用c++实现aes128加密

可以使用 OpenSSL 库来实现 AES128 加密，以下是一个简单的示例代码：

#include <openssl/aes.h>

void aes128_encrypt(unsigned char *plaintext, int plaintext_len, unsigned char *key, unsigned char *iv, unsigned char *ciphertext) {
    AES_KEY aes_key;
    AES_set_encrypt_key(key, 128, &aes_key);
    AES_cbc_encrypt(plaintext, ciphertext, plaintext_len, &aes_key, iv, AES_ENCRYPT);
}

void aes128_decrypt(unsigned char *ciphertext, int ciphertext_len, unsigned char *key, unsigned char *iv, unsigned char *plaintext) {
    AES_KEY aes_key;
    AES_set_decrypt_key(key, 128, &aes_key);
    AES_cbc_encrypt(ciphertext, plaintext, ciphertext_len, &aes_key, iv, AES_DECRYPT);
}

其中，`plaintext` 是明文，`plaintext_len` 是明文长度，`key` 是密钥，`iv` 是初始化向量，`ciphertext` 是密文。`aes128_encrypt` 函数用于加密，`aes128_decrypt` 函数用于解密。