sm2算法演示

• 获取曲线参数
• 生成秘钥对
• 自定义userid
• 加密解密
• 签名验签
• 输出公私钥对

#include <openssl/evp.h>
#include <string.h>
#include <openssl/ec.h>
#include <openssl/bio.h>
#include <openssl/pem.h>
#include <iostream>
#include <stdlib.h>
void sm2test() {//直接创建一个group会导致i2d方法错误，原因是没有group name,可能需要调用EC_GROUP_set_curve_name()//EC_GROUP* gm_group = create_EC_group(//	"fffffffeffffffffffffffffffffffffffffffff00000000ffffffffffffffff",//	"fffffffeffffffffffffffffffffffffffffffff00000000fffffffffffffffc",//	"28e9fa9e9d9f5e344d5a9e4bcf6509a7f39789f515ab8f92ddbcbd414d940e93",//	"32c4ae2c1f1981195f9904466a39c9948fe30bbff2660be1715a4589334c74c7",//	"bc3736a2f4f6779c59bdcee36b692153d0a9877cc62a474002df32e52139f0a0",//	"fffffffeffffffffffffffffffffffff7203df6b21c6052b53bbf40939d54123",//	"1");EC_KEY* key = EC_KEY_new();EC_GROUP* gm_group = EC_GROUP_new_by_curve_name(NID_sm2);int ret = EC_KEY_set_group(key, gm_group);using namespace std;if (!ret) {cout << "set group error" << endl;return;}//生成秘钥对ret = EC_KEY_generate_key(key);if (!ret) {cout << "EC_KEY_generate_key error" << endl;return;}const BIGNUM* pri = EC_KEY_get0_private_key(key);const EC_POINT* point = EC_KEY_get0_public_key(key);EVP_PKEY* pkey = EVP_PKEY_new();ret = EVP_PKEY_set1_EC_KEY(pkey, key);if (!ret) {cout << "EVP_PKEY_set1_EC_KEY error" << endl;return;}//如果使用create_EC_group，这里需要替换成国密算法//ret = EVP_PKEY_set_alias_type(pkey, EVP_PKEY_SM2);//if (!ret) {//	cout << "EVP_PKEY_set_alias_type error" << endl;//	return;//}EVP_PKEY_CTX* pkeyCtx = EVP_PKEY_CTX_new(pkey, NULL);//设置SM2的id,idlenconst char* id = "adgdfdfdfdfd";EVP_PKEY_CTX_set1_id(pkeyCtx, id, strlen(id));EVP_PKEY_encrypt_init(pkeyCtx);const  char* data = "hello";unsigned char* out = (unsigned char*)malloc(strlen(data) + 96);size_t  outlen = strlen(data) + 96; //如果输入数据传空，返回需要的密文空间大小，ret = EVP_PKEY_encrypt(pkeyCtx, out, &outlen, (const unsigned char*)data, strlen(data));if (!ret) {cout << "EVP_PKEY_encrypt error" << endl;return;}EVP_PKEY_decrypt_init(pkeyCtx);unsigned char debuf[10] = { 0 };size_t dlen = 10;EVP_PKEY_decrypt(pkeyCtx, debuf, &dlen, out, outlen);debuf[dlen] = '\\0';printf("%s\\n", debuf);//可以加密可以解密EVP_PKEY_sign_init(pkeyCtx);const  char* tbs = "hello";size_t signlen;ret = EVP_PKEY_sign(pkeyCtx, NULL, &signlen, (const unsigned char*)tbs, (size_t)strlen((const char*)tbs));if (!ret) {cout << "EVP_PKEY_sign error" << endl;return;}string str(signlen, '\\0');//可以签名验签ret = EVP_PKEY_sign(pkeyCtx, (unsigned char*)str.data(), &signlen, (const unsigned char*)tbs, (size_t)strlen((const char*)tbs));if (!ret) {cout << "EVP_PKEY_sign error" << endl;return;}EVP_PKEY_verify_init(pkeyCtx);ret = EVP_PKEY_verify(pkeyCtx, (unsigned char*)str.data(), signlen, (const unsigned char*)tbs, (size_t)strlen((const char*)tbs));if (!ret) {cout << "EVP_PKEY_verify error" << endl;return;}ret = PEM_write_ECPrivateKey(stdout, key, NULL, NULL, 0, NULL, NULL);if (!ret) {cout << "PEM_write_ECPrivateKey error" << endl;return;}ret = PEM_write_EC_PUBKEY(stdout, key);if (!ret) {cout << "PEM_write_EC_PUBKEY error" << endl;return;}//unsigned char* der = (unsigned char*)malloc(2048);//int derlen=i2d_EC_PUBKEY(key, &der);//if (derlen > 0) {//	cout << derlen << endl;//}
}