aes算法的c++实现

以下是AES算法的C++实现代码，可以用于加密和解密：

#include <iostream>
#include <string>
#include <cstring>
#include <openssl/aes.h>

using namespace std;

string aes_encrypt(string key, string plain_text) {
    unsigned char iv[AES_BLOCK_SIZE];
    memset(iv, 0x00, AES_BLOCK_SIZE);

    AES_KEY aes_key;
    if (AES_set_encrypt_key((unsigned char*)key.c_str(), 128, &aes_key) < 0) {
        cerr << "Unable to set encryption key in AES." << endl;
        return "";
    }

    int plain_text_len = plain_text.length();
    int len = 0;
    int max_len = plain_text_len + AES_BLOCK_SIZE - plain_text_len % AES_BLOCK_SIZE;
    unsigned char* in_data = new unsigned char[max_len];
    memset(in_data, 0x00, max_len);

    memcpy(in_data, plain_text.c_str(), plain_text_len);

    unsigned char* out_data = new unsigned char[max_len];
    memset(out_data, 0x00, max_len);

    AES_cbc_encrypt(in_data, out_data, max_len, &aes_key, iv, AES_ENCRYPT);

    string encrypted_text((char*)out_data, max_len);

    delete[] in_data;
    delete[] out_data;

    return encrypted_text;
}

string aes_decrypt(string key, string encrypted_text) {
    unsigned char iv[AES_BLOCK_SIZE];
    memset(iv, 0x00, AES_BLOCK_SIZE);

    AES_KEY aes_key;
    if (AES_set_decrypt_key((unsigned char*)key.c_str(), 128, &aes_key) < 0) {
        cerr << "Unable to set decryption key in AES." << endl;
        return "";
    }

    int encrypted_text_len = encrypted_text.length();
    int len = 0;
    int max_len = encrypted_text_len + AES_BLOCK_SIZE - encrypted_text_len % AES_BLOCK_SIZE;
    unsigned char* in_data = new unsigned char[max_len];
    memset(in_data, 0x00, max_len);

    memcpy(in_data, encrypted_text.c_str(), encrypted_text_len);

    unsigned char* out_data = new unsigned char[max_len];
    memset(out_data, 0x00, max_len);

    AES_cbc_encrypt(in_data, out_data, max_len, &aes_key, iv, AES_DECRYPT);

    string decrypted_text((char*)out_data);

    delete[] in_data;
    delete[] out_data;

    return decrypted_text;
}

int main() {
    string key = "1234567890123456"; // 16-byte (128-bit) key
    string plain_text = "This is a test message.";

    string encrypted_text = aes_encrypt(key, plain_text);
    cout << "Encrypted text: " << encrypted_text << endl;

    string decrypted_text = aes_decrypt(key, encrypted_text);
    cout << "Decrypted text: " << decrypted_text << endl;

    return 0;
}

注意：需要安装OpenSSL库才能正常编译和运行此代码。