ECDH example

#include <errno.h>
#include <openssl/crypto.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>

#include <openssl/opensslconf.h>
#ifdef OPENSSL_FIPS
#include <openssl/fips.h>
#endif /* OPENSSL_FIPS */

#include "ica_api.h"
#include "testcase.h"
#include <openssl/obj_mac.h>

#define MAX_ECC_PRIV_SIZE		66 /* 521 bits */
#define MAX_ECDSA_SIG_SIZE		2*MAX_ECC_PRIV_SIZE


int main(int argc, char **argv)
{
	ica_adapter_handle_t adapter_handle;
	unsigned int rc;
	unsigned char shared_secret[MAX_ECC_PRIV_SIZE];
	unsigned int privlen = 0;
	unsigned int nid = NID_X9_62_prime256v1;
	ICA_EC_KEY *eckey1, *eckey2;


	rc = ica_open_adapter(&adapter_handle);
	if (rc != 0) {
		V_(printf("ica_open_adapter failed and returned %d (0x%x).\n", rc, rc));
	}

	/* Create EC key 1 */
	eckey1 = ica_ec_key_new(nid, &privlen);
	if (!eckey1) {
		printf("Unsupported curve.\n");
		return rc;
	}

	rc = ica_ec_key_generate(adapter_handle, eckey1);
	if (rc) {
		printf("EC key for curve %i could not be generated, rc=%i.\n", nid, rc);
		return rc;
	}

	/* Create EC key 2 */
	eckey2 = ica_ec_key_new(nid, &privlen);
	if (!eckey2) {
		printf("Unsupported curve.\n");
		return rc;
	}

	rc = ica_ec_key_generate(adapter_handle, eckey2);
	if (rc) {
		printf("EC key for curve %i could not be generated, rc=%i.\n", nid, rc);
		return rc;
	}

	/* Now derive the shared secret */
	rc = ica_ecdh_derive_secret(adapter_handle, eckey1, eckey2,
				shared_secret, privlen);
	if (rc) {
		printf("Shared secret could not be derived, rc=%i.\n", rc);
		return rc;
	}

	ica_close_adapter(adapter_handle);

	return rc;
}