# 从私钥中获取公钥算法
void gm_get_publickey_from_privatekey(gm_point_t * p, const gm_bn_t key) {
// 从私钥中计算公钥
gm_point_mul(p, key, GM_MONT_G);
}
1
2
3
4
2
3
4
# 密钥对生成
/**
* 生成SM2密钥对
* @param private_key 私钥输出缓冲区
* @param public_key 公钥输出缓冲区
*/
void gm_sm2_gen_keypair(gm_bn_t private_key, gm_point_t * public_key) {
unsigned char buf[256];
do {
// rand private_key in [1, n - 2]
do {
do {
randombytes(buf, 256);
#ifdef GM_RAND_SM3
gm_sm3(buf, 256, buf);
#endif
gm_bn_from_bytes(private_key, buf);
} while (gm_bn_cmp(private_key, GM_BN_N_SUB_ONE) >= 0);
} while (gm_bn_is_zero(private_key));
// 从私钥中计算公钥
gm_point_mul(public_key, private_key, GM_MONT_G);
// check public key
} while(gm_sm2_check_public_key(public_key) != 1);
}
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
单元测试代码：
void test_sm2_gen_keypair() {
gm_bn_t k;
gm_point_t p;
int i;
gm_sm2_gen_keypair(k, &p);
char buf[132] = {0};
gm_bn_to_hex(k, buf);
printf("private key: %s\n", buf);
gm_point_encode(&p, buf, 1);
for (i = 0; i < 33; i++) {
sprintf(buf + 33 + i * 2, "%02X", (buf[i] & 0x0FF));
}
buf[99] = 0;
printf("public key compressed: %s\n", buf + 33);
gm_point_to_hex(&p, buf);
buf[128] = 0;
printf("public key: 04%s\n", buf);
}
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
main函数增加：
if(strcmp(argv[1], "sm2_gen_keypair") == 0) {
test_sm2_gen_keypair();
}
1
2
3
2
3
执行结果：
192:c saint$ time ./gm_test sm2_gen_keypair
private key: 79A7804B09D7E7C42D9154E1178B7DB150BDFF9BEBE827E956F6715AAB397682
public key compressed: 0219AB8F767E970A8AEBB269E9321336A2609A95A25EF9EFA4318F945158FFA259
public key: 0419AB8F767E970A8AEBB269E9321336A2609A95A25EF9EFA4318F945158FFA2598B3ED65CD88ADCE1683B9A59701E8FCCBC79303565FA134D8F676666387A3CC6
real 0m0.014s
user 0m0.009s
sys 0m0.003s
1
2
3
4
5
6
7
8
2
3
4
5
6
7
8
未经本人同意，禁止转载！