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Colt
Active Contributor
[Last Update 2024.03.01]


Hello fellow SAP security enthusiasts!

I wanted to share some exciting news with you. I've been busy creating a couple of LinkedIn blogs that delve into the fascinating world of the SAP Secure Login Service for SAP GUI. As I was exploring this topic, I thought, why not bring all this valuable knowledge together into one comprehensive blog post?

I hope you enjoy reading it as much as I enjoyed writing it!

 

 

TOC


Introduction
Multiple Factors Propel SAP's Move Towards New Solution for Enhanced Authentication
Brief Overview of the SAP Secure Login Service for SAP GUI
Background
Embracing Change: Switching from Active Directory to Native Azure AD Environments
Ramifications on SAP Authentication Landscape
The Migration to Azure AD
The Exodus of Kerberos
Introducing Azure Active Directory Domain Services
The Implications for SAP GUI
HTTP-Driven SAP Applications and SAML 2.0
Exploring the SAP Secure Login Service for SAP GUI: An In-Depth Review
Basic Setup of the Service (SAP BTP & IAS)
Customization Options for X.509 DN in Issued Certificates
Certificate Chain of the SAP-Managed PKI
Aspects and Some Nice Features of SNC User Mapping
What's Still Missing and What Could Come Nex
Compilation of frequently asked questions

Introduction


The highly anticipated SAP Secure Login Service for SAP GUI has emerged as a testament to innovation, merging the stalwart functionality of the esteemed SAP Single Sign-On with the expansive capabilities of cloud computing.

On May 4, 2023, SAP introduced the SAP Secure Login Service for SAP GUI, a cloud-centric solution that advances the concept of single sign-on. For comprehensive details, I direct your attention to the Release Blog post available here

By opting to retire the traditional AS Java platform, not only are cost efficiencies achieved but resource optimization is also realized. With a rhythmic alignment with Kerberos and X.509, coupled with seamless integration into cloud-driven identity frameworks, the opportune moment has arrived to engage with the SAP SSO cohort. The SAP Secure Login Service (SLS) builds upon the bedrock of SAP Single Sign-On, elevating the single sign-on experience to the cloud milieu. Embrace a lean cloud service seamlessly harmonizing with your corporate identity provider, as you embark on this transformative journey.

 

Source: SAP Secure Login Service for SAP GUI - Solution Overview



Multiple Factors Propel SAP's Move Towards New Solution for Enhanced Authentication


Let's begin by examining the key drivers behind SAP's introduction of this new solution. Currently, SAP SSO 3.0 remains in maintenance mode, with no new feature integrations from SAP. Notably, there are no plans for the release of Version 4.0.

Over time, certain scenarios have become obsolete, magnifying the demand to transition specific components (such as the Secure Login Server) to the cloud, a demand that has grown increasingly pronounced in recent years.

With the expansion of IT infrastructures reliant on cloud-native technologies and Azure AD, and in the absence of Active Directory (AD), there exists a pressing requirement for Multi-Factor Authentication (MFA) within the SAP GUI environment. The retirement of SAP AS Java has emerged as a pivotal factor thus far, underscoring the multifaceted motivations driving this shift. Indeed, it appears that a multitude of reasons converge to shape this transition.

Brief Overview of the SAP Secure Login Service for SAP GUI

 

The SAP Secure Login Service for SAP GUI is a multi-tenant SAP Business Technology Platform (BTP) cloud application designed to facilitate multifactor authentication (MFA) and single sign-on (SSO) when utilizing the SAP GUI interface.

 

Building upon the achievements of SAP Single Sign-On, the Secure Login Service (SLS) preserves its core functionalities while enhancing them to align with the demands of the cloud era. It seamlessly integrates with cloud-based identity providers, reinforcing authentication and single sign-on for business applications. By establishing connections with central authentication solutions like identity providers, this service streamlines access, enhances user efficiency, and reinforces data security through robust authentication methods.

 

It's all about keeping things simple and secure for your SAP GUI users. This new solution comes packed with a whole set of enhanced capabilities. One of the coolest things about this cloud-powered gem is the way it handles X.509 certificates. No more fussing around with on-premise servers or SAP NetWeaver Application Server Java. The cloud service takes care of all the certificate enrollment, leaving you with more time to binge-watch your favorite shows. So long, AS Java!

 

But wait, there's more! You can now flex your existing identity provider solution, like SAP Cloud Identity Services or other popular ones such as Microsoft Azure Active Directory and Okta. These authentication superheroes bring their mighty multi-factor authentication powers to the table, ensuring only the worthy can access your SAP GUI kingdom.

 

Highlights:




    • Secure Login Client can authenticate SAP users based on the SAML standard (SAML & X.509).

 

    • Supports SSO and MFA for SAP GUI without the need for a SAP NetWeaver AS Java instance (SLS).

 

    • Enables previously missing functionalities such as SAP GUI SSO integration with SAML IdPs and MFA for SAP GUI without AS Java (SAP Secure Login Server).

 

    • Provides an alternative to the Kerberos scenario (e.g. in pure Azure AD environments without KDC).



How it works in a nutshell:




    • The Secure Login Client communicates with the new cloud service which can authenticate the user through IAS and/or an existing Corporate IdP (Azure|ADFS|Okta...).

 

    • The "SLS in the Cloud" (user certificate service) issues a temporary SSO certificate.

 

    • Technically, (after the SAML flow) this still involves an SNC connection with X.509 CBA (certificate-based authentication) to the AS ABAP or S/4HANA system.



 

Source: SAP Secure Login Service for SAP GUI - Solution Overview

 

Key Features:




    • Configuration is based on your SAP Cloud Identity Services tenant or corporate Identity Provider (IdP). Various authentication factors such as passwords, Time-Based One-Time Password (TOTP) tokens, local X.509 certificates, and authentication devices like Windows Hello, macOS Touch ID, or FIDO can be configured.

 

    • The Software-as-a-Service (SaaS) application offers a web-based user interface (UI) for administrative purposes. While the current Secure Login Service Web UI has limited settings, it's anticipated that additional features will be added in the future.

 

    • Authentication takes place within an embedded web browser (part of the Secure Login Client in Windows) or the standard web browser (macOS version), contributing to an excellent user experience.

 

    • Successful user authentication yields a short-lived user certificate, usable for Secure Network Communication (SNC), Secure Store and Forward (SSF), or Transport Layer Security (TLS).

 

    • Users can authenticate to an AS ABAP (Advanced Business Application Programming) using X.509 certificates and Kerberos via SNC communication.

 

    • Notably, the migration to the new service can be carried out seamlessly in parallel without disrupting the existing setup.



 

Source: SAP Secure Login Service for SAP GUI - Solution Overview

 

For more information, you can refer to the solution overview provided in this link: https://www.sap.com/documents/2023/05/50bf62e4-707e-0010-bca6-c68f7e60039b.html

 

To delve deeper into the topic of SAP Secure Login Service for SAP GUI, we recommend exploring the following resources for comprehensive information:




 

 



Background


Before delving into the depths, let us initially provide a concise overview of why the current topic of Active Directory / Azure Active Directory holds relevance.

Embracing Change: Switching from Active Directory to Native Azure AD Environments


In the dynamic landscape of technological evolution, change stands as a pivotal determinant. Currently, a significant paradigm shift is underway, marked by the transition from conventional Active Directory (AD) environments to the native constructs of Azure Active Directory (AAD).

Especially prevalent in the initiatives of nascent enterprises commencing from their inception, a pronounced inclination towards a cloud-exclusive approach is often observed. In such scenarios, the conventional notion of a Domain, as commonly understood, may indeed lose its pertinence or operative status.

By harnessing the capabilities of cloud-based services and platforms, many organizations effectively obviate the need for traditional, on-premises domains, allowing them to fully leverage the advantages inherent to a cloud-native milieu. Facilitated by robust identity and access management solutions offered by cloud service providers, these enterprises can orchestrate secure and streamlined operations, thereby concentrating their efforts on fundamental business imperatives.

As these forward-looking entities wholeheartedly embrace the cloud as their principal infrastructure, they reap the rewards of its inherent flexibility, scalability, and cost-efficiency. Concurrently, the prevalence of cloud-native solutions and platforms renders the requirement for on-premises domains progressively obsolete, enabling enterprises to harness the potency of cloud services to fulfill both their IT and business prerequisites.

By committing to a cloud-exclusive methodology, these enterprises fully harness the capabilities proffered by cloud giants such as Microsoft Azure, AWS, or Google Cloud. They architect their infrastructure, applications, and services directly atop these platforms, capitalizing on the innate security, scalability, and availability features inherent in the cloud paradigm.

This transition toward an exclusive cloud-centric approach affords enterprises the luxury of concentrating on core business pursuits, unfettered by the complexities of managing and upkeeping conventional on-premises domains. Instead, they avail themselves of the cloud provider's infrastructure, empowering swift deployment and scalability of applications and services congruent with their burgeoning operations.

Furthermore, by embracing cloud-native offerings such as Azure Active Directory, enterprises can still uphold stringent access management and identity federation protocols without necessitating an on-premises domain. Azure AD extends an all-encompassing spectrum of identity and access management capabilities, encompassing Single Sign-On (SSO), Multi-Factor Authentication (MFA), and Conditional Access policies, seamlessly amalgamating with cloud-centric environments.

Ramifications on SAP Authentication Landscape


Thus, esteemed readers, let us pivot our attention to the trajectory of transition toward Azure's cloud-native approach and the ensuing implications on your SAP SSO landscape, particularly if you have traditionally relied on Kerberos authentication and have not yet traversed the realm of X.509 certificates for SAP GUI authentication.

The Migration to Azure AD


A growing cohort of global enterprises is unequivocally embracing the Azure and Intune ecosystem, bidding adieu to the conventional AD-domain construct. With Azure AD, clients emancipate themselves from the shackles of internal Active Directory systems, signifying the discontinuation of domain controllers and the prevailing of Kerberos Key Distribution Centers (KDCs). A farewell to erstwhile companions, indeed!

The Exodus of Kerberos


In the SAP domain, our endeavors have perennially revolved around realizing a seamless SSO experience via Kerberos authentication. However, in the nascent domain of Azure AD, this approach no longer retains its efficacy. The absence of domain controllers renders our cherished SAP GUI SSO solution, founded on SNC with Kerberos tokens, no longer as efficacious.

Introducing Azure Active Directory Domain Services


At this point, you might ask, "Can we use Kerberos in these new infrastructures?" The answer is found in Azure Active Directory Domain Services, which is like having two Domain Controllers offered as a service – quite a complex setup. When there's a noticeable lack of an LDAP infrastructure, some businesses might consider using these services to meet this need. I haven't had much experience with SAP SSO combined with these services so far. However, I'm keen to learn from anyone who has explored this option.

The Implications for SAP GUI


This technological shift undoubtedly impinges on SAP GUI. Ensuring encryption and SSO mandates continued safeguarding of all SAP proprietary DIAG and RFC communications through Secure Network Communications (SNC). Consequently, the necessity for the SAP SSO 3.0 solution (Secure Login Client) on client-side installations remains relatively unchanged within this novel framework.

HTTP-Driven SAP Applications and SAML 2.0


In recent times, SAML 2.0 has become the central standard in the SAP environment, especially for applications that operate over HTTP. Within the SAP ecosystem, which includes AS ABAP, AS Java, S/4HANA, and HANA DB, these systems act as service providers. They work together seamlessly with either the Azure Identity Provider (IDP) or the Identity Authentication Service (IAS), both of which are aligned with Azure AD. This forms a harmonious collaboration, like a symphony of interconnected champions.

When integrated with Azure AD, a world of opportunities emerges, with SAML 2.0 playing a pivotal role in single sign-on technology. This leads to the implementation of Conditional Access, Multi-Factor Authentication, and Intune policies for device recognition – a collection of security measures that can be likened to having your own team of security superheroes.

In the realm of SAP, whether within the On-Premises milieu or the SAP Cloud continuum (encompassing SaaS/BTP), the ascendancy of SAP Cloud Identity Services and SAP IAS remains unchallenged, serving as the paragons of Identity Providers. The integration with Azure AD not only remains a viable proposition but also avails itself of a multitude of advantages. For an in-depth elucidation, I direct your attention to this blog post.


SAP Cloud Identity Services

    • Ideal for browser-based SAP access

 

    • Enables SSO across cloud and on-premises apps

 

    • Simplifies IAM for unified landscapes

 

    • Supports SAML and OpenID Connect



SAP Single Sign-On 3.0

    • Crucial for SAP GUI and on-premise systems

 

    • Utilizes X.509 certificates or Kerberos (SNC)

 

    • Ensures end-user SSO in various scenarios



SAP Secure Login Service for SAP GUI

    • Official successor to SAP Single Sign-On 3.0 (post-2027)

 

    • Enhances SAP GUI security

 

    • Enables SAML-based authentication with Secure Login Client

 

    • Integrates with existing SAML Identity Providers via SAP IAS

 

    • Offers MFA support for SAP GUI, even without SAP NetWeaver AS Java (SLS)

 

    • Replacement for Kerberos in pure Azure AD (Entra ID) environments



Big Picture: Authentication and SSO in a hybrid SAP system landscape

 

 

This graphic combines these three solutions to address your IAM and SSO needs, delivering a secure and user-friendly experience in your SAP landscape


 

Exploring the SAP Secure Login Service for SAP GUI: An In-Depth Review

 

In this chapter, you can expect the following:




    • Information about the basic setup of the service (SAP BTP & IAS)

 

    • Customization options for the X.509 DN of issued certificates

 

    • Insights and some niceties about SNC User Mapping

 

    • What's still missing and what could potentially be added in the future



Basic Setup of the Service (SAP BTP & IAS)

 

I was genuinely impressed by how straightforward the setup process is! While a few steps need to be followed, they are quite easy to manage. At a high level, without delving too deeply into the specifics, here are the 10 steps to success:




    1. License Assignment (Global Account Level): Assign the license to your Global Account (SAP SE).

 

    1. Define target BTP Subaccount: Establish a new BTP subaccount dedicated to the Secure Login Service (SLS).

 

    1. Trust Establishment: Establish trust between the SLS subaccount and your Identity Authentication Service (IAS) tenant.

 

    1. Configure Entitlement: Set up the entitlement and link the service to the SLS subaccount.

 

    1. Subscription: Subscribe to the Secure Login Service and generate a service instance.

 

    1. Group Setup in IAS: Create groups in IAS to control access to the Secure Login Service web UI.

 

    1. SSO Certificate Lifetime Configuration: Configure the lifespan of Single Sign-On (SSO) certificates in the SLS web UI.

 

    1. Common Name Attribute Setup: Establish the Common Name attribute for user certificates in IAS.

 

    1. Secure Login Client Deployment, Configuration and Policy Loading: Configure the Secure Login Client and provide the policy.

 

    1. Customization of SNC Names and CERTRULE: Customize the Secure Network Communication (SNC) names and certificate rules.



For detailed information, you can refer to the SAP Help guide for the SAP Secure Login Service for SAP GUI: https://help.sap.com/docs/SAP%20SECURE%20LOGIN%20SERVICE/c35917ca71e941c5a97a11d2c55dcacd/28d654c445...

 

In short:




    • Licensing is tied to your Global Account and can be allocated to a pre-existing or new subaccount (Service Entitlement). This subaccount then hosts an instance of the SAP Secure Login Service for SAP GUI (Subscription). To establish this, the BTP subaccount must establish an OpenID Trust connection with one of your IAS tenants.

 

    • Interestingly, it's worth noting that an IAS tenant from a different Global Account (with the same customer number) can also be leveraged, which is a beneficial feature.

 

    • In conclusion, within IAS, you'll discover two applications: the Subaccount Trust XSUAA_<subaccount> (associated with your BTP subaccount trust) and the <secure-login-service>_<region> (your instance of the User Certificate Service). For the latter application, you can set up a Conditional Authentication Rule that allows optional redirection to your Corporate Identity Provider, which, in our case, was Azure AD.

 

    • Accessing the web UI necessitates membership in two groups: SecureLoginServiceAdministrator and SecureLoginServiceViewer in IAS. Importantly, the SAP Secure Login Service for SAP GUI doesn't have its own set of BTP cockpit roles or role collections; instead, service access authorizations are administered through the trusted IAS tenant.

 

    • From there, you can obtain the Client Policy Groups Host URL (found as enrollURL0), a crucial element for configuring the Secure Login Client Policy. This configuration ultimately enables the acquisition of certificates from the cloud certificate service operating within your BTP subaccount.

 

    • By the way, the Client Setup process has remained unchanged. The Secure Login Client (SLC) can still be deployed manually or through automated means, and configuration can be automated using Registry Keys (Intune, GPO etc.).



And with that, the essentials have been covered.

Customization Options for X.509 DN in Issued Certificates

 

Regarding X.509 DN, well, it's just how it is.

 

While the common names (CN) of user certificates are unique and dynamic, the static suffix is generated by the Secure Login Service and represents the identifier for the IAS tenant and SLS region. The CN part of the certificate's Distinguished Name is configured within the IAS application, following this procedure: https://help.sap.com/docs/SAP%20SECURE%20LOGIN%20SERVICE/c35917ca71e941c5a97a11d2c55dcacd/81fe0a1211...

 

In our scenario, we aimed to include the email address from IAS as the CN in the certificate. This email attribute is sourced from the IAS user store (IdDS), which is synchronized with users from our Azure AD tenant. However, you could also retrieve this attribute directly from your chosen Corporate Identity Provider (IdP), especially if you don't have profiles in IAS (no Identity Federation).

 

The certificate's structure will be formed using the following X.509 DN - Example:




CN=<E-Mail>, L=<ias-tenant>.accounts.ondemand.com, OU=<SLS-region-id>, OU=SAP BTP Clients, O=SAP SE, C=DE

 

This customization allows for tailoring the certificate to incorporate specific attributes from your chosen identity source, enhancing the certificate's relevance and usefulness within your system.

 

 

Source: SAP Secure Login Service for SAP GUI - Solution Overview



Certificate Chain of the SAP-Managed PKI

 

By the way, the certificate chain of the issued temporary SSO certificates can be traced back to the SAP Cloud Root CA, which has a validity of 20 years. This is the well-known certification authority that also issues SAP Passports (S-User Certificates), among other things.

 

Beneath this, there is the SAP BTP Client CA with a validity of 10 years, followed by the actual Issuing CA, SAP PKI Certificate Service Client CA, which has a validity of 2 months and is regularly renewed by SAP. Ultimately, in the SAP backend, the trust relationship to the root certificate must be established within the necessary PSE containers.

 

Here's the complete CA chain:



SAP Cloud Root CA

  |- SAP BTP Client CA

     |- SAP PKI Certificate Service Client CA

 

Aspects and Some Nice Features of SNC User Mapping

 

When implementing the new solution, adjustments to SNC names become necessary. There are various approaches to mass-set SNC names. While using the RSUSR300 report might pose some challenges, a Central User Administration (CUA) or Identity Management (IDM) systems are equally helpful.

 

Custom reports, as well as tools like our XAMS can also be used. With those you can easily create an Excel sheet with a generic formula, upload the sheet, and voilà, you're good to go.

 

By the way, it's worth noting that you can shorten parts of the long Distinguished Name (DN) using SAP CCL (CommonCryptoLib) ccl/* profile parameters. However, this requires configuration in the default profile on a per-system basis. Further information can be found here:

 

https://help.sap.com/docs/SAP_SINGLE_SIGN-ON/df185fd53bb645b1bd99284ee4e4a750/ca4af653ac444b54ba7fbb... and in SAP Note 2338952: https://me.sap.com/notes/2338952/E

 

Here's an example of how the configuration might look



ccl/snc/namealias/value_1 = L=<iastenant>.accounts.ondemand.com

ccl/snc/namealias/replacement_1 = L=My-IAS

ccl/snc/namealias/value_2 = OU=<region>-secure-login-service

ccl/snc/namealias/replacement_2 = OU=SLS

ccl/snc/namealias/value_3 = OU=SAP BTP Clients

ccl/snc/namealias/replacement_3 = OU=BTP

 

Original SNC Name:




p:CN=<E-Mail>, L=<iastenant>.accounts.ondemand.com, OU=<region>-secure-login-service, OU=SAP BTP Clients, O=SAP SE, C=DE

 

After applying the configurations, the modified SNC name would appear as follows:




p:CN=<E-Mail>, L=My-IAS, OU=SLS, OU=BTP, O=SAP SE, C=DE

 

Additionally, in the transaction CERTRULE, you can create a new rule quite easily. We simply mapped the CN part to the SU01 field "E-Mail" and filtered out all other DN elements like L, OU, O, and C.



What's Still Missing and What Could Come Next

 

Please bear in mind that I am not part of SAP's Product Management team 😇, and the following points are based on my personal opinion.

 

Certain aspects from the SAP SSO 3.0 suite are not currently covered by the new solution, and there hasn't been much change in this regard. Nevertheless, we would like to address some current limitations of the service and provide insights into its potential future developments.

 

Here are some points we'd like to share with you:

 

Customization of X.509 DN is currently not possible: Currently, adjusting the X.509 DN is not feasible, and it follows a fixed structure. It would be fantastic if the lengthy part after the CN could be customized. Unfortunately, the X.509 DN is even so lengthy that the RSUSR300 report (SNC1) struggles to handle it due to a field length restriction.



UPDATE: As of November 6, 2023, SAP Note 3396732 (SNC1/RSUSR300) has been released, providing support for extended prefix and suffix values. This update addresses the previous limitation, now allowing a field length of up to 200 characters.

 

According to SAP, the X.509 DN will become configurable once the custom cloud CA (Certificate Authority) support goes live. Integrating a customer-specific cloud CA is on the roadmap. However, it's unlikely that a similar option to the old SLS, using Remote CAs through NDES & Cloud Connector, will be available.

 

Profiles/Profile Groups Not Currently Supported: Presently, using profiles or profile groups to enforce true Multi-Factor Authentication (MFA) requirements for specific SAP systems isn't feasible. In the previous SLS version, certificates could be removed after a timeout, or there was the option to automatically log off from the profile when the last SNC session was closed. With the new solution, this isn't currently achievable for individual GssTargetNames.

 

Different profiles can only be represented through separate subscriptions, which is a bit of a drawback. Additionally, some settings familiar from SLS 3.0 are not yet available in the new cloud solution. SAP might observe customer demand before implementing these.

 

Certificate Lifecycle Management (CLM) Similar to the old SAP SLS 3.0: The management of certificate lifecycles (CLM), akin to the old SLS, is not currently planned. SAP hasn't provided a timeline, but this will be explored more closely once the custom cloud CA support is in place. Currently, customers would need to license both solutions – the minimum bundle for SAP SSO 3.0, and the new solution.

 

As the solution evolves and more feedback is gathered from users, SAP might address these limitations and introduce new features. The complexities surrounding certificate management and authentication are areas of ongoing development. Let's see how the solution will evolve over time.


We conclude this blog with a collection of FAQs.

Compilation of frequently asked questions

 

Q: What happens if the cloud service is unavailable due to IaaS provider network issues (SAP/AWS/Microsoft Azure/Google CP)?

A: The certificate service operates on SAP BTP, following platform availability commitments. While cloud service is needed for certificate provisioning, typical validity spans a workday. Users access the service once daily, enabling independent ABAP system use. In case of service unavailability, alternative on-premises solutions like certificates, smart cards, or Kerberos are recommended.

Q: Can users of SAP SSO 3.0 and SAP Secure Login Server transition to the cloud? Are there commercial advantages or parallel product usage?

A: SAP SSO 3.0 and SLS differ in licensing and features. SLS benefits include better cloud identity provider integration and reduced total cost of ownership by eliminating AS Java operation. Technical intricacies of SLS 3.0 might not fully transfer. Commercial transition details can be discussed with your SAP Account Executive.

Q: Can CPEA Global Accounts subscribe to SAP Secure Login Service for SAP GUI?

A: Currently, CPEA is not supported. Minimal subscriptions are available through SAP contacts to facilitate starting. No trial version is offered by SAP SE at present.

Q: Is SAP Secure Login Service the official successor to SAP Single Sign-On 3.0 after 2027 end of maintenance?

A: Yes, SAP Secure Login Service for SAP GUI will replace SAP Single Sign-On 3.0.

Q: What benefits does SAP Secure Login Service offer over SAP Single Sign-On 3.0 for complex on-premise SAP landscapes using Kerberos?

A: Both products offer Kerberos-based single sign-on with no difference. Transition isn't necessary unless supporting multiple ADs/Forests or consolidating authentication via central Azure AD tenant. Migration enhances flexibility and future-proofing.

Q: Does SAP Secure Login Service for SAP GUI support SAP Fiori or SAP GUI HTML?

A: Http-based apps can use SAML 2.0 or X.509 certificates, possibly without this solution. SPNEGO is feasible if SAP Secure Login Service for SAP GUI functions solely as a Kerberos solution.

Q: Is SAP Cloud Identity Authentication Service (IAS) essential for SAP Secure Login Service for SAP GUI?

A: Identity Authentication Service is integral, but can proxy Azure AD. This way, users interact only with Azure AD interfaces.

[Last Update 2024.03.01]


Hello fellow SAP security enthusiasts!

I wanted to share some exciting news with you. I've been busy creating a couple of LinkedIn blogs that delve into the fascinating world of the SAP Secure Login Service for SAP GUI. As I was exploring this topic, I thought, why not bring all this valuable knowledge together into one comprehensive blog post?

I hope you enjoy reading it as much as I enjoyed writing it!

 

 

TOC


Introduction
Multiple Factors Propel SAP's Move Towards New Solution for Enhanced Authentication
Brief Overview of the SAP Secure Login Service for SAP GUI
Background
Embracing Change: Switching from Active Directory to Native Azure AD Environments
Ramifications on SAP Authentication Landscape
The Migration to Azure AD
The Exodus of Kerberos
Introducing Azure Active Directory Domain Services
The Implications for SAP GUI
HTTP-Driven SAP Applications and SAML 2.0
Exploring the SAP Secure Login Service for SAP GUI: An In-Depth Review
Basic Setup of the Service (SAP BTP & IAS)
Customization Options for X.509 DN in Issued Certificates
Certificate Chain of the SAP-Managed PKI
Aspects and Some Nice Features of SNC User Mapping
What's Still Missing and What Could Come Nex
Compilation of frequently asked questions

Introduction


The highly anticipated SAP Secure Login Service for SAP GUI has emerged as a testament to innovation, merging the stalwart functionality of the esteemed SAP Single Sign-On with the expansive capabilities of cloud computing.

On May 4, 2023, SAP introduced the SAP Secure Login Service for SAP GUI, a cloud-centric solution that advances the concept of single sign-on. For comprehensive details, I direct your attention to the Release Blog post available here

By opting to retire the traditional AS Java platform, not only are cost efficiencies achieved but resource optimization is also realized. With a rhythmic alignment with Kerberos and X.509, coupled with seamless integration into cloud-driven identity frameworks, the opportune moment has arrived to engage with the SAP SSO cohort. The SAP Secure Login Service (SLS) builds upon the bedrock of SAP Single Sign-On, elevating the single sign-on experience to the cloud milieu. Embrace a lean cloud service seamlessly harmonizing with your corporate identity provider, as you embark on this transformative journey.

Colt_0-1709290522050.png

 

 

Source: SAP Secure Login Service for SAP GUI - Solution Overview



Multiple Factors Propel SAP's Move Towards New Solution for Enhanced Authentication


Let's begin by examining the key drivers behind SAP's introduction of this new solution. Currently, SAP SSO 3.0 remains in maintenance mode, with no new feature integrations from SAP. Notably, there are no plans for the release of Version 4.0.

Over time, certain scenarios have become obsolete, magnifying the demand to transition specific components (such as the Secure Login Server) to the cloud, a demand that has grown increasingly pronounced in recent years.

With the expansion of IT infrastructures reliant on cloud-native technologies and Azure AD, and in the absence of Active Directory (AD), there exists a pressing requirement for Multi-Factor Authentication (MFA) within the SAP GUI environment. The retirement of SAP AS Java has emerged as a pivotal factor thus far, underscoring the multifaceted motivations driving this shift. Indeed, it appears that a multitude of reasons converge to shape this transition.

Brief Overview of the SAP Secure Login Service for SAP GUI

 

The SAP Secure Login Service for SAP GUI is a multi-tenant SAP Business Technology Platform (BTP) cloud application designed to facilitate multifactor authentication (MFA) and single sign-on (SSO) when utilizing the SAP GUI interface.

 

Building upon the achievements of SAP Single Sign-On, the Secure Login Service (SLS) preserves its core functionalities while enhancing them to align with the demands of the cloud era. It seamlessly integrates with cloud-based identity providers, reinforcing authentication and single sign-on for business applications. By establishing connections with central authentication solutions like identity providers, this service streamlines access, enhances user efficiency, and reinforces data security through robust authentication methods.

 

It's all about keeping things simple and secure for your SAP GUI users. This new solution comes packed with a whole set of enhanced capabilities. One of the coolest things about this cloud-powered gem is the way it handles X.509 certificates. No more fussing around with on-premise servers or SAP NetWeaver Application Server Java. The cloud service takes care of all the certificate enrollment, leaving you with more time to binge-watch your favorite shows. So long, AS Java!

 

But wait, there's more! You can now flex your existing identity provider solution, like SAP Cloud Identity Services or other popular ones such as Microsoft Azure Active Directory and Okta. These authentication superheroes bring their mighty multi-factor authentication powers to the table, ensuring only the worthy can access your SAP GUI kingdom.

 

Highlights:




    • Secure Login Client can authenticate SAP users based on the SAML standard (SAML & X.509).

 

    • Supports SSO and MFA for SAP GUI without the need for a SAP NetWeaver AS Java instance (SLS).

 

    • Enables previously missing functionalities such as SAP GUI SSO integration with SAML IdPs and MFA for SAP GUI without AS Java (SAP Secure Login Server).

 

    • Provides an alternative to the Kerberos scenario (e.g. in pure Azure AD environments without KDC).



How it works in a nutshell:




    • The Secure Login Client communicates with the new cloud service which can authenticate the user through IAS and/or an existing Corporate IdP (Azure|ADFS|Okta...).

 

    • The "SLS in the Cloud" (user certificate service) issues a temporary SSO certificate.

 

    • Technically, (after the SAML flow) this still involves an SNC connection with X.509 CBA (certificate-based authentication) to the AS ABAP or S/4HANA system.



Colt_1-1709290522050.png

 

 

Source: SAP Secure Login Service for SAP GUI - Solution Overview

 

Key Features:




    • Configuration is based on your SAP Cloud Identity Services tenant or corporate Identity Provider (IdP). Various authentication factors such as passwords, Time-Based One-Time Password (TOTP) tokens, local X.509 certificates, and authentication devices like Windows Hello, macOS Touch ID, or FIDO can be configured.

 

    • The Software-as-a-Service (SaaS) application offers a web-based user interface (UI) for administrative purposes. While the current Secure Login Service Web UI has limited settings, it's anticipated that additional features will be added in the future.

 

    • Authentication takes place within an embedded web browser (part of the Secure Login Client in Windows) or the standard web browser (macOS version), contributing to an excellent user experience.

 

    • Successful user authentication yields a short-lived user certificate, usable for Secure Network Communication (SNC), Secure Store and Forward (SSF), or Transport Layer Security (TLS).

 

    • Users can authenticate to an AS ABAP (Advanced Business Application Programming) using X.509 certificates and Kerberos via SNC communication.

 

    • Notably, the migration to the new service can be carried out seamlessly in parallel without disrupting the existing setup.



Colt_2-1709290522051.png

 

 

Source: SAP Secure Login Service for SAP GUI - Solution Overview

 

For more information, you can refer to the solution overview provided in this link: https://www.sap.com/documents/2023/05/50bf62e4-707e-0010-bca6-c68f7e60039b.html

 

To delve deeper into the topic of SAP Secure Login Service for SAP GUI, we recommend exploring the following resources for comprehensive information:




 

 



Background


Before delving into the depths, let us initially provide a concise overview of why the current topic of Active Directory / Azure Active Directory holds relevance.

Embracing Change: Switching from Active Directory to Native Azure AD Environments


In the dynamic landscape of technological evolution, change stands as a pivotal determinant. Currently, a significant paradigm shift is underway, marked by the transition from conventional Active Directory (AD) environments to the native constructs of Azure Active Directory (AAD).

Especially prevalent in the initiatives of nascent enterprises commencing from their inception, a pronounced inclination towards a cloud-exclusive approach is often observed. In such scenarios, the conventional notion of a Domain, as commonly understood, may indeed lose its pertinence or operative status.

By harnessing the capabilities of cloud-based services and platforms, many organizations effectively obviate the need for traditional, on-premises domains, allowing them to fully leverage the advantages inherent to a cloud-native milieu. Facilitated by robust identity and access management solutions offered by cloud service providers, these enterprises can orchestrate secure and streamlined operations, thereby concentrating their efforts on fundamental business imperatives.

As these forward-looking entities wholeheartedly embrace the cloud as their principal infrastructure, they reap the rewards of its inherent flexibility, scalability, and cost-efficiency. Concurrently, the prevalence of cloud-native solutions and platforms renders the requirement for on-premises domains progressively obsolete, enabling enterprises to harness the potency of cloud services to fulfill both their IT and business prerequisites.

By committing to a cloud-exclusive methodology, these enterprises fully harness the capabilities proffered by cloud giants such as Microsoft Azure, AWS, or Google Cloud. They architect their infrastructure, applications, and services directly atop these platforms, capitalizing on the innate security, scalability, and availability features inherent in the cloud paradigm.

This transition toward an exclusive cloud-centric approach affords enterprises the luxury of concentrating on core business pursuits, unfettered by the complexities of managing and upkeeping conventional on-premises domains. Instead, they avail themselves of the cloud provider's infrastructure, empowering swift deployment and scalability of applications and services congruent with their burgeoning operations.

Furthermore, by embracing cloud-native offerings such as Azure Active Directory, enterprises can still uphold stringent access management and identity federation protocols without necessitating an on-premises domain. Azure AD extends an all-encompassing spectrum of identity and access management capabilities, encompassing Single Sign-On (SSO), Multi-Factor Authentication (MFA), and Conditional Access policies, seamlessly amalgamating with cloud-centric environments.

Ramifications on SAP Authentication Landscape


Thus, esteemed readers, let us pivot our attention to the trajectory of transition toward Azure's cloud-native approach and the ensuing implications on your SAP SSO landscape, particularly if you have traditionally relied on Kerberos authentication and have not yet traversed the realm of X.509 certificates for SAP GUI authentication.

The Migration to Azure AD


A growing cohort of global enterprises is unequivocally embracing the Azure and Intune ecosystem, bidding adieu to the conventional AD-domain construct. With Azure AD, clients emancipate themselves from the shackles of internal Active Directory systems, signifying the discontinuation of domain controllers and the prevailing of Kerberos Key Distribution Centers (KDCs). A farewell to erstwhile companions, indeed!

The Exodus of Kerberos


In the SAP domain, our endeavors have perennially revolved around realizing a seamless SSO experience via Kerberos authentication. However, in the nascent domain of Azure AD, this approach no longer retains its efficacy. The absence of domain controllers renders our cherished SAP GUI SSO solution, founded on SNC with Kerberos tokens, no longer as efficacious.

Introducing Azure Active Directory Domain Services


At this point, you might ask, "Can we use Kerberos in these new infrastructures?" The answer is found in Azure Active Directory Domain Services, which is like having two Domain Controllers offered as a service – quite a complex setup. When there's a noticeable lack of an LDAP infrastructure, some businesses might consider using these services to meet this need. I haven't had much experience with SAP SSO combined with these services so far. However, I'm keen to learn from anyone who has explored this option.

The Implications for SAP GUI


This technological shift undoubtedly impinges on SAP GUI. Ensuring encryption and SSO mandates continued safeguarding of all SAP proprietary DIAG and RFC communications through Secure Network Communications (SNC). Consequently, the necessity for the SAP SSO 3.0 solution (Secure Login Client) on client-side installations remains relatively unchanged within this novel framework.

HTTP-Driven SAP Applications and SAML 2.0


In recent times, SAML 2.0 has become the central standard in the SAP environment, especially for applications that operate over HTTP. Within the SAP ecosystem, which includes AS ABAP, AS Java, S/4HANA, and HANA DB, these systems act as service providers. They work together seamlessly with either the Azure Identity Provider (IDP) or the Identity Authentication Service (IAS), both of which are aligned with Azure AD. This forms a harmonious collaboration, like a symphony of interconnected champions.

When integrated with Azure AD, a world of opportunities emerges, with SAML 2.0 playing a pivotal role in single sign-on technology. This leads to the implementation of Conditional Access, Multi-Factor Authentication, and Intune policies for device recognition – a collection of security measures that can be likened to having your own team of security superheroes.

In the realm of SAP, whether within the On-Premises milieu or the SAP Cloud continuum (encompassing SaaS/BTP), the ascendancy of SAP Cloud Identity Services and SAP IAS remains unchallenged, serving as the paragons of Identity Providers. The integration with Azure AD not only remains a viable proposition but also avails itself of a multitude of advantages. For an in-depth elucidation, I direct your attention to this blog post.

Colt_3-1709290522053.png

 


SAP Cloud Identity Services

    • Ideal for browser-based SAP access

 

    • Enables SSO across cloud and on-premises apps

 

    • Simplifies IAM for unified landscapes

 

    • Supports SAML and OpenID Connect



SAP Single Sign-On 3.0

    • Crucial for SAP GUI and on-premise systems

 

    • Utilizes X.509 certificates or Kerberos (SNC)

 

    • Ensures end-user SSO in various scenarios



SAP Secure Login Service for SAP GUI

    • Official successor to SAP Single Sign-On 3.0 (post-2027)

 

    • Enhances SAP GUI security

 

    • Enables SAML-based authentication with Secure Login Client

 

    • Integrates with existing SAML Identity Providers via SAP IAS

 

    • Offers MFA support for SAP GUI, even without SAP NetWeaver AS Java (SLS)

 

    • Replacement for Kerberos in pure Azure AD (Entra ID) environments



Big Picture: Authentication and SSO in a hybrid SAP system landscape

 

Colt_4-1709290522053.png

 

 

This graphic combines these three solutions to address your IAM and SSO needs, delivering a secure and user-friendly experience in your SAP landscape


 

Exploring the SAP Secure Login Service for SAP GUI: An In-Depth Review

 

In this chapter, you can expect the following:




    • Information about the basic setup of the service (SAP BTP & IAS)

 

    • Customization options for the X.509 DN of issued certificates

 

    • Insights and some niceties about SNC User Mapping

 

    • What's still missing and what could potentially be added in the future



Basic Setup of the Service (SAP BTP & IAS)

 

I was genuinely impressed by how straightforward the setup process is! While a few steps need to be followed, they are quite easy to manage. At a high level, without delving too deeply into the specifics, here are the 10 steps to success:




    1. License Assignment (Global Account Level): Assign the license to your Global Account (SAP SE).

 

    1. Define target BTP Subaccount: Establish a new BTP subaccount dedicated to the Secure Login Service (SLS).

 

    1. Trust Establishment: Establish trust between the SLS subaccount and your Identity Authentication Service (IAS) tenant.

 

    1. Configure Entitlement: Set up the entitlement and link the service to the SLS subaccount.

 

    1. Subscription: Subscribe to the Secure Login Service and generate a service instance.

 

    1. Group Setup in IAS: Create groups in IAS to control access to the Secure Login Service web UI.

 

    1. SSO Certificate Lifetime Configuration: Configure the lifespan of Single Sign-On (SSO) certificates in the SLS web UI.

 

    1. Common Name Attribute Setup: Establish the Common Name attribute for user certificates in IAS.

 

    1. Secure Login Client Deployment, Configuration and Policy Loading: Configure the Secure Login Client and provide the policy.

 

    1. Customization of SNC Names and CERTRULE: Customize the Secure Network Communication (SNC) names and certificate rules.



For detailed information, you can refer to the SAP Help guide for the SAP Secure Login Service for SAP GUI: https://help.sap.com/docs/SAP%20SECURE%20LOGIN%20SERVICE/c35917ca71e941c5a97a11d2c55dcacd/28d654c445...

 

In short:




    • Licensing is tied to your Global Account and can be allocated to a pre-existing or new subaccount (Service Entitlement). This subaccount then hosts an instance of the SAP Secure Login Service for SAP GUI (Subscription). To establish this, the BTP subaccount must establish an OpenID Trust connection with one of your IAS tenants.

 

    • Interestingly, it's worth noting that an IAS tenant from a different Global Account (with the same customer number) can also be leveraged, which is a beneficial feature.

 

    • In conclusion, within IAS, you'll discover two applications: the Subaccount Trust XSUAA_<subaccount> (associated with your BTP subaccount trust) and the <secure-login-service>_<region> (your instance of the User Certificate Service). For the latter application, you can set up a Conditional Authentication Rule that allows optional redirection to your Corporate Identity Provider, which, in our case, was Azure AD.

 

    • Accessing the web UI necessitates membership in two groups: SecureLoginServiceAdministrator and SecureLoginServiceViewer in IAS. Importantly, the SAP Secure Login Service for SAP GUI doesn't have its own set of BTP cockpit roles or role collections; instead, service access authorizations are administered through the trusted IAS tenant.

 

    • From there, you can obtain the Client Policy Groups Host URL (found as enrollURL0), a crucial element for configuring the Secure Login Client Policy. This configuration ultimately enables the acquisition of certificates from the cloud certificate service operating within your BTP subaccount.

 

    • By the way, the Client Setup process has remained unchanged. The Secure Login Client (SLC) can still be deployed manually or through automated means, and configuration can be automated using Registry Keys (Intune, GPO etc.).



And with that, the essentials have been covered.

Customization Options for X.509 DN in Issued Certificates

 

Regarding X.509 DN, well, it's just how it is.

 

While the common names (CN) of user certificates are unique and dynamic, the static suffix is generated by the Secure Login Service and represents the identifier for the IAS tenant and SLS region. The CN part of the certificate's Distinguished Name is configured within the IAS application, following this procedure: https://help.sap.com/docs/SAP%20SECURE%20LOGIN%20SERVICE/c35917ca71e941c5a97a11d2c55dcacd/81fe0a1211...

 

In our scenario, we aimed to include the email address from IAS as the CN in the certificate. This email attribute is sourced from the IAS user store (IdDS), which is synchronized with users from our Azure AD tenant. However, you could also retrieve this attribute directly from your chosen Corporate Identity Provider (IdP), especially if you don't have profiles in IAS (no Identity Federation).

 

The certificate's structure will be formed using the following X.509 DN - Example:




CN=<E-Mail>, L=<ias-tenant>.accounts.ondemand.com, OU=<SLS-region-id>, OU=SAP BTP Clients, O=SAP SE, C=DE

 

This customization allows for tailoring the certificate to incorporate specific attributes from your chosen identity source, enhancing the certificate's relevance and usefulness within your system.

 

Colt_5-1709290522052.png

 

 

Source: SAP Secure Login Service for SAP GUI - Solution Overview



Certificate Chain of the SAP-Managed PKI

 

By the way, the certificate chain of the issued temporary SSO certificates can be traced back to the SAP Cloud Root CA, which has a validity of 20 years. This is the well-known certification authority that also issues SAP Passports (S-User Certificates), among other things.

 

Beneath this, there is the SAP BTP Client CA with a validity of 10 years, followed by the actual Issuing CA, SAP PKI Certificate Service Client CA, which has a validity of 2 months and is regularly renewed by SAP. Ultimately, in the SAP backend, the trust relationship to the root certificate must be established within the necessary PSE containers.

 

Here's the complete CA chain:



SAP Cloud Root CA

  |- SAP BTP Client CA

     |- SAP PKI Certificate Service Client CA

 

Aspects and Some Nice Features of SNC User Mapping

 

When implementing the new solution, adjustments to SNC names become necessary. There are various approaches to mass-set SNC names. While using the RSUSR300 report might pose some challenges, a Central User Administration (CUA) or Identity Management (IDM) systems are equally helpful.

 

Custom reports, as well as tools like our XAMS can also be used. With those you can easily create an Excel sheet with a generic formula, upload the sheet, and voilà, you're good to go.

 

By the way, it's worth noting that you can shorten parts of the long Distinguished Name (DN) using SAP CCL (CommonCryptoLib) ccl/* profile parameters. However, this requires configuration in the default profile on a per-system basis. Further information can be found here:

 

https://help.sap.com/docs/SAP_SINGLE_SIGN-ON/df185fd53bb645b1bd99284ee4e4a750/ca4af653ac444b54ba7fbb... and in SAP Note 2338952: https://me.sap.com/notes/2338952/E

 

Here's an example of how the configuration might look



ccl/snc/namealias/value_1 = L=<iastenant>.accounts.ondemand.com

ccl/snc/namealias/replacement_1 = L=My-IAS

ccl/snc/namealias/value_2 = OU=<region>-secure-login-service

ccl/snc/namealias/replacement_2 = OU=SLS

ccl/snc/namealias/value_3 = OU=SAP BTP Clients

ccl/snc/namealias/replacement_3 = OU=BTP

 

Original SNC Name:




p:CN=<E-Mail>, L=<iastenant>.accounts.ondemand.com, OU=<region>-secure-login-service, OU=SAP BTP Clients, O=SAP SE, C=DE

 

After applying the configurations, the modified SNC name would appear as follows:




p:CN=<E-Mail>, L=My-IAS, OU=SLS, OU=BTP, O=SAP SE, C=DE

 

Additionally, in the transaction CERTRULE, you can create a new rule quite easily. We simply mapped the CN part to the SU01 field "E-Mail" and filtered out all other DN elements like L, OU, O, and C.



What's Still Missing and What Could Come Next

 

Please bear in mind that I am not part of SAP's Product Management team 😇, and the following points are based on my personal opinion.

 

Certain aspects from the SAP SSO 3.0 suite are not currently covered by the new solution, and there hasn't been much change in this regard. Nevertheless, we would like to address some current limitations of the service and provide insights into its potential future developments.

 

Here are some points we'd like to share with you:

 

Customization of X.509 DN is currently not possible: Currently, adjusting the X.509 DN is not feasible, and it follows a fixed structure. It would be fantastic if the lengthy part after the CN could be customized. Unfortunately, the X.509 DN is even so lengthy that the RSUSR300 report (SNC1) struggles to handle it due to a field length restriction.



UPDATE: As of November 6, 2023, SAP Note 3396732 (SNC1/RSUSR300) has been released, providing support for extended prefix and suffix values. This update addresses the previous limitation, now allowing a field length of up to 200 characters.

 

According to SAP, the X.509 DN will become configurable once the custom cloud CA (Certificate Authority) support goes live. Integrating a customer-specific cloud CA is on the roadmap. However, it's unlikely that a similar option to the old SLS, using Remote CAs through NDES & Cloud Connector, will be available.

 

Profiles/Profile Groups Not Currently Supported: Presently, using profiles or profile groups to enforce true Multi-Factor Authentication (MFA) requirements for specific SAP systems isn't feasible. In the previous SLS version, certificates could be removed after a timeout, or there was the option to automatically log off from the profile when the last SNC session was closed. With the new solution, this isn't currently achievable for individual GssTargetNames.

 

Different profiles can only be represented through separate subscriptions, which is a bit of a drawback. Additionally, some settings familiar from SLS 3.0 are not yet available in the new cloud solution. SAP might observe customer demand before implementing these.

 

Certificate Lifecycle Management (CLM) Similar to the old SAP SLS 3.0: The management of certificate lifecycles (CLM), akin to the old SLS, is not currently planned. SAP hasn't provided a timeline, but this will be explored more closely once the custom cloud CA support is in place. Currently, customers would need to license both solutions – the minimum bundle for SAP SSO 3.0, and the new solution.

 

As the solution evolves and more feedback is gathered from users, SAP might address these limitations and introduce new features. The complexities surrounding certificate management and authentication are areas of ongoing development. Let's see how the solution will evolve over time.


We conclude this blog with a collection of FAQs.

Compilation of frequently asked questions

 

Q: What happens if the cloud service is unavailable due to IaaS provider network issues (SAP/AWS/Microsoft Azure/Google CP)?

A: The certificate service operates on SAP BTP, following platform availability commitments. While cloud service is needed for certificate provisioning, typical validity spans a workday. Users access the service once daily, enabling independent ABAP system use. In case of service unavailability, alternative on-premises solutions like certificates, smart cards, or Kerberos are recommended.

Q: Can users of SAP SSO 3.0 and SAP Secure Login Server transition to the cloud? Are there commercial advantages or parallel product usage?

A: SAP SSO 3.0 and SLS differ in licensing and features. SLS benefits include better cloud identity provider integration and reduced total cost of ownership by eliminating AS Java operation. Technical intricacies of SLS 3.0 might not fully transfer. Commercial transition details can be discussed with your SAP Account Executive.

Q: Can CPEA Global Accounts subscribe to SAP Secure Login Service for SAP GUI?

A: Currently, CPEA is not supported. Minimal subscriptions are available through SAP contacts to facilitate starting. No trial version is offered by SAP SE at present.

Q: Is SAP Secure Login Service the official successor to SAP Single Sign-On 3.0 after 2027 end of maintenance?

A: Yes, SAP Secure Login Service for SAP GUI will replace SAP Single Sign-On 3.0.

Q: What benefits does SAP Secure Login Service offer over SAP Single Sign-On 3.0 for complex on-premise SAP landscapes using Kerberos?

A: Both products offer Kerberos-based single sign-on with no difference. Transition isn't necessary unless supporting multiple ADs/Forests or consolidating authentication via central Azure AD tenant. Migration enhances flexibility and future-proofing.

Q: Does SAP Secure Login Service for SAP GUI support SAP Fiori or SAP GUI HTML?

A: Http-based apps can use SAML 2.0 or X.509 certificates, possibly without this solution. SPNEGO is feasible if SAP Secure Login Service for SAP GUI functions solely as a Kerberos solution.

Q: Is SAP Cloud Identity Authentication Service (IAS) essential for SAP Secure Login Service for SAP GUI?

A: Identity Authentication Service is integral, but can proxy Azure AD. This way, users interact only with Azure AD interfaces.

Q:Is there a direct correlation between the number of "SAP Secure Login Service for SAP GUI" instances and "SAP Cloud Authentication Service" instances? Specifically, if a customer has three IAS instances due to a one-to-one relationship with SuccessFactors instances (Production, Non-Production 1, and Non-Production 2), each linked to corresponding SuccessFactors and S4HANA environments, is it necessary to have three separate SAP Secure Login Service instances for SSO in S4HANA environments (Prod, Test, Development)? Also, does the pricing for SAP Secure Login Service only apply to production usage?

A: SAP Secure Login Service doesn't have its own user store and always relies on the identity provider, such as IAS, for authentication. To enable SSO for a specific S/4HANA system, an SAP Secure Login Service instance must be integrated with an IAS tenant containing the relevant user accounts. If the productive IAS tenant lacks certain user accounts, additional SAP Secure Login Service instances are required for other IAS tenants. Pricing is determined by the number of users or employees, not by the number of SAP Secure Login Service instances.

Q: Can Azure Idp be used without a BTP tenant for authentication?

A: Secure Login Client relies on BTP's SAP Secure Login Service for certificate provisioning and Identity Authentication Service for authentication. Azure AD integration is enabled through proxy configuration in Identity Authentication Service and Azure AD.

Q: Does "SAP Secure Login Service for SAP GUI" include Certificate Lifecycle Management (CLM)?

A: Current version lacks CLM. SAP considers cloud-based alternatives to on-premise Java stack for future CLM inclusion, with details and timelines pending.

Q: How can we perform tasks such as creating root certificates, intermediates, signing certificates with CSR, and installing them into ABAP/JAVA systems using the new SAP Secure Login Service for SAP GUI?

A: Currently, the new service primarily deals with client certificates for SSO using an SAP-managed CA. Support for customer-managed CAs in the cloud is on the roadmap, but not yet available. Certificate Lifecycle Management is under consideration, but the scope and roadmap haven't been finalized. Thus, the functionality of the on-premise server for creating root certificates, intermediates, signing certificates with CSR etc. is not available in the cloud service at this time.

Q: Does the Secure Login Service for SAP GUI running on SAP Business Technology Platform - will only function within the client's network, as it may not be able to communicate with the corporate on-premises IDP (Identity Provider) from outside the network due to potential connectivity restrictions?

A: In this case, SAP utilize the IAS identity provider proxy mechanism, detailed at https://help.sap.com/docs/identity-authentication/identity-authentication/corporate-identity-provide.... This setup eliminates the need for a network connection between the two identity providers, as all communication occurs through the end user's browser. The only requirement is that both the identity authentication service and your corporate IdP must be accessible from the end user's desktop.

 
Got more juicy tidbits to add or feeling the itch to sprinkle your magical feedback dust? Don't be a stranger – drop a line, a joke, or even your favorite recipe! Feel free to leave a comment 📣

26 Comments
ShailendarAnugu
Product and Topic Expert
Product and Topic Expert
0 Kudos
Nice blog!!
nizarfanany
Explorer
0 Kudos
Thanks for sharing, Nice blog
GrahamNewport
Explorer
Does the secure login service require a cloud connector if setting up for an on premise SAPGUI logon using an Azure AD?
Christian_Cohrs
Product and Topic Expert
Product and Topic Expert
0 Kudos
The cloud connector is not required as the communication is always triggered from the end user desktop. So the end user needs to be able to connect to the Azure AD logon page using the browser, and they need to be able to connect to the ABAP system using SAP GUI.

Best regards,

Christian
javier_iribarne1
Explorer
0 Kudos
Hello Carsten

 

Nice blog.

I have a question,

In the specific case that the SAP system is already working with SSO through kerberos and snc, could it be configured "ADDITIONALLY" to authenticate through SLS (Secure Login Service)?

I will explain. The SAP system has already configured SSO. A SAPService<SID> user was configured in the onpremise Active Directory, and an SPN was assigned via setspn....
The SNCWIZARD wizard was already configured at the time, and a branch is already available in the STRUST for the sapcryptolib, the snc parameters of the instance profiles were already configured, etc....
On the user PC in addition to the saplogon Secure Login Client is installed, and the saplogon entry has the SNC flag enabled with the SNC name.
In the SAP user master (SU01) , all users have the SNC tab filled in with their own SNC username.

In other words, the SSO via kerberos ticket granted by the onpremise AD Windows is already working.

Now we have purchased Secure Login Service for SAPgui because we want to provide access to users, from outside the corporate network, but in a secure way, authenticating against an Azure AD (which is synchronized with the on premise AD) We have already made the configurations of the BTP sub-account, and we already have the IAS configured, and we have the SLS available. At the moment we have not configured IAS as a proxy, we simply want to test this part, the new authentication against SLS and IAS.

But we run into a conceptual problem. In order to use this new authentication method (without affecting the one we currently have working) we will need the SAP system to have a new SNC identity? If so, SAP allows to have 2 SNC names?

I ask this because in the first tests that we are already doing we have achieved that when logging into the saplogon the authentication is done against the IAS (this seems correct to us), we receive the certificate from SLS (you can see in Secure Login Client) but then we get GSS-API error (min): Peer certificate path not trusted target = "p:CN=.....".

I understand that this is because the SAP system currently has a SNC identity, and that it is determined by the snc/identity/as parameter.

Is it possible to configure the new authentication using SLS and IAS, without affecting the current configuration?

If it is possible, how would it have to be done? Would it be necessary to modify the snc/identity/as parameter? Should we modify the SNC SAPCryptolib branch of the STRUST transaction?.....

Or is it not possible to get this coexistence?

Thanks
Regards

Javier
Colt
Active Contributor
0 Kudos
Hi Javier,

first of all, thank you so much for reading my blog and for putting in the effort to formulate your question so comprehensively. I think it's fantastic; that doesn't happen very often around here. What you're describing and your plan are certainly possible and a common requirement.

The hybrid operation, combining Kerberos/SPNEGO with X.509 as token formats for the SNC interface, is a special feature of SAP SSO solutions. You just need to be mindful that in this scenario, your SAP system (mostly) requires a signed SNC certificate (Server Authentication) in the STRUST.

Typically, your system has an SNC ID name in the form: p:CN=<SID>, O=<Company>, C=<Country>. However, even if it looks different, you should have your certification authority sign this certificate, similar to your TLS certificate, except you don't need a SAN attribute in the SNC certificate.

Now, your clients (outside the corporate network) should trust the PKI (Root CA) underlying the SNC certificate, and you can ensure that. Subsequently, in STRUST, you also need to add the SAP Global Root CA certificate as trusted. With these steps, nothing should hinder mTLS, and the certificate can be verified bidirectionally.

Depending on the configuration of the Secure Login Client, the corporate PC either requests an SAP/<SID> service ticket from the KDC and uses Kerberos for SNC, or with the new solution, the external user obtains a certificate after authentication at the IdP and sends it to the SNC layer. So, everything is achievable! Hope this helps.

Cheers Carsten
javier_iribarne1
Explorer
0 Kudos

Hello Carsten

 

Thank you very much for your information. We have been able to move forward using a certificate signed by a CA.

Now the problem we have is that when we login from saplogon, it gives us an error related to the canonical SNC name. It seems that it needs to use the SLS SNC name, and not the one we currently have.

I attach some screenshots, so you can see it.

It seems, therefore, that we should change the SNC name of the SAP system?

 

SU01:

SNC Parameters

 

STRUST

 

SPNEGO

 

 

SLS

 

SAPLOGON

 

Mapping IAS

 

 

final error

 

Would you be so kind as to clarify what we would be missing?

Thank you

Javier

 

Colt
Active Contributor
0 Kudos
Hi Javier,

well, that looks great already. It seems your user is receiving their certificate from the SLS (Cloud Service), and you should be able to see it in the Secure Login Client. There, you can copy the SNC name via right-click.

Now, you're arriving at the SAP system with an X.509 certificate instead of a Kerberos ticket. The message in the last screenshot indicates that your user cannot be logged in with the certificate from the SLS because the system can't find a user with the SNC name = X.509 DN.

As a result, you have to assign the SNC name p:CN=<IAS Login Name>, L=.... to your intended SAP user. Your other users will still use Kerberos p:CN=<ADUSER>@<DOMAIN> thus having those kind of SNC Names in SU01 while the Secure Login Service for SAP GUI users must have a X.509 DN as the SNC Name.

 

Okay?

 

Cheers Carsten
javier_iribarne1
Explorer
0 Kudos
Hello Carsten

 

Thank you very much for your help, finally we have been able to configure it.

But now we have a question. Our SAP system is in SAP RISE, and the logon works only when we are inside the corporate network. Externally we can not access. The authentication part against the IAS/SLS works fine, it returns the certificate, but then the saplogon , logically, can not access the SAP system because it is hosted in the SAP cloud (RISE).

I understand that we should ask the SAP Rise team for port opening? or something else is missing?

Thanks

Javier
Colt
Active Contributor
0 Kudos
Hello Javier,

technically, operating SAP systems in the private cloud (HEC, now called "ECS") is no different from an on-premises system. ECS systems are not public cloud systems. In a private cloud, users typically need to access resources through a secure network connection such as VPN, similar to an on-premises system. Alternatively, solutions like Citrix or VDI can be used for a managed and controlled access.

For accessing HTTP applications like Fiori in a private cloud environment, similar security measures are necessary to ensure a protected connection. It's important to adhere to security policies and protocols according to the requirements of the private cloud environment.

Best regards
Carsten
javier_iribarne1
Explorer
0 Kudos
Hello Carlsten

Thank you for your quick response.

Anyway we understand that this product is intended precisely to be able to access externally, otherwise it would not make much sense.

In any case we will consult the SAP Rise team to tell us how to proceed.

Thank you

Javier
Kamal_N
Newcomer
0 Kudos

Hi @Colt ,

Thanks for putting all the content in one blog. It's really nice blog.
I've implemented the same SAP Secure Login Service in our environment to utilize the SSO functionality. Earlier we weren't using the SSO by any means.
Voila, it's working perfectly.

The only challenge we are facing is managing the SNC SAPCryptolib certificate. Currently we have installed the Self signed SNC SAPcryptolib certificate in the local machine for each system. but it's big pain to manage individual certificate for each system. 
Is there a way if I can replace the self-signed SNC SAPcryptoblib certificate across the systems with any universal or single certificate across the landscape?

Will be waiting for your response.

Regards
Kamal

 

Colt
Active Contributor
0 Kudos

Hello Kamal,

given that each SAP system is expected to have its own dedicated SNC identity (snc/identity/as) like e. g.  p:CN=<SID>, O=<Org>, C=<Country>, and considering that SNC certificates typically lack the Subject Alternative Name (SAN) extension utilized in TLS certificates, I'm uncertain of a practical solution.

Ultimately, it appears necessary to sign the certificate through a Certificate Authority (CA) and strike a balance between runtime and security considerations.

Ok?
Cheers Carsten

afrontini_avvale
Newcomer
0 Kudos

Hello

The above solution proposed by @Colt  is the best solution in order to manage the SNC certificates.

If you have all the SNC individual certificates signed by the same CA ( also an internal CA is good ) , all of them will be automatically trusted by every client and server that already trusted the CA:

you don't need to send to them the individual SNC certificates one by one.

Regards

Alessandro

dyaryura
Active Participant
0 Kudos

Just to add...

There are some items on the roadmap related to custom CA, not sure on the specific details since it's not fully clear.

https://roadmaps.sap.com/board?range=CURRENT-LAST&PRODUCT=AF740456A03F1EDDAA9212F748EDC3E2#Q1%202024

Technically you can generate one certificate with the CN of the SAPCryptolib, include a SAN in the certificate and use it for "SSL Server" as well as "SNC SAPCryptolib". this can be signed by your company internal CA that is already trusted by all workstations

Henk
Active Participant
0 Kudos

We have set this up and it works like a charm. I came across your fine blog in search for a solution regarding the SNC Names. We don't want to provide to thousands of users an SNC Name through SU01, since this is a tedious operation. Due to the fact that a mapping based on (obviously a variable) email-address is used, report RSUSR300 doesn't seem to be useful here. So we looked at transaction CERTRULE, which @Colt also mentions. But... Isn't CERTRULE only meant for HTTPS-traffic? It doesn't seem to work with SAP Logon / SAP GUI via SNC.

Colt
Active Contributor

Hi Henk, you are right, certrule is only for ICM-based access (ICF-Services) based on X.509 certs (mTLS). Besides RSUSR300 (SNC1) you may want to use custom ABAPs, own tools/logic, IDM, Xiting XAMS etc. to automate SNC user mapping which is still required for SAP GUI (SNC).
Cheers Colt

 

BrianHolmes
Discoverer
0 Kudos

Thank you Colt for the info.

We have run into one issue that I seem to be stuck on.  The SAP Secure Client for SAP GUI service has been setup in one of our SBX environments and all seems well with the connection tests so far. We can setup the connection in the Logon App and connecting using the secure communication (Icon=Locked). However, we have many users that use web URLs to open SAP GUI (not WEBGUI).  I am stuck in finding a way for the web URL to force the use of the secure login service through the SLS. So far, it appears that SAP GUI is opening without secure communications when using the web links. (Icon=Not locked)

Can you point me to some information that may help this this?  Thank you.

Colt
Active Contributor

Hi Brian, sounds like you're dealing with SAP GUI shortcuts generated via a portal or something similar. These shortcuts typically achieve SSO with trusted systems. This SSO method was once popular for easy access to SICF services (ABAP Web AS) or launching SAP GUI via shortcuts. However, due to various operational and security drawbacks, as well as domain restrictions associated with the use of SAP Login Tickets, this approach has fallen out of favor.

SAP SE itself has been recommending for over eight years, as documented in SAP Note 2117110, the adoption of standardized SSO technologies such as Kerberos/SPNEGO, X.509, or SAML 2.0. The note also highlights limited support and the inadequacy of technical security standards of the cryptographic methods used. The cookie mechanism carries the risk of unauthorized data transmission interception. Specifically, a copy of the SAP login ticket could be used to gain unauthorized access to protected resources through hijacking/replay attacks.

Given the evolution of security technologies and best practices, it might be a good time to reassess and update your SSO strategy. To tackle this issue, you should first ensure that SNC (Secure Network Communications) is activated and correctly configured, including SNC User Mapping, etc. You can also pass SNC parameters via the sapgui.exe or work with environment variables to integrate a secure SNC connection directly into your links, depending on how those links are generated. For more details, maybe check out here
Cheers Colt

Jacopo_Carrara
Explorer
0 Kudos

Hy,

thanks for the post.
I have this situation and i don't understand some point:
The customer ask for MFA on his current on-premise systems s/4 hana and fiori(not embedded but as a gateway but also he have a system where fiori in embedded)
First scenario(s/4 hana and fiori embedded)
1) Can i use SAP Secure Login Service for SAP GUI for both or should i use SAP Cloud Identity Services for fiori?
2) MFA is also avaliable when you use only SAP IAS or you need to use a corporate IDP?
Second scenario(s/4 hana and fiori not embedded with a gateway system)
1)What should i do in this scenario?SAP Secure Login Service for SAP GUI on s/4 and SAP Cloud Identity Services for the second?

Kind regards,

JC

Colt
Active Contributor

Hi JC,

your aim is to provide your client with a seamless and straightforward SSO/Multi-Factor Authentication scenario. It is about implementing MFA for their SAP S/4HANA system(s), whether it's through Fiori Embedded or in the Gateway (GW) is not crucial. What matters is that both access methods, DIAG/RFC using SNC (SAP Logon) and HTTP/TLS (ICM), need to be considered.

Your client is utilizing the SAP Secure Login Service for SAP GUI, which includes the SAP Cloud Identity Services (IAS) as part of the package. Therefore, both solutions are always available with this new service.

To address your queries:

  1. You'll be utilizing the SAP Secure Login Client and X.509 certificates for logging into SAP Logon. For SAP GUI, this entails configuring S/4HANA for Secure Network Communication (SNC). The authentication token/method here is X.509 CBA (mTLS). For accessing all HTTP-based applications like ICF-Services (flp, etc.), SAML2 should be used. Authentication here also goes through the Identity Authentication Service (IAS), which can be the same as for the SAP Secure Login Service for SAP GUI (or another one if you prefer for some reason). MFA can be resolved via IAS or Corporate IdP here as well. This is the best practice. ALWAYS use SAP IAS for all SAP systems, whether On-Prem or BTP/SaaS. It's that simple.

  2. Authentication always occurs at the SAP IAS. It can handle various MFA methods from TOTP to FIDO2, but typically, this task is outsourced to a Corporate IdP, whichever is chosen, it doesn't have to be Entra ID.

Hope this clarifies things. Feel free to reach out again if needed!

Cheers Colt

Jacopo_Carrara
Explorer
0 Kudos

Hy Colt,

thanks for the answer, i understand that for SSO with GUI this is the best solution,but as far as i understand i can also use SAP Cloud Identity Services - Identity Authentication for saml2 authentication with a S/4 hana system for the gui.

So it's change the authentication token/method here for improve the security o what?

Kind regards,

JC

 

 

Colt
Active Contributor

Hey JC,

nope, for SAP GUI you must use the SAP Secure Login Client with SNC, that is not possible with saml2 authentication, that just works for http-based applications. There is SNC (DIAG/RFC) supporting Kerberos and X.509 certs and HTTP (TLS) supporting SPNEGO, X.509 and SAML2 + more

Cheers Carsten

 

uwe_klein
Explorer
0 Kudos

Hi,

We already have maintained SNC Names for every user in SU01 with format p:CN=XXXX@YYYYYYY.

Now we get following error :

"No user exist with SNC name "p:CN=XXXX, L=slsserver.accounts.ondemand.com, OU......."

We don't want to change the already maintained SNC names in SU01. CETRULE is not working.

Which other options do we have to map the SNC name to the user ?

Regards

Uwe

uwe_klein_0-1715788835249.png

 

Colt
Active Contributor
0 Kudos

Dear Uwe, 

none. You have to map (change) the SNC names.

 

Christian_Cohrs
Product and Topic Expert
Product and Topic Expert

Hi Uwe and Carsten,

there might be 2 options to look into:

- Use CommonCryptoLib namealias parameters to change the new SNC name in such a way that it is equal to the old one. Whether this is possible depends on the difference between the two. See https://me.sap.com/notes/2338952/E

- Use a customer-managed CA and wait for the roadmap item that allows you to specify the subject any way you want. See https://roadmaps.sap.com/board?range=CURRENT-LAST&PRODUCT=AF740456A03F1EDDAA9212F748EDC3E2#Q2%202024...

 

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