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 

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"

Register the brand protection record into the NDEF C library

ifx_record_bp_register();

Create a new brand protection record

ifx_record_handle_t handle;
ifx_record_bp_new(&handle);

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;
}

Set the custom certificate encoder and decoder handles

ifx_record_bp_set_certificate_handlers(&handle, x509_certificate_encoder, x509_certificate_decoder);

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;

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);

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.

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);

Get the certificate from the record handle

ifx_record_bp_get_certificate(&get_record_handle, &certificate);

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.

Fig. 8 Software architecture of the NDEF brand protection 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.

Fig. 9 Interaction between the components of the NDEF brand protection library.

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