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.
To learn more about Amazon Cognito, see Amazon Cognito Overview in
Amazon Web Services SDK for Android Developer Guide and Amazon Cognito Overview in the
Amazon Web Services SDK for iOS 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:
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.
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.
example
Use a bare-bones client and the command you need to make an API call.
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.
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.
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.
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 Overview in Amazon Web Services SDK for Android Developer Guide and Amazon Cognito Overview in the Amazon Web Services SDK for iOS Developer Guide.
Calling
AssumeRoleWithWebIdentitydoes 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 ofAssumeRoleWithWebIdentitywith 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
AssumeRoleWithWebIdentitylast for one hour. However, you can use the optionalDurationSecondsparameter 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 theAssumeRole*API operations or theassume-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
AssumeRoleWithWebIdentitycan be used to make API calls to any Amazon Web Services service with the following exception: you cannot call the STSGetFederationTokenorGetSessionTokenAPI 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
PackedPolicySizeresponse 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
AssumeRoleWithWebIdentitycan 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
AssumeRoleWithWebIdentityAPI, 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.
Use a bare-bones client and the command you need to make an API call.
import { STSClient, AssumeRoleWithWebIdentityCommand } from "@aws-sdk/client-sts"; // ES Modules import // const { STSClient, AssumeRoleWithWebIdentityCommand } = require("@aws-sdk/client-sts"); // CommonJS import const client = new STSClient(config); const command = new AssumeRoleWithWebIdentityCommand(input); const response = await client.send(command);AssumeRoleWithWebIdentityCommandInput for command's
inputshape.AssumeRoleWithWebIdentityCommandOutput for command's
responseshape.config for STSClient's
configshape.ExpiredTokenException (client fault)
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 (client fault)
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 (client fault)
The identity provider (IdP) reported that authentication failed. This might be because the claim is invalid.
If this error is returned for the
AssumeRoleWithWebIdentityoperation, it can also mean that the claim has expired or has been explicitly revoked.InvalidIdentityTokenException (client fault)
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 (client fault)
The request was rejected because the policy document was malformed. The error message describes the specific error.
PackedPolicyTooLargeException (client fault)
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 (client fault)
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.
To assume a role as an OpenID Connect-federated user
// const input = { "DurationSeconds": 3600, "Policy": "{\"Version\":\"2012-10-17\",\"Statement\":[{\"Sid\":\"Stmt1\",\"Effect\":\"Allow\",\"Action\":\"s3:ListAllMyBuckets\",\"Resource\":\"*\"}]}", "ProviderId": "www.amazon.com", "RoleArn": "arn:aws:iam::123456789012:role/FederatedWebIdentityRole", "RoleSessionName": "app1", "WebIdentityToken": "Atza%7CIQEBLjAsAhRFiXuWpUXuRvQ9PZL3GMFcYevydwIUFAHZwXZXXXXXXXXJnrulxKDHwy87oGKPznh0D6bEQZTSCzyoCtL_8S07pLpr0zMbn6w1lfVZKNTBdDansFBmtGnIsIapjI6xKR02Yc_2bQ8LZbUXSGm6Ry6_BG7PrtLZtj_dfCTj92xNGed-CrKqjG7nPBjNIL016GGvuS5gSvPRUxWES3VYfm1wl7WTI7jn-Pcb6M-buCgHhFOzTQxod27L9CqnOLio7N3gZAGpsp6n1-AJBOCJckcyXe2c6uD0srOJeZlKUm2eTDVMf8IehDVI0r1QOnTV6KzzAI3OY87Vd_cVMQ" }; const command = new AssumeRoleWithWebIdentityCommand(input); const response = await client.send(command); /* response == { "AssumedRoleUser": { "Arn": "arn:aws:sts::123456789012:assumed-role/FederatedWebIdentityRole/app1", "AssumedRoleId": "AROACLKWSDQRAOEXAMPLE:app1" }, "Audience": "client.5498841531868486423.1548@apps.example.com", "Credentials": { "AccessKeyId": "AKIAIOSFODNN7EXAMPLE", "Expiration": "2014-10-24T23:00:23Z", "SecretAccessKey": "wJalrXUtnFEMI/K7MDENG/bPxRfiCYzEXAMPLEKEY", "SessionToken": "AQoDYXdzEE0a8ANXXXXXXXXNO1ewxE5TijQyp+IEXAMPLE" }, "PackedPolicySize": 123, "Provider": "www.amazon.com", "SubjectFromWebIdentityToken": "amzn1.account.AF6RHO7KZU5XRVQJGXK6HEXAMPLE" } *\/ // example id: to-assume-a-role-as-an-openid-connect-federated-user-1480533445696