Connecting to Microsoft GraphAPI Using PowerShell

Recently I have been looking to use Microsoft Graph to query specific information for Microsoft 365 services.

Microsoft Graph is an development tool that connects to multiple Microsoft 365 services to allow querying data and automate tasks.

There are a few steps required to start using Graph which involves creating a app registration on Azure to issue authentication tokens and API permission to view data.

Use the Microsoft Graph API – Microsoft Graph | Microsoft Docs

I also used a blog post by adamtheautomator as this was very good at explaining the process and goes more in depth.

Using the Microsoft Graph API with PowerShell (adamtheautomator.com)

In this post we will be going through configuring the app registration and query some data from Azure AD.

First step is to logon to the Azure portal > Azure AD > App registration and click on New registration.

Give the app a name and specify the support account type in this case we only want account from our tenant.

Once completed, we should now see the app has been created.

Next step we need to configure the API permissions, depending on the type of access required we will use either delegated or application permission as some data can only be access by either permission types.

below is a extract from the Microsft Docs on permission types

Microsoft identity platform developer glossary | Microsoft Docs

permissions

client application gains access to a resource server by declaring permission requests. Two types are available:

  • “Delegated” permissions, which specify scope-based access using delegated authorization from the signed-in resource owner, are presented to the resource at run-time as “scp” claims in the client’s access token.
  • “Application” permissions, which specify role-based access using the client application’s credentials/identity, are presented to the resource at run-time as “roles” claims in the client’s access token.

To assign permission go to the app registration we created earlier and go to API permissions > Add a permission and select Microsoft Graph.

To check which permissions are required I used the below Microsoft Docs .

Microsoft Graph permissions reference – Microsoft Graph | Microsoft Docs

Select the permission type and the required permission in this case I want to be able to read groups, users and directory so.

Once the required permissions are added if they required admin permission those will need to be granted using the grant admin consent option below.

There are many different way’s to connect to Microsoft Graph but in this post we will be using client secret.

We will need the application ID

We will create a client secret

Give the client secret a name and set the expire in this case we will use 1 year.

There should now be client secret and the value is used to authenticate. (Take note of the value and save in secure location like a password vault or Azure Key vault as once you leave the app blade the value will be hidden and if you lose will have to be recreated.)

Once we have the above configured we can connect to GraphApi to generate a token. We will used Invoke-RestMethod.

The secret can be hardcoded but I decided to use read-host so that I could add the secret manually, as it’s not recommend to have any password/secret hardcoded in script.

Below is the command I used to get the token.

$ApplicationID = ""
$TenatDomainName = ""
$AccessSecret = Read-Host "Enter Secret"


$Body = @{    
Grant_Type    = "client_credentials"
Scope         = "https://graph.microsoft.com/.default"
client_Id     = $ApplicationID
Client_Secret = $AccessSecret


$ConnectGraph = Invoke-RestMethod -Uri "https://login.microsoftonline.com/$TenatDomainName/oauth2/v2.0/token" `
-Method POST -Body $Body

$token = $ConnectGraph.access_token

To verify we have a token run the variable $ConnectGraph to view.

Now that we have a token we can run a queries against GraphAPI.

Below we will be running a query for Azure AD groups and selecting display name.

$GrapGroupUrl = 'https://graph.microsoft.com/v1.0/Groups/'
(Invoke-RestMethod -Headers @{Authorization = "Bearer $($token)"} -Uri $GrapGroupUrl -Method Get).value.displayName

To view some examples we can use Graph Explorer.

Graph Explorer – Microsoft Graph

In a future post we will be going through more query’s and automating tasks using GraphAPI.

Create Azure conditional access policy with named location

In this post we will be going through creating an Azure conditional access policy to restrict logging on to Azure / Office 365 from specific locations.

Conditional access policies are used to set requirements for accessing Azure or Office 365 resource, when using Named locations we can then set based on IP range, Trusted locations or Countries and regions.

Below diagram is from Microsoft on how conditionals access works.

What is Conditional Access in Azure Active Directory? | Microsoft Docs

Conceptual Conditional Access process flow

First step is to logon to Azure and go to Azure AD conditional access

Create a named location that will be used to restrict access.

Once in named location we can either create a location based on IP range or countries / regions. In this case we will be using a country.

Next we will create the conditional policy

Give the policy a name, we will be using a group to apply the policy but this could be change to all users or by directory role. (We can use select users or groups to apply the policy to a specific group as if applied to all users there could be a risk of locking yourself out of Azure portal)

Next we can apply the policy to specific apps or all apps. (If applying to all apps there will be a warning to not lock yourself out)

Next we set the conditions in this case we will be using location, I will be applying the policy to any location.

We can then set the named location as excluded in the policy so that it wont be applied if the access is coming from a country that is on the allowed named location.

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Next we can set the access control settings, in this case we will block access but this could be changed to require MFA or other settings below.

Last step is to set session options to use conditional access app control, force sign-in frequency, Persistent browser session. We wont be setting any of the session settings as this policy is to block access.

There are three options report-only, on or off. To test the policy and check what will be blocked without running the risk of blocking real users set to report-only (This would be recommend for testing policy before rolling out to all users.)

Click create and the policy should now show and the state should be report-only.

To test if the policy is going to be applied we can check a users sign-ins, click on a signing log and go to Report-only, click on the three dots and show details.

This will show what part of the policy has been satisfied and not satisfied. Since the location has not been satisfied (as we are connecting from a excluded location) and the policy is not applied.

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When the users tries to access from a country that is not in the allowed location, the result will be a failure and the users would be blocked from accessing.

Once testing has been completed and there are no unexpected blocks we can then go back to the conditional access policy and change the state to on, to apply the policy to users.

Now when a restricted user try’s to access an Azure / Office 365 resource from country not in the named location they will receive a message like the below.

Configure MFA For Azure Application Proxy

On the last post we setup Azure Application Proxy to allow internal application’s to be made available externally using AAD integration.

To add additional security to the setup we can enable MFA for the group or users that will be allowed access.

To enable MFA we need to create a conditional access policy and enable on the application proxy.

First step Login to Azure

Go to Azure Active Directory (AAD)AZ1

Go to Enterprise applications

AZ3

Select the Application proxy that will require MFA to be enabledMFA6

Once in the Application proxy go to Conditional Access and select New policyMFA1

Give the policy a meaningful name as it will appear in the overall Conditional Access policy’s aswell as on the Application. This will make it easier to manage if there are multiple policy’s.

Then select Users and groups and select the required users or groupMFA2

Next select the cloud apps that will require MFA in this case it is the Exchange ECP application that was configured previouslyMFA3

We will not setup conditions but if this is required it can be set to only allow access from certain devices types, location & sign-in risk level.

Next go to Access controls and then Grant tab. Select Grant access, tick Require multi-factor authentication and Requires one of the selected controls MFA4

Last step is to Enable the policy

MFA7

Click create at the bottom of the policy

The policy should now show and have tick under Enabled MFA5

Now when we try to access the ECP Application proxy URL,

we should be prompted for MFA MFA8

and asked to register and verify a device to be use for MFAMFA9

It is a good idea to enable MFA for application as it gives an additional layer of security.

Configure Azure Application Proxy To Access Internal Application

To access internal applications we can use Azure Application proxy to integrate with Azure AD and allow remote access to internal resources.

To use Azure Application Proxy requires Azure AD basic,  Premium P1 or Premium P2 subscription.

An Account with Global administrator rights

The Azure application proxy connector requires Windows Server 2012 R2 or later

Below are pre-req ports and URL’s

See link below to Microsoft documentation

https://docs.microsoft.com/en-us/azure/active-directory/manage-apps/application-proxy

Port number How it’s used
80 Downloading certificate revocation lists (CRLs) while validating the SSL certificate
443 All outbound communication with the Application Proxy service
URL How it’s used
*.msappproxy.net
*.servicebus.windows.net
Communication between the connector and the Application Proxy cloud service
mscrl.microsoft.com:80
crl.microsoft.com:80
ocsp.msocsp.com:80
http://www.microsoft.com:80
Azure uses these URLs to verify certificates
login.windows.net
login.microsoftonline.com
The connector uses these URLs during the registration process.

The following diagram shows how Azure AD and Application Proxy work together to provide single sign-on to on-premises applications.azureappproxxy

To start we need to download and configure the proxy connector

Login to Azure

Go to Azure Active Directory (AAD)AZ1

Once in AAD go to Application proxy

AZ2

Click Download connector serviceAPinstall0

Once downloaded run the MSI on the server that will be used as the application proxy connector (I used a server in a DMZ zone). It will prompt for an Azure account with Global admins rights.

Once configured the server should now show in the application proxy tabAPinstall4

Once connected and active next step is to configure application

Go to AAD and Enterprise applications

AZ3

Once in Enterprise applications click on New application APinstall7

Click on On-premises applicationAPinstall8

Below is a description for each field and option available in the application proxy

Name:
The name of the application that will appear on the access panel and in the Azure portal.

Internal URL:
The URL for accessing the application from inside your private network. You can provide a specific path on the backend server to publish, while the rest of the server is unpublished. In this way, you can publish different sites on the same server as different apps, and give each one its own name and access rules.
If you publish a path, make sure that it includes all the necessary images, scripts, and style sheets for your application. For example, if your app is at https://yourapp/app and uses images located at https://yourapp/media, then you should publish https://yourapp/ as the path. This internal URL doesn’t have to be the landing page your users see. For more information, see Set a custom home page for published apps.

External URL:

The address for users to access the app from outside your network. If you don’t want to use the default Application Proxy domain, read about custom domains in Azure AD Application Proxy.

Pre Authentication:
How Application Proxy verifies users before giving them access to your application.

Azure Active Directory – Application Proxy redirects users to sign in with Azure AD, which authenticates their permissions for the directory and application. Microsoft recommend keeping this option as the default, so that you can take advantage of Azure AD security features like conditional access and Multi-Factor Authentication. Azure Active Directory is required for monitoring the application with Microsoft Cloud Application Security.

Passthrough – Users don’t have to authenticate against Azure Active Directory to access the application. You can still set up authentication requirements on the backend.

Connector Group:
Connectors process the remote access to your application, and connector groups help you organize connectors and apps by region, network, or purpose. If you don’t have any connector groups created yet, your app is assigned to Default.
If your application uses WebSockets to connect, all connectors in the group must be version 1.5.612.0 or later.

 

Fill out the details required. I am using passthrough for pre authentication for the web site but this can be changed to AAD which then requires authentication before the site can be accessed.

(I created a basic IIS page on an internal web server to test with)APinstall9

Next step copy the external URL and try to access the site. There should be no prompt and the site should load

(Yay my lovely test site is available 🙂 )APinstall13

I decided to also allow access to my internal Exchange server and to also test the AAD pre-authentication.

First create a second application proxy and set the Pre Authentication to Azure Active DirectoryAPinstall14

I wanted to use a custom domain name for the second application proxy so I changed the external URL to the custom domain name in Azure.

Once a custom domain is selected we can add a certificate to match the URL.

There will be a warning that a CNAME entry will be required to point from the custom URL to the msappproxy.net addressAPinstall18

(This will require a CNAME record to be created on public DNS server that will map the application proxy to msappproxy.net)CNAME

Once configured we need to add a user or group to allow access.

Go to the application proxy, select the required application proxy and click on Users and groups, Add user and select either the user or group that will be allowed accessAPinstall16APinstall15

Copy the link for the application proxy.

Unless a valid cert was also uploaded you will receive a cert error click continue to site.

It should now prompt for AAD authentication. Use an account that has access right to the proxyAPinstall11

Once logged in the ECP page should now show. APinstall10