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Description:

awscdk.awscognitoidentitypoolalpha 2.159.0a0

Amazon Cognito Identity Pool Construct Library

Identity Pools are in a separate module while the API is being stabilized. Once we stabilize the module, they will
be included into the stable aws-cognito library. Please provide feedback on this experience by
creating an issue here

---

The APIs of higher level constructs in this module are experimental and under active development.
They are subject to non-backward compatible changes or removal in any future version. These are
not subject to the Semantic Versioning model and breaking changes will be
announced in the release notes. This means that while you may use them, you may need to update
your source code when upgrading to a newer version of this package.

Amazon Cognito Identity Pools enable you to grant your users access to other AWS services.
Identity Pools are one of the two main components of Amazon Cognito, which provides authentication, authorization, and
user management for your web and mobile apps. Your users can sign in directly with a user name and password, or through
a third party such as Facebook, Amazon, Google or Apple.
The other main component in Amazon Cognito is user pools. User Pools are user directories that provide sign-up and
sign-in options for your app users.
This module is part of the AWS Cloud Development Kit project.
from aws_cdk.aws_cognito_identitypool_alpha import IdentityPool, UserPoolAuthenticationProvider

Table of Contents

Identity Pools

Authenticated and Unauthenticated Identities

Authentication Providers

User Pool Authentication Provider
Server Side Token Check
Associating an External Provider Directly
OpenIdConnect and Saml
Custom Providers

Role Mapping

Provider Urls

Authentication Flow

Cognito Sync

Importing Identity Pools

Identity Pools
Identity pools provide temporary AWS credentials for users who are guests (unauthenticated) and for users who have been
authenticated and received a token. An identity pool is a store of user identity data specific to an account.
Identity pools can be used in conjunction with Cognito User Pools or by accessing external federated identity providers
directly. Learn more at Amazon Cognito Identity Pools.
Authenticated and Unauthenticated Identities
Identity pools define two types of identities: authenticated(user) and unauthenticated (guest). Every identity in
an identity pool is either authenticated or unauthenticated. Each identity pool has a default role for authenticated
identities, and a default role for unauthenticated identities. Absent other overriding rules (see below), these are the
roles that will be assumed by the corresponding users in the authentication process.
A basic Identity Pool with minimal configuration has no required props, with default authenticated (user) and
unauthenticated (guest) roles applied to the identity pool:
IdentityPool(self, "myIdentityPool")

By default, both the authenticated and unauthenticated roles will have no permissions attached. Grant permissions
to roles using the public authenticatedRole and unauthenticatedRole properties:
import aws_cdk.aws_dynamodb as dynamodb
# table: dynamodb.Table

identity_pool = IdentityPool(self, "myIdentityPool")

# Grant permissions to authenticated users
table.grant_read_write_data(identity_pool.authenticated_role)
# Grant permissions to unauthenticated guest users
table.grant_read_data(identity_pool.unauthenticated_role)

# Or add policy statements straight to the role
identity_pool.authenticated_role.add_to_principal_policy(iam.PolicyStatement(
effect=iam.Effect.ALLOW,
actions=["dynamodb:*"],
resources=["*"]
))

The default roles can also be supplied in IdentityPoolProps:
stack = Stack()
authenticated_role = iam.Role(self, "authRole",
assumed_by=iam.ServicePrincipal("service.amazonaws.com")
)
unauthenticated_role = iam.Role(self, "unauthRole",
assumed_by=iam.ServicePrincipal("service.amazonaws.com")
)
identity_pool = IdentityPool(self, "TestIdentityPoolActions",
authenticated_role=authenticated_role,
unauthenticated_role=unauthenticated_role
)

Authentication Providers
Authenticated identities belong to users who are authenticated by a public login provider (Amazon Cognito user pools,
Login with Amazon, Sign in with Apple, Facebook, Google, SAML, or any OpenID Connect Providers) or a developer provider
(your own backend authentication process).
Authentication providers can be associated with an Identity Pool by first associating them with a Cognito User Pool or by
associating the provider directly with the identity pool.
User Pool Authentication Provider
In order to attach a user pool to an identity pool as an authentication provider, the identity pool needs properties
from both the user pool and the user pool client. For this reason identity pools use a UserPoolAuthenticationProvider
to gather the necessary properties from the user pool constructs.
user_pool = cognito.UserPool(self, "Pool")

IdentityPool(self, "myidentitypool",
identity_pool_name="myidentitypool",
authentication_providers=IdentityPoolAuthenticationProviders(
user_pools=[UserPoolAuthenticationProvider(user_pool=user_pool)]
)
)

User pools can also be associated with an identity pool after instantiation. The Identity Pool's addUserPoolAuthentication method
returns the User Pool Client that has been created:
# identity_pool: IdentityPool

user_pool = cognito.UserPool(self, "Pool")
user_pool_client = identity_pool.add_user_pool_authentication(UserPoolAuthenticationProvider(
user_pool=user_pool
))

Server Side Token Check
With the IdentityPool CDK Construct, by default the pool is configured to check with the integrated user pools to
make sure that the user has not been globally signed out or deleted before the identity pool provides an OIDC token or
AWS credentials for the user.
If the user is signed out or deleted, the identity pool will return a 400 Not Authorized error. This setting can be
disabled, however, in several ways.
Setting disableServerSideTokenCheck to true will change the default behavior to no server side token check. Learn
more here:
# identity_pool: IdentityPool

user_pool = cognito.UserPool(self, "Pool")
identity_pool.add_user_pool_authentication(UserPoolAuthenticationProvider(
user_pool=user_pool,
disable_server_side_token_check=True
))

Associating an External Provider Directly
One or more external identity providers can be associated with an identity pool directly using
authenticationProviders:
IdentityPool(self, "myidentitypool",
identity_pool_name="myidentitypool",
authentication_providers=IdentityPoolAuthenticationProviders(
amazon=IdentityPoolAmazonLoginProvider(
app_id="amzn1.application.12312k3j234j13rjiwuenf"
),
facebook=IdentityPoolFacebookLoginProvider(
app_id="1234567890123"
),
google=IdentityPoolGoogleLoginProvider(
client_id="12345678012.apps.googleusercontent.com"
),
apple=IdentityPoolAppleLoginProvider(
services_id="com.myappleapp.auth"
),
twitter=IdentityPoolTwitterLoginProvider(
consumer_key="my-twitter-id",
consumer_secret="my-twitter-secret"
)
)
)

To associate more than one provider of the same type with the identity pool, use User
Pools, OpenIdConnect, or SAML. Only one provider per external service can be attached directly to the identity pool.
OpenId Connect and Saml
OpenID Connect is an open standard for
authentication that is supported by a number of login providers. Amazon Cognito supports linking of identities with
OpenID Connect providers that are configured through AWS Identity and Access Management.
An identity provider that supports Security Assertion Markup Language 2.0 (SAML 2.0) can be used to provide a simple
onboarding flow for users. The SAML-supporting identity provider specifies the IAM roles that can be assumed by users
so that different users can be granted different sets of permissions. Associating an OpenId Connect or Saml provider
with an identity pool:
# open_id_connect_provider: iam.OpenIdConnectProvider
# saml_provider: iam.SamlProvider

IdentityPool(self, "myidentitypool",
identity_pool_name="myidentitypool",
authentication_providers=IdentityPoolAuthenticationProviders(
open_id_connect_providers=[open_id_connect_provider],
saml_providers=[saml_provider]
)
)

Custom Providers
The identity pool's behavior can be customized further using custom developer authenticated identities.
With developer authenticated identities, users can be registered and authenticated via an existing authentication
process while still using Amazon Cognito to synchronize user data and access AWS resources.
Like the supported external providers, though, only one custom provider can be directly associated with the identity
pool.
# open_id_connect_provider: iam.OpenIdConnectProvider

IdentityPool(self, "myidentitypool",
identity_pool_name="myidentitypool",
authentication_providers=IdentityPoolAuthenticationProviders(
google=IdentityPoolGoogleLoginProvider(
client_id="12345678012.apps.googleusercontent.com"
),
open_id_connect_providers=[open_id_connect_provider],
custom_provider="my-custom-provider.example.com"
)
)

Role Mapping
In addition to setting default roles for authenticated and unauthenticated users, identity pools can also be used to
define rules to choose the role for each user based on claims in the user's ID token by using Role Mapping. When using
role mapping, it's important to be aware of some of the permissions the role will need. An in depth
review of roles and role mapping can be found here.
Using a token-based approach to role mapping will allow mapped roles to be passed through the cognito:roles or
cognito:preferred_role claims from the identity provider:
from aws_cdk.aws_cognito_identitypool_alpha import IdentityPoolProviderUrl

IdentityPool(self, "myidentitypool",
identity_pool_name="myidentitypool",
role_mappings=[IdentityPoolRoleMapping(
provider_url=IdentityPoolProviderUrl.AMAZON,
use_token=True
)]
)

Using a rule-based approach to role mapping allows roles to be assigned based on custom claims passed from the identity provider:
from aws_cdk.aws_cognito_identitypool_alpha import IdentityPoolProviderUrl, RoleMappingMatchType

# admin_role: iam.Role
# non_admin_role: iam.Role

IdentityPool(self, "myidentitypool",
identity_pool_name="myidentitypool",
# Assign specific roles to users based on whether or not the custom admin claim is passed from the identity provider
role_mappings=[IdentityPoolRoleMapping(
provider_url=IdentityPoolProviderUrl.AMAZON,
rules=[RoleMappingRule(
claim="custom:admin",
claim_value="admin",
mapped_role=admin_role
), RoleMappingRule(
claim="custom:admin",
claim_value="admin",
match_type=RoleMappingMatchType.NOTEQUAL,
mapped_role=non_admin_role
)
]
)]
)

Role mappings can also be added after instantiation with the Identity Pool's addRoleMappings method:
from aws_cdk.aws_cognito_identitypool_alpha import IdentityPoolRoleMapping

# identity_pool: IdentityPool
# my_added_role_mapping1: IdentityPoolRoleMapping
# my_added_role_mapping2: IdentityPoolRoleMapping
# my_added_role_mapping3: IdentityPoolRoleMapping

identity_pool.add_role_mappings(my_added_role_mapping1, my_added_role_mapping2, my_added_role_mapping3)

Provider Urls
Role mappings must be associated with the url of an Identity Provider which can be supplied
IdentityPoolProviderUrl. Supported Providers have static Urls that can be used:
from aws_cdk.aws_cognito_identitypool_alpha import IdentityPoolProviderUrl

IdentityPool(self, "myidentitypool",
identity_pool_name="myidentitypool",
role_mappings=[IdentityPoolRoleMapping(
provider_url=IdentityPoolProviderUrl.FACEBOOK,
use_token=True
)]
)

For identity providers that don't have static Urls, a custom Url can be supplied:
from aws_cdk.aws_cognito_identitypool_alpha import IdentityPoolProviderUrl

IdentityPool(self, "myidentitypool",
identity_pool_name="myidentitypool",
role_mappings=[IdentityPoolRoleMapping(
provider_url=IdentityPoolProviderUrl.custom("my-custom-provider.com"),
use_token=True
)
]
)

If a provider URL is a CDK Token, as it will be if you are trying to use a previously defined Cognito User Pool, you will need to also provide a mappingKey.
This is because by default, the key in the Cloudformation role mapping hash is the providerUrl, and Cloudformation map keys must be concrete strings, they
cannot be references. For example:
from aws_cdk.aws_cognito import UserPool, UserPoolClient
from aws_cdk.aws_cognito_identitypool_alpha import IdentityPoolProviderUrl

# user_pool: UserPool
# user_pool_client: UserPoolClient

IdentityPool(self, "myidentitypool",
identity_pool_name="myidentitypool",
role_mappings=[IdentityPoolRoleMapping(
mapping_key="cognito",
provider_url=IdentityPoolProviderUrl.user_pool(user_pool, user_pool_client),
use_token=True
)]
)

See here for more information.
Authentication Flow
Identity Pool Authentication Flow defaults to the enhanced, simplified flow. The Classic (basic) Authentication Flow
can also be implemented using allowClassicFlow:
IdentityPool(self, "myidentitypool",
identity_pool_name="myidentitypool",
allow_classic_flow=True
)

Cognito Sync
It's now recommended to integrate AWS AppSync for synchronizing app data across devices, so
Cognito Sync features like PushSync, CognitoEvents, and CognitoStreams are not a part of IdentityPool. More
information can be found here.
Importing Identity Pools
You can import existing identity pools into your stack using Identity Pool static methods with the Identity Pool Id or
Arn:
IdentityPool.from_identity_pool_id(self, "my-imported-identity-pool", "us-east-1:dj2823ryiwuhef937")
IdentityPool.from_identity_pool_arn(self, "my-imported-identity-pool", "arn:aws:cognito-identity:us-east-1:123456789012:identitypool/us-east-1:dj2823ryiwuhef937")