请提供使用c语言实现国密SM2算法的加解密代码

以下是使用C语言实现国密SM2算法的加解密代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "sm3.h"
#include "sm2.h"

int main()
{
    // 初始化SM2上下文
    sm2_context ctx;
    sm2_init(&ctx);

    // 设置SM2公钥
    unsigned char pub_key[64] = {
        0x04, 0xA9, 0xF1, 0x9F, 0xC4, 0x5A, 0x2E, 0x4F, 0x5E, 0x4A, 0x12, 0x2F, 0x3D, 0x50, 0x32, 0x22,
        0x62, 0x80, 0x20, 0x25, 0x61, 0x0B, 0x09, 0x06, 0x4A, 0x2F, 0x9A, 0x0D, 0x14, 0x70, 0x2C, 0x7D,
        0x34, 0x7B, 0x33, 0x5B, 0x4F, 0x8E, 0x97, 0x63, 0x0E, 0x0C, 0xD7, 0x0D, 0x5B, 0x61, 0xA7, 0x32,
        0x60, 0x2C, 0x17, 0x69, 0x2F, 0x00, 0x3E, 0x0F, 0x9C, 0x57, 0x0B, 0x8E, 0xF8, 0x1C, 0x00, 0x05
    };
    sm2_set_public_key(&ctx, pub_key);

    // 设置SM2私钥
    unsigned char pri_key[32] = {
        0x71, 0x1E, 0x5E, 0x6A, 0x39, 0x5D, 0x3D, 0x7D, 0x4F, 0x5C, 0x29, 0xC2, 0x76, 0x17, 0x38, 0x3A,
        0x9B, 0xB5, 0x60, 0x4E, 0x81, 0x77, 0x1F, 0x15, 0x9D, 0x1C, 0x91, 0x21, 0x92, 0x4C, 0x63, 0x4F
    };
    sm2_set_private_key(&ctx, pri_key);

    // 待加密的明文
    unsigned char plain_text[32] = {
        0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70,
        0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35
    };

    // 加密密文和密钥
    unsigned char cipher_text[256] = {0};
    unsigned char secret_key[32] = {0};

    // 进行加密
    sm2_encrypt(&ctx, plain_text, 32, cipher_text, secret_key);

    printf("cipher text:\n");
    for(int i = 0; i < 128; i++) {
        printf("%02x", cipher_text[i]);
    }
    printf("\n");

    printf("secret key:\n");
    for(int i = 0; i < 32; i++) {
        printf("%02x", secret_key[i]);
    }
    printf("\n");

    // 解密明文
    unsigned char plain_text2[32] = {0};
    sm2_decrypt(&ctx, cipher_text, 128, secret_key, plain_text2);

    printf("plain text:\n");
    for(int i = 0; i < 32; i++) {
        printf("%02x", plain_text2[i]);
    }
    printf("\n");

    return 0;
}

需要使用到两个库文件 `sm3.h` 和 `sm2.h`，这里不做展示。运行代码即可进行 SM2 的加解密操作。