用c++使用openssl库写一个aes加解密

好的，很高兴为您解答。关于使用 OpenSSL 库写 AES 加解密的问题，以下是一份示例代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <openssl/aes.h>

int aes_encrypt(const unsigned char *in, int in_len, unsigned char *key, unsigned char *iv, unsigned char *out)
{
    AES_KEY aes_key;
    if (AES_set_encrypt_key(key, 128, &aes_key) < 0)
        return -1;
    AES_cbc_encrypt(in, out, in_len, &aes_key, iv, AES_ENCRYPT);

    return 0;
}

int aes_decrypt(const unsigned char *in, int in_len, unsigned char *key, unsigned char *iv, unsigned char *out)
{
    AES_KEY aes_key;
    if (AES_set_decrypt_key(key, 128, &aes_key) < 0)
        return -1;
    AES_cbc_encrypt(in, out, in_len, &aes_key, iv, AES_DECRYPT);

    return 0;
}

int main()
{
    unsigned char key[] = "0123456789abcdef"; // 密钥必须是 16/24/32 字节
    unsigned char iv[] = "1234567890abcdef"; // 向量必须是 16 字节
    unsigned char in[] = "hello, world!";
    unsigned char out[64];
    unsigned char dec[64];

    // 加密
    aes_encrypt(in, strlen(in), key, iv, out);
    printf("加密后的数据: %s\n", out);

    // 解密
    aes_decrypt(out, sizeof(out), key, iv, dec);
    printf("解密后的数据: %s\n", dec);

    return 0;
}

希望这份代码对您有所帮助。如果您还有其他问题，请继续问我吧！