CDSA - Common Data Security Architecture

Enhanced Definition

The Common Data Security Architecture (CDSA) is a modular, extensible framework that provides a standardized application programming interface (API) for cryptographic services. In the z/OS environment, CDSA enables applications to access various cryptographic functions, such as encryption, decryption, hashing, and digital signatures, often leveraging underlying hardware accelerators. It aims to provide a consistent security services layer for applications, abstracting the complexities of different cryptographic implementations.

Key Characteristics

- Modular Architecture: CDSA is designed with a plug-in architecture, allowing different cryptographic service providers (CSPs) to be integrated, including software-based modules and hardware cryptographic devices.
- Standardized API: It offers a consistent set of APIs for applications to perform cryptographic operations, promoting interoperability and reducing application development complexity.
- Provider Independence: Applications written to the CDSA API can utilize different cryptographic providers without requiring code changes, offering flexibility in choosing the most suitable security implementation.
- Integration with z/OS Security: CDSA can integrate with z/OS security components like ICSF (Integrated Cryptographic Service Facility) to leverage hardware cryptographic features and RACF (Resource Access Control Facility) for access control to cryptographic resources.
- Support for Cryptographic Algorithms: It supports a wide range of cryptographic algorithms, including symmetric (e.g., AES, DES) and asymmetric (e.g., RSA) encryption, hashing (e.g., SHA), and digital signature algorithms.

Use Cases

- Secure Communications: Applications requiring secure network communication (e.g., SSL/TLS, IPSec) can use CDSA to perform the necessary cryptographic operations for key exchange, encryption, and data integrity.
- Data Encryption: Encrypting sensitive data at rest (e.g., files, databases) or in transit within z/OS applications to protect confidentiality.
- Digital Signatures: Generating and verifying digital signatures to ensure data authenticity and integrity for critical transactions or documents.
- Key Management: Providing cryptographic primitives that facilitate the secure generation, storage, and usage of cryptographic keys.
- Kerberos Integration: IBM's Network Authentication Service (Kerberos for z/OS) utilizes CDSA for its underlying cryptographic functions, such as ticket encryption and authentication.

Related Concepts

CDSA often works in conjunction with ICSF (Integrated Cryptographic Service Facility) on z/OS, where ICSF acts as a primary cryptographic service provider, allowing CDSA to leverage the high-performance and secure hardware cryptographic features of the mainframe (e.g., CPACF, Crypto Express adapters). RACF (or another external security manager) is crucial for defining and controlling access permissions to CDSA services and cryptographic keys. Applications using System SSL or implementing PKI (Public Key Infrastructure) on z/OS may indirectly or directly interact with CDSA for their cryptographic needs.

Best Practices:

Leverage Hardware Cryptography: Configure CDSA to utilize ICSF and the underlying z/OS hardware cryptographic features (CPACF, Crypto Express) whenever possible to achieve optimal performance and enhanced security.
Secure Key Management: Implement robust key management practices, ensuring that cryptographic keys used by CDSA are securely generated, stored, protected by RACF profiles, and regularly rotated according to security policies.
Monitor and Audit: Regularly monitor CDSA usage and cryptographic operations through system logs and SMF records to detect unusual activity, ensure compliance, and maintain an audit trail.
Stay Updated: Keep CDSA components, cryptographic libraries, and ICSF up-to-date with the latest maintenance to benefit from security fixes, performance enhancements, and support for modern cryptographic algorithms.
Integrate with ESM: Ensure that appropriate RACF (or equivalent ESM) definitions are in place to control which users and applications can access specific CDSA services and cryptographic resources.