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Returns a set of temporary security credentials for users who have been authenticated
in a mobile or web application with a web identity provider. Example providers include
the OAuth 2.0 providers Login with Amazon and Facebook, or any OpenID Connect-compatible
identity provider such as Google or Amazon
Cognito federated identities.
For mobile applications, we recommend that you use Amazon Cognito. You can use Amazon
Cognito with the Amazon Web Services SDK
for iOS Developer Guide and the Amazon
Web Services SDK for Android Developer Guide to uniquely identify a user. You
can also supply the user with a consistent identity throughout the lifetime of an
application.
To learn more about Amazon Cognito, see Amazon
Cognito identity pools in Amazon Cognito Developer Guide.
Calling AssumeRoleWithWebIdentity does not require the use of Amazon Web Services
security credentials. Therefore, you can distribute an application (for example, on
mobile devices) that requests temporary security credentials without including long-term
Amazon Web Services credentials in the application. You also don't need to deploy
server-based proxy services that use long-term Amazon Web Services credentials. Instead,
the identity of the caller is validated by using a token from the web identity provider.
For a comparison of AssumeRoleWithWebIdentity with the other API operations
that produce temporary credentials, see Requesting
Temporary Security Credentials and Comparing
the Amazon Web Services STS API operations in the IAM User Guide.
The temporary security credentials returned by this API consist of an access key ID, a secret access key, and a security token. Applications can use these temporary security credentials to sign calls to Amazon Web Services service API operations.
Session Duration
By default, the temporary security credentials created by AssumeRoleWithWebIdentity
last for one hour. However, you can use the optional DurationSeconds parameter
to specify the duration of your session. You can provide a value from 900 seconds
(15 minutes) up to the maximum session duration setting for the role. This setting
can have a value from 1 hour to 12 hours. To learn how to view the maximum value for
your role, see View
the Maximum Session Duration Setting for a Role in the IAM User Guide.
The maximum session duration limit applies when you use the AssumeRole* API
operations or the assume-role* CLI commands. However the limit does not apply
when you use those operations to create a console URL. For more information, see Using IAM
Roles in the IAM User Guide.
Permissions
The temporary security credentials created by AssumeRoleWithWebIdentity can
be used to make API calls to any Amazon Web Services service with the following exception:
you cannot call the STS GetFederationToken or GetSessionToken API operations.
(Optional) You can pass inline or managed session policies to this operation. You can pass a single JSON policy document to use as an inline session policy. You can also specify up to 10 managed policy Amazon Resource Names (ARNs) to use as managed session policies. The plaintext that you use for both inline and managed session policies can't exceed 2,048 characters. Passing policies to this operation returns new temporary credentials. The resulting session's permissions are the intersection of the role's identity-based policy and the session policies. You can use the role's temporary credentials in subsequent Amazon Web Services API calls to access resources in the account that owns the role. You cannot use session policies to grant more permissions than those allowed by the identity-based policy of the role that is being assumed. For more information, see Session Policies in the IAM User Guide.
Tags
(Optional) You can configure your IdP to pass attributes into your web identity token as session tags. Each session tag consists of a key name and an associated value. For more information about session tags, see Passing Session Tags in STS in the IAM User Guide.
You can pass up to 50 session tags. The plaintext session tag keys can’t exceed 128 characters and the values can’t exceed 256 characters. For these and additional limits, see IAM and STS Character Limits in the IAM User Guide.
An Amazon Web Services conversion compresses the passed inline session policy, managed
policy ARNs, and session tags into a packed binary format that has a separate limit.
Your request can fail for this limit even if your plaintext meets the other requirements.
The PackedPolicySize response element indicates by percentage how close the
policies and tags for your request are to the upper size limit.
You can pass a session tag with the same key as a tag that is attached to the role. When you do, the session tag overrides the role tag with the same key.
An administrator must grant you the permissions necessary to pass session tags. The administrator can also create granular permissions to allow you to pass only specific session tags. For more information, see Tutorial: Using Tags for Attribute-Based Access Control in the IAM User Guide.
You can set the session tags as transitive. Transitive tags persist during role chaining. For more information, see Chaining Roles with Session Tags in the IAM User Guide.
Identities
Before your application can call AssumeRoleWithWebIdentity, you must have an
identity token from a supported identity provider and create a role that the application
can assume. The role that your application assumes must trust the identity provider
that is associated with the identity token. In other words, the identity provider
must be specified in the role's trust policy.
Calling AssumeRoleWithWebIdentity can result in an entry in your CloudTrail
logs. The entry includes the Subject
of the provided web identity token. We recommend that you avoid using any personally
identifiable information (PII) in this field. For example, you could instead use a
GUID or a pairwise identifier, as suggested
in the OIDC specification.
For more information about how to use web identity federation and the AssumeRoleWithWebIdentity
API, see the following resources:
Using Web Identity Federation API Operations for Mobile Apps and Federation Through a Web-based Identity Provider.
Web Identity Federation Playground. Walk through the process of authenticating through Login with Amazon, Facebook, or Google, getting temporary security credentials, and then using those credentials to make a request to Amazon Web Services.
Amazon Web Services SDK for iOS Developer Guide and Amazon Web Services SDK for Android Developer Guide. These toolkits contain sample apps that show how to invoke the identity providers. The toolkits then show how to use the information from these providers to get and use temporary security credentials.
Web Identity Federation with Mobile Applications. This article discusses web identity federation and shows an example of how to use web identity federation to get access to content in Amazon S3.
This is an asynchronous operation using the standard naming convention for .NET 4.5 or higher. For .NET 3.5 the operation is implemented as a pair of methods using the standard naming convention of BeginAssumeRoleWithWebIdentity and EndAssumeRoleWithWebIdentity.
Namespace: Amazon.SecurityToken
Assembly: AWSSDK.SecurityToken.dll
Version: 3.x.y.z
public abstract Task<AssumeRoleWithWebIdentityResponse> AssumeRoleWithWebIdentityAsync( AssumeRoleWithWebIdentityRequest request, CancellationToken cancellationToken )
Container for the necessary parameters to execute the AssumeRoleWithWebIdentity service method.
A cancellation token that can be used by other objects or threads to receive notice of cancellation.
| Exception | Condition |
|---|---|
| ExpiredTokenException | The web identity token that was passed is expired or is not valid. Get a new identity token from the identity provider and then retry the request. |
| IDPCommunicationErrorException | The request could not be fulfilled because the identity provider (IDP) that was asked to verify the incoming identity token could not be reached. This is often a transient error caused by network conditions. Retry the request a limited number of times so that you don't exceed the request rate. If the error persists, the identity provider might be down or not responding. |
| IDPRejectedClaimException | The identity provider (IdP) reported that authentication failed. This might be because the claim is invalid. If this error is returned for the AssumeRoleWithWebIdentity operation, it can also mean that the claim has expired or has been explicitly revoked. |
| InvalidIdentityTokenException | The web identity token that was passed could not be validated by Amazon Web Services. Get a new identity token from the identity provider and then retry the request. |
| MalformedPolicyDocumentException | The request was rejected because the policy document was malformed. The error message describes the specific error. |
| PackedPolicyTooLargeException | The request was rejected because the total packed size of the session policies and session tags combined was too large. An Amazon Web Services conversion compresses the session policy document, session policy ARNs, and session tags into a packed binary format that has a separate limit. The error message indicates by percentage how close the policies and tags are to the upper size limit. For more information, see Passing Session Tags in STS in the IAM User Guide. You could receive this error even though you meet other defined session policy and session tag limits. For more information, see IAM and STS Entity Character Limits in the IAM User Guide. |
| RegionDisabledException | STS is not activated in the requested region for the account that is being asked to generate credentials. The account administrator must use the IAM console to activate STS in that region. For more information, see Activating and Deactivating Amazon Web Services STS in an Amazon Web Services Region in the IAM User Guide. |
.NET Core App:
Supported in: 3.1
.NET Standard:
Supported in: 2.0
.NET Framework:
Supported in: 4.5