View Source AWS.STS (aws-elixir v1.0.4)
Security Token Service
Security Token Service (STS) enables you to request temporary, limited-privilege credentials for users.
This guide provides descriptions of the STS API. For more information about using this service, see Temporary Security Credentials.
Link to this section Summary
Functions
Returns a set of temporary security credentials that you can use to access Amazon Web Services resources.
Returns a set of temporary security credentials for users who have been authenticated via a SAML authentication response.
Returns a set of temporary security credentials for users who have been authenticated in a mobile or web application with a web identity provider.
Returns a set of short term credentials you can use to perform privileged tasks in a member account.
Decodes additional information about the authorization status of a request from an encoded message returned in response to an Amazon Web Services request.
Returns the account identifier for the specified access key ID.
Returns details about the IAM user or role whose credentials are used to call the operation.
Returns a set of temporary security credentials (consisting of an access key ID, a secret access key, and a security token) for a user.
Returns a set of temporary credentials for an Amazon Web Services account or IAM user.
Link to this section Functions
Returns a set of temporary security credentials that you can use to access Amazon Web Services resources.
These temporary credentials consist of an access key ID, a secret access key,
and a security token. Typically, you use AssumeRole within your account or for
cross-account access. For a comparison of AssumeRole with other API operations
that produce temporary credentials, see Requesting Temporary Security Credentials
and Compare STS credentials
in the IAM User Guide.
permissions
Permissions
The temporary security credentials created by AssumeRole can be used to
make API calls to any Amazon Web Services service with the following exception:
You cannot call the
Amazon Web Services STS GetFederationToken or GetSessionToken API
operations.
(Optional) You can pass inline or managed session policies 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 policy Amazon Resource Names (ARNs) to use as managed session policies. The plaintext that you use for both inline and managed session policies can't exceed 2,048 characters. Passing policies to this operation returns new temporary credentials. The resulting session's permissions are the intersection of the role's identity-based policy and the session policies. You can use the role's temporary credentials in subsequent Amazon Web Services API calls to access resources in the account that owns the role. You cannot use session policies to grant more permissions than those allowed by the identity-based policy of the role that is being assumed. For more information, see Session Policies in the IAM User Guide.
When you create a role, you create two policies: a role trust policy that specifies who can assume the role, and a permissions policy that specifies what can be done with the role. You specify the trusted principal that is allowed to assume the role in the role trust policy.
To assume a role from a different account, your Amazon Web Services account must be trusted by the role. The trust relationship is defined in the role's trust policy when the role is created. That trust policy states which accounts are allowed to delegate that access to users in the account.
A user who wants to access a role in a different account must also have
permissions that
are delegated from the account administrator. The administrator must attach a
policy that
allows the user to call AssumeRole for the ARN of the role in the other
account.
To allow a user to assume a role in the same account, you can do either of the following:
*
Attach a policy to the user that allows the user to call AssumeRole
(as long as the role's trust policy trusts the account).
* Add the user as a principal directly in the role's trust policy.
You can do either because the role’s trust policy acts as an IAM resource-based policy. When a resource-based policy grants access to a principal in the same account, no additional identity-based policy is required. For more information about trust policies and resource-based policies, see IAM Policies in the IAM User Guide.
tags
Tags
(Optional) You can pass tag key-value pairs to your session. These tags 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.
You can set the session tags as transitive. Transitive tags persist during role chaining. For more information, see Chaining Roles with Session Tags in the IAM User Guide.
using-mfa-with-assumerole
Using MFA with AssumeRole
(Optional) You can include multi-factor authentication (MFA) information when
you call
AssumeRole. This is useful for cross-account scenarios to ensure that the
user that assumes the role has been authenticated with an Amazon Web Services
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 IAM User Guide 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 device
produces.
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 Amazon Web Services 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 Compare STS credentials
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 Amazon Web Services services.
session-duration
Session Duration
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.
Role chaining
limits your CLI or Amazon Web Services API role
session to a maximum of one hour. When you use the AssumeRole API operation
to assume a role, you can specify the duration of your role session with the
DurationSeconds parameter. You can specify a parameter value of up to
43200 seconds (12 hours), depending on the maximum session duration setting for
your
role. However, if you assume a role using role chaining and provide a
DurationSeconds parameter value greater than one hour, the operation
fails.
permissions
Permissions
The temporary security credentials created by AssumeRoleWithSAML can be
used to make API calls to any Amazon Web Services service with the following
exception: you cannot call
the STS GetFederationToken or GetSessionToken API
operations.
(Optional) You can pass inline or managed session policies 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 policy Amazon Resource Names (ARNs) to use as managed session policies. The plaintext that you use for both inline and managed session policies can't exceed 2,048 characters. Passing policies to this operation returns new temporary credentials. The resulting session's permissions are the intersection of the role's identity-based policy and the session policies. You can use the role's temporary credentials in subsequent Amazon Web Services API calls to access resources in the account that owns the role. You cannot use session policies to grant more permissions than those allowed by the identity-based policy of the role that is being assumed. For more information, see Session Policies in the IAM User Guide.
Calling AssumeRoleWithSAML does not require the use of Amazon Web Services
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 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).
tags
Tags
(Optional) You can configure your IdP to pass attributes into your SAML assertion as 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.
You can pass up to 50 session tags. The plaintext 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.
An Amazon Web Services conversion compresses the passed inline session policy,
managed policy ARNs,
and session tags into a packed binary format that has a separate limit. Your
request can
fail for this limit even if your plaintext 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 attached to the role. When you do, session tags override the role's tags with the same key.
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.
You can set the session tags as transitive. Transitive tags persist during role chaining. For more information, see Chaining Roles with Session Tags in the IAM User Guide.
saml-configuration
SAML Configuration
Before your application can call AssumeRoleWithSAML, you must configure
your SAML identity provider (IdP) to issue the claims required by Amazon Web
Services. Additionally, you
must use Identity and Access Management (IAM) to create a SAML provider entity
in your Amazon Web Services account that
represents your identity provider. You must also create an IAM role that
specifies this
SAML provider in its trust policy.
For more information, see the following resources:
*
About SAML 2.0-based Federation in the IAM User Guide.
*
Creating SAML Identity Providers in the IAM User Guide.
*
Configuring a Relying Party and Claims in the IAM User Guide.
*
Creating a Role for SAML 2.0 Federation in the IAM User Guide.
Returns a set of temporary security credentials for users who have been authenticated in a mobile or web application with a web identity provider.
Example providers include the OAuth 2.0 providers Login with Amazon and Facebook, or any OpenID Connect-compatible identity provider such as Google or Amazon Cognito federated identities.
For mobile applications, we recommend that you use Amazon Cognito. You can use Amazon Cognito with the Amazon Web Services SDK for iOS Developer Guide and the Amazon Web Services SDK for Android Developer Guide to uniquely identify a user. You can also supply the user with a consistent identity throughout the lifetime of an application.
To learn more about Amazon Cognito, see Amazon Cognito identity pools in Amazon Cognito Developer Guide.
Calling AssumeRoleWithWebIdentity does not require the use of Amazon Web
Services
security credentials. Therefore, you can distribute an application (for example,
on mobile
devices) that requests temporary security credentials without including
long-term Amazon Web Services
credentials in the application. You also don't need to deploy server-based proxy
services
that use long-term Amazon Web Services credentials. Instead, the identity of the
caller is validated by
using a token from the web identity provider. For a comparison of
AssumeRoleWithWebIdentity with the other API operations that produce
temporary credentials, see Requesting Temporary Security Credentials
and Compare STS credentials
in the IAM User Guide.
The temporary security credentials returned by this API 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 Amazon Web Services service API operations.
session-duration
Session Duration
By default, the temporary security credentials created by
AssumeRoleWithWebIdentity last for one hour. However, you can use the
optional DurationSeconds parameter to specify the duration of your session.
You can provide a 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 Update the maximum session duration 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.
permissions
Permissions
The temporary security credentials created by AssumeRoleWithWebIdentity can
be used to make API calls to any Amazon Web Services service with the following
exception: you cannot
call the STS GetFederationToken or GetSessionToken API
operations.
(Optional) You can pass inline or managed session policies 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 policy Amazon Resource Names (ARNs) to use as managed session policies. The plaintext that you use for both inline and managed session policies can't exceed 2,048 characters. Passing policies to this operation returns new temporary credentials. The resulting session's permissions are the intersection of the role's identity-based policy and the session policies. You can use the role's temporary credentials in subsequent Amazon Web Services API calls to access resources in the account that owns the role. You cannot use session policies to grant more permissions than those allowed by the identity-based policy of the role that is being assumed. For more information, see Session Policies in the IAM User Guide.
tags
Tags
(Optional) You can configure your IdP to pass attributes into your web identity token as 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.
You can pass up to 50 session tags. The plaintext 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.
An Amazon Web Services conversion compresses the passed inline session policy,
managed policy ARNs,
and session tags into a packed binary format that has a separate limit. Your
request can
fail for this limit even if your plaintext 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 attached to the role. When you do, the session tag overrides the role tag with the same key.
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.
You can set the session tags as transitive. Transitive tags persist during role chaining. For more information, see Chaining Roles with Session Tags in the IAM User Guide.
identities
Identities
Before your application can call AssumeRoleWithWebIdentity, you must have
an identity token from a supported identity provider and create a role that the
application
can assume. The role that your application assumes must trust the identity
provider that is
associated with the identity token. In other words, the identity provider must
be specified
in the role's trust policy.
Calling AssumeRoleWithWebIdentity can result in an entry in your
CloudTrail logs. The entry includes the
Subject of the provided web identity token. We recommend that you avoid using any
personally
identifiable information (PII) in this field. For example, you could instead use
a GUID
or a pairwise identifier, as suggested
in the OIDC
specification.
For more information about how to use OIDC federation and the
AssumeRoleWithWebIdentity API, see the following resources:
*
Using Web Identity Federation API Operations for Mobile Apps and Federation Through a Web-based Identity Provider.
*
Amazon Web Services SDK for iOS Developer Guide and Amazon Web Services SDK for Android Developer Guide. These toolkits contain sample apps that show how to invoke the identity providers. The toolkits then show how to use the information from these providers to get and use temporary security credentials.
Returns a set of short term credentials you can use to perform privileged tasks in a member account.
Before you can launch a privileged session, you must have enabled centralized root access in your organization. For steps to enable this feature, see Centralize root access for member accounts in the IAM User Guide.
The global endpoint is not supported for AssumeRoot. You must send this request to a Regional STS endpoint. For more information, see Endpoints.
You can track AssumeRoot in CloudTrail logs to determine what actions were performed in a session. For more information, see Track privileged tasks in CloudTrail in the IAM User Guide.
Decodes additional information about the authorization status of a request from an encoded message returned in response to an Amazon Web Services request.
For example, if a user is not authorized to perform an operation that he or she
has
requested, the request returns a Client.UnauthorizedOperation response (an
HTTP 403 response). Some Amazon Web Services operations additionally return an
encoded message that can
provide details about this authorization failure.
Only certain Amazon Web Services operations return an encoded authorization message. The documentation for an individual operation indicates whether that operation returns an encoded message in addition to returning an HTTP code.
The message is encoded because the details of the authorization status can
contain
privileged information that the user who requested the operation should not see.
To decode
an authorization status message, a user must be granted permissions through an
IAM
policy to
request the DecodeAuthorizationMessage
(sts:DecodeAuthorizationMessage) action.
The decoded message includes the following type of information:
Whether the request was denied due to an explicit deny or due to the absence of an explicit allow. For more information, see Determining Whether a Request is Allowed or Denied in the IAM User Guide*.
* The principal who made the request.
* The requested action.
* The requested resource.
* The values of condition keys in the context of the user's request.
Returns the account identifier for the specified access key ID.
Access keys consist of two parts: an access key ID (for example,
AKIAIOSFODNN7EXAMPLE) and a secret access key (for example,
wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY). For more information about
access keys, see Managing Access Keys for IAM Users
in the IAM User Guide.
When you pass an access key ID to this operation, it returns the ID of the
Amazon Web Services account
to which the keys belong. Access key IDs beginning with AKIA are long-term
credentials for an IAM user or the Amazon Web Services account root user. Access
key IDs
beginning with ASIA are temporary credentials that are created using STS
operations. If the account in the response belongs to you, you can sign in as
the root user and review your root user access keys. Then, you can pull a
credentials report
to learn which IAM user owns the keys. To learn who
requested the temporary credentials for an ASIA access key, view the STS
events in your CloudTrail logs
in the IAM User Guide.
This operation does not indicate the state of the access key. The key might be active, inactive, or deleted. Active keys might not have permissions to perform an operation. Providing a deleted access key might return an error that the key doesn't exist.
Returns details about the IAM user or role whose credentials are used to call the operation.
No permissions are required to perform this operation. If an administrator
attaches a
policy to your identity that explicitly denies access to the
sts:GetCallerIdentity action, you can still perform this operation.
Permissions are not required because the same information is returned when
access is
denied. To view an example response, see I Am Not Authorized to Perform: iam:DeleteVirtualMFADevice
in the
IAM User Guide.
Returns a set of temporary security credentials (consisting of an access key ID, a secret access key, and a security token) for a 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 safeguarded, 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 Compare STS credentials
in the IAM User Guide.
Although it is possible to call GetFederationToken using the security
credentials of an Amazon Web Services account root user rather than an IAM user
that you
create for the purpose of a proxy application, we do not recommend it. For more
information, see Safeguard your root user credentials and don't use them for everyday
tasks
in the
IAM User Guide.
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.
session-duration
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 obtained by using the root user credentials have a maximum duration of 3,600 seconds (1 hour).
permissions
Permissions
You can use the temporary credentials created by GetFederationToken in any
Amazon Web Services service with the following exceptions:
* You cannot call any IAM operations using the CLI or the Amazon Web Services API. This limitation does not apply to console sessions.
*
You cannot call any STS operations except GetCallerIdentity.
You can use temporary credentials for single sign-on (SSO) to the console.
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 policy Amazon Resource Names (ARNs) to use as managed session policies. The plaintext 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
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.
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.
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.
Returns a set of temporary credentials for an Amazon Web Services account or IAM user.
The credentials consist of an access key ID, a secret access key, and a security
token.
Typically, you use GetSessionToken if you want to use MFA to protect
programmatic calls to specific Amazon Web Services API operations like Amazon
EC2
StopInstances.
MFA-enabled IAM users must call GetSessionToken and submit
an MFA code that is associated with their MFA device. Using the temporary
security
credentials that the call returns, IAM users can then make programmatic
calls to API operations that require MFA authentication. An incorrect MFA code
causes the
API to return an access denied error. For a comparison of GetSessionToken with
the other API operations that produce temporary credentials, see Requesting Temporary Security
Credentials
and Compare STS credentials
in the IAM User Guide.
No permissions are required for users to perform this operation. The purpose of
the
sts:GetSessionToken operation is to authenticate the user using MFA. You
cannot use policies to control authentication operations. For more information,
see
Permissions for GetSessionToken
in the
IAM User Guide.
session-duration
Session Duration
The GetSessionToken operation must be called by using the long-term Amazon Web
Services
security credentials of an IAM user. Credentials that are created by IAM users
are valid for the duration that you specify. This duration can range
from 900 seconds (15 minutes) up to a maximum of 129,600 seconds (36 hours),
with a default
of 43,200 seconds (12 hours). Credentials based on account credentials can range
from 900
seconds (15 minutes) up to 3,600 seconds (1 hour), with a default of 1 hour.
permissions
Permissions
The temporary security credentials created by GetSessionToken can be used
to make API calls to any Amazon Web Services service with the following
exceptions:
* You cannot call any IAM API operations unless MFA authentication information is included in the request.
You cannot call any STS API except*
AssumeRole or GetCallerIdentity.
The credentials that GetSessionToken returns are based on permissions
associated with the IAM user whose credentials were used to call the
operation. The temporary credentials have the same permissions as the IAM user.
Although it is possible to call GetSessionToken using the security
credentials of an Amazon Web Services account root user rather than an IAM user,
we do
not recommend it. If GetSessionToken is called using root user
credentials, the temporary credentials have root user permissions. For more
information, see Safeguard your root user credentials and don't use them for everyday
tasks
in the
IAM User Guide
For more information about using GetSessionToken to create temporary
credentials, see Temporary Credentials for Users in Untrusted
Environments
in the
IAM User Guide.