# Permissions for the IAM Role Assigned to Amazon Config
An IAM role lets you define a set of permissions. Amazon Config assumes the role that you assign to it to write to your S3 bucket, publish to your SNS topic, and make `Describe` or `List` API requests to get configuration details for your Amazon resources. For more information about IAM roles, see [IAM Roles](https://docs.amazonaws.cn/IAM/latest/UserGuide/WorkingWithRoles.html) in the *IAM User Guide*.
When you use the Amazon Config console to create or update an IAM role, Amazon Config automatically attaches the required permissions for you. For more information, see [Setting Up Amazon Config with the Console](gs-console.md).
**Policies and compliance results**
[IAM policies](https://docs.amazonaws.cn/IAM/latest/UserGuide/access_policies.html) and [other policies managed in Amazon Organizations](https://docs.amazonaws.cn/organizations/latest/userguide/orgs_manage_policies.html) can impact whether Amazon Config has permissions to record configuration changes for your resources. Additionally, rules directly evaluate the configuration of a resource and rules don't take into account these policies when running evaluations. Make sure that the policies in effect align with how you intend to use Amazon Config.
**Contents**
+ [Creating IAM Role Policies](#iam-role-policies)
+ [Adding an IAM Trust Policy to your Role](#iam-trust-policy)
+ [IAM Role Policy for your S3 Bucket](#iam-role-policies-S3-bucket)
+ [IAM Role Policy for KMS Key](#iam-role-policies-S3-kms-key)
+ [IAM Role Policy for Amazon SNS Topic](#iam-role-policies-sns-topic)
+ [IAM Role Policy for Getting Configuration Details](#iam-role-policies-describe-apis)
+ [Managing Permissions for S3 Bucket Recording](#troubleshooting-recording-s3-bucket-policy)
## Creating IAM Role Policies
When you use the Amazon Config console to create an IAM role, Amazon Config automatically attaches the required permissions to the role for you.
If you are using the Amazon CLI to set up Amazon Config or you are updating an existing IAM role, you must manually update the policy to allow Amazon Config to access your S3 bucket, publish to your SNS topic, and get configuration details about your resources.
### Adding an IAM Trust Policy to your Role
You can create an IAM trust policy that enables Amazon Config to assume a role and use it to track your resources. For more information about trust policies, see [Roles terms and concepts](https://docs.amazonaws.cn/IAM/latest/UserGuide/d_roles_terms-and-concepts.html) in the* IAM User Guide*.
The following is an example trust policy for Amazon Config roles:
------
#### [ JSON ]
****
```
{
"Version":"2012-10-17",
"Statement": [
{
"Sid": "",
"Effect": "Allow",
"Principal": {
"Service": "config.amazonaws.com"
},
"Action": "sts:AssumeRole",
"Condition": {
"StringEquals": {
"AWS:SourceAccount": "{{sourceAccountID}}"
}
}
}
]
}
```
------
You can use the `AWS:SourceAccount` condition in the IAM Role Trust relationship above to restrict the Config service principal to only interact with the Amazon IAM Role when performing operations on behalf of specific accounts.
Amazon Config also supports the `AWS:SourceArn` condition which restricts the Config service principal to only assume the IAM Role when performing operations on behalf of the owning account. When using the Amazon Config service principal, the `AWS:SourceArn` property will always be set to `arn:aws:config:sourceRegion:sourceAccountID:*` where `sourceRegion` is the region of the customer managed configuration recorder and `sourceAccountID` is the ID of the account containing the customer managed configuration recorder.
For example, add the following condition restrict the Config service principal to only assume the IAM Role only on behalf of a customer managed configuration recorder in the `us-east-1` region in the account `123456789012`: `"ArnLike": {"AWS:SourceArn": "arn:aws:config:us-east-1:123456789012:*"}`.
### IAM Role Policy for your S3 Bucket
The following example policy grants Amazon Config permission to access your S3 bucket:
------
#### [ JSON ]
****
```
{
"Version":"2012-10-17",
"Statement":[
{
"Effect":"Allow",
"Action":[
"s3:PutObject",
"s3:PutObjectAcl"
],
"Resource":[
"arn:aws-cn:s3:::{{amzn-s3-demo-bucket}}/{{prefix}}/AWSLogs/{{myAccountID}}/*"
],
"Condition":{
"StringLike":{
"s3:x-amz-acl":"bucket-owner-full-control"
}
}
},
{
"Effect":"Allow",
"Action":[
"s3:GetBucketAcl"
],
"Resource":"arn:aws-cn:s3:::{{amzn-s3-demo-bucket}}"
}
]
}
```
------
### IAM Role Policy for KMS Key
The following example policy grants Amazon Config permission to use KMS-based encryption on new objects for S3 bucket delivery:
------
#### [ JSON ]
****
```
{
"Version":"2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"kms:Decrypt",
"kms:GenerateDataKey"
],
"Resource": "arn:aws-cn:kms:us-east-1:123456789012:key/12345678-1234-1234-1234-123456789012"
}
]
}
```
------
### IAM Role Policy for Amazon SNS Topic
The following example policy grants Amazon Config permission to access your SNS topic:
------
#### [ JSON ]
****
```
{
"Version":"2012-10-17",
"Statement":
[
{
"Effect":"Allow",
"Action":"sns:Publish",
"Resource":"arn:aws-cn:sns:us-east-1:123456789012:MyTopic"
}
]
}
```
------
If your SNS topic is encrypted for additional setup instructions, see [Configuring Amazon KMS Permissions](https://docs.amazonaws.cn/sns/latest/dg/sns-server-side-encryption.html#sns-what-permissions-for-sse) in the *Amazon Simple Notification Service Developer Guide*.
### IAM Role Policy for Getting Configuration Details
It is recommended to use the Amazon Config service-linked role: `AWSServiceRoleForConfig`. Service-linked roles are predefined and include all the permissions that Amazon Config requires to call other Amazon Web Services services. The Amazon Config service-linked role is required for service-linked configuration recorders. For more information, see [Using Service-Linked Roles for Amazon Config](https://docs.amazonaws.cn/config/latest/developerguide/using-service-linked-roles.html).
If you create or update a role with the console, Amazon Config attaches the **AWSServiceRoleForConfig** for you.
If you use the Amazon CLI, use the `attach-role-policy` command and specify the Amazon Resource Name (ARN) for **AWSServiceRoleForConfig**:
```
$ aws iam attach-role-policy --role-name {{myConfigRole}} --policy-arn arn:aws:iam::aws:policy/aws-service-role/AWSServiceRoleForConfig
```
### Managing Permissions for S3 Bucket Recording
Amazon Config records and delivers notifications when an S3 bucket is created, updated, or deleted.
It is recommended to use the Amazon Config service-linked role: `AWSServiceRoleForConfig`. Service-linked roles are predefined and include all the permissions that Amazon Config requires to call other Amazon Web Services services. The Amazon Config service-linked role is required for service-linked configuration recorders. For more information, see [Using Service-Linked Roles for Amazon Config](https://docs.amazonaws.cn/config/latest/developerguide/using-service-linked-roles.html).