openssl下aes128算法xts模式加解密运算实例

aes128算法xts接口

加密

int openssl_aes128_encrypt_xts(unsigned char *key,unsigned char *iv, unsigned char *in_buf, int in_len, unsigned char *out_buf,int* out_len)
{
    int len = 0;

    // 创建并初始化加密上下文
    EVP_CIPHER_CTX *ctx = EVP_CIPHER_CTX_new();
    if (!ctx) {
        perror("EVP_CIPHER_CTX_new failed");
        return -1;
    }
    printf("%s %d\n", __func__, __LINE__);

    // 初始化加密操作（AES-256-XTS模式）
    if (1 != EVP_EncryptInit_ex(ctx, EVP_aes_128_xts(), NULL, NULL, NULL)) {
        perror("EVP_EncryptInit_ex failed for AES-XTS mode");
        return -1;
    }

    // 设置密钥和 IV（AES-XTS模式）
    if (1 != EVP_EncryptInit_ex(ctx, NULL, NULL, key, iv)) {
        perror("EVP_EncryptInit_ex failed for key and IV");
        return -1;
    }

    if (1 != EVP_EncryptUpdate(ctx, out_buf, &len, in_buf, in_len)) {
        perror("EVP_EncryptUpdate failed");
        return -1;
    }

    // 记录加密输出的长度
    *out_len = len;

    // 完成加密
    if (1 != EVP_EncryptFinal_ex(ctx, out_buf + len, &len)) {
        perror("EVP_EncryptFinal_ex failed");
        return -1;
    }

    *out_len += len;

    // 输出密文
//    printf("Ciphertext: ");
//    data_dump(out_buf, *out_len);

    // 清理上下文
    EVP_CIPHER_CTX_free(ctx);

    return 0;
}

解密

int openssl_aes128_decrypt_xts(unsigned char *key,unsigned char *iv, unsigned char *in_buf, int in_len, unsigned char *out_buf,int* out_len)
{
    int ret = 0;
    EVP_CIPHER_CTX* ctx = NULL;
    ctx = EVP_CIPHER_CTX_new();
    printf("%s %d\n", __func__, __LINE__);

    EVP_DecryptInit_ex(ctx, EVP_aes_128_xts(), NULL, key, iv);

    if (!EVP_DecryptUpdate(ctx, out_buf, out_len, in_buf, in_len))
    {
        EVP_CIPHER_CTX_free(ctx);
        return -1;
    }

    int tmplen = 0;
    ret = EVP_DecryptFinal_ex(ctx, out_buf + *out_len, &tmplen);
    if (ret)
    {
    //        RSP_TRACE("%s EVP_DecryptFinal_ex error ret=%d\n", __func__, ret);
        EVP_CIPHER_CTX_free(ctx);
        return -2;
    }

    *out_len += tmplen;

    EVP_CIPHER_CTX_free(ctx);
    return 0;
}