Configuring ONLYOFFICE SP and AD FS IdP

Introduction

Single Sign-on (SSO) is a technology that allows users to sign in only once and then get access to multiple applications/services without re-authentication.

SSO is always ensured by the joint operation of two applications: an Identity Provider and a Service Provider (hereinafter referred to as "IdP" and "SP"). ONLYOFFICE SSO implements the SP only. A lot of different providers can act as an IdP, but this article considers the Active Directory Federation Services (AD FS) implementation.

Preparing ONLYOFFICE Workspace for the SSO setup

1. Install ONLYOFFICE Workspace for Docker or any later version with the SSO support (AD FS is supported starting from Community Server v9.5).
2. Add a domain name, e.g., myportal-address.com.
3. On your portal, go to the Control Panel -> HTTPS, create and apply the letsencrypt certificate for the traffic encryption (to enable HTTPS on your portal).

Preparing AD FS for the SSO setup

1. Install the latest AD DS (Active Directory Domain Service) version with all official updates and patches.
2. Install the latest AD FS version with all official updates and patches.
   To deploy AD FS from scratch you can use the following instructions.
3. Verify that the link to the AD FS metadata is publicly available. To do that,
   1. In the Server Manager, open Tools -> AD FS Management,
   2. Go to AD FS \ Service \ Endpoints,
   3. Find the row with the Federation Metadata type in the table. The link to the IdP metadata is constructed under the following scheme:

      https://{ad-fs-domain}/{path-to-FederationMetadata.xml}

      

      Alternatively, you can use the following PowerShell command:

      PS C:\Users\Administrator> (Get-ADFSEndpoint | Where {$_.Protocol -eq "FederationMetadata" -or $_.Protocol -eq "Federation Metadata"}).FullUrl.ToString()

      As a result you should get a link that looks like this:

      https://onlyofficevm.northeurope.cloudapp.azure.com/FederationMetadata/2007-06/FederationMetadata.xml

   4. To verify that AD FS has been started correctly, open the received link in a web browser. The xml should be displayed or downloaded. Copy the link to the metadata xml: it will be required at the next step.

Configuring ONLYOFFICE SP

1. Make sure that you are signed in as an Administrator to your ONLYOFFICE Control Panel and click the SSO tab in the PORTAL SETTINGS section on the left sidebar.
   You can only register one enterprise Identity Provider for your organization on the ONLYOFFICE portal.
   
2. Enable SSO using the Enable Single Sign-on Authentication switcher and paste the link copied from the AD FS into the URL to Idp Metadata XML field.
   

   Press the button with the upward arrow to load the IdP metadata. The ONLYOFFICE SP Settings form will be automatically filled in with your data from the AD FS IdP.

3. In the Custom login button caption field, you can enter any text instead of the default one (Single Sign-on). This text will be displayed on the button used to login to the portal with the Single Sign-on service at the ONLYOFFICE authentication page.
   
4. In the NameID Format selector, choose the following value: urn:oasis:names:tc:SAML:1.1:nameid-format:emailAddress.
   
5. In the IdP Public Certificates \ Advanced settings section, uncheck the Verify Logout Response Signature option, as AD FS does not require that by default.
   
6. Now you need to add certificates to the SP Certificates section. You can generate self-signed certificates or add any other certificates.
   in the New Certificate window, switch the Use for selector to the signing and encrypt option, as AD FS IdP is automatically configured to verify digital signatures and encrypt data.
   

   You should get nearly the same result:

   
7. In the SP Certificates \ Advanced settings, uncheck the Sign Logout Responses, as AD FS does not require that by default.
   
   It is not necessary to adjust the Attribute Mapping form, as we will set these parameters in the AD FS IdP later. In the Advanced Settings section, you can check the Hide auth page option to hide the default authentication page and automatically redirect to the SSO service.
   ImportantIf you need to restore the default authentication page (to be able to access the portal if you your IDP server fails), you can add the /Auth.aspx?skipssoredirect=true key after the domain name of your portal in the browser address bar.
8. Click the Save button. The ONLYOFFICE SP Metadata section should be opened.
   

   Verify that our settings are publicly available by clicking the Download SP Metadata XML button. The XML file contents should be displayed.

9. Copy the link to the ONLYOFFICE SP metadata from the SP Entity ID (link to metadata XML) field and go to the machine where AD FS is installed.
   

Configuring AD FS IdP

1. Enable strong authentication for .NET applications.

   The .NET Framework 3.5/4.0/4.5.x applications can switch the default protocol to TLS 1.2 by enabling the SchUseStrongCrypto registry key. This registry key will force .NET applications to use TLS 1.2.

   For AD FS on Windows Server 2016 and Windows Server 2012 R2 you need to use the .NET Framework 4.0/4.5.x key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework\v4.0.30319

   For the .NET Framework 3.5 use the following registry key:

   [HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\.NETFramework\v2.0.50727] "SchUseStrongCrypto"=dword:00000001

   For the .NET Framework 4.0/4.5.x use the following registry key:

   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework\v4.0.30319 "SchUseStrongCrypto"=dword:00000001

   

   Alternatively, you can use the following PowerShell command:

   New-ItemProperty -path 'HKLM:\SOFTWARE\Microsoft\.NetFramework\v4.0.30319' -name 'SchUseStrongCrypto' -value '1' -PropertyType 'DWord' -Force | Out-Null

   For more details, please refer to this article.

2. In the Server Manager, open Tools -> AD FS Management,
   
3. In the AD FS Management panel, select the Trust Relationships > Relying Party Trusts. Click the Add Relying Party Trust... option on the right. The Add Relying Party Trust Wizard opens,
   
4. In the wizard window, select the Import data about the relying party published online or on a local network radio button, paste the previously copied link to the ONLYOFFICE SP metadata into the Federation metadata address (host name or URL) field and click the Next button,
   
5. In the Display name field, specify any name and click the Next button,
   
6. Select the I do not want to configure multi-factor authentication settings for this relying party trust at this time option and click the Next button,
   
7. Select the Permit all users to access this relying party option and click the Next button,
   
8. Check the resulting settings and click the Next button,
   
9. Leave the default option unchanged and click the Close button,
   
10. A new window opens. At the Issuance Transform Rules tab, click the Add Rule... button,
    
11. Select the Send LDAP Attributes as Claims option from the Claim rule template list and click the Next button,
    
12. Type in any name in the Claim rule name field. Select the Active Directory option from the Attribute store list and fill in the Mapping of LDAP attributes to outgoing claim types form according to the table below. When ready, click Finish.

    LDAP Attribute (Select or type to add more)	Outgoing Claim Type (Select or type to add more)
    Given-Name	givenName
    Surname	sn
    E-Mail-Addresses	mail
    Telephone-Number	mobile
    Title	title
    physicalDeliveryOfficeName	l

    
13. In the Edit Claim Rules window, click the Add Rule... button once again, select the Transform an Incoming Claim option from the Claim rule template list and click the Next button,
    
14. Type in any name in the Claim rule name field and select the following options from the lists:
    • Incoming claim type: mail,
    • Outgoing claim type: Name ID,
    • Outgoing name ID format: Email
    

    When ready, click the Finish button.

    You should get nearly the same result:

    

    If logout from AD FS does not work, it's recommended to add a Custom Claim Rule replacing {portal-domain} with your SP domain and changing {ad-fs-domain} to your IdP domain:

    c:[Type == "mail"]=> issue(Type = "http://schemas.xmlsoap.org/ws/2005/05/identity/claims/nameidentifier", Issuer = c.Issuer, OriginalIssuer = c.OriginalIssuer, Value = c.Value, ValueType = c.ValueType, Properties["http://schemas.xmlsoap.org/ws/2005/05/identity/claimproperties/format"] = "urn:oasis:names:tc:SAML:1.1:nameid-format:emailAddress", Properties["http://schemas.xmlsoap.org/ws/2005/05/identity/claimproperties/namequalifier"] = "http://{ad-fs-domain}/adfs/services/trust", Properties["http://schemas.xmlsoap.org/ws/2005/05/identity/claimproperties/spnamequalifier"] = "https://{portal-domain}/sso/metadata");

    
15. Click the OK button,
16. So that SSO can work from the intranet you need to enable the Forms Authentication option in the Edit Global Authentication Policy (contextual menu AD FS / Authentication Policies),
    
17. Open the properties of the created relying party trust and switch to the Advanced tab,
    

    Select the SHA-1 option in the Secure hash algorithm list.

    

Checking the work of the ONLYOFFICE SP with the AD FS IdP

Profiles for users added with SSO authentication

The possibility to edit user profiles created using the SSO authentication is restricted. The user profile fields received from the IdP are disabled for editing (i.e., First Name, Last Name, Email, Title and Location). You can edit these fields from your IdP account only.

The figure below shows the Actions menu for an SSO user:

The following figure shows an SSO user profile opened for editing:

The users created using the SSO authentication are marked with the SSO icon in the user list for the portal administrators: