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AWS Security Token Service
API Reference (API Version 2011-06-15)

AssumeRoleWithSAML

Returns a set of temporary security credentials for users who have been authenticated via a SAML authentication response. This operation provides a mechanism for tying an enterprise identity store or directory to role-based AWS access without user-specific credentials or configuration. For a comparison of AssumeRoleWithSAML 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.

The temporary security credentials returned by this operation 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 AWS services.

By default, the temporary security credentials created by AssumeRoleWithSAML last for one hour. However, you can use the optional DurationSeconds parameter to specify the duration of your session. Your role session lasts for the duration that you specify, or until the time specified in the SAML authentication response's SessionNotOnOrAfter value, whichever is shorter. You can provide a DurationSeconds 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.

The temporary security credentials created by AssumeRoleWithSAML can be used to make API calls to any AWS service with the following exception: you cannot call the STS service's GetFederationToken or GetSessionToken API operations.

Optionally, you can pass an IAM permissions policy to this operation. If you pass a policy to this operation, the resulting temporary credentials have the permissions of the assumed role and the policy that you pass. This gives you a way to further restrict the permissions for the resulting temporary security credentials. You cannot use the passed policy to grant permissions that are in excess of those allowed by the permissions policy of the role that is being assumed. For more information, see Permissions for AssumeRole, AssumeRoleWithSAML, and AssumeRoleWithWebIdentity in the IAM User Guide.

Before your application can call AssumeRoleWithSAML, you must configure your SAML identity provider (IdP) to issue the claims required by AWS. Additionally, you must use AWS Identity and Access Management (IAM) to create a SAML provider entity in your AWS account that represents your identity provider. You must also create an IAM role that specifies this SAML provider in its trust policy.

Calling AssumeRoleWithSAML does not require the use of AWS security credentials. The identity of the caller is validated by using keys in the metadata document that is uploaded for the SAML provider entity for your identity provider.

Important

Calling AssumeRoleWithSAML can result in an entry in your AWS CloudTrail logs. The entry includes the value in the NameID element of the SAML assertion. We recommend that you use a NameIDType that is not associated with any personally identifiable information (PII). For example, you could instead use the Persistent Identifier (urn:oasis:names:tc:SAML:2.0:nameid-format:persistent).

For more information, see the following resources:

Request Parameters

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

DurationSeconds

The duration, in seconds, of the role session. Your role session lasts for the duration that you specify for the DurationSeconds parameter, or until the time specified in the SAML authentication response's SessionNotOnOrAfter value, whichever is shorter. You can provide a DurationSeconds 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. If you specify a value higher than this setting, the operation fails. For example, if you specify a session duration of 12 hours, but your administrator set the maximum session duration to 6 hours, your operation fails. 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.

By default, the value is set to 3600 seconds.

Note

The DurationSeconds parameter is separate from the duration of a console session that you might request using the returned credentials. The request to the federation endpoint for a console sign-in token takes a SessionDuration parameter that specifies the maximum length of the console session. For more information, see Creating a URL that Enables Federated Users to Access the AWS Management Console in the IAM User Guide.

Type: Integer

Valid Range: Minimum value of 900. Maximum value of 43200.

Required: No

Policy

An IAM policy in JSON format.

The policy parameter is optional. If you pass a policy to this operation, the resulting temporary credentials have the permissions of the assumed role and the policy that you pass. This gives you a way to further restrict the permissions for the resulting temporary security credentials. You cannot use the passed policy to grant permissions that are in excess of those allowed by the permissions policy of the role that is being assumed. For more information, see Permissions for AssumeRole, AssumeRoleWithSAML, and AssumeRoleWithWebIdentity in the IAM User Guide.

The format for this parameter, as described by its regex pattern, is a string of characters up to 2048 characters in length. The characters can be any ASCII character from the space character to the end of the valid character list (\u0020-\u00FF). It can also include the tab (\u0009), linefeed (\u000A), and carriage return (\u000D) characters.

Note

The policy plaintext must be 2048 bytes or shorter. However, an internal conversion compresses it into a packed binary format with a separate limit. The PackedPolicySize response element indicates by percentage how close to the upper size limit the policy is, where 100 percent is the maximum allowed size.

Type: String

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

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

Required: No

PrincipalArn

The Amazon Resource Name (ARN) of the SAML provider in IAM that describes the IdP.

Type: String

Length Constraints: Minimum length of 20. Maximum length of 2048.

Pattern: [\u0009\u000A\u000D\u0020-\u007E\u0085\u00A0-\uD7FF\uE000-\uFFFD\u10000-\u10FFFF]+

Required: Yes

RoleArn

The Amazon Resource Name (ARN) of the role that the caller is assuming.

Type: String

Length Constraints: Minimum length of 20. Maximum length of 2048.

Pattern: [\u0009\u000A\u000D\u0020-\u007E\u0085\u00A0-\uD7FF\uE000-\uFFFD\u10000-\u10FFFF]+

Required: Yes

SAMLAssertion

The base-64 encoded SAML authentication response provided by the IdP.

For more information, see Configuring a Relying Party and Adding Claims in the IAM User Guide.

Type: String

Length Constraints: Minimum length of 4. Maximum length of 100000.

Required: Yes

Response Elements

The following elements are returned by the service.

AssumedRoleUser

The identifiers for the temporary security credentials that the operation returns.

Type: AssumedRoleUser object

Audience

The value of the Recipient attribute of the SubjectConfirmationData element of the SAML assertion.

Type: String

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. As of this writing, the typical size is less than 4096 bytes, but that can vary. Also, future updates to AWS might require larger sizes.

Type: Credentials object

Issuer

The value of the Issuer element of the SAML assertion.

Type: String

NameQualifier

A hash value based on the concatenation of the Issuer response value, the AWS account ID, and the friendly name (the last part of the ARN) of the SAML provider in IAM. The combination of NameQualifier and Subject can be used to uniquely identify a federated user.

The following pseudocode shows how the hash value is calculated:

BASE64 ( SHA1 ( "https://example.com/saml" + "123456789012" + "/MySAMLIdP" ) )

Type: String

PackedPolicySize

A percentage value that indicates the size of the policy in packed form. The service rejects any policy with a packed size greater than 100 percent, which means the policy exceeded the allowed space.

Type: Integer

Valid Range: Minimum value of 0.

Subject

The value of the NameID element in the Subject element of the SAML assertion.

Type: String

SubjectType

The format of the name ID, as defined by the Format attribute in the NameID element of the SAML assertion. Typical examples of the format are transient or persistent.

If the format includes the prefix urn:oasis:names:tc:SAML:2.0:nameid-format, that prefix is removed. For example, urn:oasis:names:tc:SAML:2.0:nameid-format:transient is returned as transient. If the format includes any other prefix, the format is returned with no modifications.

Type: String

Errors

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

ExpiredToken

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.

HTTP Status Code: 400

IDPRejectedClaim

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.

HTTP Status Code: 403

InvalidIdentityToken

The web identity token that was passed could not be validated by AWS. Get a new identity token from the identity provider and then retry the request.

HTTP Status Code: 400

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 policy document was too large. The error message describes how big the policy document is, in packed form, as a percentage of what the API allows.

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

See Also

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