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Scopes and permissions in the Microsoft identity platform

  • Članak

The Microsoft identity platform implements the OAuth 2.0 authorization protocol. OAuth 2.0 is a method through which a third-party app can access web-hosted resources on behalf of a user. Any web-hosted resource that integrates with the Microsoft identity platform has a resource identifier, or application ID URI.

In this article, you'll learn about scopes and permissions in the identity platform.

The following list shows some examples of Microsoft web-hosted resources:

  • Microsoft Graph: https://graph.microsoft.com
  • Microsoft 365 Mail API: https://outlook.office.com
  • Azure Key Vault: https://vault.azure.net

The same is true for any third-party resources that have integrated with the Microsoft identity platform. Any of these resources can also define a set of permissions that can be used to divide the functionality of that resource into smaller chunks. As an example, Microsoft Graph has defined permissions to do the following tasks, among others:

  • Read a user's calendar
  • Write to a user's calendar
  • Send mail as a user

Because of these types of permission definitions, the resource has fine-grained control over its data and how API functionality is exposed. A third-party app can request these permissions from users and administrators, who must approve the request before the app can access data or act on a user's behalf.

When a resource's functionality is chunked into small permission sets, third-party apps can be built to request only the permissions that they need to perform their function. Users and administrators can know what data the app can access. And they can be more confident that the app isn't behaving with malicious intent. Developers should always abide by the principle of least privilege, asking for only the permissions they need for their applications to function.

In OAuth 2.0, these types of permission sets are called scopes. They're also often referred to as permissions. In the Microsoft identity platform, a permission is represented as a string value. An app requests the permissions it needs by specifying the permission in the scope query parameter. Identity platform supports several well-defined OpenID Connect scopes and resource-based permissions (each permission is indicated by appending the permission value to the resource's identifier or application ID URI). For example, the permission string https://graph.microsoft.com/Calendars.Read is used to request permission to read users calendars in Microsoft Graph.

In requests to the authorization server, for the Microsoft identity platform, if the resource identifier is omitted in the scope parameter, the resource is assumed to be Microsoft Graph. For example, scope=User.Read is equivalent to https://graph.microsoft.com/User.Read.

Admin-restricted permissions

Permissions in the Microsoft identity platform can be set to admin restricted. For example, many higher-privilege Microsoft Graph permissions require admin approval. If your app requires admin-restricted permissions, an organization's administrator must consent to those scopes on behalf of the organization's users. The following section gives examples of these kinds of permissions:

  • User.Read.All: Read all user's full profiles
  • Directory.ReadWrite.All: Write data to an organization's directory
  • Groups.Read.All: Read all groups in an organization's directory

Note

In requests to the authorization, token or consent endpoints for the Microsoft identity platform, if the resource identifier is omitted in the scope parameter, the resource is assumed to be Microsoft Graph. For example, scope=User.Read is equivalent to https://graph.microsoft.com/User.Read.

Although a consumer user might grant an application access to this kind of data, organizational users can't grant access to the same set of sensitive company data. If your application requests access to one of these permissions from an organizational user, the user receives an error message that says they're not authorized to consent to your app's permissions.

If the application requests application permissions and an administrator grants these permissions this grant isn't done on behalf of any specific user. Instead, the client application is granted permissions directly. These types of permissions should only be used by daemon services and other non-interactive applications that run in the background. For more information on the direct access scenario, see Access scenarios in the Microsoft identity platform.

For a step by step guide on how to expose scopes in a web API, see Configure an application to expose a web API.

OpenID Connect scopes

The Microsoft identity platform implementation of OpenID Connect has a few well-defined scopes that are also hosted on Microsoft Graph: openid, email, profile, and offline_access. The address and phone OpenID Connect scopes aren't supported.

If you request the OpenID Connect scopes and a token, you'll get a token to call the UserInfo endpoint.

The openid scope

If an app signs in by using OpenID Connect, it must request the openid scope. The openid scope appears on the work account consent page as the Sign you in permission.

By using this permission, an app can receive a unique identifier for the user in the form of the sub claim. The permission also gives the app access to the UserInfo endpoint. The openid scope can be used at the Microsoft identity platform token endpoint to acquire ID tokens. The app can use these tokens for authentication.

The email scope

The email scope can be used with the openid scope and any other scopes. It gives the app access to the user's primary email address in the form of the email claim.

The email claim is included in a token only if an email address is associated with the user account, which isn't always the case. If your app uses the email scope, the app needs to be able to handle a case in which no email claim exists in the token.

The profile scope

The profile scope can be used with the openid scope and any other scope. It gives the app access to a large amount of information about the user. The information it can access includes, but not limited to, the user's given name, surname, preferred username, and object ID.

For a complete list of the profile claims available in the id_tokens parameter for a specific user, see the id_tokens reference.

The offline_access scope

The offline_access scope gives your app access to resources on behalf of the user for an extended time. On the consent page, this scope appears as the Maintain access to data you have given it access to permission.

When a user approves the offline_access scope, your app can receive refresh tokens from the Microsoft identity platform token endpoint. Refresh tokens are long-lived. Your app can get new access tokens as older ones expire.

Note

This permission currently appears on all consent pages, even for flows that don't provide a refresh token (such as the implicit flow). This setup addresses scenarios where a client can begin within the implicit flow and then move to the code flow where a refresh token is expected.

On the Microsoft identity platform (requests made to the v2.0 endpoint), your app must explicitly request the offline_access scope, to receive refresh tokens. So when you redeem an authorization code in the OAuth 2.0 authorization code flow, you'll only receive an access token from the /token endpoint.

The access token is usually valid for around one hour. At that point, your app needs to redirect the user back to the /authorize endpoint to request a new authorization code. During this redirect and depending on app type, the user may need to enter their credentials again or consent to permissions again.

The refresh token has a longer expiry than the access token, and is usually valid for a day. For more information about how to get and use refresh tokens, see the Microsoft identity platform protocol reference.

The .default scope

The .default scope is used to refer generically to a resource service (API) in a request, without identifying specific permissions. If consent is necessary, using .default signals that consent should be prompted for all required permissions listed in the application registration (for all APIs in the list).

The scope parameter value is constructed by using the identifier URI for the resource and .default, separated by a forward slash (/). For example, if the resource's identifier URI is https://contoso.com, the scope to request is https://contoso.com/.default. For cases where you must include a second slash to correctly request the token, see the section about trailing slashes.

Using scope={resource-identifier}/.default is functionally the same as resource={resource-identifier} on the v1.0 endpoint (where {resource-identifier} is the identifier URI for the API, for example https://graph.microsoft.com for Microsoft Graph).

The .default scope can be used in any OAuth 2.0 flow and to initiate admin consent. Its use is required in the On-Behalf-Of flow and client credentials flow.

Clients can't combine static (.default) consent and dynamic consent in a single request. So scope=https://graph.microsoft.com/.default Mail.Read results in an error because it combines scope types.

The .default scope parameter only triggers a consent prompt if consent hasn't been granted for any delegated permission between the client and the resource, on behalf of the signed-in user.

If consent exists, the returned token contains all scopes granted for that resource for the signed-in user. However, if no permission has been granted for the requested resource (or if the prompt=consent parameter has been provided), a consent prompt is shown for all required permissions configured on the client application registration, for all APIs in the list.

For example, if the scope https://graph.microsoft.com/.default is requested, your application is requesting an access token for the Microsoft Graph API. If at least one delegated permission has been granted for Microsoft Graph on behalf of the signed-in user, the sign-in will continue and all Microsoft Graph delegated permissions that have been granted for that user will be included in the access token. If no permissions have been granted for the requested resource (Microsoft Graph, in this example), then a consent prompt will be presented for all required permissions configured on the application, for all APIs in the list.

Example 1: The user, or tenant admin, has granted permissions

In this example, the user or a tenant administrator has granted the Mail.Read and User.Read Microsoft Graph permissions to the client.

If the client requests scope=https://graph.microsoft.com/.default, no consent prompt is shown, regardless of the contents of the client application's registered permissions for Microsoft Graph. The returned token contains the scopes Mail.Read and User.Read.

Example 2: The user hasn't granted permissions between the client and the resource

In this example, the user hasn't granted consent between the client and Microsoft Graph, nor has an administrator. The client has registered for the permissions User.Read and Contacts.Read. It has also registered for the Azure Key Vault scope https://vault.azure.net/user_impersonation.

When the client requests a token for scope=https://graph.microsoft.com/.default, the user sees a consent page for the Microsoft Graph User.Read and Contacts.Read scopes, and for the Azure Key Vault user_impersonation scope. The returned token contains only the User.Read and Contacts.Read scopes, and it can be used only against Microsoft Graph.

Example 3: The user has consented, and the client requests more scopes

In this example, the user has already consented to Mail.Read for the client. The client has registered for the Contacts.Read scope.

The client first performs a sign-in with scope=https://graph.microsoft.com/.default. Based on the scopes parameter of the response, the application's code detects that only Mail.Read has been granted. The client then initiates a second sign-in using scope=https://graph.microsoft.com/.default, and this time forces consent using prompt=consent. If the user is allowed to consent for all the permissions that the application registered, they'll be shown the consent prompt. (If not, they'll be shown an error message or the admin consent request form.) Both Contacts.Read and Mail.Read will be in the consent prompt. If consent is granted and the sign-in continues, the token returned is for Microsoft Graph, and contains Mail.Read and Contacts.Read.

Using the .default scope with the client

In some cases, a client can request its own .default scope. The following example demonstrates this scenario.

// Line breaks are for legibility only.

GET https://login.microsoftonline.com/{tenant}/oauth2/v2.0/authorize
    ?response_type=token            //Code or a hybrid flow is also possible here
    &client_id=00001111-aaaa-2222-bbbb-3333cccc4444
    &scope=9ada6f8a-6d83-41bc-b169-a306c21527a5/.default
    &redirect_uri=https%3A%2F%2Flocalhost
    &state=1234

This code example produces a consent page for all registered permissions if the preceding descriptions of consent and .default apply to the scenario. Then the code returns an id_token, rather than an access token.

This setup shouldn't be used by new clients that target the Microsoft identity platform. Be sure to Migrate to the Microsoft Authentication Library (MSAL) from Azure AD Authentication Library (ADAL).

Client credentials grant flow and .default

Another use of .default is to request app roles (also known as application permissions) in a non-interactive application like a daemon app that uses the client credentials grant flow to call a web API.

To define app roles (application permissions) for a web API, see Add app roles in your application.

Client credentials requests in your client service must include scope={resource}/.default. Here, {resource} is the web API that your app intends to call, and wishes to obtain an access token for. Issuing a client credentials request by using individual application permissions (roles) is not supported. All the app roles (application permissions) that have been granted for that web API are included in the returned access token.

To grant access to the app roles you define, including granting admin consent for the application, see Configure a client application to access a web API.

Trailing slash and .default

Some resource URIs have a trailing forward slash, for example, https://contoso.com/ as opposed to https://contoso.com. The trailing slash can cause problems with token validation. Problems occur primarily when a token is requested for Azure Resource Manager (https://management.azure.com/).

In this case, a trailing slash on the resource URI means the slash must be present when the token is requested. So when you request a token for https://management.azure.com/ and use .default, you must request https://management.azure.com//.default (notice the double slash!).

In general, if you verify that the token is being issued, and if the token is being rejected by the API that should accept it, consider adding a second forward slash and trying again.

See also