# Identity and access management for AWS IoT Greengrass
AWS Identity and Access Management (IAM) is an AWS service that helps an administrator securely control access to AWS resources. IAM administrators control who can be *authenticated* (signed in) and *authorized* (have permissions) to use AWS IoT Greengrass resources. IAM is an AWS service that you can use with no additional charge.
**Note**
This topic describes IAM concepts and features. For information about IAM features supported by AWS IoT Greengrass, see [How AWS IoT Greengrass works with IAM](security_iam_service-with-iam.md).
## Audience
How you use AWS Identity and Access Management (IAM) differs based on your role:
+ **Service user** - request permissions from your administrator if you cannot access features (see [Troubleshooting identity and access issues for AWS IoT Greengrass](security_iam_troubleshoot.md))
+ **Service administrator** - determine user access and submit permission requests (see [How AWS IoT Greengrass works with IAM](security_iam_service-with-iam.md))
+ **IAM administrator** - write policies to manage access (see [Identity-based policy examples for AWS IoT Greengrass](security_iam_id-based-policy-examples.md))
## Authenticating with identities
Authentication is how you sign in to AWS using your identity credentials. You must be authenticated as the AWS account root user, an IAM user, or by assuming an IAM role.
You can sign in as a federated identity using credentials from an identity source like AWS IAM Identity Center (IAM Identity Center), single sign-on authentication, or Google/Facebook credentials. For more information about signing in, see [How to sign in to your AWS account](https://docs.aws.amazon.com/signin/latest/userguide/how-to-sign-in.html) in the *AWS Sign-In User Guide*.
For programmatic access, AWS provides an SDK and CLI to cryptographically sign requests. For more information, see [AWS Signature Version 4 for API requests](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_sigv.html) in the *IAM User Guide*.
### AWS account root user
When you create an AWS account, you begin with one sign-in identity called the AWS account *root user* that has complete access to all AWS 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.aws.amazon.com/IAM/latest/UserGuide/id_root-user.html#root-user-tasks) in the *IAM User Guide*.
### IAM users and groups
An *[IAM user](https://docs.aws.amazon.com/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 AWS using temporary credentials](https://docs.aws.amazon.com/IAM/latest/UserGuide/best-practices.html#bp-users-federation-idp) in the *IAM User Guide*.
An [https://docs.aws.amazon.com/IAM/latest/UserGuide/id_groups.html](https://docs.aws.amazon.com/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.aws.amazon.com/IAM/latest/UserGuide/gs-identities-iam-users.html) in the *IAM User Guide*.
### IAM roles
An *[IAM role](https://docs.aws.amazon.com/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.aws.amazon.com/IAM/latest/UserGuide/id_roles_use_switch-role-console.html) or by calling an AWS CLI or AWS API operation. For more information, see [Methods to assume a role](https://docs.aws.amazon.com/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.aws.amazon.com/IAM/latest/UserGuide/access_policies-cross-account-resource-access.html) in the *IAM User Guide*.
## Managing access using policies
You control access in AWS by creating policies and attaching them to AWS identities or resources. A policy defines permissions when associated with an identity or resource. AWS evaluates these policies when a principal makes a request. Most policies are stored in AWS as JSON documents. For more information about JSON policy documents, see [Overview of JSON policies](https://docs.aws.amazon.com/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
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.aws.amazon.com/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.aws.amazon.com/IAM/latest/UserGuide/access_policies-choosing-managed-or-inline.html) in the *IAM User Guide*.
### Resource-based policies
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.aws.amazon.com/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 AWS managed policies from IAM in a resource-based policy.
### Access control lists (ACLs)
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, AWS WAF, and Amazon VPC are examples of services that support ACLs. To learn more about ACLs, see [Access control list (ACL) overview](https://docs.aws.amazon.com/AmazonS3/latest/userguide/acl-overview.html) in the *Amazon Simple Storage Service Developer Guide*.
### Other policy types
AWS 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.aws.amazon.com/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 AWS Organizations. For more information, see [Service control policies](https://docs.aws.amazon.com/organizations/latest/userguide/orgs_manage_policies_scps.html) in the *AWS 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.aws.amazon.com/organizations/latest/userguide/orgs_manage_policies_rcps.html) in the *AWS 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.aws.amazon.com/IAM/latest/UserGuide/access_policies.html#policies_session) in the *IAM User Guide*.
### Multiple policy types
When multiple types of policies apply to a request, the resulting permissions are more complicated to understand. To learn how AWS determines whether to allow a request when multiple policy types are involved, see [Policy evaluation logic](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_evaluation-logic.html) in the *IAM User Guide*.
## See also
+ [How AWS IoT Greengrass works with IAM](security_iam_service-with-iam.md)
+ [Identity-based policy examples for AWS IoT Greengrass](security_iam_id-based-policy-examples.md)
+ [Troubleshooting identity and access issues for AWS IoT Greengrass](security_iam_troubleshoot.md)
# How AWS IoT Greengrass works with IAM
Before you use IAM to manage access to AWS IoT Greengrass, you should understand the IAM features that you can use with AWS IoT Greengrass.
| IAM feature | Supported by Greengrass? |
| --- | --- |
| [Identity-based policies with resource-level permissions](#security_iam_service-with-iam-id-based-policies) | Yes |
| [Resource-based policies](#security_iam_service-with-iam-resource-based-policies) | No |
| [Access control lists (ACLs)](#security_iam_service-with-iam-acls) | No |
| [Tags-based authorization](#security_iam_service-with-iam-tags) | Yes |
| [Temporary credentials](#security_iam_service-with-iam-roles-tempcreds) | Yes |
| [Service-linked roles](#security_iam_service-with-iam-roles-service-linked) | No |
| [Service roles](#security_iam_service-with-iam-roles-service-linked) | Yes |
For a high-level view of how other AWS services work with IAM, see [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*.
## Identity-based policies for AWS IoT Greengrass
With IAM identity-based policies, you can specify allowed or denied actions and resources and the conditions under which actions are allowed or denied. AWS IoT Greengrass supports specific actions, resources, and condition keys. To learn about all of the elements that you use in a policy, see [IAM JSON policy elements reference](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_elements.html) in the *IAM User Guide*.
### Actions
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.
Policy actions for AWS IoT Greengrass use the `greengrass:` prefix before the action. For example, to allow someone to use the `ListCoreDevices` API operation to list the core devices in their AWS account, you include the `greengrass:ListCoreDevices` action in their policy. Policy statements must include either an `Action` or `NotAction` element. AWS IoT Greengrass defines its own set of actions that describe tasks that you can perform with this service.
To specify multiple actions in a single statement, list them between brackets (`[` `]`) and separate them with commas, as follows:
```
"Action": [
"greengrass:action1",
"greengrass:action2",
"greengrass:action3"
]
```
You can use wildcards (`*`) to specify multiple actions. For example, to specify all actions that begin with the word `List`, include the following action:
```
"Action": "greengrass:List*"
```
**Note**
We recommend that you avoid the use of wildcards to specify all available actions for a service. As a best practice, you should grant least privilege and narrowly scope permissions in a policy. For more information, see [Grant minimum possible permissions](security-best-practices.md#least-privilege).
For the complete list of AWS IoT Greengrass actions, see [Actions Defined by AWS IoT Greengrass](https://docs.aws.amazon.com/IAM/latest/UserGuide/list_awsiotgreengrass.html#awsiotgreengrass-actions-as-permissions) in the *IAM User Guide*.
### Resources
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": "*"
```
The following table contains the AWS IoT Greengrass resource ARNs that can be used in the `Resource` element of a policy statement. For a mapping of supported resource-level permissions for AWS IoT Greengrass actions, see [Actions Defined by AWS IoT Greengrass](https://docs.aws.amazon.com/IAM/latest/UserGuide/list_awsiotgreengrass.html#awsiotgreengrass-actions-as-permissions) in the *IAM User Guide*.
Some AWS IoT Greengrass actions (for example, some list operations), cannot be performed on a specific resource. In those cases, you must use the wildcard alone.
```
"Resource": "*"
```
To specify multiple resource ARNs in a statement, list them between brackets (`[` `]`) and separate them with commas, as follows:
```
"Resource": [
"resource-arn1",
"resource-arn2",
"resource-arn3"
]
```
For more information about ARN formats, see [Amazon Resource Names (ARNs) and AWS service namespaces](https://docs.aws.amazon.com/general/latest/gr/aws-arns-and-namespaces.html) in the *Amazon Web Services General Reference*.
### Condition keys
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*.
### Examples
To view examples of AWS IoT Greengrass identity-based policies, see [Identity-based policy examples for AWS IoT Greengrass](security_iam_id-based-policy-examples.md).
## Resource-based policies for AWS IoT Greengrass
AWS IoT Greengrass does not support [resource-based policies](security-iam.md#security_iam_access-manage-resource-based-policies).
## Access control lists (ACLs)
AWS IoT Greengrass does not support [ACLs](security-iam.md#security_iam_access-manage-acl).
## Authorization based on AWS IoT Greengrass tags
You can attach tags to supported AWS IoT Greengrass resources or pass tags in a request to AWS IoT Greengrass. 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/${TagKey}`, `aws:RequestTag/${TagKey}`, or `aws:TagKeys` condition keys. For more information, see [Tag your AWS IoT Greengrass Version 2 resources](tag-resources.md).
## IAM roles for AWS IoT Greengrass
An [IAM role](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles.html) is an entity within your AWS account that has specific permissions.
### Using temporary credentials with AWS IoT Greengrass
Temporary credentials are used to sign in with federation, assume an IAM role, or to assume a cross-account role. You obtain temporary security credentials by calling AWS STS API operations such as [AssumeRole](https://docs.aws.amazon.com/STS/latest/APIReference/API_AssumeRole.html) or [GetFederationToken](https://docs.aws.amazon.com/STS/latest/APIReference/API_GetFederationToken.html).
On the Greengrass core, temporary credentials for the [device role](device-service-role.md) are made available to Greengrass components. If your components use the AWS SDK, you don't need to add logic to obtain the credentials because the AWS SDK does this for you.
### Service-linked roles
AWS IoT Greengrass does not support [service-linked roles](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_terms-and-concepts.html#iam-term-service-linked-role).
### Service roles
This feature allows a service to assume a [service role](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_terms-and-concepts.html#iam-term-service-role) on your behalf. This role allows the service to access resources in other services to complete an action on your behalf. Service roles appear in your IAM account and are owned by the account. This means that an IAM administrator can change the permissions for this role. However, doing so might break the functionality of the service.
AWS IoT Greengrass core devices use a service role to allow Greengrass components and Lambda functions to access some of your AWS resources on your behalf. For more information, see [Authorize core devices to interact with AWS services](device-service-role.md).
AWS IoT Greengrass uses a service role to access some of your AWS resources on your behalf. For more information, see [Greengrass service role](greengrass-service-role.md).
# Identity-based policy examples for AWS IoT Greengrass
By default, IAM users and roles don't have permission to create or modify AWS IoT Greengrass resources. They also can't perform tasks using the AWS Management Console, AWS CLI, or AWS API. An IAM administrator must create IAM policies that grant users and roles permission to perform specific API operations on the specified resources they need. The administrator must then attach those policies to the IAM users or groups that require those permissions.
## Policy best practices
Identity-based policies determine whether someone can create, access, or delete AWS IoT Greengrass resources in your account. These actions can incur costs for your AWS account. When you create or edit identity-based policies, follow these guidelines and recommendations:
+ **Get started with AWS managed policies and move toward least-privilege permissions** – To get started granting permissions to your users and workloads, use the *AWS managed policies* that grant permissions for many common use cases. They are available in your AWS account. We recommend that you reduce permissions further by defining AWS customer managed policies that are specific to your use cases. For more information, see [AWS managed policies](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies_managed-vs-inline.html#aws-managed-policies) or [AWS managed policies for job functions](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies_job-functions.html) in the *IAM User Guide*.
+ **Apply least-privilege permissions** – When you set permissions with IAM policies, grant only the permissions required to perform a task. You do this by defining the actions that can be taken on specific resources under specific conditions, also known as *least-privilege permissions*. For more information about using IAM to apply permissions, see [ Policies and permissions in IAM](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies.html) in the *IAM User Guide*.
+ **Use conditions in IAM policies to further restrict access** – You can add a condition to your policies to limit access to actions and resources. For example, you can write a policy condition to specify that all requests must be sent using SSL. You can also use conditions to grant access to service actions if they are used through a specific AWS service, such as CloudFormation. For more information, see [ IAM JSON policy elements: Condition](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_elements_condition.html) in the *IAM User Guide*.
+ **Use IAM Access Analyzer to validate your IAM policies to ensure secure and functional permissions** – IAM Access Analyzer validates new and existing policies so that the policies adhere to the IAM policy language (JSON) and IAM best practices. IAM Access Analyzer provides more than 100 policy checks and actionable recommendations to help you author secure and functional policies. For more information, see [Validate policies with IAM Access Analyzer](https://docs.aws.amazon.com/IAM/latest/UserGuide/access-analyzer-policy-validation.html) in the *IAM User Guide*.
+ **Require multi-factor authentication (MFA)** – If you have a scenario that requires IAM users or a root user in your AWS account, turn on MFA for additional security. To require MFA when API operations are called, add MFA conditions to your policies. For more information, see [ Secure API access with MFA](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_credentials_mfa_configure-api-require.html) in the *IAM User Guide*.
For more information about best practices in IAM, see [Security best practices in IAM](https://docs.aws.amazon.com/IAM/latest/UserGuide/best-practices.html) in the *IAM User Guide*.
## Policy examples
The following example customer-defined policies grant permissions for common scenarios.
**Topics**
+ [Allow users to view their own permissions](#security_iam_id-based-policy-examples-view-own-permissions)
To learn how to create an IAM identity-based policy using these example JSON policy documents, see [Creating policies on the JSON tab](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies_create.html#access_policies_create-json-editor) in the *IAM User Guide*.
### Allow users to view their own permissions
This example shows how you might create a policy that allows IAM users to view the inline and managed policies that are attached to their user identity. This policy includes permissions to complete this action on the console or programmatically using the AWS CLI or AWS API.
```
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "ViewOwnUserInfo",
"Effect": "Allow",
"Action": [
"iam:GetUserPolicy",
"iam:ListGroupsForUser",
"iam:ListAttachedUserPolicies",
"iam:ListUserPolicies",
"iam:GetUser"
],
"Resource": ["arn:aws:iam::*:user/${aws:username}"]
},
{
"Sid": "NavigateInConsole",
"Effect": "Allow",
"Action": [
"iam:GetGroupPolicy",
"iam:GetPolicyVersion",
"iam:GetPolicy",
"iam:ListAttachedGroupPolicies",
"iam:ListGroupPolicies",
"iam:ListPolicyVersions",
"iam:ListPolicies",
"iam:ListUsers"
],
"Resource": "*"
}
]
}
```
# Authorize core devices to interact with AWS services
AWS IoT Greengrass core devices use the AWS IoT Core credentials provider to authorize calls to AWS services. The AWS IoT Core credentials provider enables devices to use their X.509 certificates as the unique device identity to authenticate AWS requests. This eliminates the need to store an AWS access key ID and secret access key on your AWS IoT Greengrass core devices. For more information, see [Authorizing direct calls to AWS services](https://docs.aws.amazon.com/iot/latest/developerguide/authorizing-direct-aws.html) in the *AWS IoT Core Developer Guide*.
When you run the AWS IoT Greengrass Core software, you can choose to provision the AWS resources that the core device requires. This includes the AWS Identity and Access Management (IAM) role that your core device assumes through the AWS IoT Core credentials provider. Use the `--provision true` argument to configure a role and policies that allow the core device to get temporary AWS credentials. This argument also configures an AWS IoT role alias that points to this IAM role. You can specify the name of the IAM role and AWS IoT role alias to use. If you specify `--provision true` without these other name parameters, the Greengrass core device creates and uses the following default resources:
+ IAM role: `GreengrassV2TokenExchangeRole`
This role has a policy named `GreengrassV2TokenExchangeRoleAccess` and a trust relationship that allows `credentials.iot.amazonaws.com` to assume the role. The policy includes the minimum permissions for the core device.
**Important**
This policy doesn't include access to files in S3 buckets. You must add permissions to the role to allow core devices to retrieve component artifacts from S3 buckets. For more information, see [Allow access to S3 buckets for component artifacts](#device-service-role-access-s3-bucket).
+ AWS IoT role alias: `GreengrassV2TokenExchangeRoleAlias`
This role alias refers to the IAM role.
For more information, see [Step 3: Install the AWS IoT Greengrass Core software](install-greengrass-v2.md).
You can also set the role alias for an existing core device. To do so, configure the `iotRoleAlias` configuration parameter of the [Greengrass nucleus component](greengrass-nucleus-component.md).
You can acquire temporary AWS credentials for this IAM role to perform AWS operations in your custom components. For more information, see [Interact with AWS services](interact-with-aws-services.md).
**Topics**
+ [Service role permissions for core devices](#device-service-role-permissions)
+ [Allow access to S3 buckets for component artifacts](#device-service-role-access-s3-bucket)
## Service role permissions for core devices
The role allows the following service to assume the role:
+ `credentials.iot.amazonaws.com`
If you use the AWS IoT Greengrass Core software to create this role, it uses the following permissions policy to allow core devices to connect and send logs to AWS. The policy's name defaults to the name of the IAM role ending with `Access`. For example, if you use the default IAM role name, then this policy's name is `GreengrassV2TokenExchangeRoleAccess`.
------
#### [ Greengrass nucleus v2.5.0 and later ]
------
#### [ JSON ]
****
```
{
"Version":"2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"logs:CreateLogGroup",
"logs:CreateLogStream",
"logs:PutLogEvents",
"logs:DescribeLogStreams",
"s3:GetBucketLocation"
],
"Resource": "*"
}
]
}
```
------
------
#### [ v2.4.x ]
------
#### [ JSON ]
****
```
{
"Version":"2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"iot:DescribeCertificate",
"logs:CreateLogGroup",
"logs:CreateLogStream",
"logs:PutLogEvents",
"logs:DescribeLogStreams",
"s3:GetBucketLocation"
],
"Resource": "*"
}
]
}
```
------
------
#### [ Earlier than v2.4.0 ]
------
#### [ JSON ]
****
```
{
"Version":"2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"iot:DescribeCertificate",
"logs:CreateLogGroup",
"logs:CreateLogStream",
"logs:PutLogEvents",
"logs:DescribeLogStreams",
"iot:Connect",
"iot:Publish",
"iot:Subscribe",
"iot:Receive",
"s3:GetBucketLocation"
],
"Resource": "*"
}
]
}
```
------
------
## Allow access to S3 buckets for component artifacts
The default core device role doesn't allow core devices to access S3 buckets. To deploy components that have artifacts in S3 buckets, you must add the `s3:GetObject` permission to allow core devices to download component artifacts. You can add a new policy to the core device role to grant this permission.
**To add a policy that allows access to component artifacts in Amazon S3**
1. Create a file called `component-artifact-policy.json` and copy the following JSON into the file. This policy allows access to all files in an S3 bucket. Replace amzn-s3-demo-bucket with the name of the S3 bucket to allow the core device to access.
------
#### [ JSON ]
****
```
{
"Version":"2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"s3:GetObject"
],
"Resource": "arn:aws:s3:::amzn-s3-demo-bucket/*"
}
]
}
```
------
1. Run the following command to create the policy from the policy document in `component-artifact-policy.json`.
------
#### [ Linux or Unix ]
```
aws iam create-policy \
--policy-name MyGreengrassV2ComponentArtifactPolicy \
--policy-document file://component-artifact-policy.json
```
------
#### [ Windows Command Prompt (CMD) ]
```
aws iam create-policy ^
--policy-name MyGreengrassV2ComponentArtifactPolicy ^
--policy-document file://component-artifact-policy.json
```
------
#### [ PowerShell ]
```
aws iam create-policy `
--policy-name MyGreengrassV2ComponentArtifactPolicy `
--policy-document file://component-artifact-policy.json
```
------
Copy the policy Amazon Resource Name (ARN) from the policy metadata in the output. You use this ARN to attach this policy to the core device role in the next step.
1. Run the following command to attach the policy to the core device role. Replace *GreengrassV2TokenExchangeRole* with the name of the role that you specified when you ran the AWS IoT Greengrass Core software. Then, replace the policy ARN with the ARN from the previous step.
------
#### [ Linux or Unix ]
```
aws iam attach-role-policy \
--role-name GreengrassV2TokenExchangeRole \
--policy-arn arn:aws:iam::123456789012:policy/MyGreengrassV2ComponentArtifactPolicy
```
------
#### [ Windows Command Prompt (CMD) ]
```
aws iam attach-role-policy ^
--role-name GreengrassV2TokenExchangeRole ^
--policy-arn arn:aws:iam::123456789012:policy/MyGreengrassV2ComponentArtifactPolicy
```
------
#### [ PowerShell ]
```
aws iam attach-role-policy `
--role-name GreengrassV2TokenExchangeRole `
--policy-arn arn:aws:iam::123456789012:policy/MyGreengrassV2ComponentArtifactPolicy
```
------
If the command has no output, it succeeded, and your core device can access artifacts that you upload to this S3 bucket.
# Minimal IAM policy for installer to provision resources
When you install the AWS IoT Greengrass Core software, you can provision required AWS resources, such as an AWS IoT thing and an IAM role for your device. You can also deploy local development tools to the device. The installer requires AWS credentials so that it can perform these actions in your AWS account. For more information, see [Install the AWS IoT Greengrass Core software](install-greengrass-core-v2.md).
The following example policy includes the minimum set of actions that the installer requires to provision these resources. These permissions are required if you specify the `--provision` argument for the installer. Replace *account-id* with your AWS account ID, and replace *GreengrassV2TokenExchangeRole* with the name of the token exchange role that you specify with the `--tes-role-name` [installer argument](configure-installer.md).
**Note**
The `DeployDevTools` policy statement is required only if you specify the `--deploy-dev-tools` argument for the installer.
------
#### [ Greengrass nucleus v2.5.0 and later ]
------
#### [ JSON ]
****
```
{
"Version":"2012-10-17",
"Statement": [
{
"Sid": "CreateTokenExchangeRole",
"Effect": "Allow",
"Action": [
"iam:AttachRolePolicy",
"iam:CreatePolicy",
"iam:CreateRole",
"iam:GetPolicy",
"iam:GetRole",
"iam:PassRole"
],
"Resource": [
"arn:aws:iam::123456789012:role/GreengrassV2TokenExchangeRole",
"arn:aws:iam::123456789012:policy/GreengrassV2TokenExchangeRoleAccess",
"arn:aws:iam::aws:policy/GreengrassV2TokenExchangeRoleAccess"
]
},
{
"Sid": "CreateIoTResources",
"Effect": "Allow",
"Action": [
"iot:AddThingToThingGroup",
"iot:AttachPolicy",
"iot:AttachThingPrincipal",
"iot:CreateKeysAndCertificate",
"iot:CreatePolicy",
"iot:CreateRoleAlias",
"iot:CreateThing",
"iot:CreateThingGroup",
"iot:DescribeEndpoint",
"iot:DescribeRoleAlias",
"iot:DescribeThingGroup",
"iot:GetPolicy"
],
"Resource": "*"
},
{
"Sid": "DeployDevTools",
"Effect": "Allow",
"Action": [
"greengrass:CreateDeployment",
"iot:CancelJob",
"iot:CreateJob",
"iot:DeleteThingShadow",
"iot:DescribeJob",
"iot:DescribeThing",
"iot:DescribeThingGroup",
"iot:GetThingShadow",
"iot:UpdateJob",
"iot:UpdateThingShadow"
],
"Resource": "*"
}
]
}
```
------
------
#### [ Earlier than v2.5.0 ]
------
#### [ JSON ]
****
```
{
"Version":"2012-10-17",
"Statement": [
{
"Sid": "CreateTokenExchangeRole",
"Effect": "Allow",
"Action": [
"iam:AttachRolePolicy",
"iam:CreatePolicy",
"iam:CreateRole",
"iam:GetPolicy",
"iam:GetRole",
"iam:PassRole"
],
"Resource": [
"arn:aws:iam::123456789012:role/GreengrassV2TokenExchangeRole",
"arn:aws:iam::123456789012:policy/GreengrassV2TokenExchangeRoleAccess",
"arn:aws:iam::aws:policy/GreengrassV2TokenExchangeRoleAccess"
]
},
{
"Sid": "CreateIoTResources",
"Effect": "Allow",
"Action": [
"iot:AddThingToThingGroup",
"iot:AttachPolicy",
"iot:AttachThingPrincipal",
"iot:CreateKeysAndCertificate",
"iot:CreatePolicy",
"iot:CreateRoleAlias",
"iot:CreateThing",
"iot:CreateThingGroup",
"iot:DescribeEndpoint",
"iot:DescribeRoleAlias",
"iot:DescribeThingGroup",
"iot:GetPolicy"
],
"Resource": "*"
},
{
"Sid": "DeployDevTools",
"Effect": "Allow",
"Action": [
"greengrass:CreateDeployment",
"iot:CancelJob",
"iot:CreateJob",
"iot:DeleteThingShadow",
"iot:DescribeJob",
"iot:DescribeThing",
"iot:DescribeThingGroup",
"iot:GetThingShadow",
"iot:UpdateJob",
"iot:UpdateThingShadow"
],
"Resource": "*"
}
]
}
```
------
------
# Greengrass service role
The Greengrass service role is an AWS Identity and Access Management (IAM) service role that authorizes AWS IoT Greengrass to access resources from AWS services on your behalf. This role makes it possible for AWS IoT Greengrass to verify the identity of client devices and manage core device connectivity information.
**Note**
AWS IoT Greengrass V1 also uses this role to perform essential tasks. For more information, see [Greengrass service role](https://docs.aws.amazon.com/greengrass/v1/developerguide/service-role.html) in the *AWS IoT Greengrass V1 Developer Guide*.
To allow AWS IoT Greengrass to access your resources, the Greengrass service role must be associated with your AWS account and specify AWS IoT Greengrass as a trusted entity. The role must include the [AWSGreengrassResourceAccessRolePolicy](https://console.aws.amazon.com/iam/home#/policies/arn:aws:iam::aws:policy/service-role/AWSGreengrassResourceAccessRolePolicy) managed policy or a custom policy that defines equivalent permissions for the AWS IoT Greengrass features that you use. AWS maintains this policy, which defines the set of permissions that AWS IoT Greengrass uses to access your AWS resources. For more information, see [AWS managed policy: AWSGreengrassResourceAccessRolePolicy](security-iam-aws-managed-policies.md#aws-managed-policies-AWSGreengrassResourceAccessRolePolicy).
You can reuse the same Greengrass service role across AWS Regions, but you must associate it with your account in every AWS Region where you use AWS IoT Greengrass. If the service role isn't configured in the current AWS Region, core devices fail to verify client devices and fail to update connectivity information.
The following sections describe how to create and manage the Greengrass service role with the AWS Management Console or AWS CLI.
**Topics**
+ [Manage the Greengrass service role (console)](#manage-greengrass-service-role-console)
+ [Manage the Greengrass service role (CLI)](#manage-service-role-cli)
+ [See also](#service-role-see-also)
**Note**
In addition to the service role that authorizes service-level access, you assign a *token exchange role* to Greengrass core devices. The token exchange role is a separate IAM role that controls how Greengrass components and Lambda functions on the core device can access AWS services. For more information, see [Authorize core devices to interact with AWS services](device-service-role.md).
## Manage the Greengrass service role (console)
The AWS IoT console makes it easy to manage your Greengrass service role. For example, when you configure client device discovery for a core device, the console checks whether your AWS account is attached to a Greengrass service role in the current AWS Region. If not, the console can create and configure a service role for you. For more information, see [Create the Greengrass service role (console)](#create-greengrass-service-role-console).
You can use the console for the following role management tasks:
**Topics**
+ [Find your Greengrass service role (console)](#get-greengrass-service-role-console)
+ [Create the Greengrass service role (console)](#create-greengrass-service-role-console)
+ [Change the Greengrass service role (console)](#update-greengrass-service-role-console)
+ [Detach the Greengrass service role (console)](#remove-greengrass-service-role-console)
**Note**
The user who is signed in to the console must have permissions to view, create, or change the service role.
### Find your Greengrass service role (console)
Use the following steps to find the service role that AWS IoT Greengrass uses in the current AWS Region.
1. Navigate to the [AWS IoT console](https://console.aws.amazon.com/iot).
1. In the navigation pane, choose **Settings**.
1. Scroll to the **Greengrass service role** section to see your service role and its policies.
If you don't see a service role, the console can create or configure one for you. For more information, see [Create the Greengrass service role](#create-greengrass-service-role-console).
### Create the Greengrass service role (console)
The console can create and configure a default Greengrass service role for you. This role has the following properties.
| Property | Value |
| --- | --- |
| Name | Greengrass\$1ServiceRole |
| Trusted entity | AWS service: greengrass |
| Policy | [AWSGreengrassResourceAccessRolePolicy](https://console.aws.amazon.com/iam/home#/policies/arn:aws:iam::aws:policy/service-role/AWSGreengrassResourceAccessRolePolicy) |
**Note**
If you create this role with the [AWS IoT Greengrass V1 device setup script](https://docs.aws.amazon.com/greengrass/v1/developerguide/quick-start.html), the role name is `GreengrassServiceRole_random-string`.
When you configure client device discovery for a core device, the console checks whether a Greengrass service role is associated with your AWS account in the current AWS Region. If not, the console prompts you to allow AWS IoT Greengrass to read and write to AWS services on your behalf.
If you grant permission, the console checks whether a role named `Greengrass_ServiceRole` exists in your AWS account.
+ If the role exists, the console attaches the service role to your AWS account in the current AWS Region.
+ If the role doesn't exist, the console creates a default Greengrass service role and attaches it to your AWS account in the current AWS Region.
**Note**
If you want to create a service role with custom role policies, use the IAM console to create or modify the role. For more information, see [Creating a role to delegate permissions to an AWS service](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_create_for-service.html) or [Modifying a role](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_manage_modify.html) in the *IAM User Guide*. Make sure that the role grants permissions that are equivalent to the `AWSGreengrassResourceAccessRolePolicy` managed policy for the features and resources that you use. We recommend that you also include the `aws:SourceArn` and `aws:SourceAccount` global condition context keys in your trust policy to help prevent the *confused deputy* security problem. The condition context keys restrict access to allow only those requests that come from the specified account and Greengrass workspace. For more information about the confused deputy problem, see [Cross-service confused deputy prevention](cross-service-confused-deputy-prevention.md).
If you create a service role, return to the AWS IoT console and attach the role to your AWS account. You can do this under **Greengrass service role** on the **Settings** page.
### Change the Greengrass service role (console)
Use the following procedure to choose a different Greengrass service role to attach to your AWS account in the AWS Region currently selected in the console.
1. Navigate to the [AWS IoT console](https://console.aws.amazon.com/iot).
1. In the navigation pane, choose **Settings**.
1. Under **Greengrass service role**, choose **Change role**.
The **Update Greengrass service role** dialog box opens and shows the IAM roles in your AWS account that define AWS IoT Greengrass as a trusted entity.
1. Choose the Greengrass service role to attach.
1. Choose **Attach role**.
### Detach the Greengrass service role (console)
Use the following procedure to detach the Greengrass service role from your AWS account in the current AWS Region. This revokes permissions for AWS IoT Greengrass to access AWS services in the current AWS Region.
**Important**
Detaching the service role might interrupt active operations.
1. Navigate to the [AWS IoT console](https://console.aws.amazon.com/iot).
1. In the navigation pane, choose **Settings**.
1. Under **Greengrass service role**, choose **Detach role**.
1. In the confirmation dialog box, choose **Detach**.
**Note**
If you no longer need the role, you can delete it in the IAM console. For more information, see [Deleting roles or instance profiles](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_manage_delete.html) in the *IAM User Guide*.
Other roles might allow AWS IoT Greengrass to access your resources. To find all roles that allow AWS IoT Greengrass to assume permissions on your behalf, in the IAM console, on the **Roles** page, look for roles that include **AWS service: greengrass** in the **Trusted entities** column.
## Manage the Greengrass service role (CLI)
In the following procedures, we assume that the AWS Command Line Interface is installed and configured to use your AWS account. For more information, see [Installing, updating, and uninstalling the AWS CLI](https://docs.aws.amazon.com/cli/latest/userguide/installing.html) and [Configuring the AWS CLI](https://docs.aws.amazon.com/cli/latest/userguide/cli-chap-getting-started.html) in the *AWS Command Line Interface User Guide*.
You can use the AWS CLI for the following role management tasks:
**Topics**
+ [Get the Greengrass service role (CLI)](#get-service-role)
+ [Create the Greengrass service role (CLI)](#create-service-role)
+ [Remove the Greengrass service role (CLI)](#remove-service-role)
### Get the Greengrass service role (CLI)
Use the following procedure to find out if a Greengrass service role is associated with your AWS account in an AWS Region.
+ Get the service role. Replace *region* with your AWS Region (for example, `us-west-2`).
```
aws greengrassv2 get-service-role-for-account --region region
```
If a Greengrass service role is already associated with your account, the request returns the following role metadata.
```
{
"associatedAt": "timestamp",
"roleArn": "arn:aws:iam::account-id:role/path/role-name"
}
```
If the request doesn't return role metadata, then you must create the service role (if it doesn't exist) and associate it with your account in the AWS Region.
### Create the Greengrass service role (CLI)
Use the following steps to create a role and associate it with your AWS account.
**To create the service role using IAM**
1. Create a role with a trust policy that allows AWS IoT Greengrass to assume the role. This example creates a role named `Greengrass_ServiceRole`, but you can use a different name. We recommend that you also include the `aws:SourceArn` and `aws:SourceAccount` global condition context keys in your trust policy to help prevent the *confused deputy* security problem. The condition context keys restrict access to allow only those requests that come from the specified account and Greengrass workspace. For more information about the confused deputy problem, see [Cross-service confused deputy prevention](cross-service-confused-deputy-prevention.md).
------
#### [ Linux or Unix ]
```
aws iam create-role --role-name Greengrass_ServiceRole --assume-role-policy-document '{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": {
"Service": "greengrass.amazonaws.com"
},
"Action": "sts:AssumeRole",
"Condition": {
"ArnLike": {
"aws:SourceArn": "arn:aws:greengrass:region:account-id:*"
},
"StringEquals": {
"aws:SourceAccount": "account-id"
}
}
}
]
}'
```
------
#### [ Windows Command Prompt (CMD) ]
```
aws iam create-role --role-name Greengrass_ServiceRole --assume-role-policy-document "{\"Version\":\"2012-10-17\", \"Statement\":[{\"Effect\":\"Allow\",\"Principal\":{\"Service\":\"greengrass.amazonaws.com\"},\"Action\":\"sts:AssumeRole\",\"Condition\":{\"ArnLike\":{\"aws:SourceArn\":\"arn:aws:greengrass:region:account-id:*\"},\"StringEquals\":{\"aws:SourceAccount\":\"account-id\"}}}]}"
```
------
#### [ PowerShell ]
```
aws iam create-role --role-name Greengrass_ServiceRole --assume-role-policy-document '{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": {
"Service": "greengrass.amazonaws.com"
},
"Action": "sts:AssumeRole",
"Condition": {
"ArnLike": {
"aws:SourceArn": "arn:aws:greengrass:region:account-id:*"
},
"StringEquals": {
"aws:SourceAccount": "account-id"
}
}
}
]
}'
```
------
1. Copy the role ARN from the role metadata in the output. You use the ARN to associate the role with your account.
1. Attach the `AWSGreengrassResourceAccessRolePolicy` policy to the role.
```
aws iam attach-role-policy --role-name Greengrass_ServiceRole --policy-arn arn:aws:iam::aws:policy/service-role/AWSGreengrassResourceAccessRolePolicy
```
**To associate the service role with your AWS account**
+ Associate the role with your account. Replace *role-arn* with the service role ARN and *region* with your AWS Region (for example, `us-west-2`).
```
aws greengrassv2 associate-service-role-to-account --role-arn role-arn --region region
```
If successful, the request returns the following response.
```
{
"associatedAt": "timestamp"
}
```
### Remove the Greengrass service role (CLI)
Use the following steps to disassociate the Greengrass service role from your AWS account.
+ Disassociate the service role from your account. Replace *region* with your AWS Region (for example, `us-west-2`).
```
aws greengrassv2 disassociate-service-role-from-account --region region
```
If successful, the following response is returned.
```
{
"disassociatedAt": "timestamp"
}
```
**Note**
You should delete the service role if you're not using it in any AWS Region. First use [https://docs.aws.amazon.com/cli/latest/reference/iam/delete-role-policy.html](https://docs.aws.amazon.com/cli/latest/reference/iam/delete-role-policy.html) to detach the `AWSGreengrassResourceAccessRolePolicy` managed policy from the role, and then use [https://docs.aws.amazon.com/cli/latest/reference/iam/delete-role.html](https://docs.aws.amazon.com/cli/latest/reference/iam/delete-role.html) to delete the role. For more information, see [Deleting roles or instance profiles](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_manage_delete.html) in the *IAM User Guide*.
## See also
+ [Creating a role to delegate permissions to an AWS service](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_create_for-service.html) in the *IAM User Guide*
+ [Modifying a role](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_manage_modify.html) in the *IAM User Guide*
+ [Deleting roles or instance profiles](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_manage_delete.html) in the *IAM User Guide*
+ AWS IoT Greengrass commands in the *AWS CLI Command Reference*
+ [associate-service-role-to-account](https://docs.aws.amazon.com/cli/latest/reference/greengrassv2/associate-service-role-to-account.html)
+ [disassociate-service-role-from-account](https://docs.aws.amazon.com/cli/latest/reference/greengrassv2/disassociate-service-role-from-account.html)
+ [get-service-role-for-account](https://docs.aws.amazon.com/cli/latest/reference/greengrassv2/get-service-role-for-account.html)
+ IAM commands in the *AWS CLI Command Reference*
+ [attach-role-policy](https://docs.aws.amazon.com/cli/latest/reference/iam/attach-role-policy.html)
+ [create-role](https://docs.aws.amazon.com/cli/latest/reference/iam/create-role.html)
+ [delete-role](https://docs.aws.amazon.com/cli/latest/reference/iam/delete-role.html)
+ [delete-role-policy](https://docs.aws.amazon.com/cli/latest/reference/iam/delete-role-policy.html)
# AWS managed policies for AWS IoT Greengrass
An AWS managed policy is a standalone policy that is created and administered by AWS. AWS managed policies are designed to provide permissions for many common use cases so that you can start assigning permissions to users, groups, and roles.
Keep in mind that AWS managed policies might not grant least-privilege permissions for your specific use cases because they're available for all AWS customers to use. We recommend that you reduce permissions further by defining [ customer managed policies](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies_managed-vs-inline.html#customer-managed-policies) that are specific to your use cases.
You cannot change the permissions defined in AWS managed policies. If AWS updates the permissions defined in an AWS managed policy, the update affects all principal identities (users, groups, and roles) that the policy is attached to. AWS is most likely to update an AWS managed policy when a new AWS service is launched or new API operations become available for existing services.
For more information, see [AWS managed policies](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies_managed-vs-inline.html#aws-managed-policies) in the *IAM User Guide*.
**Topics**
+ [AWS managed policy: AWSGreengrassFullAccess](#aws-managed-policies-AWSGreengrassFullAccess)
+ [AWS managed policy: AWSGreengrassReadOnlyAccess](#aws-managed-policies-AWSGreengrassReadOnlyAccess)
+ [AWS managed policy: AWSGreengrassResourceAccessRolePolicy](#aws-managed-policies-AWSGreengrassResourceAccessRolePolicy)
+ [AWS IoT Greengrass updates to AWS managed policies](#aws-managed-policy-updates)
## AWS managed policy: AWSGreengrassFullAccess
You can attach the `AWSGreengrassFullAccess` policy to your IAM identities.
This policy grants administrative permissions that allow a principal full access to all AWS IoT Greengrass actions.
**Permissions details**
This policy includes the following permissions:
+ `greengrass` – Allows principals full access to all AWS IoT Greengrass actions.
------
#### [ JSON ]
****
```
{
"Version":"2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"greengrass:*"
],
"Resource": "*"
}
]
}
```
------
## AWS managed policy: AWSGreengrassReadOnlyAccess
You can attach the `AWSGreengrassReadOnlyAccess` policy to your IAM identities.
This policy grants read-only permissions that allow a principal to view, but not modify, information in AWS IoT Greengrass. For example, principals with these permissions can view the list of components deployed to a Greengrass core device, but can't create a deployment to change the components that run on that device.
**Permissions details**
This policy includes the following permissions:
+ `greengrass` – Allows principals to perform actions that return either a list of items or details about an item. This includes API operations that start with `List` or `Get`.
------
#### [ JSON ]
****
```
{
"Version":"2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"greengrass:List*",
"greengrass:Get*"
],
"Resource": "*"
}
]
}
```
------
## AWS managed policy: AWSGreengrassResourceAccessRolePolicy
You can attach the `AWSGreengrassResourceAccessRolePolicy` policy to your IAM entities. AWS IoT Greengrass also attaches this policy to a service role that allows AWS IoT Greengrass to perform actions on your behalf. For more information, see [Greengrass service role](greengrass-service-role.md).
This policy grants administrative permissions that allow AWS IoT Greengrass to perform essential tasks, such as retrieving your Lambda functions, managing AWS IoT device shadows, and verifying Greengrass client devices.
**Permissions details**
This policy includes the following permissions.
+ `greengrass` – Manage Greengrass resources.
+ `iot` (`*Shadow`) – Manage AWS IoT shadows that have the following special identifiers in their names. These permissions are required so that AWS IoT Greengrass can communicate with core devices.
+ `*-gci` – AWS IoT Greengrass uses this shadow to store core device connectivity information, so client devices can discover and connect to core devices.
+ `*-gcm` – AWS IoT Greengrass V1 uses this shadow to notify the core device that the Greengrass group's certificate authority (CA) certificate has rotated.
+ `*-gda` – AWS IoT Greengrass V1 uses this shadow to notify the core device of a deployment.
+ `GG_*` – Unused.
+ `iot` (`DescribeThing` and `DescribeCertificate`) – Retrieve information about AWS IoT things and certificates. These permissions are required so that AWS IoT Greengrass can verify client devices that connect to a core device. For more information, see [Interact with local IoT devices](interact-with-local-iot-devices.md).
+ `lambda` – Retrieve information about AWS Lambda functions. This permission is required so that AWS IoT Greengrass V1 can deploy Lambda functions to Greengrass cores. For more information, see [Run Lambda function on the AWS IoT Greengrass core](https://docs.aws.amazon.com/greengrass/v1/developerguide/lambda-functions.html) in the *AWS IoT Greengrass V1 Developer Guide*.
+ `secretsmanager` – Retrieve the value of AWS Secrets Manager secrets whose names start with `greengrass-`. This permission is required so that AWS IoT Greengrass V1 can deploy Secrets Manager secrets to Greengrass cores. For more information, see [Deploy secrets to the AWS IoT Greengrass core](https://docs.aws.amazon.com/greengrass/v1/developerguide/secrets.html) in the *AWS IoT Greengrass V1 Developer Guide*.
+ `s3` – Retrieve files objects from S3 buckets whose names contain `greengrass` or `sagemaker`. These permissions are required so that AWS IoT Greengrass V1 can deploy machine learning resources that you store in S3 buckets. For more information, see [Machine learning resources](https://docs.aws.amazon.com/greengrass/v1/developerguide/ml-inference.html#ml-resources) in the *AWS IoT Greengrass V1 Developer Guide*.
+ `sagemaker` – Retrieve information about Amazon SageMaker AI machine learning inference models. This permission is required so that AWS IoT Greengrass V1 can deploy ML models to Greengrass cores. For more information, see [Perform machine learning inference](https://docs.aws.amazon.com/greengrass/v1/developerguide/ml-inference.html) in the *AWS IoT Greengrass V1 Developer Guide*.
------
#### [ JSON ]
****
```
{
"Version":"2012-10-17",
"Statement": [
{
"Sid": "AllowGreengrassAccessToShadows",
"Action": [
"iot:DeleteThingShadow",
"iot:GetThingShadow",
"iot:UpdateThingShadow"
],
"Effect": "Allow",
"Resource": [
"arn:aws:iot:*:*:thing/GG_*",
"arn:aws:iot:*:*:thing/*-gcm",
"arn:aws:iot:*:*:thing/*-gda",
"arn:aws:iot:*:*:thing/*-gci"
]
},
{
"Sid": "AllowGreengrassToDescribeThings",
"Action": [
"iot:DescribeThing"
],
"Effect": "Allow",
"Resource": "arn:aws:iot:*:*:thing/*"
},
{
"Sid": "AllowGreengrassToDescribeCertificates",
"Action": [
"iot:DescribeCertificate"
],
"Effect": "Allow",
"Resource": "arn:aws:iot:*:*:cert/*"
},
{
"Sid": "AllowGreengrassToCallGreengrassServices",
"Action": [
"greengrass:*"
],
"Effect": "Allow",
"Resource": "*"
},
{
"Sid": "AllowGreengrassToGetLambdaFunctions",
"Action": [
"lambda:GetFunction",
"lambda:GetFunctionConfiguration"
],
"Effect": "Allow",
"Resource": "*"
},
{
"Sid": "AllowGreengrassToGetGreengrassSecrets",
"Action": [
"secretsmanager:GetSecretValue"
],
"Effect": "Allow",
"Resource": "arn:aws:secretsmanager:*:*:secret:greengrass-*"
},
{
"Sid": "AllowGreengrassAccessToS3Objects",
"Action": [
"s3:GetObject"
],
"Effect": "Allow",
"Resource": [
"arn:aws:s3:::*Greengrass*",
"arn:aws:s3:::*GreenGrass*",
"arn:aws:s3:::*greengrass*",
"arn:aws:s3:::*Sagemaker*",
"arn:aws:s3:::*SageMaker*",
"arn:aws:s3:::*sagemaker*"
]
},
{
"Sid": "AllowGreengrassAccessToS3BucketLocation",
"Action": [
"s3:GetBucketLocation"
],
"Effect": "Allow",
"Resource": "*"
},
{
"Sid": "AllowGreengrassAccessToSageMakerTrainingJobs",
"Action": [
"sagemaker:DescribeTrainingJob"
],
"Effect": "Allow",
"Resource": [
"arn:aws:sagemaker:*:*:training-job/*"
]
}
]
}
```
------
## AWS IoT Greengrass updates to AWS managed policies
You can view details about updates to AWS managed policies for AWS IoT Greengrass from the time this service began tracking these changes. For automatic alerts about changes to this page, subscribe to the RSS feed on the [AWS IoT Greengrass V2 document history page](document-history.md).
| Change | Description | Date |
| --- | --- | --- |
| AWS IoT Greengrass started tracking changes | AWS IoT Greengrass started tracking changes for its AWS managed policies. | July 2, 2021 |
# Cross-service confused deputy prevention
The confused deputy problem is a security issue where an entity that doesn't have permission to perform an action can coerce a more-privileged entity to perform the action. In AWS, cross-service impersonation can result in the confused deputy problem. Cross-service impersonation can occur when one service (the *calling service*) calls another service (the *called service*). The calling service can be manipulated to use its permissions to act on another customer's resources in a way it should not otherwise have permission to access. To prevent this, AWS provides tools that help you protect your data for all services with service principals that have been given access to resources in your account.
We recommend using the [https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_condition-keys.html#condition-keys-sourcearn](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_condition-keys.html#condition-keys-sourcearn) and [https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_condition-keys.html#condition-keys-sourceaccount](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_condition-keys.html#condition-keys-sourceaccount) global condition context keys in resource policies to limit the permissions that AWS IoT Greengrass gives another service to the resource. If you use both global condition context keys, the `aws:SourceAccount` value and the account in the `aws:SourceArn` value must use the same account ID when used in the same policy statement.
The value of `aws:SourceArn` must be the Greengrass customer resource that is associated with the `sts:AssumeRole` request.
The most effective way to protect against the confused deputy problem is to use the `aws:SourceArn` global condition context key with the full ARN of the resource. If you don't know the full ARN of the resource or if you are specifying multiple resources, use the `aws:SourceArn` global context condition key with wildcards (`*`) for the unknown portions of the ARN. For example, `arn:aws:greengrass::account-id:*`.
For an example of a policy that uses the `aws:SourceArn` and `aws:SourceAccount` global condition context keys, see [Create the Greengrass service role](greengrass-service-role.md#create-service-role).
# Troubleshooting identity and access issues for AWS IoT Greengrass
Use the following information to help you diagnose and fix common issues that you might encounter when working with AWS IoT Greengrass and IAM.
**Topics**
+ [I'm not authorized to perform an action in AWS IoT Greengrass](#security_iam_troubleshoot-no-permissions)
+ [I'm not authorized to perform iam:PassRole](#security_iam_troubleshoot-passrole)
+ [I'm an administrator and want to allow others to access AWS IoT Greengrass](#security_iam_troubleshoot-admin-delegate)
+ [I want to allow people outside of my AWS account to access my AWS IoT Greengrass resources](#security_iam_troubleshoot-cross-account-access)
For general troubleshooting help, see [Troubleshooting AWS IoT Greengrass V2](troubleshooting.md).
## I'm not authorized to perform an action in AWS IoT Greengrass
If you receive an error that states you're not authorized to perform an action, you must contact your administrator for assistance. Your administrator is the person who provided you with your user name and password.
The following example error occurs when the `mateojackson` IAM user tries to view details about a core device, but does not have `greengrass:GetCoreDevice` permissions.
```
User: arn:aws:iam::123456789012:user/mateojackson is not authorized to perform: greengrass:GetCoreDevice on resource: arn:aws:greengrass:us-west-2:123456789012:coreDevices/MyGreengrassCore
```
In this case, Mateo asks his administrator to update his policies to allow him to access the `arn:aws:greengrass:us-west-2:123456789012:coreDevices/MyGreengrassCore` resource using the `greengrass:GetCoreDevice` action.
The following are general IAM issues that you might encounter when working with AWS IoT Greengrass.
## I'm not authorized to perform iam:PassRole
If you receive an error that you're not authorized to perform the `iam:PassRole` action, your policies must be updated to allow you to pass a role to AWS IoT Greengrass.
Some AWS services allow you to pass an existing role to that service instead of creating a new service role or service-linked role. To do this, you must have permissions to pass the role to the service.
The following example error occurs when an IAM user named `marymajor` tries to use the console to perform an action in AWS IoT Greengrass. However, the action requires the service to have permissions that are granted by a service role. Mary does not have permissions to pass the role to the service.
```
User: arn:aws:iam::123456789012:user/marymajor is not authorized to perform: iam:PassRole
```
In this case, Mary's policies must be updated to allow her to perform the `iam:PassRole` action.
If you need help, contact your AWS administrator. Your administrator is the person who provided you with your sign-in credentials.
## I'm an administrator and want to allow others to access AWS IoT Greengrass
To allow others to access AWS IoT Greengrass, you must grant permission to the people or applications that need access. If you are using AWS IAM Identity Center to manage people and applications, you assign permission sets to users or groups to define their level of access. Permission sets automatically create and assign IAM policies to IAM roles that are associated with the person or application. For more information, see [Permission sets](https://docs.aws.amazon.com/singlesignon/latest/userguide/permissionsetsconcept.html) in the *AWS IAM Identity Center User Guide*.
If you are not using IAM Identity Center, you must create IAM entities (users or roles) for the people or applications that need access. You must then attach a policy to the entity that grants them the correct permissions in AWS IoT Greengrass. After the permissions are granted, provide the credentials to the user or application developer. They will use those credentials to access AWS. To learn more about creating IAM users, groups, policies, and permissions, see [IAM Identities](https://docs.aws.amazon.com/IAM/latest/UserGuide/id.html) and [Policies and permissions in IAM](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies.html) in the *IAM User Guide*.
## I want to allow people outside of my AWS account to access my AWS IoT Greengrass resources
You can create an IAM role that users in other accounts or people outside of your organization can use to access your AWS resources. You can specify the who is trusted to assume the role. For more information, see [Providing access to an IAM user in another AWS account that you own](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_common-scenarios_aws-accounts.html) and [Providing access to AWS accounts owned by third parties](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_common-scenarios_third-party.html) in the *IAM User Guide*.
AWS IoT Greengrass doesn't support cross-account access based on resource-based policies or access control lists (ACLs).