GetFederationToken - AWS Security Token Service
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GetFederationToken

Returns a set of temporary security credentials (consisting of an access key ID, a secret access key, and a security token) for a federated user. A typical use is in a proxy application that gets temporary security credentials on behalf of distributed applications inside a corporate network. You must call the GetFederationToken operation using the long-term security credentials of an IAM user. As a result, this call is appropriate in contexts where those credentials can be safely stored, usually in a server-based application. For a comparison of GetFederationToken with the other API operations that produce temporary credentials, see Requesting Temporary Security Credentials and Comparing the AWS STS API operations in the IAM User Guide.

Note

You can create a mobile-based or browser-based app that can authenticate users using a web identity provider like Login with Amazon, Facebook, Google, or an OpenID Connect-compatible identity provider. In this case, we recommend that you use Amazon Cognito or AssumeRoleWithWebIdentity. For more information, see Federation Through a Web-based Identity Provider in the IAM User Guide.

You can also call GetFederationToken using the security credentials of an AWS account root user, but we do not recommend it. Instead, we recommend that you create an IAM user for the purpose of the proxy application. Then attach a policy to the IAM user that limits federated users to only the actions and resources that they need to access. For more information, see IAM Best Practices in the IAM User Guide.

Session duration

The temporary credentials are valid for the specified duration, from 900 seconds (15 minutes) up to a maximum of 129,600 seconds (36 hours). The default session duration is 43,200 seconds (12 hours). Temporary credentials that are obtained by using AWS account root user credentials have a maximum duration of 3,600 seconds (1 hour).

Permissions

You can use the temporary credentials created by GetFederationToken in any AWS service except the following:

  • You cannot call any IAM operations using the AWS CLI or the AWS API.

  • You cannot call any STS operations except GetCallerIdentity.

You must pass an inline or managed session policy 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 policies to use as managed session policies. The plain text that you use for both inline and managed session policies can't exceed 2,048 characters.

Though the session policy parameters are optional, if you do not pass a policy, then the resulting federated user session has no permissions. When you pass session policies, the session permissions are the intersection of the IAM user policies and the session policies that you pass. This gives you a way to further restrict the permissions for a federated user. You cannot use session policies to grant more permissions than those that are defined in the permissions policy of the IAM user. For more information, see Session Policies in the IAM User Guide. For information about using GetFederationToken to create temporary security credentials, see GetFederationToken—Federation Through a Custom Identity Broker.

You can use the credentials to access a resource that has a resource-based policy. If that policy specifically references the federated user session in the Principal element of the policy, the session has the permissions allowed by the policy. These permissions are granted in addition to the permissions granted by the session policies.

Tags

(Optional) You can pass tag key-value pairs to your session. These are called session tags. For more information about session tags, see Passing Session Tags in STS in the IAM User Guide.

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.

Tag key–value pairs are not case sensitive, but case is preserved. This means that you cannot have separate Department and department tag keys. Assume that the user that you are federating has the Department=Marketing tag and you pass the department=engineering session tag. Department and department are not saved as separate tags, and the session tag passed in the request takes precedence over the user tag.

Request Parameters

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

DurationSeconds

The duration, in seconds, that the session should last. Acceptable durations for federation sessions range from 900 seconds (15 minutes) to 129,600 seconds (36 hours), with 43,200 seconds (12 hours) as the default. Sessions obtained using AWS account root user credentials are restricted to a maximum of 3,600 seconds (one hour). If the specified duration is longer than one hour, the session obtained by using root user credentials defaults to one hour.

Type: Integer

Valid Range: Minimum value of 900. Maximum value of 129600.

Required: No

Name

The name of the federated user. The name is used as an identifier for the temporary security credentials (such as Bob). For example, you can reference the federated user name in a resource-based policy, such as in an Amazon S3 bucket policy.

The regex used to validate this parameter is a string of characters consisting of upper- and lower-case alphanumeric characters with no spaces. You can also include underscores or any of the following characters: =,.@-

Type: String

Length Constraints: Minimum length of 2. Maximum length of 32.

Pattern: [\w+=,.@-]*

Required: Yes

Policy

An IAM policy in JSON format that you want to use as an inline session policy.

You must pass an inline or managed session policy 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 policies to use as managed session policies.

This parameter is optional. However, if you do not pass any session policies, then the resulting federated user session has no permissions.

When you pass session policies, the session permissions are the intersection of the IAM user policies and the session policies that you pass. This gives you a way to further restrict the permissions for a federated user. You cannot use session policies to grant more permissions than those that are defined in the permissions policy of the IAM user. For more information, see Session Policies in the IAM User Guide.

The resulting credentials can be used to access a resource that has a resource-based policy. If that policy specifically references the federated user session in the Principal element of the policy, the session has the permissions allowed by the policy. These permissions are granted in addition to the permissions that are granted by the session policies.

The plain text that you use for both inline and managed session policies can't exceed 2,048 characters. The JSON policy characters can be any ASCII character from the space character to the end of the valid character list (\u0020 through \u00FF). It can also include the tab (\u0009), linefeed (\u000A), and carriage return (\u000D) characters.

Note

An AWS conversion compresses the passed session policies and session tags into a packed binary format that has a separate limit. Your request can fail for this limit even if your plain text 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.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 2048.

Pattern: [\u0009\u000A\u000D\u0020-\u00FF]+

Required: No

PolicyArns.member.N

The Amazon Resource Names (ARNs) of the IAM managed policies that you want to use as a managed session policy. The policies must exist in the same account as the IAM user that is requesting federated access.

You must pass an inline or managed session policy 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 policies to use as managed session policies. The plain text that you use for both inline and managed session policies can't exceed 2,048 characters. You can provide up to 10 managed policy ARNs. For more information about ARNs, see Amazon Resource Names (ARNs) and AWS Service Namespaces in the AWS General Reference.

This parameter is optional. However, if you do not pass any session policies, then the resulting federated user session has no permissions.

When you pass session policies, the session permissions are the intersection of the IAM user policies and the session policies that you pass. This gives you a way to further restrict the permissions for a federated user. You cannot use session policies to grant more permissions than those that are defined in the permissions policy of the IAM user. For more information, see Session Policies in the IAM User Guide.

The resulting credentials can be used to access a resource that has a resource-based policy. If that policy specifically references the federated user session in the Principal element of the policy, the session has the permissions allowed by the policy. These permissions are granted in addition to the permissions that are granted by the session policies.

Note

An AWS conversion compresses the passed session policies and session tags into a packed binary format that has a separate limit. Your request can fail for this limit even if your plain text 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.

Type: Array of PolicyDescriptorType objects

Required: No

Tags.member.N

A list of 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.

This parameter is optional. You can pass up to 50 session tags. The plain text 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.

Note

An AWS conversion compresses the passed session policies and session tags into a packed binary format that has a separate limit. Your request can fail for this limit even if your plain text 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 already attached to the user you are federating. When you do, session tags override a user tag with the same key.

Tag key–value pairs are not case sensitive, but case is preserved. This means that you cannot have separate Department and department tag keys. Assume that the role has the Department=Marketing tag and you pass the department=engineering session tag. Department and department are not saved as separate tags, and the session tag passed in the request takes precedence over the role tag.

Type: Array of Tag objects

Array Members: Maximum number of 50 items.

Required: No

Response Elements

The following elements are returned by the service.

Credentials

The temporary security credentials, which include an access key ID, a secret access key, and a security (or session) token.

Note

The size of the security token that STS API operations return is not fixed. We strongly recommend that you make no assumptions about the maximum size.

Type: Credentials object

FederatedUser

Identifiers for the federated user associated with the credentials (such as arn:aws:sts::123456789012:federated-user/Bob or 123456789012:Bob). You can use the federated user's ARN in your resource-based policies, such as an Amazon S3 bucket policy.

Type: FederatedUser object

PackedPolicySize

A percentage value that indicates the packed size of the session policies and session tags combined passed in the request. The request fails if the packed size is greater than 100 percent, which means the policies and tags exceeded the allowed space.

Type: Integer

Valid Range: Minimum value of 0.

Errors

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

MalformedPolicyDocument

The request was rejected because the policy document was malformed. The error message describes the specific error.

HTTP Status Code: 400

PackedPolicyTooLarge

The request was rejected because the total packed size of the session policies and session tags combined was too large. An AWS 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.

HTTP Status Code: 400

RegionDisabled

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 AWS STS in an AWS Region in the IAM User Guide.

HTTP Status Code: 403

Example

Sample Request

https://sts.amazonaws.com/ ?Version=2011-06-15 &Action=GetFederationToken &Name=Bob &PolicyArns.member.1.arn=arn:aws:iam::123456789012:policy/federateduserdemopolicy1 &PolicyArns.member.2.arn=arn:aws:iam::123456789012:policy/federateduserdemopolicy2 &Policy=%7B%22Version%22%3A%222012-10-17%22%2C%22Statement%22%3A%5B%7B%22Sid%22%3A%22Stmt1%22%2C%22Effect%22% 3A%22Allow%22%2C%22Action%22%3A%22s3%3A*%22%2C%22Resource%22%3A%22*%22%7D %5D%7D &DurationSeconds=3600 &Tags.member.1.Key=Dept&Tags.member.1.Value=Accounting &Tags.member.2.Key=Cost-Center&Tags.member.2.Value=12345 &AUTHPARAMS

Sample Response

<GetFederationTokenResponse xmlns="https://sts.amazonaws.com/doc/ 2011-06-15/"> <GetFederationTokenResult> <Credentials> <SessionToken> AQoDYXdzEPT//////////wEXAMPLEtc764bNrC9SAPBSM22wDOk4x4HIZ8j4FZTwdQW LWsKWHGBuFqwAeMicRXmxfpSPfIeoIYRqTflfKD8YUuwthAx7mSEI/qkPpKPi/kMcGd QrmGdeehM4IC1NtBmUpp2wUE8phUZampKsburEDy0KPkyQDYwT7WZ0wq5VSXDvp75YU 9HFvlRd8Tx6q6fE8YQcHNVXAkiY9q6d+xo0rKwT38xVqr7ZD0u0iPPkUL64lIZbqBAz +scqKmlzm8FDrypNC9Yjc8fPOLn9FX9KSYvKTr4rvx3iSIlTJabIQwj2ICCR/oLxBA== </SessionToken> <SecretAccessKey> wJalrXUtnFEMI/K7MDENG/bPxRfiCYzEXAMPLEKEY </SecretAccessKey> <Expiration>2011-07-15T23:28:33.359Z</Expiration> <AccessKeyId>ASIAIOSFODNN7EXAMPLE</AccessKeyId> </Credentials> <FederatedUser> <Arn>arn:aws:sts::123456789012:federated-user/Bob</Arn> <FederatedUserId>123456789012:Bob</FederatedUserId> </FederatedUser> <PackedPolicySize>6</PackedPolicySize> </GetFederationTokenResult> <ResponseMetadata> <RequestId>c6104cbe-af31-11e0-8154-cbc7ccf896c7</RequestId> </ResponseMetadata> </GetFederationTokenResponse>

See Also

For more information about using this API in one of the language-specific AWS SDKs, see the following: