Tag Archives: Authorization

Authorization to Microsoft Graph: Azure Registered Apps API permissions

Being authenticated to Microsoft 365 tenant means Microsoft 365 knows who is trying to get access. To actually be able read/write or manage resource, your app must be Authorized to this resource.

For details – pls refer to MS authorization and Microsoft Graph API permissions. But again, in short in our case that means we need to have an API permission configured for our azure registered app. There are two kinds of API permissions – delegated and application.

Delegated permissions are intended to allow currently authenticated user to have access to the resource. Effective user permissions in this app would be an intersection of user own permissions and app permissions. So if an app have “Sites.FullControl.All” SharePoint delegated API permissions – that does not mean that user will have full control over all sites.

Application permissions are what it says – once permissions are configured – application will have access to the resources according to API permissions.

Generally, application permissions allow an app to have access to all resources of the same kind in tenant, e.g. to get one specific groups owners an app must have “GroupMember.Read.All” permission that allows an app to read all tenant groups and their members. There are some exceptions – e.g. for Teams Microsoft developed RSC that allows scoped app access. For SharePoint there is a similar option – “Sites.Selected” API permissions.

API permissions must have an Admin consent (see below).

References

Your SharePoint tenant admin doesn’t allow site collection admins…

Scenario

You are trying to register an application at SharePoint site with appregnew.aspx page and you are getting an error or notification message “Your SharePoint tenant admin doesn’t allow site collection admins to create an Azure Access Control (ACS) principal“.

Your SharePoint tenant admin doesn't allow site collection admins to create an Azure Access Control (ACS) principal. Please contact your SharePoint tenant administrator

Or you are trying to provide ACS-based permissions for an application to SharePoint site with appinv.aspx page and you are getting “Your SharePoint tenant admin doesn’t allow site collection admins to update app permissions. Please contact your SharePoint administrator.

Your SharePoint tenant admin doesn't allow site collection admins to update app permissions. Please contact your SharePoint tenant administrator

You can still view and even delete your apps permissions from /_layouts/15/appprincipals.aspx page:

Reason

This is due to a recent update to Microsoft 365 (tenant governance security measures enhancement MC660075) implemented by Microsoft in Aug/Sep 2023. According to the update, only tenant administrators can create or update ACS service principal by default.

The root cause for this is that the Microsoft is pushing developers out of that legacy ACS-based SharePoint Apps-only service principals towards Azure-registered applications with Sites.Selected API permissions as they are more secure etc.
In Nov 2023 Microsoft announcement retirement of ACS principals.

Key differences between ASC and Sites.Selected are:

ACS-based SharePoint app/permissionsApps registered in Azure with Sites.Selected API permissions
Support authentication with client secret only, Secrets are valid for 1 year exactly.Support authentication with client secret and/or certificate, custom expiration time.
Support granular access to SharePoint site, e.g. to site collection or web (subsite) or a specific list or library.Support only access to entire site collection (but Microsoft says granular access is coming)
Support only classic SharePoint REST API and CSOMSupport both – classic SharePoint REST API and CSOM and Microsoft Graph API
App id (client id) is created via appregnew.aspx at a specific SharePoint site by site collection administrator (disabled in Sep 2023).App id (client id) is created in Azure portal (Entra Id), API Sites.Selected permissions are configured via Azure portal (Entra Id) and require tenant admin consent.
Permissions for the app to a site are provided at the site by site collection administrator via appinv.aspx page (disabled in Sep 2023).Permissions for the App to to a specific SharePoint site are provided via Graph API by SharePoint admin with PowerShell script.

Solution #1 – switch to Sites.Selected

  1. Register an application in Azure (via Entra Id – Azure portal GUI, PowerShell script or your company’s specific helpdesk/servicedesk request)
  2. Update the app so both – MS Graph API Sites.Selected and SharePoint Sites.Selected permissions are configured, then
  3. API permissions must be consented – so you’d seek/request your tenant admin consent
  4. Obtain and upload client certificate (recommended) or generate client secret
    (at this moment you should be able to authenticate to tenant)
  5. Request access for the app to a specific SharePoint site – your SharePoint service admin should be able to do that
    (at this moment you should be able to authorize to your SharePoint site).
  6. Validate your app has access to the target SharePoint site with PowerShell
    (check validation scripts below under References).
  7. Use recommended by Microsoft technique, code samples are available for the most popular languages/platforms – Python, C#, Java etc. (check below under References).
  8. Secure your certificate and/or secret. It is not a good idea to use hard-coded secrets, so consider using special services/storages for secrets (aka Vaults)

If you are hosting your application in Azure – consider using managed identity.

Step-by-step guide with screenshot – how to get app with Sites.Selected permissions

Video guide on using Sites.Selected to access SharePoint as application:

There are 3-rd party (and Microsoft) apps developed using classic approach (examples – Azure data Factory, Alteryx). So in some cases Sites.Selected permissions are not enough to get access to SharePoint.

Solution #2 – admin to register/update an ACS app

This option is acceptable if you have existing application that require ACS-based access.
This option is not recommended for new development, as ACS is deprecated and scheduled for retirement.

Microsoft (MC660075 in Message Center): “site collection admin will be unable to register app or update app permissions through above pages unless authorized explicitly by the SharePoint tenant admin” and “With this update site owners will not be able to register/update apps unless the tenant admin explicitly allows it.”

That is incorrect. Site collection admin cannot register app (appregnew) or provide permissions to the app (appinv) anymore. Tenant admin does not authorize site collection admins. Instead tenant (or SharePoint) admin can register an app or provide permissions to the app at a specific site (not changing the entire default behavior back…). But there was no such option (!) in the middle of October 2023, when this feature was enabled at all tenants. Even having a SharePoint admin or tenant admin permissions – if you tried to register an app with AppRegNew.aspx – you got the same error message “Your SharePoint tenant admin doesn’t allow site collection admins to…”.

Later (Checked today – Nov 6, 2023) it seems like Microsoft has implemented it! E.g. now SharePoint or tenant admin is able to register an app with AppRegNew.aspx or update it with AppInv.aspx at any specific site collection. SharePoint or tenant admin must also be among this site collection admins.

It is ok (and I’d say the preferred way) to provide ACS permissions to the app registered in Azure, so do not register apps in SharePoint anymore (do not use AppRegNew.aspx).

Bottom line: if ACS-based permissions are required for app here you go:

  • register application in Azure (Entra id)
  • activate your SharePoint service/tenant admin role
  • ensure you are also target site collection administrator
  • navigate to the site appinv.aspx page – e.g.
    “https://yourtenant.sharepoint.com/sites/yoursite/_layouts/15/appinv.aspx”
    and us Azure registered app (client) Id. E.g. for lookup provide
    • Azure registered app (client) Id for – click lookup
    • localhost as app domain
    • https://localhost as redirect url
    • Permission Request XML – depending on permissions you need, e.g. for full app access to entire site collection:
<AppPermissionRequests AllowAppOnlyPolicy="true">  
   <AppPermissionRequest Scope="http://sharepoint/content/sitecollection" 
    Right="FullControl" />
</AppPermissionRequests>

Solution #3 – step back (not recommended)

It is possible to switch back this new default behavior that prevents site collection admin to register/update apps at SharePoint. This is done with PowerShell command

Set-SPOTenant -SiteOwnerManageLegacyServicePrincipalEnabled $true

To run this command – you’d need to be a SharePoint service or tenant admin.

But this will be a step back on your journey in improving m365 tenant safety, as after that you’ll have a self-registered service principals out of control again. So devs will be using it not being aware of ACS retirement and when Microsoft switch off ACS – it will be a disaster, as all app will stop working. That is why Microsoft implemented this feature to soft-disable ACS and allowed us 2 years to redesign or apps and migrate from ACS to Entra Id apps with Sites.Selected. So this solution is not recommended.

In case you really need an exception to provide an ACS-based service principal – there is Solution number 2.

Full text of Microsoft’s MC660075 message

(Updated) SharePoint admin control for App registration / update

Tag
MAJOR UPDATE ADMIN IMPACT FEATURE UPDATE

Message Summary
Updated August 30, 2023: We have updated the content below for clarity. Thank you for your patience.

This is an enhancement to the security measures for administrative governance that modifies the default procedures for SharePoint app registration via AppRegNew.aspx page and permission updates via AppInv.aspx page. Following the implementation of this change, site collection admin will be unable to register app or update app permissions through above pages unless authorized explicitly by the SharePoint tenant admin.

Upon attempting to register an application on AppRegnew.aspx page, a notification will be displayed stating “Your SharePoint tenant admin doesn’t allow site collection admins to create an Azure Access Control (ACS) principal. Please contact your SharePoint tenant administrator.”

Similarly, upon attempting to update app permissions on AppInv.aspx page, a notification will be displayed stating “Your SharePoint tenant admin doesn’t allow site collection admins to update app permissions. Please contact your SharePoint tenant administrator.”

Kindly note that app registration and permission update via Microsoft Azure portal are not impacted by this change.

When this will happen:

The rollout process is scheduled to commence in late August and is expected to conclude in mid-September.

How this will affect your organization:

With this update site owners will not be able to register/update apps unless the tenant admin explicitly allows it.

To modify the default behavior, the tenant administrator must execute the following shell command to explicitly establish the flag as TRUE, thereby superseding the default value of FALSE. The service principal can only be created or updated by the tenant administrator by default. However, when the flag is set to TRUE, both the SharePoint tenant admin and site collection admin will be able to create or update the service principal through SharePoint.

The shell command is: Set-SPOTenant -SiteOwnerManageLegacyServicePrincipalEnabled $true

Note: The property ‘SiteOwnerManageLegacyServicePrincipalEnabled’ becomes visible in tenant settings after SharePoint Online Management shell is updated to 16.0.23710.12000 or a later version. But before this rollout, the value will always be TRUE even explicitly set to FALSE. It will only automatically be switched to FALSE as the default value after the rollout is launched.

What you need to do to prepare:

No proactive measures are required to prepare for this change. Nevertheless, it is advisable to inform your users of this modification and update any relevant documentation as necessary.

References

Sites.Selected API permissions for SharePoint access

Sites.Selected permissions are required for the non-interactive application to get access to a specific SharePoint site using Microsoft Graph API and/or SharePoint API.

Below are the steps to get access to SharePoint site with Sites.Selected API permissions:

1. Register an application in Azure (via Azure portal GUI, PowerShell script or helpdesk/servicedesk request), e.g. with GUI you’d login to portal.azure.com,
the search for “App registrations” and select “+ New registration”:

2. Update the app “API permissions” – so both – MS Graph API Sites.Selected and SharePoint Sites.Selected application API permissions are configured:

Provide or request tenant admin consent for your API permissions. Finally your app registration “API permissions” should look like:

3. Under Certificates and secrets – generate client secret, copy secret value to safe location.

4. At the Overview page – grab your app client id and tenant id :

At this moment, having tenant id, app (client) id and client secret – you should be able to authenticate against Microsoft 365 tenant with app-only authentication path.

But! Having just Sites.Selected API permissions configured for app does not mean your app has access to SharePoint site. Access for the app to a specific site is provided by SharePoint team using PowerShell script or Graph API calls. That leads us to the next step.

5. Request access for the app to the SharePoint site (your SharePoint service admin should be able to do that via PowerShell script or Graph API calls )
Here is the Graph API

6. Once your SharePoint tenant/service admin confirmed that access has been provided – you can use app client id and client secret to work with SharePoint from your code using Graph API.
If any concerns – you can validate your app access to the target SharePoint site with simple PowerShell scripts: here is the sample code

7. Secure your certificate and/or secret
You do not hard-code secrets. Consider using vault to keep certificate/secret. If you host your application in Azure – consider using managed identity.

Note 1: Sites.Selected API permissions allows you call Microsoft Graph API with client Id and client secret. Calling SharePoint API with client secret is not supported. You have to use client id and certificate to call SharePoint API having app with Sites.Selected permissions.

Call SharePoint API with client Id and client secret is possible only if ACS-based permissions are provided for the app to the site, which is not recommended (see below).

Comparison between Azure Apps and Entra Id Sites.Selected API permissions vs SharePoint app-only spn and ACS-based permissions.

Note 2: ACS-based permissions are going to be deprecated soon:
Your SharePoint admin doesn’t allow site owners to create/update ACS principal ⋆ Vladilen Microsoft 365 engineer

Update:
Microsoft announced decommissioning of ACS permissions. So do not use ACS for any new development.

It might be acceptable to provide ACS permissions for existing custom apps or 3-rd party or Microsoft apps/web apps (e.g. Alteryx, Azure Data factory) – apps that only support client id and secret and using SharePoint API under the hood – but just to not to break business processes and being aware of ACS EOL and planning a replacement of theses apps before 2026.

References

SharePoint AppRegNew.aspx and AppInv.aspx

There are well-known SharePoint app-only service principals and ACS-based permissions. It is kind of old-school way – introduced as part of Add-Ins for SharePoint 2013 – to get unattended access to SharePoint site (application access, i.e. access without user presence). Such apps are called daemon apps or service apps or background jobs etc…

Microsoft announced retirement of ACS in 2026 and takes measures to stop using ACS in new and existing tenants. For you to smoothly switch to new, recommended Entra Id based service principals and permissions – it is important to know some details about classic app-only service principals and ACS-based permissions.

As you know, any access is a two-step procedure:

  • Authentication, when systems ensures you are indeed the one you claim you are
  • Authorization, when system grants you access to the resource, as it knows that this id is allowed to access such and such resource with these permissions

So, when it comes to deprecated SharePoint app-only service principals and ACS-based permissions, AppRegNew is responsible for authentication and AppInv is responsible for authorization.

AppRegNew.aspx

To get a SharePoint app-only service principal – you’d need to register a new one at any SharePoint site using the AppRegNew.aspx page. This page is not available from GUI, so you’d need to type the Url manually. You’d need to be a site collection admin to register a new app.

Let say, your site Url is “https://YourTenant.sharepoint.com/teams/YourSite“.
Then this appregnew page’s Url would be
“https://YourTenant.sharepoint.com/teams/YourSite/_layouts/15/appregnew.aspx

If you go to this page, you’ll see (*) something like

You’d click generate client id, then generate client secret and type your app display name. I usually use “localhost” as app domain and “https://localhost” as redirect Url.

If all good – you’d get app id (client id) and app secret (client secret) and you’d be able to authenticate to your SharePoint site.

AppInv.aspx

Providing permissions for your SharePoint app-only service principal to your SharePoint site is done using AppInv.aspx page. This page is also not available from GUI, so you’d need to type the Url manually again. You’d need to be a site collection admin to use this page.

Let say, your site Url is “https://YourTenant.sharepoint.com/teams/YourSite“.
Then this appinv page’s Url would be
“https://YourTenant.sharepoint.com/teams/YourSite/_layouts/15/appinv.aspx

If you go to this page, you’ll see (*) something like

At this moment – you need to enter app (client) id here and click lookup – so all the app metadata would be populated, then you’d need to enter Permission Request XML.
Via this “Permission Request XML” you are specifying exact permissions your app will have in this site. E.g. you can specify scope – all site collection or one specific subsite (web) or even one specific list or library. Also you can specify permissions level – e.g. read, read/write, manage or full control. This is tricky, but let me share some examples with you.

Permission Request XML for the app to have full control over entire site collection:

<AppPermissionRequests AllowAppOnlyPolicy="true">  
   <AppPermissionRequest Scope="http://sharepoint/content/sitecollection" 
    Right="FullControl" />
</AppPermissionRequests>

Permission Request XML for the app to have read access to a subsite (web):

<AppPermissionRequests AllowAppOnlyPolicy="true">  
  <AppPermissionRequest Scope="http://sharepoint/content/sitecollection/web" 
   Right="Read" />
</AppPermissionRequests>

Permission Request XML for the app to have read/write access to a list/library:

<AppPermissionRequests AllowAppOnlyPolicy="true">  
   <AppPermissionRequest Scope="http://sharepoint/content/sitecollection/web/list" 
    Right="Write" />
</AppPermissionRequests>

Any mistake in XML might prevent app access, so be very careful.

Finally, your AppInv.aspx page would look like

If you specify scope as web – you’d do it on the specific web url, e.g.
“https://YourTenant.sharepoint.com/teams/YourSite/SubSite/_layouts/15/appinv.aspx”

If you specify scope as list – you’d do it on the specific web url, e.g.
“https://YourTenant.sharepoint.com/teams/YourSite/SubSite/_layouts/15/appinv.aspx”
and after you click “Save” – there will be a page – you’ll be asked to choose a list from available web lists.

After all, you’ll be asked to confirm that you trust the app:

And after that your app (SharePoint app-only service principal) will have access (ACS-based access) to you site.

AppPrincipals.aspx

From site settings page (/_layouts/15/settings.aspx) you should be able to see apps registered on your site with “Site app permissions” or “Site collection app permissions” links available via GUI. That would be “appprincipals.aspx” page.

Unfortunately, you cannot see you app permissions here or your secret expiration time. Some date can be pulled via PowerShell with Get-PnPAzureACSPrincipal

Possible complications

After Microsoft announced retirement of ACS – you can see this message on appinv and appregnew pages:

You might also see “Your SharePoint tenant admin doesn’t allow site collection admins to create an Azure Access Control (ACS) principal” message at appregnew page and “Your SharePoint tenant admin doesn’t allow site collection admins to update app permissions. Please contact your SharePoint administrator.” at appinv page.

That’s because a recent update to Microsoft 365 (MC660075) pushed by Microsoft in Aug/Sep 2023 changes default behavior so only tenant administrators can create or update ACS service principal by default.

If you are facing issues above – or you want to switch to modern Entra Id service principals, but by some reasons you need ACS-based permissions – here is the article on “Entra Id vs ACS for SharePoint and how to survive during transition period

References

Connecting to SharePoint Online programmatically: Secret vs Certificate

Update: Sites.Selected API MS Graph permissions was introduced by Microsoft in 2021. It was a good move towards site-level development, but still developers were limited with only what MS Graph API provides for SharePoint dev.
So devs had to use AppInv.aspx at site level to provide ACS permissions to their apps to be able to use SharePoint CSOM and REST APIs.
Recently Microsoft introduced Sites.Selected SharePoint API permissions for registered Azure Apps! So now devs should be fully happy without ACS-based permissions.

Scenario

You have an application that needs access to Microsoft 365 SharePoint Online site/list/documents. Application is running without interaction with users – e.g. unattended, as daemon job.

There are two options you can authenticate to Microsoft 365 – with the secret or with the certificate. Authenticating with certificate is considered more secure.

Questions

  • What happens if SharePoint-Apps only principal is disabled
    (i.e. ‘set-spotenant -DisableCustomAppAuthentication $true’ )?
  • Why I’m getting 401 error when authenticating to SPO?
  • Why I’m getting 403 error when authenticating to SPO with secret?
  • What permissions to I need to work with SPO?

Findings

Note: we will use PowerShell 7.2 and PnP.PowerShell 1.9 to illustrate it.

Disabled SharePoint-Apps only principal

If SharePoint-Apps only principal is disabled in your tenant
(i.e. ‘Get-PnPTenant | select DisableCustomAppAuthentication’ returns $true ), then the only way you work with SPO from code is:

  • an App registered in Azure
  • API permissions provided via Azure (MS Graph, SharePoint)
  • Certificate is used

In all other cases (even your Connect-PnPOnline command complete successfully) – you will be getting error 401 (unauthorized) when trying Get-PnPTenant or Get-PnPTenantSite or Get-PnPSite

Enabled SharePoint-Apps only principal

If SharePoint-Apps only principals are enabled in your tenant
(i.e. ‘Get-PnPTenant | select DisableCustomAppAuthentication’ returns $false ), then you have three options to work with SPO from code:

  • Azure App with a secret (Client Id + Client Secret) and permissions to SharePoint provided via SharePoint (AppInv.aspx) to access SharePoint REST API
  • Azure App with a certificate (Client Id + Certificate) and permissions provided via Azure to access SharePoint REST API
  • Azure App with a certificate or secret (Client Id + Secret or Certificate) and permissions provided via Azure to access SharePoint via Microsoft Graph API

Connect to SharePoint Online and MS Graph Interactively with Client App and MSAL token

Scenario

You have a Microsoft 365 subscription with SharePoint Online. You use PowerShell, PnP.PowerShell module and MS Graph API to work with SharePoint under current user’s credential. You need to authenticate to SharePoint Online via Connect-PnPOnline and to Microsoft Graph API interactively on behalf of a current user.

Problem

Unfortunately, both “Connect-PnPOnline -Interactive -Url <siteUrl>” or “Connect-PnPOnline -UseWebLogin -Url <siteUrl>” might fail with something like “Need admin approval”, “App needs permission to access resources in your organization that only an admin can grant. Please ask an admin to grant permission to this app before you can use it.” or “Permissions requested” or similar

Solution

  • register an Azure App. Choose “single tenant”
  • configure authentication blade:
    – add platform – “Mobile and Desktop app”
    select “https://login.microsoftonline.com/common/oauth2/nativeclient”
    add custom Redirect URI: “http://localhost”
  • configure API permissions blade:
    – add delegated permissions you need (refer to specific API you’ll use)
    e.g. Microsoft Graph Sites.FullControl.All and SharePoint AllSites.FullControl
  • use the following code samples

PnP.PowerShell

$siteUrl = "https://contoso.sharepoint.com/teams/myTeamsSite"
$appId = "" # Client Id
Connect-PnPOnline -ClientId $appId -Url $siteUrl -Interactive
Get-PnPSite

A pop-up window will appear to authenticate interactively. If you are already authenticated with another credentials (or single-sigh-on) – an interactive window might pop up and disappear – that prevents you enter your other id.
To ensure Connect-PnPOnline prompts you for your credentials – use ” -ForceAuthentication” option.

If you are a SharePoint tenant admin – you can connect to a tenant with:

$orgName = "yourTenantPrefix" 
$adminUrl = "https://$orgName-admin.sharepoint.com" 
$appId = "" # Client Id 
$connection = Connect-PnPOnline -ClientId $appId -Url $adminUrl -Interactive -ReturnConnection # -ForceAuthentication 
$connection 

Microsoft Graph API

Use MSAL.PS module to get an msal token then use token in Microsoft graph-based requests:

$tenantId = ""
$clientid = ""
$url = ""
$token = Get-MsalToken -ClientId $clientid -TenantId $tenantId -Interactive

By default token expires in ~ 1 hour. But you can refresh it silently.
This helps you in long-running PowerShell scripts that takes hours to complete.
So you can include something like this in the loop:

if ($token.ExpiresOn.LocalDateTime -lt $(get-date).AddMinutes(10)) {    
  $token = Get-MsalToken -ClientId $clientid -TenantId $tenantId -ForceRefresh -Silent    
  Write-Host "Token will expire on:" $token.ExpiresOn.LocalDateTime
}

Application permissions

Somehow using Connect-PnPOnline with AccessToken option did not work if the token was acquired with MSAL.PS interactively. But it did work when you get msal.ps token unattended (using App credentials). So…

If you can get an Application (non Delegated) permissions to your azure-registerd-app,
you can use msal token to connect to site with PnP

=========================

NB: For delegated permissions, the effective permissions of your app are the intersection of the delegated permissions the app has been granted (via consent) and the privileges of the currently signed-in user. Your app can never have more privileges than the signed-in user.