ecdh_optiga.c

#if defined (CY_USING_HAL)
#include "cyhal.h"
#endif
#include "cybsp.h"
#include "cy_retarget_io.h"
#include "ecp.h"
#include "optiga_util.h"
#include "optiga_crypt.h"
#include "optiga_lib_common.h"



void print_uint8_data(uint8_t* data, size_t len)
{
    char print[10];
    for (uint8_t i=0; i < len; i++)
    {
        if ((i % 16) == 0)
        {
            printf("\r\n");
        }
        sprintf(print,"0x%02X ", *(data+i));
        printf("%s", print);
    }
    printf("\r\n");
}


void print_ecp_point_data(mbedtls_ecp_point* data, mbedtls_ecp_group *grp)
{
	unsigned char buffer[100] = {0};
	size_t buflen = 0; //ECP_KEY_LENGTH

    mbedtls_ecp_point_write_binary(grp, data, MBEDTLS_ECP_PF_UNCOMPRESSED,
    		&buflen, buffer, sizeof(buffer));
    print_uint8_data(buffer, buflen);
}

void print_mpi_data(mbedtls_mpi* data)
{
	size_t len = mbedtls_mpi_size(data);
	unsigned char buffer[100] = {0};
    mbedtls_mpi_write_binary(data, buffer, len);
    print_uint8_data(buffer, len);
}


optiga_lib_status_t opstatus = OPTIGA_UTIL_BUSY;

void handlerFunc(void *callback_ctx, optiga_lib_status_t event){
	opstatus = event;
}

void wait(){
	while (opstatus == OPTIGA_UTIL_BUSY);
}

int main(void)
{
    cy_rslt_t result;

    /* Initialize the device and board peripherals */
    result = cybsp_init();

    /* Board init failed. Stop program execution */
    if (result != CY_RSLT_SUCCESS)
    {
        CY_ASSERT(0);
    }

    /* Enable global interrupts */
    __enable_irq();

    /* Initialize retarget-io to use the debug UART port */
    result = cy_retarget_io_init(CYBSP_DEBUG_UART_TX, CYBSP_DEBUG_UART_RX,
    		CY_RETARGET_IO_BAUDRATE);

    /* UART port init failed. Stop program execution */
	if (result != CY_RSLT_SUCCESS)
	{
	   CY_ASSERT(0);
	}

    /* \x1b[2J\x1b[;H - ANSI ESC sequence for clear screen */
    printf("\x1b[2J\x1b[;H");

	printf("PSOC_OPTIGA_IOT_KIT template is ready to start.\r\n");

	optiga_util_t* utilcreate = optiga_util_create(0, handlerFunc, NULL);

	opstatus = OPTIGA_UTIL_BUSY;

	optiga_util_open_application(utilcreate, 0);

	wait();

	if (opstatus != 0){
		printf("Utill open unsuccessfull\n\r");
		return 0;
	}

	optiga_crypt_t* opcreate = optiga_crypt_create(0, handlerFunc, NULL);

	opstatus = OPTIGA_UTIL_BUSY;

	uint8_t alicepubkey[100] = {0};
	uint16_t alicepublen = sizeof(alicepubkey);
	optiga_key_id_t aliceprivate = OPTIGA_KEY_ID_E0F2;

	optiga_crypt_ecc_generate_keypair(opcreate, OPTIGA_ECC_CURVE_NIST_P_256, OPTIGA_KEY_USAGE_KEY_AGREEMENT, 0, &aliceprivate, &alicepubkey, &alicepublen);

	wait();

	if (opstatus != 0){
		printf("Alice key generation unsuccessucful\n\r");
		return 0;
	}
	printf("Alice successfull key generation\n\r");
	opstatus = OPTIGA_UTIL_BUSY;

	uint8_t bobpubkey[100] = {0};
	uint16_t bobpublen = sizeof(bobpubkey);
	optiga_key_id_t bobprivate = OPTIGA_KEY_ID_E0F3;

	optiga_crypt_ecc_generate_keypair(opcreate, OPTIGA_ECC_CURVE_NIST_P_256, OPTIGA_KEY_USAGE_KEY_AGREEMENT, 0, &bobprivate, &bobpubkey, &bobpublen);

	wait();

	if (opstatus != 0){
		printf("Bob key generation unsuccessucful\n\r");
		return 0;
	}
	printf("Bob successfull key generation\n\r");
	opstatus = OPTIGA_UTIL_BUSY;

	public_key_from_host_t bob;
	bob.public_key = bobpubkey;
	bob.length = bobpublen;
	bob.key_type = OPTIGA_ECC_CURVE_NIST_P_256;

	uint8_t alicesharekey[32] = {0};

	optiga_crypt_ecdh(opcreate, aliceprivate, &bob, 1, &alicesharekey);

	wait();

		if (opstatus != 0){
			printf("Alice shared key generation unsuccessucful\n\r");
			return 0;
		}
		printf("Alice successfull shared key generation\n\r");
		opstatus = OPTIGA_UTIL_BUSY;


	public_key_from_host_t alice;
	alice.public_key = alicepubkey;
	alice.length = alicepublen;
	alice.key_type = OPTIGA_ECC_CURVE_NIST_P_256;


	uint8_t bobsharekey[32] = {0};
	optiga_crypt_ecdh(opcreate, bobprivate, &alice, 1, &bobsharekey);

	wait();
	if (opstatus != 0){
		printf("Bob shared key generation unsuccessucful\n\r");
		return 0;
	}
	printf("Bob successfull shared key generation\n\r");
	opstatus = OPTIGA_UTIL_BUSY;

	if (memcmp(alicesharekey, bobsharekey, 32) == 0) {
	    printf("Shared keys match!\r\n");
	} else {
	    printf("Shared keys DO NOT match!\r\n");
	}

	printf("Shared Key: \n\r");

	print_uint8_data(alicesharekey, 32);

	print_uint8_data(bobsharekey, 32);

}

/* [] END OF FILE */