The MyTimetable Office 365 integration is able to connect to a user's calendar using the Outlook Calendar the Microsoft Graph REST API. This page describes how to grant MyTimetable access to the Outlook Calendar Microsoft Graph REST API. MyTimetable will then be able to access calendars without explicit consent of a user.
Table of Contents
| Table of Contents |
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Registering MyTimetable as an application in Azure AD and getting the manifest
- Visit the Microsoft Azure classic Management Portal at manage.windowsazure.com, using the credential of your Microsoft tenant that has the subscription to Office 365 you wish to use.
- Click "Activity Directory".
- Click the Active Directory you would like to manage.
- On the Directory page, click "Applications".
- Click "Add" in the bottom menu bar.
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- SIGN-ON URL. The URL where users can sign in and use your app. You can change this later as needed. Any URL is possible, MyTimetable does not use this value.
- APP ID URI. The URI used as a unique logical identifier for your app. Use for example https://mytimetable.institution.ac.uk.
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Your application is now registered with Azure AD. Proceed with the next step to register the authentication certificate with Azure.
Generating a X.509 certificate and configuring Azure
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- First we need to create a self-signed certificate. This can be done using the minimal openssl install found at https://files.eveoh.nl/openssl_min.zip (for Windows) or an OpenSSL install included in the OS (Linux). From the command line, create a self-signed certificate and enter a password (remember this), the university name, country and domain name of your MyTimetable instance (common name):
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openssl req -x509 -newkey rsa:2048 -keyout key.pem -out cert.pem -days 3650 -config openssl.cnf |
Now, we need to find some properties of the certificate we have generated. This can be done using the Unix shell or using Windows Powershell.
- From the Unix command line, run the following:
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# keyid
uuidgen | tr "[:upper:]" "[:lower:]"
# base64Value
openssl x509 -in cert.pem -outform DER | openssl base64
# base64Thumbprint
openssl x509 -in cert.pem -outform DER | openssl dgst -binary -sha1 | openssl base64 |
- Or, from the Windows Powershell prompt, run the following (replace the path to the certificate):
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$cer = New-Object System.Security.Cryptography.X509Certificates.X509Certificate2("C:\Full\Path\To\Certificate\cert.pem")
$bin = $cer.GetRawCertData()
$base64Value = [System.Convert]::ToBase64String($bin)
$bin = $cer.GetCertHash()
$base64Thumbprint = [System.Convert]::ToBase64String($bin)
$keyid = [System.Guid]::NewGuid().ToString()
$base64Value
$base64Thumbprint
$keyid |
- Store the values for $base64Thumbprint, $base64Value and $keyid (the Powershell script echoes them at the end).
Configuring Azure AD
Now, we need to update the application manifest in Azure AD.
- Open the downloaded manifest in a text editor and replace the empty KeyCredentials property with the following JSON. Make sure the $-variables are replaced by the values you have stored in the "Generating the X.509 certificate" previous step.
| Code Block | ||
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"keyCredentials": [
{
"customKeyIdentifier" : "$base64Thumbprint_from_above",
"keyId": "$keyid_from_above",
"type": "AsymmetricX509Cert",
"usage": "Verify",
"value": "$base64Value_from_above"
}
], |
- Save your changes to the manifest.
Uploading the manifest and specifying app permissions
Finally, we need to upload the manifest and specify the app permissions, allowing read/write access to the calendars of the users.
- In the Azure Management Portal, select your application and choose "Configure" in the top menu.
- In the bottom menu bar, click "Manage manifest" and choose "Upload manifest".
- Upload the manifest created in the previous section.
- Scroll down to "Permissions to other applications", and click "Add application".
- Select the "Office 365 Exchange Online" so that it appears in the "Selected" column. Click the check mark in the lower right to return to the main configuration page. "Office 365 Exchange Online" has now been added to the applications list.
- Click the "Application permissions" dropdown menu for "Office 365 Exchange Online" and check the box for "Read and write calendars in all mailboxes".
| Note |
|---|
| The "Read and write calendars in all mailboxes" application permission is described by Microsoft as "Allows the app to create, read, update, and delete events of all calendars without a signed-in user". Less restrictive scopes that allow MyTimetable to perform the operations required are not available at the moment. MyTimetable only reads, updates and deletes calendar events it has created itself, but this is something that is enforced in the synchronisation backend, not by Office 365. So while MyTimetable does not read, update or delete other calendar events, it does have the permissions to do so. |
- Remove the "Windows Azure Active Directory" application in the permissions list.
- Click "Save" to save the configuration.
Information required for MyTimetable configuration
In order to enable service calls to the Outlook Calendar REST API, MyTimetable requires the X.509 certificate generated in the previous steps.
- The certificate needs to be converted to a Java keystore. First convert it to PKCS12, using OpenSSL:
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openssl pkcs12 -export -in cert.pem -inkey key.pem -out cert.pfx |
- Then convert it to a JKS file, using keytool (available in the JRE/JDK):
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keytool -importkeystore -srckeystore cert.pfx -srcstoretype pkcs12 -destkeystore cert.jks -deststoretype JKS |
Please make sure the following data is available at the server which will handle the Office 365 synchronisation:
- JKS keystore exported in the previous step.
- Password for the JKS keystore.
- Azure AD tentant name.
- Client ID of the registered app.
Certificate rollover
It is possible to configure multiple X.509 certificates for the application, for example for rollover scenarios.
- First, generate a new X.509 certificate, as described in "Generating the X.509 certificate". Store the values for keyid, base64Thumbprint and base64Value.
- Visit the Microsoft Azure classic Management Portal at manage.windowsazure.com, using the credential of your Microsoft tenant that has the subscription to Office 365 you wish to use.
- Click "Activity Directory".
- Click the Active Directory you would like to manage.
- On the Directory page, click "Applications".
- Select the previously defined application for MyTimetable.
- In the bottom menu bar, click "Manage manifest" and choose "Download Manifest" and download the manifest.
- Open the downloaded manifest in a text editor and add a new KeyCredentials property to the JSON. Make sure the $-variables are replaced by the values you have stored in the "Generating the X.509 certificate" previous step. In the example below, the first block contains the original KeyCredential. A second one is added with the newly generated values.
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"keyCredentials": [
{
"customKeyIdentifier" : "IgGH4KCp1BBMAEjV+PfyLZdujno=",
"keyId": "580bdcde-c31f-4559-8f16-ce03863404d6",
"type": "AsymmetricX509Cert",
"usage": "Verify",
"value": "MIIDsDCCApgCCQCg...IAg3"
},
{
"customKeyIdentifier" : "$base64Thumbprint_from_above",
"keyId": "$keyid_from_above",
"type": "AsymmetricX509Cert",
"usage": "Verify",
"value": "$base64Value_from_above"
}
], |
- Save your changes to the manifest.
- In the Azure Management Portal, click "Manage manifest" and choose "Upload manifest".
- Upload the manifest created in the previous section.
- Securely send the new private and public key to Eveoh, including the password for the private key.
Sources
Determine authorization method
There are two ways to authorise MyTimetable to access calendars: application permissions or delegated permissions.
When using application permissions, MyTimetable is granted access to all calendars or a subset of calendars limited by a mail-enabled security group in advance. This means MyTimetable can setup synchronisations without further actions from the user, which is appropriate for scenarios where a synchronisation needs to be setup as soon as a user is provisioned in MyTimetable. This uses the OAuth 2 client credentials flow.
When using delegated permissions, MyTimetable is granted access when the user requests to setup a synchronisation from MyTimetable. Depending on the settings, this will also show the user a consent prompt. This scenario is appropriate when users do not need to have an active synchronisation by default, and limits the security footprint of MyTimetable. This uses the OAuth 2 authorization code flow.
Setup Azure AD application
If MyTimetable is hosted by Semestry, our support department will supply you with an authentication certificate which you will need in step 1. If you are hosting MyTimetable on-premises, first create this certificate using the steps outlined on On-premises: creating a certificate.
When using application permissions, perform the following steps:
When using delegated permissions, perform the following steps:
In order to enable service calls to the Microsoft Graph REST API, the following information is required:
Azure AD tenant ID
Application (client) ID of the registered app
When using managed hosting, please send this information to the Semestry support department. When using on-premises hosting, you will need to enter these details in the MyTimetable EC configuration.