Getting credentials
You can use Amazon Cognito to deliver temporary, limited-privilege credentials to your application, so that your users can access AWS resources. This section describes how to get credentials and how to retrieve an Amazon Cognito identity from an identity pool.
Amazon Cognito supports both authenticated and unauthenticated identities. Unauthenticated users do not have their identity verified, making this role appropriate for guest users of your app or in cases when it doesn't matter if users have their identities verified. Authenticated users log in to your application through a third-party identity provider, or a user pool, that verifies their identities. Make sure you scope the permissions of resources appropriately so you don't grant access to them from unauthenticated users.
Amazon Cognito identities are not credentials. They are exchanged for credentials using web
identity federation support in the AWS Security Token Service (AWS STS). To obtain AWS credentials for your
app users, use your AWS SDK's Cognito identity pool credential provider. For example, in the
AWS SDK for JavaScript (v3), use the fromCognitoIdentityPool function from the
@aws-sdk/credential-providers package. The identity is then exchanged for
credentials using AWS STS.
Web identity credentials providers are part of the default credential provider chain in
AWS SDKs. To set your identity pool token in a local config file for an AWS
SDK or the AWS CLI, add a web_identity_token_file profile entry. See Assume
role credential provider in the AWS SDKs and Tools Reference Guide.
To learn more about how to populate web identity credentials in your SDK, refer to the SDK developer guide. For best results, start your project with the identity pool integration that's built in to AWS Amplify.
AWS SDK resources for getting and setting credentials with identity pools
-
Identity Pool Federation
(Android) in the Amplify Dev Center -
Identity Pool Federation
(iOS) in the Amplify Dev Center -
Using Amazon Cognito Identity to authenticate users in the AWS SDK for JavaScript Developer Guide
-
Amazon Cognito credentials provider in the AWS SDK for .NET Developer Guide
-
Specify Credentials Programmatically
in the AWS SDK for Go Developer Guide -
Supply temporary credentials in code in the AWS SDK for Java 2.x Developer Guide
-
assumeRoleWithWebIdentityCredentialProvider provider in the AWS SDK for PHP Developer Guide
-
Assume Role With Web Identity Provider
in the AWS SDK for Python (Boto3) documentation -
Specifying your credentials and default region in the AWS SDK for Rust Developer Guide
The following sections provide example code in some legacy AWS SDKs.
You can use Amazon Cognito to deliver temporary, limited-privilege credentials to your application, so that your users can access AWS resources. Amazon Cognito supports both authenticated and unauthenticated identities. To provide AWS credentials to your app, follow the steps below.
To use a Amazon Cognito identity pool in an Android app, set up AWS Amplify. For more
information, see Authentication
Retrieving an Amazon Cognito identity
If you're allowing unauthenticated users, you can retrieve a unique Amazon Cognito identifier (identity ID) for your end user immediately. If you're authenticating users, you can retrieve the identity ID after you've set the login tokens in the credentials provider:
String identityId = credentialsProvider.getIdentityId(); Log.d("LogTag", "my ID is " + identityId);
Note
Do not call getIdentityId(), refresh(), or
getCredentials() in the main thread of your application. As of Android
3.0 (API Level 11), your app will automatically fail and throw a NetworkOnMainThreadExceptionAsyncTask. For more information, consult the Android documentationgetCachedIdentityId()
to retrieve an ID, but only if one is already cached locally. Otherwise, the method will
return null.
You can use Amazon Cognito to deliver temporary, limited-privilege credentials to your application, so that your users can access AWS resources. Amazon Cognito identity pools support both authenticated and unauthenticated identities. To provide AWS credentials to your app, complete the following steps.
To use a Amazon Cognito identity pool in an iOS app, set up AWS Amplify. For more
information, see Swift
Authentication
Retrieving an Amazon Cognito identity
You can retrieve a unique Amazon Cognito identifier (identity ID) for your end user immediately if you're allowing unauthenticated users or after you've set the login tokens in the credentials provider if you're authenticating users:
// Retrieve your Amazon Cognito ID [[credentialsProvider getIdentityId] continueWithBlock:^id(AWSTask *task) { if (task.error) { NSLog(@"Error: %@", task.error); } else { // the task result will contain the identity id NSString *cognitoId = task.result; } return nil; }];
Note
getIdentityId is an asynchronous call. If an identity ID is already set on
your provider, you can call credentialsProvider.identityId to retrieve that
identity, which is cached locally. However, if an identity ID is not set on your
provider, calling credentialsProvider.identityId will return
nil. For more information, consult the Amplify iOS SDK reference
You can use Amazon Cognito to deliver temporary, limited-privilege credentials to your application so that your users can access AWS resources. Amazon Cognito supports both authenticated and unauthenticated identities. To provide AWS credentials to your app, follow the steps below.
To use a Amazon Cognito identity pool in an iOS app, set up AWS Amplify. For more
information, see Swift
Authentication
Retrieving an Amazon Cognito identity
You can retrieve a unique Amazon Cognito identifier (identity ID) for your end user immediately if you're allowing unauthenticated users or after you've set the login tokens in the credentials provider if you're authenticating users:
// Retrieve your Amazon Cognito ID credentialsProvider.getIdentityId().continueWith(block: { (task) -> AnyObject? in if (task.error != nil) { print("Error: " + task.error!.localizedDescription) } else { // the task result will contain the identity id let cognitoId = task.result! print("Cognito id: \(cognitoId)") } return task; })
Note
getIdentityId is an asynchronous call. If an identity ID is already set on
your provider, you can call credentialsProvider.identityId to retrieve that
identity, which is cached locally. However, if an identity ID is not set on your
provider, calling credentialsProvider.identityId will return
nil. For more information, consult the Amplify iOS SDK reference
If you have not yet created one, create an identity pool in the Amazon Cognito consolefromCognitoIdentityPool.
After you configure an identity pool with your identity providers, you can use the
fromCognitoIdentityPool function from the
@aws-sdk/credential-providers package to authenticate users. Rather than
setting a global AWS.config.credentials, attach the credentials provider
directly to each service client through its credentials property. The v3 SDK
resolves the provider lazily the first time the client makes a request, so there is no
separate call to obtain credentials. The following example attaches the provider to an
S3Client:
import { S3Client } from "@aws-sdk/client-s3"; import { fromCognitoIdentityPool } from "@aws-sdk/credential-providers"; // Set the region where your identity pool exists (for example, us-east-1 or eu-west-1) const region = "REGION"; // Attach the credentials provider to your service client const client = new S3Client({ region, credentials: fromCognitoIdentityPool({ identityPoolId: "IDENTITY_POOL_ID", logins: { // optional tokens, used for authenticated login "graph.facebook.com": "FBTOKEN", "www.amazon.com": "AMAZONTOKEN", "accounts.google.com": "GOOGLETOKEN", "appleid.apple.com": "APPLETOKEN" }, clientConfig: { region }, }), }); // Credentials are resolved lazily when the client first makes a request. // To inspect them directly, call the provider and await the result // (from inside an async function): const credentials = await client.config.credentials(); const { accessKeyId, secretAccessKey, sessionToken } = credentials;
The optional logins property is a map of identity provider names to the
identity tokens for those providers. How you get the token from your identity provider
depends on the provider you use. For example, if Facebook is one of your identity
providers, you might use the FB.login function from the Facebook SDK
FB.login(function (response) { if (response.authResponse) { // logged in const region = "us-east-1"; const client = new S3Client({ region, credentials: fromCognitoIdentityPool({ identityPoolId: "us-east-1:1699ebc0-7900-4099-b910-2df94f52a030", logins: { "graph.facebook.com": response.authResponse.accessToken }, clientConfig: { region }, }), }); console.log('You are now logged in.'); } else { console.log('There was a problem logging you in.'); } });
Retrieving an Amazon Cognito identity
You can retrieve a unique Amazon Cognito identifier (identity ID) for your end user. If you
allow unauthenticated users, you can retrieve it immediately. If you authenticate users,
retrieve it after you set the login tokens. The fromCognitoIdentityPool
provider exposes the identityId on the credentials that it resolves, so you
can read it from the resolved credentials of a client that uses the provider:
// Inside an async function: const { identityId } = await client.config.credentials();
You can use Amazon Cognito to deliver temporary, limited-privilege credentials to your application, so that your users can access AWS resources. Amazon Cognito supports both authenticated and unauthenticated identities. To provide AWS credentials to your app, follow the steps below.
The AWS SDK for
Unity is now part of the SDK for .NET. To get started with
Amazon Cognito in the SDK for .NET, see Amazon Cognito credentials
provider in the AWS SDK for .NET Developer Guide. Or see Amplify Dev Center
Retrieving an Amazon Cognito identity
You can retrieve a unique Amazon Cognito identifier (identity ID) for your end user immediately if you're allowing unauthenticated users or after you've set the login tokens in the credentials provider if you're authenticating users:
credentials.GetIdentityIdAsync(delegate(AmazonCognitoIdentityResult<string> result) { if (result.Exception != null) { //Exception! } string identityId = result.Response; });
You can use Amazon Cognito to deliver temporary, limited-privilege credentials to your application so that your users can access AWS resources. Amazon Cognito supports both authenticated and unauthenticated identities. To provide AWS credentials to your app, follow the steps below.
The AWS SDK for Xamarin is now part of the SDK for .NET. To get started with
Amazon Cognito in the SDK for .NET, see Amazon Cognito credentials
provider in the AWS SDK for .NET Developer Guide. Or see Amplify Dev Center
Note
Note: If you created your identity pool before February
2015, you must reassociate your roles with your identity pool in order to use this
constructor without the roles as parameters. To do so, open the Amazon Cognito console
Retrieving an Amazon Cognito identity
You can retrieve a unique Amazon Cognito identifier (identity ID) for your end user immediately if you're allowing unauthenticated users or after you've set the login tokens in the credentials provider if you're authenticating users:
var identityId = await credentials.GetIdentityIdAsync();