Request Syntax Request Parameters Response Syntax Response Elements Errors Examples See Also

IsAuthorized

Makes an authorization decision about a service request described in the parameters. The information in the parameters can also define additional context that Verified Permissions can include in the evaluation. The request is evaluated against all matching policies in the specified policy store. The result of the decision is either Allow or Deny, along with a list of the policies that resulted in the decision.

Request Syntax


{
   "action": { 
      "actionId": "string",
      "actionType": "string"
   },
   "context": { ... },
   "entities": { ... },
   "policyStoreId": "string",
   "principal": { 
      "entityId": "string",
      "entityType": "string"
   },
   "resource": { 
      "entityId": "string",
      "entityType": "string"
   }
}

Request Parameters

For information about the parameters that are common to all actions, see Common Parameters.

The request accepts the following data in JSON format.

Note

In the following list, the required parameters are described first.

policyStoreId

Specifies the ID of the policy store. Policies in this policy store will be used to make an authorization decision for the input.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 200.

Pattern: [a-zA-Z0-9-]*

Required: Yes

action

Specifies the requested action to be authorized. For example, is the principal authorized to perform this action on the resource?

Type: ActionIdentifier object

Required: No

context

Specifies additional context that can be used to make more granular authorization decisions.

Type: ContextDefinition object

Note: This object is a Union. Only one member of this object can be specified or returned.

Required: No

entities

Specifies the list of resources and principals and their associated attributes that Verified Permissions can examine when evaluating the policies.

Note

You can include only principal and resource entities in this parameter; you can't include actions. You must specify actions in the schema.

Type: EntitiesDefinition object

Note: This object is a Union. Only one member of this object can be specified or returned.

Required: No

principal

Specifies the principal for which the authorization decision is to be made.

Type: EntityIdentifier object

Required: No

resource

Specifies the resource for which the authorization decision is to be made.

Type: EntityIdentifier object

Required: No

Response Syntax


{
   "decision": "string",
   "determiningPolicies": [ 
      { 
         "policyId": "string"
      }
   ],
   "errors": [ 
      { 
         "errorDescription": "string"
      }
   ]
}

Response Elements

If the action is successful, the service sends back an HTTP 200 response.

The following data is returned in JSON format by the service.

decision

An authorization decision that indicates if the authorization request should be allowed or denied.

Type: String

Valid Values: ALLOW | DENY

determiningPolicies

The list of determining policies used to make the authorization decision. For example, if there are two matching policies, where one is a forbid and the other is a permit, then the forbid policy will be the determining policy. In the case of multiple matching permit policies then there would be multiple determining policies. In the case that no policies match, and hence the response is DENY, there would be no determining policies.

Type: Array of DeterminingPolicyItem objects

errors

Errors that occurred while making an authorization decision, for example, a policy references an Entity or entity Attribute that does not exist in the slice.

Type: Array of EvaluationErrorItem objects

Errors

For information about the errors that are common to all actions, see Common Errors.

AccessDeniedException

You don't have sufficient access to perform this action.

HTTP Status Code: 400

InternalServerException

The request failed because of an internal error. Try your request again later

HTTP Status Code: 500

ResourceNotFoundException

The request failed because it references a resource that doesn't exist.

HTTP Status Code: 400

ThrottlingException

The request failed because it exceeded a throttling quota.

HTTP Status Code: 400

ValidationException

The request failed because one or more input parameters don't satisfy their constraint requirements. The output is provided as a list of fields and a reason for each field that isn't valid.

The possible reasons include the following:

UnrecognizedEntityType

The policy includes an entity type that isn't found in the schema.
UnrecognizedActionId

The policy includes an action id that isn't found in the schema.
InvalidActionApplication

The policy includes an action that, according to the schema, doesn't support the specified principal and resource.
UnexpectedType

The policy included an operand that isn't a valid type for the specified operation.
IncompatibleTypes

The types of elements included in a set, or the types of expressions used in an if...then...else clause aren't compatible in this context.
MissingAttribute

The policy attempts to access a record or entity attribute that isn't specified in the schema. Test for the existence of the attribute first before attempting to access its value. For more information, see the has (presence of attribute test) operator in the Cedar Policy Language Guide.
UnsafeOptionalAttributeAccess

The policy attempts to access a record or entity attribute that is optional and isn't guaranteed to be present. Test for the existence of the attribute first before attempting to access its value. For more information, see the has (presence of attribute test) operator in the Cedar Policy Language Guide.
ImpossiblePolicy

Cedar has determined that a policy condition always evaluates to false. If the policy is always false, it can never apply to any query, and so it can never affect an authorization decision.
WrongNumberArguments

The policy references an extension type with the wrong number of arguments.
FunctionArgumentValidationError

Cedar couldn't parse the argument passed to an extension type. For example, a string that is to be parsed as an IPv4 address can contain only digits and the period character.

HTTP Status Code: 400

Examples

Example 1

The following example requests an authorization decision for a principal of type User named Alice, who wants to perform the updatePhoto operation, on a resource of type Photo named VacationPhoto94.jpg.

The response shows that the request was allowed by one policy.

Sample Request


POST HTTP/1.1
Host: verifiedpermissions.us-east-1.amazonaws.com
X-Amz-Date: 20230613T200059Z
Accept-Encoding: identity
X-Amz-Target: VerifiedPermissions.IsAuthorized
User-Agent: <UserAgentString>
Authorization: AWS4-HMAC-SHA256 Credential=<Credential>, SignedHeaders=<Headers>, Signature=<Signature>
Content-Length: <PayloadSizeBytes>

{
    "principal": {
        "entityType": "PhotoFlash::User", 
        "entityId": "alice"
    },
    "action": {
        "actionType": "Action",
        "actionId": "view"
    }, 
    "resource": {
        "entityType": "PhotoFlash::Photo", 
        "entityId": "VacationPhoto94.jpg"
    },
    "policyStoreId": "PSEXAMPLEabcdefg111111"
}

Sample Response


HTTP/1.1 200 OK
Date: Tue, 13 Jun 2023 20:00:59 GMT
Content-Type: application/x-amz-json-1.0
Content-Length: <PayloadSizeBytes>
vary: origin
vary: access-control-request-method
vary: access-control-request-headers
x-amzn-requestid: a1b2c3d4-e5f6-a1b2-c3d4-EXAMPLE11111
Connection: keep-alive

{
    "decision": "ALLOW",
    "determiningPolicies": [
        {
            "policyId": "SPEXAMPLEabcdefg111111"
        }
    ],
    "errors": []
}

Example 2

The following example is a more extensive request for an authorization decision for a principal of type User named alice, who wants to perform the updatePhoto operation, on a resource of type Photo named VacationPhoto94.jpg. The request includes the optional entities element, that specifies that the photo is contained in an Album named alice_folder. Those additional entities and their attributes can be referenced and checked by conditional elements in the policies in the specified policy store.

In this example, the policy that permits access specifies that User::"alice" is allowed to update photos in the folder Album::"alice_folder"

Sample Request


POST HTTP/1.1
Host: verifiedpermissions.us-east-1.amazonaws.com
X-Amz-Date: 20230613T200059Z
Accept-Encoding: identity
X-Amz-Target: VerifiedPermissions.IsAuthorized
User-Agent: <UserAgentString>
Authorization: AWS4-HMAC-SHA256 Credential=<Credential>, SignedHeaders=<Headers>, Signature=<Signature>
Content-Length: <PayloadSizeBytes>

{
  "policyStoreId": "PSEXAMPLEabcdefg111111",
  "principal": {
      "entityType": "PhotoFlash::User",
      "entityId": "alice"
  },
  "action": {
      "actionType": "Action",
      "actionId": "updatePhoto"
  },
  "resource": {
      "entityType": "PhotoFlash::Photo",
      "entityId": "VacationPhoto94.jpg"
  },
  "entities": {
    "entityList": [
      {
        "identifier": {
            "entityType": "PhotoFlash::Photo",
            "entityId": "VacationPhoto94.jpg"
        },
        "attributes": {},
        "parents": [
            {
                "entityType": "PhotoFlash::Album",
                "entityId": "alice_folder"
            }
        ]
      },
      {
        "identifier": {
            "entityType": "PhotoFlash::Album",
            "entityId": "alice_folder"
        }
      }
    ]
  }
}

Sample Response


HTTP/1.1 200 OK
Date: Tue, 13 Jun 2023 20:00:59 GMT
Content-Type: application/x-amz-json-1.0
Content-Length: <PayloadSizeBytes>
vary: origin
vary: access-control-request-method
vary: access-control-request-headers
x-amzn-requestid: a1b2c3d4-e5f6-a1b2-c3d4-EXAMPLE11111
Connection: keep-alive

{
    "determiningPolicies": [
        {
            "determiningPolicyId": "SPEXAMPLEabcdefg111111"
        }
    ],
    "decision": "ALLOW",
    "errors": []
}

Example 3

The following example is the same as the previous example, except that the principal is User::"bob", and the policy store doesn't contain any policy that allows that user access to Album::"alice_folder". The output infers that the Deny was implicit because the list of DeterminingPolicies is empty.

Sample Request


POST HTTP/1.1
Host: verifiedpermissions.us-east-1.amazonaws.com
X-Amz-Date: 20230613T200059Z
Accept-Encoding: identity
X-Amz-Target: VerifiedPermissions.IsAuthorized
User-Agent: <UserAgentString>
Authorization: AWS4-HMAC-SHA256 Credential=<Credential>, SignedHeaders=<Headers>, Signature=<Signature>
Content-Length: <PayloadSizeBytes>

{
    "principal": {
        "entityType": "PhotoFlash::User", 
        "entityId": "bob"
    }, 
    "action": {
        "actionType": "Action",
        "actionId": "view"
    }, 
    "resource": {
        "entityType": "PhotoFlash::Photo", 
        "entityId": "VacationPhoto94.jpg"
    },
    "policyStoreId": "PSEXAMPLEabcdefg111111"
}

Sample Response


HTTP/1.1 200 OK
Date: Tue, 13 Jun 2023 20:00:59 GMT
Content-Type: application/x-amz-json-1.0
Content-Length: <PayloadSizeBytes>
vary: origin
vary: access-control-request-method
vary: access-control-request-headers
x-amzn-requestid: a1b2c3d4-e5f6-a1b2-c3d4-EXAMPLE11111
Connection: keep-alive

{
    "decision": "DENY",
    "determiningPolicies": [],
    "errors": []
}

Example 4

The following example relies on the DigitalPetStore sample app and the policy Customer Role - Get Order. To satisfy this policy, Alice must be in the Customer role and the Order must have Alice in the owner attribute. To define Alice and the order with these properties, we must dive deeper into the entities element and declare that Alice is a customer, and the order is owned by Alice. Because Alice is the customer who placed the order, Verified Permissions returns an ALLOW decision to their request for the action DigitalPetStore::GetOrder.

Sample Request


POST HTTP/1.1
Host: verifiedpermissions.us-east-1.amazonaws.com
X-Amz-Date: 20230613T200059Z
Accept-Encoding: identity
X-Amz-Target: VerifiedPermissions.IsAuthorized
User-Agent: <UserAgentString>
Authorization: AWS4-HMAC-SHA256 Credential=<Credential>, SignedHeaders=<Headers>, Signature=<Signature>
Content-Length: <PayloadSizeBytes>

                {
    "principal": {
        "entityType": "DigitalPetStore::User",
        "entityId": "Alice"
    },
    "action": {
        "actionType": "DigitalPetStore::Action",
        "actionId": "GetOrder"
    },
    "resource": {
        "entityType": "DigitalPetStore::Order",
        "entityId": "1234"
    },
    "entities": {
        "entityList": [
            {
                "identifier": {
                    "entityType": "DigitalPetStore::User",
                    "entityId": "Alice"
                },
                "attributes": {
                    "memberId": {
                        "string": "5cad60b9-209c-46d6-bfb7-536c341634ca"
                        }
                },
                "parents": [
                    {
                    "entityType": "DigitalPetStore::Role",
                    "entityId": "Customer"
                    }
                ]
            },
            {
                "identifier": {
                    "entityType": "DigitalPetStore::Order",
                    "entityId": "1234"
                },
                "attributes": {
                    "owner": {
                        "entityIdentifier": {
                            "entityType": "DigitalPetStore::User",
                            "entityId": "Alice"
                        }
                  }
                },
                "parents": []
            }
        ]
    },
    "policyStoreId": "PSEXAMPLEabcdefg111111"
}

Sample Response


HTTP/1.1 200 OK
Date: Tue, 13 Jun 2023 20:00:59 GMT
Content-Type: application/x-amz-json-1.0
Content-Length: <PayloadSizeBytes>
vary: origin
vary: access-control-request-method
vary: access-control-request-headers
x-amzn-requestid: a1b2c3d4-e5f6-a1b2-c3d4-EXAMPLE11111
Connection: keep-alive

{
    "decision": "ALLOW",
    "determiningPolicies": [
        {
            "policyId": "SPEXAMPLEabcdefg111111"
        }
    ],
    "errors": []
}