Skip to content

Class ZCL_LLM_ENCRYPTION

AI Generated documentation.

Overview

The zcl_llm_encryption class is designed to handle encryption and decryption operations using the SSF (Secure Storage Facility) framework in SAP. The class implements the zif_llm_encryption interface and provides methods for encrypting and decrypting data. The primary public methods include encrypt and decrypt, which are used to perform the encryption and decryption operations, respectively. The class also includes a class_constructor method that initializes the necessary components for encryption and decryption.

Dependencies

The class depends on several SAP function modules and interfaces:

  • zif_llm_encryption: Interface that defines the encryption and decryption methods.
  • zif_llm_auth: Interface for authorization checks.
  • SSF_KRN_DEVELOPE: Function module used for decrypting data.
  • SSF_KRN_ENVELOPE: Function module used for encrypting data.
  • SSFPSE_FILENAME: Function module used to get the profile filename.
  • SSFC_GET_CERTIFICATE: Function module used to get the certificate.
  • SSFC_PARSE_CERTIFICATE: Function module used to parse the certificate.

Details

The zcl_llm_encryption class interacts with various SAP function modules and handles encryption and decryption using the SSF framework. Below is a detailed breakdown of the class's internal workings and interactions:

Class Structure

The class is divided into three sections: PUBLIC, PROTECTED, and PRIVATE.

  • PUBLIC Section:

  • Methods:

    • class_constructor: Initializes the encryption object, including setting up the authorization class and retrieving the necessary profile and certificate.
    • encrypt: Encrypts the given unencrypted data.
    • decrypt: Decrypts the given encrypted data.

  • PROTECTED Section:

  • Class Data:
    • subject: Stores the subject of the encryption.
    • addrbook: Stores the address book profile.
    • auth_class: Reference to the authorization class.

  • Constants:

    • application: Application identifier.
    • bin_line: Size of the binary line (255 bytes).

  • PRIVATE Section:

  • No additional data or methods are defined in this section.

Encryption and Decryption Flow

The encryption and decryption processes involve several steps, including authorization checks, data conversion, and interaction with SSF function modules. Below is a Mermaid diagram illustrating the flow of the encrypt method:

graph TD
    A[Start] --> B[Check if unencrypted data is initial]
    B -- No --> C[Convert unencrypted data to xstring]
    C --> D[Check authorization]
    D --> E[Split data into 255-byte chunks]
    E --> F[Call SSF_KRN_ENVELOPE function module]
    F --> G[Concatenate enveloped data]
    G --> H[Return encrypted data]
    B -- Yes --> H

Decryption Flow

The decryption process is similar but involves the SSF_KRN_DEVELOPE function module. Below is a Mermaid diagram illustrating the flow of the decrypt method:

graph TD
    A[Start] --> B[Check if encrypted data is initial]
    B -- No --> C[Check authorization]
    C --> D[Split encrypted data into 255-byte chunks]
    D --> E[Call SSF_KRN_DEVELOPE function module]
    E --> F[Convert output data to string]
    F --> G[Return decrypted data]
    B -- Yes --> G

Error Handling

The class includes robust error handling for various scenarios, such as memory issues, invalid parameters, and function module errors. Exceptions are raised using the zcx_llm_validation class, with specific text IDs and attributes to indicate the nature of the error.

Authorization

The class_constructor method initializes the authorization class by calling the get_authorization_impl method of the llm_badi BAdI (Business Add-In). This ensures that the encryption and decryption operations are performed with the necessary permissions.

Profile and Certificate Management

The class retrieves the profile and certificate using the SSFPSE_FILENAME, SSFC_GET_CERTIFICATE, and SSFC_PARSE_CERTIFICATE function modules. These steps are crucial for setting up the encryption environment and ensuring that the correct certificate is used for encryption and decryption operations.

This detailed overview provides a comprehensive understanding of the zcl_llm_encryption class, its interactions, and its internal workings.