Attribute Based Access Control (ABAC) – Data Block...

AmitKrSingh · ‎2020 Apr 27

Introduction

In this blog post, we will learn how to configure Data Block in Payment Transactions tab of BP transaction to block access to Bank Details information of certain business partners.

Attribute based authorizations are dynamic determination mechanism which determines whether a user is authorized to access specific data sets which can be based on the context attributes of the user and data (for example, price of certain sensitive materials are masked).

The end result for authorized users will appear as:

The end result for unauthorized users will appear as:

Prerequisite

UI Data Protection Masking for SAP S/4HANA is a solution that allows you to protect restricted and sensitive data values at field level by masking, clearing, or disabling fields for those users who are not authorized to view or edit this data.

Product “UI data protection masking for SAP S/4HANA” is used in this scenario to protect sensitive data at field level and must be installed in the S/4HANA system.

The product is a cross-application product which can be used to mask/protect any field in SAP GUI, SAPUI5/SAP Fiori, CRM Web Client UI, and Web Dynpro ABAP.

Let’s begin

Configuration to achieve data block

Logical Attribute is a functional modelling of how any attribute such as Social Security Number, Bank Account Number, Amounts, Pricing information, Quantity etc. should behave with masking.

Configure Logical Attribute – Follow the given path:

SPRO -> SAP NetWeaver -> UI Data Protection Masking for SAP S/4HANA -> Maintain Metadata Configuration -> Maintain Logical Attributes

Bank Details

Configure Derived Attribute

Derived Attributes are user defined attributes which are populated at run time. The derivation of these attributes can be maintained in a class method. The name of the Class can be specified while maintaining a derived attribute in the IMG.

Follow the given path:

SPRO -> SAP NetWeaver -> UI Data Protection Masking for SAP S/4HANA -> Maintain Metadata Configuration -> Maintain Attributes and Ranges for Policy – Follow below mentioned steps:

Business Partner

Click on “New Entries” button

Enter “Derived Field” as “DA_BUSINESS_PARTNER”

Enter “Class Name” as “ZCL_BUSINESS_PARTNER”

Select “Application Module” as “* Cross-Application”

Enter “Description” as “Business Partner”

Click on “Save” button

Implementation of Derived Attribute for Business Partner

For the given case, we are blocking Bank Details information of Business Partners in BP transaction. The context for our rule i.e. BP Number (BUT000-PARTNER) is not available as context in Payment Transaction tab (as in case of Module Pool programs, Context of only sub-screen fields are available), Hence, there is a need to create a Derived Attribute for Business Partner.

Steps to implement Class for Derived Attribute:

Execute transaction SE24

Create Derived Attribute Class mentioned in the configuration (i.e. ZCL_BUSINESS_PARTNER)

Implement the Interface: /UISM/IF_DERIVED_ATTR_VALUE in the Class

Sample implementation of Method: /UISM/IF_DERIVED_ATTR_VALUE~EXECUTE

Configure Value Range

Value Ranges are a set of pre-populated values which can be used to derive the context under which an action should be executed.

Follow the given path:

SPRO -> SAP NetWeaver -> UI Data Protection Masking for SAP S/4HANA -> Maintain Metadata Configuration -> Maintain Attributes and Ranges for Policy – Follow below mentioned steps:

Range of Blocked BP

Click on “New Entries” button

Enter “Value Range” as “VR_BLOCKED_BP”

Select “Application Module” as “F Financial accounting”

Enter “Description” as “Range of Blocked BP”

Click on “Save” button

Enter entries in “VR_BLOCKED_BP” Value Range

Execute Transaction Code “/UISM/V_RANGE”

Click on “VR_BLOCKED_BP” Value Range

Click on “Display<- -> Change” button

Click on “Add New Entry” button

Add following entries under “Include Value” tab and click on “Save” button

Value Description

0000000011 Global Business Properties

0000000012 Food for You

0000000382 Petra Planstelle

Maintain Technical Address

In this step, we will associate the Technical Address of the fields to be masked with the Logical Attributes.

You can get the Technical Address of a GUI field by pressing “F1” on the field.

Follow the given path:

SPRO -> SAP NetWeaver -> UI Data Protection Masking for SAP S/4HANA -> Maintain Metadata Configuration -> Maintain Technical Address

Follow below mentioned steps:

Under “GUI Table Field Mapping”, maintain technical address for following fields.

Business Partner

Enter “Table Name” as “BUSBANKCHECK”

Enter “Field Name” as “BANKN”

Enter “Logical Attribute” as “LA_BP_SUPPRESSION”

Enter “Description” as “Bank Account”

Click on “Save” button

Click on “Mass Configuration” button which is required to generate technical addresses for Module Pool Programs

Policy Configuration

A Policy is a combination of rules and actions which are defined in one or more blocks. The actions are executed on a sensitive entity (field to be protected) which has to be assigned to a Policy. The conditions are based on contextual attributes which help derive the context.

Context Attributes are logical attributes which are used in designing the rules of a policy. They are mapped to fields which are used to derive the context under which an action is to be executed on a sensitive entity.

Sensitive Entities are logical attributes which are sensitive and need to be protected from unauthorized access.

Follow the given path:

SPRO -> SAP NetWeaver -> UI Data Protection Masking for SAP S/4HANA -> Data Protection Configuration -> Maintain Policy Details for Attribute based Authorizations – Follow below mentioned steps:

Click on “New Entries” button

Enter “Policy Name” as “BP_SUPPRESSION”

Select “Type” as “Data Blocking”

Select “Application Module” as “Cross-Application”

Enter “Description” as “BP Suppression”

Click on “Save” button

Write following logic into Policy

Maintain Data Blocking Configuration

Here, we will define how masking will behave with the logical attribute that we created in above step.

Follow the given path:

SPRO -> SAP NetWeaver -> UI Data Protection Masking for SAP S/4HANA -> Data Protection Configuration -> Maintain Data Blocking Configuration

Follow below mentioned steps:

Click on “New Entries” button

Enter “Sensitive Entity” as “LA_BP_SUPPRESSION” and press “Enter” key. “Description” and “Application Module” will get populated in corresponding fields

Check “Enable Configuration” check-box

Select “Attribute Based Authorization” option

Enter “Policy Name” as “BP_SUPPRESSION”

Enter “Message Class” as “/UISM/UI“

Enter “Message Number” as “902“

Click on “Save” button

API Implementation

“UI Data Protection Masking for SAP S/4HANA” solution provides an API which can be employed to completely block access to a Business transaction within SAP. The API can also be used to suppress some records from a list.

The below approach needs to be followed to implement Data Block API:

Developer need to analyze the business transaction to find a relevant enhancement option ( E.g. BAdI, Customer Exit, User Exit or Implicit enhancement Point, etc.) where UI Data Protection Data Block API can be called.

Call the Data Blocking API in interception point by passing the data reference of the key information which needs to be blocked/suppressed.

Optionally, pass the underlying Table name-Field name of the key information.

The API will suppress the applicable records from the Bank Details list.

Raise a relevant message if Indicator is ‘Blocked’ or ‘Suppressed’.

Sample code is given below –

IF GT_BUT0BK IS NOT INITIAL.

data : lt_field_map TYPE /UISM/T_FIELD_SEM_MAP.

data : ls_field_map TYPE /UISM/S_FIELD_SEM_MAP.



ls_field_map-tabname = 'BUSBANKCHECK'.

ls_field_map-fieldname = 'BANKN'.



append ls_field_map to lt_field_map.



DATA : cr_data          TYPE REF TO data.



  GET REFERENCE OF GT_BUT0BK[] INTO cr_data.



/UISM/CL_DATA_PROTECTION_API=>data_block_api(

  EXPORTING

    it_field_map = lt_field_map    " Field name & Sementic Attributes Mapping

*    iv_uname     =     " ABAP System Field: Name of Current User

  IMPORTING

    ev_indicator = data(lv_indicator) " Data block = 'B'  or Suppression = 'S'

    es_return    = data(ls_return)    " Return Parameter

  CHANGING

    cr_data      = cr_data

).



ENDIF.

Conclusion

In this blog post, we have learnt how Data Blocking is achieved in Payment transactions tab of BP transaction for blocking access to Bank Details information of certain business partners using API.