如何在Linux C++中利用多線程加速加密解密

在Linux中使用C++和多線程加速加密解密，你可以使用C++11標準中的 <thread> 庫

#include <iostream>
#include <thread>
#include <vector>
#include <mutex>
#include <openssl/aes.h>

std::mutex mtx;

void encrypt_block(unsigned char *plaintext, unsigned char *ciphertext, const AES_KEY *key, int num_blocks) {
    for (int i = 0; i < num_blocks; ++i) {
        AES_encrypt(plaintext + i * AES_BLOCK_SIZE, ciphertext + i * AES_BLOCK_SIZE, key);
    }
}

void decrypt_block(unsigned char *ciphertext, unsigned char *plaintext, const AES_KEY *key, int num_blocks) {
    for (int i = 0; i < num_blocks; ++i) {
        AES_decrypt(ciphertext + i * AES_BLOCK_SIZE, plaintext + i * AES_BLOCK_SIZE, key);
    }
}

void encrypt(unsigned char *plaintext, unsigned char *ciphertext, const AES_KEY *key, int num_blocks, int num_threads) {
    std::vector<std::thread> threads;
    int block_size = AES_BLOCK_SIZE;
    int blocks_per_thread = num_blocks / num_threads;

    for (int i = 0; i < num_threads; ++i) {
        int start_block = i * blocks_per_thread;
        int end_block = (i == num_threads - 1) ? num_blocks : start_block + blocks_per_thread;
        threads.emplace_back(encrypt_block, plaintext + start_block * block_size, ciphertext + start_block * block_size, key, end_block - start_block);
    }

    for (auto &t : threads) {
        t.join();
    }
}

void decrypt(unsigned char *ciphertext, unsigned char *plaintext, const AES_KEY *key, int num_blocks, int num_threads) {
    std::vector<std::thread> threads;
    int block_size = AES_BLOCK_SIZE;
    int blocks_per_thread = num_blocks / num_threads;

    for (int i = 0; i < num_threads; ++i) {
        int start_block = i * blocks_per_thread;
        int end_block = (i == num_threads - 1) ? num_blocks : start_block + blocks_per_thread;
        threads.emplace_back(decrypt_block, ciphertext + start_block * block_size, plaintext + start_block * block_size, key, end_block - start_block);
    }

    for (auto &t : threads) {
        t.join();
    }
}

int main() {
    // Initialize AES key
    AES_KEY key;
    AES_set_encrypt_key(reinterpret_cast<const unsigned char*>("0123456789abcdef"), 128, &key);

    // Example plaintext and ciphertext
    const int num_blocks = 16; // 128-bit blocks
    unsigned char plaintext[num_blocks * AES_BLOCK_SIZE] = { /* ... */ };
    unsigned char ciphertext[num_blocks * AES_BLOCK_SIZE] = { /* ... */ };

    // Encrypt
    encrypt(plaintext, ciphertext, &key, num_blocks, 4);

    // Decrypt
    decrypt(ciphertext, plaintext, &key, num_blocks, 4);

    return 0;
}

這個示例中，我們使用了OpenSSL庫中的AES加密和解密函數。encrypt_block 和 decrypt_block 函數分別用于加密和解密一個數據塊。encrypt 和 decrypt 函數將任務分配給多個線程，并等待它們完成。

請注意，這個示例僅用于演示目的，實際應用中可能需要根據具體需求進行調整。在實際項目中，你可能還需要考慮錯誤處理、同步和其他性能優化。