AWS SDK Version 3 for .NET
API Reference

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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 APIs that produce temporary credentials, see Requesting Temporary Security Credentials and Comparing the AWS STS APIs 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.

The temporary security credentials are valid for the duration that you specified when calling AssumeRole, or until the time specified in the SAML authentication response's SessionNotOnOrAfter value, whichever is shorter. The duration can be from 900 seconds (15 minutes) to a maximum of 3600 seconds (1 hour). The default is 1 hour.

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 APIs.

Optionally, you can pass an IAM access policy to this operation. If you choose not to pass a policy, the temporary security credentials that are returned by the operation have the permissions that are defined in the access policy of the role that is being assumed. If you pass a policy to this operation, the temporary security credentials that are returned by the operation have the permissions that are allowed by the intersection of both the access policy of the role that is being assumed, and the policy that you pass. This means that both policies must grant the permission for the action to be allowed. 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 access 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, and 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.

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:


For .NET Core, PCL and Unity this operation is only available in asynchronous form. Please refer to AssumeRoleWithSAMLAsync.

Namespace: Amazon.SecurityToken
Assembly: AWSSDK.SecurityToken.dll
Version: 3.x.y.z


public virtual AssumeRoleWithSAMLResponse AssumeRoleWithSAML(
         AssumeRoleWithSAMLRequest request
Type: Amazon.SecurityToken.Model.AssumeRoleWithSAMLRequest

Container for the necessary parameters to execute the AssumeRoleWithSAML service method.

Return Value
The response from the AssumeRoleWithSAML service method, as returned by SecurityTokenService.


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

Version Information

.NET Framework:
Supported in: 4.5, 4.0, 3.5

Portable Class Library:
Supported in: Windows Store Apps
Supported in: Windows Phone 8.1
Supported in: Xamarin Android
Supported in: Xamarin iOS (Unified)
Supported in: Xamarin.Forms

Supported Versions: 4.6 and above
Supported Platforms: Android, iOS, Standalone

See Also