linux/server.c

// server.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include <semaphore.h>
#include <signal.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <unistd.h>
#include <zlib.h>
#include <fcntl.h>
#include <time.h>
#include <sys/stat.h>
#include <gmssl/sm4.h>
#include <gmssl/rand.h>
#include <dispatch/dispatch.h>
#include <arpa/inet.h>

#define PORT 8001
#define MAX_CLIENTS 5
#define BUFFER_SIZE 1024

// 将信号量定义为全局变量
dispatch_semaphore_t semaphore;
int log_pipe[2]; // 日志记录的管道

// 生成时间戳目录
void create_timestamp_dir(char *dir_name)
{
    time_t now = time(NULL);
    struct tm *t = localtime(&now);
    // t->tm_year：从 1900 年开始的年数，因此需要加上 1900 得到完整的年份。
    // t->tm_mon：从 0 开始的月份（0 表示 1 月），因此需要加上 1 得到实际的月份。
    // t->tm_mday：月份中的日期。
    // t->tm_hour：小时。
    // t->tm_min：分钟。
    // t->tm_sec：秒。
    sprintf(dir_name, "./files/%04d%02d%02d%02d%02d%02d",
            t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
            t->tm_hour, t->tm_min, t->tm_sec);
    mkdir("./files", 0777);
    mkdir(dir_name, 0777);
}

// 记录日志
void log_operation(const char *message)
{
    write(log_pipe[1], message, strlen(message));
}

// 文件压缩
int compress_file(const char *src, const char *dest)
{
    FILE *source = fopen(src, "rb");
    gzFile dest_file = gzopen(dest, "wb");
    if (!source || !dest_file)
        return -1;

    char buffer[BUFFER_SIZE];
    int bytes_read;
    while ((bytes_read = fread(buffer, 1, BUFFER_SIZE, source)) > 0)
    {
        gzwrite(dest_file, buffer, bytes_read);
    }
    fclose(source);
    gzclose(dest_file);
    return 0;
}

// 文件解压
int decompress_file(const char *src, const char *dest)
{
    gzFile source = gzopen(src, "rb");
    FILE *dest_file = fopen(dest, "wb");
    if (!source || !dest_file)
        return -1;

    char buffer[BUFFER_SIZE];
    int bytes_read;
    while ((bytes_read = gzread(source, buffer, BUFFER_SIZE)) > 0)
    {
        fwrite(buffer, 1, bytes_read, dest_file);
    }
    gzclose(source);
    fclose(dest_file);
    return 0;
}

// 加密文件方法
int sm4_cbc_padding_encrypt_file(const char *input_file, const char *output_file, const uint8_t *key, const uint8_t *iv)
{
    SM4_KEY enc_key;
    sm4_set_encrypt_key(&enc_key, key); // 设置加密密钥

    FILE *in_file = fopen(input_file, "rb");
    FILE *out_file = fopen(output_file, "wb");
    if (!in_file || !out_file)
    {
        perror("文件打开失败");
        return 0;
    }

    uint8_t input_block[SM4_BLOCK_SIZE];
    uint8_t output_block[SM4_BLOCK_SIZE + SM4_BLOCK_SIZE]; // 加密后可能需要填充

    size_t bytes_read, outlen;
    while ((bytes_read = fread(input_block, 1, SM4_BLOCK_SIZE, in_file)) > 0)
    {
        if (feof(in_file))
        {
            // 最后一块，带填充加密
            if (sm4_cbc_padding_encrypt(&enc_key, iv, input_block, bytes_read, output_block, &outlen) != 1)
            {
                fprintf(stderr, "加密失败。\n");
                fclose(in_file);
                fclose(out_file);
                return 0;
            }
        }
        else
        {
            // 中间块，不需要填充
            if (sm4_cbc_padding_encrypt(&enc_key, iv, input_block, SM4_BLOCK_SIZE, output_block, &outlen) != 1)
            {
                fprintf(stderr, "加密失败。\n");
                fclose(in_file);
                fclose(out_file);
                return 0;
            }
        }
        fwrite(output_block, 1, outlen, out_file);
    }

    fclose(in_file);
    fclose(out_file);
    return 1; // 成功
}

// 解密文件方法
int sm4_cbc_padding_decrypt_file(const char *input_file, const char *output_file, const uint8_t *key, const uint8_t *iv)
{
    SM4_KEY dec_key;
    sm4_set_decrypt_key(&dec_key, key); // 设置解密密钥

    FILE *in_file = fopen(input_file, "rb");
    FILE *out_file = fopen(output_file, "wb");
    if (!in_file || !out_file)
    {
        perror("文件打开失败");
        return 0;
    }

    uint8_t input_block[SM4_BLOCK_SIZE + SM4_BLOCK_SIZE]; // 假设有填充
    uint8_t output_block[SM4_BLOCK_SIZE];
    size_t bytes_read, outlen;

    while ((bytes_read = fread(input_block, 1, sizeof(input_block), in_file)) > 0)
    {
        if (feof(in_file))
        {
            // 最后一块，带填充解密
            if (sm4_cbc_padding_decrypt(&dec_key, iv, input_block, bytes_read, output_block, &outlen) != 1)
            {
                fprintf(stderr, "解密失败。\n");
                fclose(in_file);
                fclose(out_file);
                return 0;
            }
        }
        else
        {
            // 中间块，不需要处理填充
            if (sm4_cbc_padding_decrypt(&dec_key, iv, input_block, bytes_read, output_block, &outlen) != 1)
            {
                fprintf(stderr, "解密失败。\n");
                fclose(in_file);
                fclose(out_file);
                return 0;
            }
        }
        fwrite(output_block, 1, outlen, out_file);
    }

    fclose(in_file);
    fclose(out_file);
    return 1; // 成功
}

// 客户端处理线程
void *client_handler(void *arg)
{
    int client_socket = *(int *)arg;
    free(arg);

    char buffer[BUFFER_SIZE];
    // 初始化缓冲区为 0
    memset(buffer, 0, BUFFER_SIZE);

    // 接收文件名
    int bytes = read(client_socket, buffer, BUFFER_SIZE);
    if (bytes <= 0)
    {
        perror("接收文件名失败");
        return NULL;
    }
    buffer[bytes] = '\0'; // 确保以 NULL 结尾
    char file_name[256];
    snprintf(file_name, sizeof(file_name), "%s", buffer);
    printf("接收文件名：%s\n", file_name);
    // 发送 ACK 确认
    send(client_socket, "ACK", strlen("ACK"), 0);

    char origin_file_path[256], dir_name[128], file_path[256], compressed_file[256], decrypted_file[256];
    // 先生成./files目录，再生成时间戳目录，调用 create_timestamp_dir 函数，生成一个基于时间戳的目录名称，并将其存储在 dir_name 中
    create_timestamp_dir(dir_name);

    // 根据传入的文件名以及时间戳拼接生成源文件路径、加密后的文件、压缩的文件、解密的文件路径
    sprintf(origin_file_path, "%s/%s.txt", dir_name, buffer);
    sprintf(file_path, "%s/%s.enc", dir_name, buffer);
    sprintf(compressed_file, "%s/%s.gz", dir_name, buffer);
    // sprintf(decrypted_file, sizeof(decrypted_file), "%s/%s_decrypted.txt", dir_name, buffer);
    snprintf(decrypted_file, sizeof(decrypted_file), "%s/%s_decrypted.txt", dir_name, buffer);
    printf("源文件路径%s\n加密后的文件%s\n压缩的文件%s\n解密的文件路径%s\n", origin_file_path, file_path, compressed_file, decrypted_file);
    FILE *file = fopen(origin_file_path, "wb");
    if (!file)
    {
        perror("文件打开失败");
        return NULL;
    }
    // 按块读取源文件内容并保存到origin_file_path
    while (1)
    {
        int bytes = read(client_socket, buffer, BUFFER_SIZE);
        if (bytes < 0)
        {
            perror("读取数据失败");
            fclose(file);
            return NULL;
        }
        // 检测是否接收到结束标志
        if (strncmp(buffer, "EOF", 3) == 0)
            break;
        // 将数据写入文件
        if (fwrite(buffer, 1, bytes, file) != bytes)
        {
            perror("写入文件失败");
            fclose(file);
            return NULL;
        }
    }
    fclose(file);

    log_operation("文件已接收。\n");

    // 随机生成加密密钥和 IV
    uint8_t key[SM4_KEY_SIZE];
    if (rand_bytes(key, SM4_KEY_SIZE) != 1)
    {
        fprintf(stderr, "随机密钥生成失败。\n");
        return NULL;
    }
    uint8_t iv[SM4_BLOCK_SIZE];
    if (rand_bytes(iv, SM4_BLOCK_SIZE) != 1)
    {
        fprintf(stderr, "随机IV生成失败。\n");
        return NULL;
    }

    // 打印密钥和 IV
    printf("随机生成的密钥: ");
    for (size_t i = 0; i < SM4_KEY_SIZE; i++)
    {
        printf("%02X ", key[i]);
    }
    printf("\n");

    printf("随机生成的IV: ");
    for (size_t i = 0; i < SM4_BLOCK_SIZE; i++)
    {
        printf("%02X ", iv[i]);
    }
    printf("\n");

    // 加密文件
    printf("正在加密文件...\n");
    sm4_cbc_padding_encrypt_file(origin_file_path, file_path, key, iv);
    printf("文件加密完成。\n");
    char log_message_file_path[BUFFER_SIZE];
    sprintf(log_message_file_path, "文件已加密。加密文件保存路径为：%s\n", file_path);
    log_operation(log_message_file_path);
    // 压缩文件
    printf("正在压缩被加密的文件...\n");
    compress_file(file_path, compressed_file);
    printf("文件压缩完成。\n");

    // 删除加密文件
    // remove(file_path);
    char log_message_compressed_file[BUFFER_SIZE];
    sprintf(log_message_compressed_file, "文件已加密。加密文件保存路径为：%s\n", compressed_file);
    log_operation(log_message_compressed_file);

    // 等待客户端请求
    memset(buffer, 0, BUFFER_SIZE);
    read(client_socket, buffer, BUFFER_SIZE);

    if (strcmp(buffer, "DOWNLOAD") == 0)
    {
        printf("接收到下载请求...\n");

        // 读取文件名
        memset(buffer, 0, BUFFER_SIZE);
        read(client_socket, buffer, BUFFER_SIZE);
        char requested_file[256];
        snprintf(requested_file, sizeof(requested_file), "%s", buffer);
        printf("客户端请求的文件名: %s\n", requested_file);
        printf("接收到下载请求，正在解压缩文件...\n");
        decompress_file(compressed_file, decrypted_file);
        printf("文件解压缩完成。\n");

        printf("正在解密文件...\n");
        sm4_cbc_padding_decrypt_file(decrypted_file, decrypted_file, key, iv);
        printf("文件解密完成。\n");

        log_operation("文件已解压并解密，准备发送。\n");
        // 向客户端发送 "READY" 信号
        send(client_socket, "READY", strlen("READY"), 0);

        // 发送解密后的文件
        FILE *file_to_send = fopen(decrypted_file, "rb");
        while (!feof(file_to_send))
        {
            int bytes_read = fread(buffer, 1, BUFFER_SIZE, file_to_send);
            send(client_socket, buffer, bytes_read, 0);
        }
        fclose(file_to_send);

        printf("文件发送完成。\n");
        // 删除解密后的文件
        // remove(decrypted_file);
    }

    // 关闭连接
    close(client_socket);
    dispatch_semaphore_signal(semaphore);
    return NULL;
}

int main()
{

    int server_socket, client_socket;
    struct sockaddr_in server_addr, client_addr;
    socklen_t client_addr_len = sizeof(client_addr);

    // 创建服务器 socket
    server_socket = socket(AF_INET, SOCK_STREAM, 0);
    if (server_socket == -1)
    {
        perror("服务器 socket 创建失败");
        exit(EXIT_FAILURE);
    }

    // 设置服务器地址
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = INADDR_ANY;
    server_addr.sin_port = htons(PORT);

    // 绑定服务器 socket
    if (bind(server_socket, (struct sockaddr *)&server_addr, sizeof(server_addr)) == -1)
    {
        perror("绑定失败");
        close(server_socket);
        exit(EXIT_FAILURE);
    }

    // 开始监听
    if (listen(server_socket, MAX_CLIENTS) == -1)
    {
        perror("监听失败");
        close(server_socket);
        exit(EXIT_FAILURE);
    }

    // 初始化信号量
    semaphore = dispatch_semaphore_create(MAX_CLIENTS);
    if (semaphore == NULL)
    {
        fprintf(stderr, "信号量创建失败\n");
        return -1;
    }

    // 示例：客户端处理逻辑
    dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER); // 等待信号量
    // printf("客户端进入，当前资源被占用\n");

    // 创建管道
    pipe(log_pipe);
    if (fork() == 0) // 日志进程
    {
        close(log_pipe[1]); // 关闭写端
        char log_buffer[BUFFER_SIZE];
        while (read(log_pipe[0], log_buffer, BUFFER_SIZE) > 0)
        {
            printf("日志: %s\n", log_buffer);
        }
        exit(0);
    }

    printf("服务器已启动，等待客户端连接...\n");
    while (1)
    {
        dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);
        // printf("客户端进入，当前资源被占用\n");

        int client_socket = accept(server_socket, (struct sockaddr *)&client_addr, &client_addr_len);
        if (client_socket == -1)
        {
            perror("接受客户端连接失败");
            continue;
        }

        printf("客户端连接成功，地址: %s\n", inet_ntoa(client_addr.sin_addr));

        int *client_sock = malloc(sizeof(int));
        *client_sock = client_socket;

        pthread_t thread_id;
        pthread_create(&thread_id, NULL, client_handler, client_sock);
        pthread_detach(thread_id);
    }

    close(server_socket);
    // 释放信号量
    dispatch_release(semaphore);
    return 0;
}