ecdh/ecdh.cpp at master · sunlu/ecdh · GitHub

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// ecdh.cpp : 定义 DLL 应用程序的导出函数。
//

//#include "stdafx.h"
#include "openssl/ssl.h"
#include "openssl/aes.h"
#include "openssl/rsa.h"
#include "openssl/ec.h"
#include "openssl/ecdh.h"
#include "openssl/md5.h"

#define TRUE 1
#define FALSE 0

extern "C" bool GenEcdh(int nid, unsigned char *szPriKey, int *pLenPri, unsigned char *szPubKey, int *pLenPub);
extern "C" bool DoEcdh(int nid, unsigned char * szServerPubKey, int nLenServerPub, unsigned char * szLocalPriKey, int nLenLocalPri, unsigned char * szShareKey, int *pLenShareKey);

#define MD5_DIGEST_LENGTH 16

extern "C" bool GenEcdh(int nid, unsigned char *szPriKey, int *pLenPri, unsigned char *szPubKey, int *pLenPub)
{
	if (!szPriKey || !pLenPri || !szPubKey || !pLenPub)		return FALSE;

	EC_KEY *ec_key = EC_KEY_new_by_curve_name(nid);
	if (!ec_key) return FALSE;

	int ret = EC_KEY_generate_key(ec_key);
	if (1 != ret)
	{
		EC_KEY_free(ec_key);
		ec_key = NULL;
		return FALSE;
	}
	int nLenPub = i2o_ECPublicKey(ec_key, NULL);
	unsigned char *pub_key_buf = NULL;
	ret = i2o_ECPublicKey(ec_key, &pub_key_buf);
	if (!ret)
	{
		EC_KEY_free(ec_key);
		ec_key = NULL;
		return FALSE;
	}
	memcpy(szPubKey, pub_key_buf, nLenPub);
	*pLenPub = nLenPub;

	int nLenPri = i2d_ECPrivateKey(ec_key, NULL);
	unsigned char *pri_key_buf = NULL;
	ret = i2d_ECPrivateKey(ec_key, &pri_key_buf);
	if (!ret)
	{
		EC_KEY_free(ec_key);
		ec_key = NULL;
		return FALSE;
	}
	memcpy(szPriKey, pri_key_buf, nLenPri);
	*pLenPri = nLenPri;

	if (ec_key)
	{
		EC_KEY_free(ec_key);
		ec_key = NULL;
	}
	if (pub_key_buf)
	{
		OPENSSL_free(pub_key_buf);
	}
	if (pri_key_buf)
	{
		OPENSSL_free(pri_key_buf);
	}


	return TRUE;
}


void *KDF_MD5(const void *in, size_t inlen, void *out, size_t *outlen)
{
	MD5_CTX ctx;
	MD5_Init(&ctx);
	MD5_Update(&ctx, in, inlen);
	MD5_Final((unsigned char*)out, &ctx);

	*outlen = MD5_DIGEST_LENGTH;

	return out;
}

extern "C" bool DoEcdh(int nid, unsigned char * szServerPubKey, int nLenServerPub, unsigned char * szLocalPriKey, int nLenLocalPri, unsigned char * szShareKey, int *pLenShareKey)
{
	const unsigned char *public_material = (const unsigned char *)szServerPubKey;
	const unsigned char *private_material = (const unsigned char *)szLocalPriKey;

	EC_KEY *pub_ec_key = EC_KEY_new_by_curve_name(nid);
	if (!pub_ec_key)	return FALSE;
	pub_ec_key = o2i_ECPublicKey(&pub_ec_key, &public_material, nLenServerPub);
	if (!pub_ec_key)	return FALSE;

	EC_KEY *pri_ec_key = EC_KEY_new_by_curve_name(nid);
	if (!pri_ec_key)	return FALSE;
	pri_ec_key = d2i_ECPrivateKey(&pri_ec_key, &private_material, nLenLocalPri);
	if (!pri_ec_key) return FALSE;

	if (MD5_DIGEST_LENGTH != ECDH_compute_key((void *)szShareKey, MD5_DIGEST_LENGTH, EC_KEY_get0_public_key(pub_ec_key), pri_ec_key, KDF_MD5))
	{
		EC_KEY_free(pub_ec_key);
		EC_KEY_free(pri_ec_key);

		return FALSE;
	}

	*pLenShareKey = MD5_DIGEST_LENGTH;

	if (pub_ec_key)
	{
		EC_KEY_free(pub_ec_key);
		pub_ec_key = NULL;
	}

	if (pri_ec_key)
	{
		EC_KEY_free(pri_ec_key);
		pri_ec_key = NULL;
	}

	return TRUE;
}