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AssumeRole
for cross-account access or federation.
Important: You cannot call AssumeRole
by using AWS account credentials;
access will be denied. You must use IAM user credentials or temporary security credentials
to call AssumeRole
.
For cross-account access, imagine that you own multiple accounts and need to access resources in each account. You could create long-term credentials in each account to access those resources. However, managing all those credentials and remembering which one can access which account can be time consuming. Instead, you can create one set of long-term credentials in one account and then use temporary security credentials to access all the other accounts by assuming roles in those accounts. For more information about roles, see IAM Roles (Delegation and Federation) in the Using IAM.
For federation, you can, for example, grant single sign-on access to the AWS Management
Console. If you already have an identity and authentication system in your corporate
network, you don't have to recreate user identities in AWS in order to grant those
user identities access to AWS. Instead, after a user has been authenticated, you call
AssumeRole
(and specify the role with the appropriate permissions) to
get temporary security credentials for that user. With those temporary security credentials,
you construct a sign-in URL that users can use to access the console. For more information,
see Common
Scenarios for Temporary Credentials in the Using IAM.
The temporary security credentials are valid for the duration that you specified when
calling AssumeRole
, which can be from 900 seconds (15 minutes) to 3600
seconds (1 hour). The default is 1 hour.
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 both the access policy of the role that is being assumed, 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 access policy of the role that is being assumed. For more information, see Permissions for AssumeRole, AssumeRoleWithSAML, and AssumeRoleWithWebIdentity in the Using IAM.
To assume a role, your AWS account must be trusted by the role. The trust relationship
is defined in the role's trust policy when the role is created. You must also have
a policy that allows you to call sts:AssumeRole
.
Using MFA with AssumeRole
You can optionally include multi-factor authentication (MFA) information when you
call AssumeRole
. This is useful for cross-account scenarios in which
you want to make sure that the user who is assuming the role has been authenticated
using an AWS MFA device. In that scenario, the trust policy of the role being assumed
includes a condition that tests for MFA authentication; if the caller does not include
valid MFA information, the request to assume the role is denied. The condition in
a trust policy that tests for MFA authentication might look like the following example.
"Condition": {"Bool": {"aws:MultiFactorAuthPresent": true}}
For more information, see Configuring MFA-Protected API Access in the Using IAM guide.
To use MFA with AssumeRole
, you pass values for the SerialNumber
and TokenCode
parameters. The SerialNumber
value identifies
the user's hardware or virtual MFA device. The TokenCode
is the time-based
one-time password (TOTP) that the MFA devices produces.
Namespace: Amazon.SecurityToken.Model
Assembly: AWSSDK.dll
Version: (assembly version)
public class AssumeRoleRequest : AmazonSecurityTokenServiceRequest IRequestEvents
The AssumeRoleRequest type exposes the following members
Name | Description | |
---|---|---|
AssumeRoleRequest() |
Name | Type | Description | |
---|---|---|---|
DurationSeconds | System.Int32 |
Gets and sets the property DurationSeconds.
The duration, in seconds, of the role session. The value can range from 900 seconds (15 minutes) to 3600 seconds (1 hour). By default, the value is set to 3600 seconds. |
|
ExternalId | System.String |
Gets and sets the property ExternalId.
A unique identifier that is used by third parties when assuming roles in their customers' accounts. For each role that the third party can assume, they should instruct their customers to ensure the role's trust policy checks for the external ID that the third party generated. Each time the third party assumes the role, they should pass the customer's external ID. The external ID is useful in order to help third parties bind a role to the customer who created it. For more information about the external ID, see How to Use an External ID When Granting Access to Your AWS Resources to a Third Party in the Using IAM. |
|
Policy | System.String |
Gets and sets the property Policy.
An IAM policy in JSON format. This parameter is optional. If you pass a policy, the temporary security credentials that are returned by the operation have the permissions that are allowed by both (the intersection of) the access policy of the role that is being assumed, 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 access policy of the role that is being assumed. For more information, see Permissions for AssumeRole, AssumeRoleWithSAML, and AssumeRoleWithWebIdentity in the Using IAM. |
|
RoleArn | System.String |
Gets and sets the property RoleArn.
The Amazon Resource Name (ARN) of the role to assume. |
|
RoleSessionName | System.String |
Gets and sets the property RoleSessionName.
An identifier for the assumed role session. Use the role session name to uniquely identify a session when the same role is assumed by different principals or for different reasons. In cross-account scenarios, the role session name is visible to, and can be logged by the account that owns the role. The role session name is also used in the ARN of the assumed role principal. This means that subsequent cross-account API requests using the temporary security credentials will expose the role session name to the external account in their CloudTrail logs. |
|
SerialNumber | System.String |
Gets and sets the property SerialNumber.
The identification number of the MFA device that is associated with the user who is
making the |
|
TokenCode | System.String |
Gets and sets the property TokenCode.
The value provided by the MFA device, if the trust policy of the role being assumed
requires MFA (that is, if the policy includes a condition that tests for MFA). If
the role being assumed requires MFA and if the |
.NET Framework:
Supported in: 4.5, 4.0, 3.5
.NET for Windows Store apps:
Supported in: Windows 8.1, Windows 8
.NET for Windows Phone:
Supported in: Windows Phone 8.1, Windows Phone 8