C++实现ECDSA算法
时间: 2023-09-29 17:07:30 浏览: 376
ECDSA(Elliptic Curve Digital Signature Algorithm)是一种基于椭圆曲线密码学的数字签名算法。下面是用C++实现ECDSA算法的示例代码:
```
#include <iostream>
#include <cstring>
#include <openssl/ec.h>
#include <openssl/ecdsa.h>
#include <openssl/obj_mac.h>
#include <openssl/err.h>
using namespace std;
int main()
{
// 初始化EC_KEY对象
EC_KEY *ec_key = EC_KEY_new_by_curve_name(NID_secp256k1);
// 生成公私钥对
int ret = EC_KEY_generate_key(ec_key);
if (ret == 0) {
cout << "Failed to generate EC key pair" << endl;
return -1;
}
// 获取公钥
const EC_POINT *ec_public_key = EC_KEY_get0_public_key(ec_key);
if (ec_public_key == nullptr) {
cout << "Failed to get EC public key" << endl;
return -1;
}
// 获取私钥
const BIGNUM *ec_private_key = EC_KEY_get0_private_key(ec_key);
if (ec_private_key == nullptr) {
cout << "Failed to get EC private key" << endl;
return -1;
}
// 签名消息
string message = "Hello, world!";
unsigned char *msg = (unsigned char *)message.c_str();
int msg_len = message.length();
unsigned char *sig = nullptr;
unsigned int sig_len = 0;
EVP_MD_CTX *mdctx = EVP_MD_CTX_new();
if (mdctx == nullptr) {
cout << "Failed to create EVP_MD_CTX" << endl;
return -1;
}
if (EVP_DigestSignInit(mdctx, nullptr, EVP_sha256(), nullptr, ec_key) != 1) {
cout << "Failed to init digest sign" << endl;
return -1;
}
if (EVP_DigestSignUpdate(mdctx, msg, msg_len) != 1) {
cout << "Failed to update digest sign" << endl;
return -1;
}
if (EVP_DigestSignFinal(mdctx, nullptr, &sig_len) != 1) {
cout << "Failed to get signature length" << endl;
return -1;
}
sig = new unsigned char[sig_len];
if (EVP_DigestSignFinal(mdctx, sig, &sig_len) != 1) {
cout << "Failed to get signature" << endl;
return -1;
}
// 验证签名
if (EVP_DigestVerifyInit(mdctx, nullptr, EVP_sha256(), nullptr, ec_key) != 1) {
cout << "Failed to init digest verify" << endl;
return -1;
}
if (EVP_DigestVerifyUpdate(mdctx, msg, msg_len) != 1) {
cout << "Failed to update digest verify" << endl;
return -1;
}
if (EVP_DigestVerifyFinal(mdctx, sig, sig_len) != 1) {
cout << "Failed to verify signature" << endl;
return -1;
}
cout << "Signature verified successfully" << endl;
// 清理内存
delete[] sig;
EVP_MD_CTX_free(mdctx);
EC_KEY_free(ec_key);
return 0;
}
```
在这个示例中,我们使用OpenSSL库实现ECDSA算法。首先,我们创建一个EC_KEY对象并使用`EC_KEY_generate_key`方法生成公私钥对。然后,我们获取公私钥,并使用`EVP_DigestSignFinal`方法对消息进行签名。签名后,我们使用`EVP_DigestVerifyFinal`方法验证签名的有效性。最后,我们清理内存并退出程序。
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