# Example IAM policies for Amazon RAM
<a name="security-iam-policies-examples"></a>

This topic includes examples of IAM policies for Amazon RAM that demonstrate sharing specific resources and resource types and restricting sharing.

**Topics**
+ [Allow sharing of specific resources](#owner-share-specific-resources)
+ [Allow sharing of specific resource types](#owner-share-resource-types)
+ [Restrict sharing with external Amazon Web Services accounts](#control-access-owner-external)

## Example 1: Allow sharing of specific resources
<a name="owner-share-specific-resources"></a>

You can use an IAM permission policy to restrict principals to associating only specific resources with resource shares.

For example, the following policy limits principals to sharing only the resolver rule with the specified Amazon Resource Name (ARN). The operator `StringEqualsIfExists` allows a request if either the request doesn't include a `ResourceArn` parameter, or if it does include that parameter, that its value exactly matches the specified ARN.

 For more information about when and why to use `...IfExists` operators, see [...IfExists condition operators](https://docs.amazonaws.cn/IAM/latest/UserGuide/reference_policies_elements_condition_operators.html#Conditions_IfExists) in the *IAM User Guide*.

------
#### [ JSON ]

****  

```
{
    "Version":"2012-10-17",		 	 	 
    "Statement": [{
        "Effect": "Allow",
        "Action": ["ram:CreateResourceShare", "ram:AssociateResourceShare"],
        "Resource": "*",
        "Condition": {
            "StringEqualsIfExists": {
                "ram:ResourceArn": "arn:aws-cn:route53resolver:us-west-2:123456789012:resolver-rule/rslvr-rr-5328a0899aexample"
            }
        }
    }]
}
```

------

## Example 2: Allow sharing of specific resource types
<a name="owner-share-resource-types"></a>

You can use an IAM policy to limit principals to associating only specific resource types with resource shares.

The actions, `AssociateResourceShare` and `CreateResourceShare`, can accept principals and `resourceArns` as independent input parameters. Therefore, Amazon RAM authorizes each principal and resource independently, so there could be multiple [request contexts](https://docs.amazonaws.cn/IAM/latest/UserGuide/reference_policies_evaluation-logic_policy-eval-reqcontext.html). This means when a principal is being associated to a Amazon RAM resource share, the `ram:RequestedResourceType` condition key is not present in the request context. Similarly, when a resource is being associated to a Amazon RAM resource share, the `ram:Principal` condition key is not present in the request context. Therefore, to allow `AssociateResourceShare` and `CreateResourceShare` when associating principals to the Amazon RAM resource share, you can use the [`Null` condition operator](https://docs.amazonaws.cn/IAM/latest/UserGuide/reference_policies_elements_condition_operators.html#Conditions_Null). 

For example, the following policy limits principals to sharing only Amazon Route 53 resolver rules and allows them to associate any principal to that share.

------
#### [ JSON ]

****  

```
{
    "Version":"2012-10-17",		 	 	 
    "Statement": [{
        "Sid": "AllowOnlySpecificResourceType",
        "Effect": "Allow",
        "Action": ["ram:CreateResourceShare", "ram:AssociateResourceShare"],
        "Resource": "*",
        "Condition": {
            "StringEquals": {
                "ram:RequestedResourceType": "route53resolver:ResolverRule"
            }
        }
    },
    {
    "Sid": "AllowAssociatingPrincipals",
     "Effect": "Allow",
        "Action": ["ram:CreateResourceShare", "ram:AssociateResourceShare"],
        "Resource": "*",
        "Condition": {
            "Null": {
                "ram:Principal": "false"
             }
        }
    }
  ]
}
```

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## Example 3: Restrict sharing with external Amazon Web Services accounts
<a name="control-access-owner-external"></a>

You can use an IAM policy to prevent principals from sharing resources with Amazon Web Services accounts that are outside of its Amazon organization.

For example, the following IAM policy prevents principals from adding external Amazon Web Services accounts to resource shares.

------
#### [ JSON ]

****  

```
{
    "Version":"2012-10-17",		 	 	 
    "Statement": [{
        "Effect": "Allow",
        "Action": "ram:CreateResourceShare",
        "Resource": "*",
        "Condition": {
            "Bool": {
                "ram:RequestedAllowsExternalPrincipals": "false"
            }
        }
    }]
}
```

------