#root-user-tasks) in the *IAM User Guide*. 

### Federated identity
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As a best practice, require human users to use federation with an identity provider to access Amazon Web Services services using temporary credentials.

A *federated identity* is a user from your enterprise directory, web identity provider, or Amazon Directory Service that accesses Amazon Web Services services using credentials from an identity source. Federated identities assume roles that provide temporary credentials.

### IAM users and groups
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An *[IAM user](https://docs.amazonaws.cn/IAM/latest/UserGuide/id_users.html)* is an identity with specific permissions for a single person or application. We recommend using temporary credentials instead of IAM users with long-term credentials. For more information, see [Require human users to use federation with an identity provider to access Amazon using temporary credentials](https://docs.amazonaws.cn/IAM/latest/UserGuide/best-practices.html#bp-users-federation-idp) in the *IAM User Guide*.

An [https://docs.amazonaws.cn/IAM/latest/UserGuide/id_groups.html](https://docs.amazonaws.cn/IAM/latest/UserGuide/id_groups.html) specifies a collection of IAM users and makes permissions easier to manage for large sets of users. For more information, see [Use cases for IAM users](https://docs.amazonaws.cn/IAM/latest/UserGuide/gs-identities-iam-users.html) in the *IAM User Guide*.

### IAM roles
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An *[IAM role](https://docs.amazonaws.cn/IAM/latest/UserGuide/id_roles.html)* is an identity with specific permissions that provides temporary credentials. You can assume a role by [switching from a user to an IAM role (console)](https://docs.amazonaws.cn/IAM/latest/UserGuide/id_roles_use_switch-role-console.html) or by calling an Amazon CLI or Amazon API operation. For more information, see [Methods to assume a role](https://docs.amazonaws.cn/IAM/latest/UserGuide/id_roles_manage-assume.html) in the *IAM User Guide*.

IAM roles are useful for federated user access, temporary IAM user permissions, cross-account access, cross-service access, and applications running on Amazon EC2. For more information, see [Cross account resource access in IAM](https://docs.amazonaws.cn/IAM/latest/UserGuide/access_policies-cross-account-resource-access.html) in the *IAM User Guide*.

## Managing access using policies
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You control access in Amazon by creating policies and attaching them to Amazon identities or resources. A policy defines permissions when associated with an identity or resource. Amazon evaluates these policies when a principal makes a request. Most policies are stored in Amazon as JSON documents. For more information about JSON policy documents, see [Overview of JSON policies](https://docs.amazonaws.cn/IAM/latest/UserGuide/access_policies.html#access_policies-json) in the *IAM User Guide*.

Using policies, administrators specify who has access to what by defining which **principal** can perform **actions** on what **resources**, and under what **conditions**.

By default, users and roles have no permissions. An IAM administrator creates IAM policies and adds them to roles, which users can then assume. IAM policies define permissions regardless of the method used to perform the operation.

### Identity-based policies
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Identity-based policies are JSON permissions policy documents that you attach to an identity (user, group, or role). These policies control what actions identities 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.amazonaws.cn/IAM/latest/UserGuide/access_policies_create.html) in the *IAM User Guide*.

Identity-based policies can be *inline policies* (embedded directly into a single identity) or *managed policies* (standalone policies attached to multiple identities). To learn how to choose between managed and inline policies, see [Choose between managed policies and inline policies](https://docs.amazonaws.cn/IAM/latest/UserGuide/access_policies-choosing-managed-or-inline.html) in the *IAM User Guide*.

### Resource-based policies
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Resource-based policies are JSON policy documents that you attach to a resource. Examples include IAM *role trust policies* and Amazon S3 *bucket policies*. In services that support resource-based policies, service administrators can use them to control access to a specific resource. You must [specify a principal](https://docs.amazonaws.cn/IAM/latest/UserGuide/reference_policies_elements_principal.html) in a resource-based policy.

Resource-based policies are inline policies that are located in that service. You can't use Amazon managed policies from IAM in a resource-based policy.

### Access control lists (ACLs)
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Access control lists (ACLs) control which principals (account members, users, or roles) have permissions to access a resource. ACLs are similar to resource-based policies, although they do not use the JSON policy document format.

Amazon S3, Amazon WAF, and Amazon VPC are examples of services that support ACLs. To learn more about ACLs, see [Access control list (ACL) overview](https://docs.amazonaws.cn/AmazonS3/latest/userguide/acl-overview.html) in the *Amazon Simple Storage Service Developer Guide*.

### Other policy types
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Amazon supports additional policy types that can set the maximum permissions granted by more common policy types:
+ **Permissions boundaries** – Set the maximum permissions that an identity-based policy can grant to an IAM entity. For more information, see [Permissions boundaries for IAM entities](https://docs.amazonaws.cn/IAM/latest/UserGuide/access_policies_boundaries.html) in the *IAM User Guide*.
+ **Service control policies (SCPs)** – Specify the maximum permissions for an organization or organizational unit in Amazon Organizations. For more information, see [Service control policies](https://docs.amazonaws.cn/organizations/latest/userguide/orgs_manage_policies_scps.html) in the *Amazon Organizations User Guide*.
+ **Resource control policies (RCPs)** – Set the maximum available permissions for resources in your accounts. For more information, see [Resource control policies (RCPs)](https://docs.amazonaws.cn/organizations/latest/userguide/orgs_manage_policies_rcps.html) in the *Amazon Organizations User Guide*.
+ **Session policies** – Advanced policies passed as a parameter when creating a temporary session for a role or federated user. For more information, see [Session policies](https://docs.amazonaws.cn/IAM/latest/UserGuide/access_policies.html#policies_session) in the *IAM User Guide*.

### Multiple policy types
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When multiple types of policies apply to a request, the resulting permissions are more complicated to understand. To learn how Amazon determines whether to allow a request when multiple policy types are involved, see [Policy evaluation logic](https://docs.amazonaws.cn/IAM/latest/UserGuide/reference_policies_evaluation-logic.html) in the *IAM User Guide*.