The Cloud Application Programming Model (CAP) provides a powerful framework for building enterprise applications on SAP Business Technology Platform (BTP). While CAP accelerates development with best practices and reusable components, ensuring security throughout the application lifecycle is paramount.
This article explores key security considerations developers must address when building CAP applications in SAP Business Application Studio (BAS) to protect sensitive data, prevent unauthorized access, and comply with organizational and regulatory requirements.
¶ 1. Authentication and Authorization
- CAP applications rely on the XS UAA (XSUAA) service on SAP BTP for authentication and authorization.
- Use the
xs-security.json file to define roles, scopes, and attributes.
- Bind the XSUAA service instance to your CAP application and configure the security settings in the application manifest.
- Implement role-based access control (RBAC) to restrict access to different app components or service operations.
- CAP services receive JSON Web Tokens (JWT) from XSUAA after user authentication.
- Validate JWT tokens on the server side for every request to ensure the user’s identity and permissions.
- Use CAP’s built-in
@sap/cds/security package for simplifying token validation.
- Use CAP’s CDS Authorization annotations to restrict access to entities based on user roles.
- Example: Define which roles can read or modify specific entities.
- Implement selective field access to hide sensitive data from unauthorized users.
- Use CDS annotations like
@Capabilities.Restrictions.ReadRestrictions and @Capabilities.Restrictions.UpdateRestrictions.
- Always use HTTPS endpoints for communication between clients and services.
- Enable TLS encryption on SAP BTP destinations and service bindings.
- Avoid transmitting sensitive data over unsecured channels.
- Validate and sanitize all inputs to avoid common vulnerabilities like SQL Injection, Cross-Site Scripting (XSS), or command injection.
- Use CAP’s built-in validation capabilities in CDS models and service handlers.
- Sanitize user input in UI layers to prevent client-side attacks.
¶ 5. Secure Service Handlers and APIs
- Implement security checks in custom service handlers to verify user roles and permissions before processing requests.
- Use CAP’s
req.user context to extract user information for authorization logic.
- Protect REST APIs exposed by CAP with OAuth 2.0 tokens issued by XSUAA.
¶ 6. Data Encryption and Storage
- Use SAP BTP’s managed database services (like SAP HANA Cloud) that support encryption at rest and in transit.
- Avoid storing sensitive data in plaintext.
- Consider encrypting sensitive fields at the application layer if necessary.
¶ 7. Logging and Monitoring
- Enable secure logging of security-relevant events without exposing sensitive information.
- Monitor authentication attempts, authorization failures, and suspicious activities.
- Use SAP BTP’s monitoring tools to set alerts and audit logs.
- Use BAS extensions that check for security vulnerabilities and code quality.
- Regularly update dependencies to patch security flaws.
- Use environment variables or secure vaults in BAS to manage credentials and secrets safely.
- Perform regular security reviews and penetration testing before deployment.
Security in CAP development is an ongoing process that spans authentication, authorization, data protection, and secure coding practices. SAP Business Application Studio offers an integrated environment where developers can implement these security measures efficiently, leveraging SAP BTP’s built-in services.
By adopting a security-first mindset, CAP developers can build robust, compliant, and trustworthy applications that safeguard enterprise data and meet regulatory requirements.