Introduction to Crypto Module Interface in AUTOSAR

Cryptographic functionalities have become increasingly crucial in automotive systems, ensuring secure communication, data integrity, and authentication. In the context of Classic

ref="https://piembsystech.com/autosar-architecture/">AUTOSAR, the Cryptographic Interface plays a pivotal role in facilitating these security measures.

The AUTOSAR (Automotive Open System Architecture) is an open standard for automotive software architecture, aiming to provide a common platform for the development of automotive software. The Crypto Interface is a crucial component of the AUTOSAR Basic Software (BSW) module, responsible for managing cryptographic operations across various domains. This article provides a detailed overview of the Crypto Interface in the context of the Classic AUTOSAR platform, highlighting its functionality, API, and configuration.

Introduction and Functional Overview

The Crypto Interface is designed to operate between the Crypto Service Manager (CSM) and the underlying Crypto Drivers, serving as the unique interface to access cryptographic operations for all upper layers of the AUTOSAR BSW. This interface encapsulates different mechanisms of hardware and software access, ensuring the Crypto Interface implementation is independent from the underlying Crypto Drivers, which can be realized in hardware or software.

Acronyms and Abbreviations of Crypto Module

• CRYIF: Crypto Interface.
• CCRYIFSM: Crypto Service Manager
• CDD: Crypto Driver
• DET: Default Error Tracer
• E_OK: Request successful
• E_NOT_OK: Request failed
• CRYPTO_E_BUSY: Request failed, Crypto Driver Object is busy
• CRYPTO_E_KEY_EMPTY: Request failed because of uninitialized source key element
• CRYPTO_E_KEY_NOT_VALID: Request failed, the key state of the key identified by cryptoKeyId is “invalid”

Related Documentation

The Crypto Interface specification is part of the AUTOSAR Standard, Classic Platform, Release R23-11. It is accompanied by other relevant documents, including the AUTOSAR General Specification for Basic Software Modules, Specification of Crypto Driver, Specification of Crypto Service Manager, and Requirements on Crypto Modules.

Constraints and Assumptions

The Crypto Interface is designed to operate with one or multiple underlying Crypto Drivers. It assumes that the Crypto Drivers are capable of providing cryptographic services and that the Crypto Interface will forward service requests to these drivers. The interface also assumes that the Crypto Service Manager will use the Crypto Interface to access cryptographic operations.

Dependencies to Other Modules

The Crypto Interface depends on the Crypto Service Manager and the underlying Crypto Drivers. It is responsible for forwarding service requests to the Crypto Drivers and for accessing the cryptographic services provided by these drivers.

File Structure

The Crypto Interface code file structure is not defined within this specification. However, it is mentioned that the code file structure shall contain one source file CryIf.c, which contains the entire CRYIF code.

Requirements Traceability

The Crypto Interface specification includes a list of requirements that are traceable to the AUTOSAR Requirements on Crypto Modules. These requirements cover various aspects of the Crypto Interface, including its initialization, error handling, and cryptographic operations.

Functional Specification of Crypto Module

The Crypto Interface is responsible for managing cryptographic operations across various domains. It provides a unique interface to access cryptographic services, ensuring the concurrent access to these services to enable the possibility to process multiple crypto tasks at the same time. The interface also encapsulates different mechanisms of hardware and software access, ensuring the Crypto Interface implementation is independent from the underlying Crypto Drivers.

1. Crypto Driver: This term is mentioned in both the “Requirements on Crypto Stack AUTOSAR CP R20-11” and “Specification of Crypto Interface AUTOSAR CP R20-11” documents, indicating its importance in the context of the Crypto Interface.
2. Crypto Interface: This term is the title of the specification document and is also mentioned in the “Requirements on Crypto Stack AUTOSAR CP R20-11” document, highlighting its significance in the AUTOSAR Classic Platform.
3. Key Management: This term is mentioned in the “Requirements on Crypto Stack AUTOSAR CP R20-11” document, emphasizing the importance of key management in the context of the Crypto Interface.
4. Crypto Stack: This term is mentioned in the “Requirements on Crypto Stack AUTOSAR CP R20-11” document, indicating that the Crypto Interface is part of a broader cryptographic framework in the AUTOSAR Classic Platform.
5. Crypto Service Manager (CSM): This term is mentioned in the “Specification of Crypto Interface AUTOSAR CP R20-11” document, showing that the Crypto Interface interacts with the CSM, which is responsible for managing cryptographic operations in the AUTOSAR system.

Multicore Configuration in Crypto Module

In a setup with a distributed CSM and Crypto drivers assigned to different partitions, the CryIf APIs will be used in different partitions. However, the CryIf shall stay a pure forwarding component and not care about execution contexts anyway, meaning it does not differentiate between different partitions.

Error Handling in Crypto Module

The Crypto Interface specification includes a detailed description of error handling, including error types, error detection, and error reporting. It specifies that the Crypto Interface shall report detected development errors to the DET and that the DET shall handle these errors accordingly.

API Specification in Crypto Module

The Crypto Interface specification includes a detailed description of the API, including function definitions, type definitions, and call-back notifications. It specifies that the API shall provide a unique interface to access cryptographic services and that the interface shall be independent from the underlying Crypto Drivers.

Configuration Specification

The Crypto Interface specification includes a detailed description of the configuration, including containers and configuration parameters. It specifies that the configuration shall be used to configure the Crypto Interface and that the interface shall use this configuration to access cryptographic services.

Conclusion

In conclusion, the Crypto Interface in the context of the Classic AUTOSAR platform is a crucial component of the AUTOSAR Basic Software module, responsible for managing cryptographic operations across various domains. This interface provides a unique interface to access cryptographic services, ensuring the concurrent access to these services to enable the possibility to process multiple crypto tasks at the same time. The interface also encapsulates different mechanisms of hardware and software access, ensuring the Crypto Interface implementation is independent from the underlying Crypto Drivers.

The Crypto Interface specification includes a detailed description of its functionality, API, and configuration, as well as its dependencies to other modules and its requirements traceability. It also includes a detailed description of error handling, including error types, error detection, and error reporting.

The Crypto Interface is an essential component of the AUTOSAR platform, providing a common platform for the development of automotive software. Its functionality, API, and configuration make it an ideal solution for managing cryptographic operations across various domains, ensuring the security and integrity of automotive systems.