NDEF brand protection library

‍ C library to encode and decode brand protection NDEF record and messages

The NFC data exchange format (NDEF) specification by NFC Forum defines a common data format to exchange information between NFC Forum devices.

This C library provides support to build and parse the NDEF brand protection messages, with support for common NDEF record type definitions.

Features

• Build and parse the NDEF brand protection messages
• Build and parse the NDEF brand protection records

Usage

1. Include the following headers

   #include "infineon/ifx-record-bp.h"
   #include "infineon/ifx-ndef-message.h"
   #include "infineon/ifx-ndef-record.h"
   #include "infineon/ifx-utils.h"

1. Register the brand protection record into the NDEF C library

   ifx_record_bp_register();

1. Create a new brand protection record

   ifx_record_handle_t handle;
   ifx_record_bp_new(&handle);

1. Provide custom implementations to encode and decode the certificates

   Example: Certificate encoder custom implementation

   ifx_status_t x509_certificate_encoder(const void * certificate, ifx_blob_t ** certificate_bytes)
   {
     // Implement code to encode X.509 certificate into byte array
     // Code placeholder
     return IFX_SUCCESS;
   }

   Example: Certificate decoder custom implementation

   ifx_status_t x509_certificate_decoder(const ifx_blob_t * certificate_bytes, void * certificate)
   {
       // Implement code to decode X.509 certificate from byte array
       // Code placeholder
         return IFX_SUCCESS;
   }

1. Set the custom certificate encoder and decoder handles

   ifx_record_bp_set_certificate_handlers(&handle, x509_certificate_encoder, x509_certificate_decoder);

1. Example for defining the certificate data type

   // Example x509_certificate.
   typedef struct
   {
     char *issuer;
     char *subject;
     char *fingerprint;
     char *authority;
     ifx_blob_t public_key;
     ifx_blob_t signed_data;
     ifx_blob_t signature;
   } ifx_x509_certificate_example_t;

1. Assign a certificate to the created brand protection record

   // Example: Declare a certificate
   ifx_x509_certificate_example_t certificate;
   // Assign the certificate.
   ifx_record_bp_set_certificate(&handle, (void *)&certificate);

1. Use the NDEF C library to encode the brand protection record into an NDEF message

   uint32_t record_count = 0x01;
   ifx_blob_t ndef_message = {0};
   ifx_ndef_message_encode((ifx_record_handle_t *)&handle, record_count, &ndef_message);

   This NDEF message can be written into the NDEF file in the tag.

1. Use the NDEF C library to decode the brand protection record from an NDEF message

   ifx_record_handle_t get_record_handle;
   uint32_t get_number_of_records = 0x00;
   ifx_ndef_message_decode(&ndef_message, &get_number_of_records, &get_record_handle);

1. Get the certificate from the record handle

   ifx_record_bp_get_certificate(&get_record_handle, &certificate);

1. Release the memory allocated by the library

   // free-up the internally allocated memory.
   status = ifx_ndef_record_release_resource();

Architecture

Below image described the software architecture of the library.

Components

• Brand protection record models This component contains the record models that are in-built supported by the library. These record models provide the structure for the record, which can be used to build the record.
• Brand protection record payload encoders and decoders This component contains the payload encoders and decoders which can be used to encode and decode the payload details into a byte array.

Interaction

Below UML diagram describes the interaction between the components.

Directory structure

The library directory is structured according to the Pitchfork Layout.

hsw-ndef-bp
|-- .cmake/                 # Includes sources for dependency management
|-- LICENSES/               # Includes list of licenses used for the library
|-- data/                   # Includes Doxygen, cppcheck configuration files
|-- docs/                   # Includes documentation source files, images, and the generated API reference
|-- include/                # Public Headers(.h) of the library
|-- src/                    # Sources(.c) and Private headers(.h) of the library
|-- .clang-format           # clang-format configuration file
|-- .gitignore              # Library specific gitignore file
|-- CMakeLists.txt          # CMake build configurations for the library
`-- README.md               # Overview of the hsw-ndef-bp library

Dependencies

• hsw-error This dependent library is used for creating and parsing an error information.
• hsw-ndef This dependent library is used for creating the DEF RTDs and parsing the NDEF record information.
• hsw-utils This dependent library is used for utility functions such as string parsers.

References

• Infineon Technologies AG: OPTIGA™; Authenticate NBT, Extended Datasheet
• NFC Data Exchange Format (NDEF), Technical Specification, NFC Forum™, NDEF 1.0
• NFC Record Type Definition (RTD), Technical Specification, NFC Forum™, RTD 1.0