用C#写一个上传下载文件至OSS后返回文件路径用DES加密解密

using Aliyun.OSS; // 引入阿里云 OSS SDK
using System;
using System.IO;
using System.Security.Cryptography; // 引入 .NET Framework 中的加密库
using System.Text;

public class OSSHelper
{
    /// <summary>
    /// 将文件上传至 OSS，并使用 DES 算法加密返回的文件 URL
    /// </summary>
    /// <param name="accessKeyId">阿里云授权 Access Key Id</param>
    /// <param name="accessKeySecret">阿里云授权 Access Key Secret</param>
    /// <param name="endpoint">OSS 服务域名</param>
    /// <param name="bucketName">Bucket 名称</param>
    /// <param name="objectKey">Object Key，即在 OSS 上的文件名称</param>
    /// <param name="filePath">待上传的文件本地路径</param>
    /// <param name="desKey">DES 密钥</param>
    /// <param name="desIV">DES 向量</param>
    /// <returns>加密后的文件 URL</returns>
    public static string UploadFileToOSS(string accessKeyId, string accessKeySecret, string endpoint, string bucketName, string objectKey, string filePath, byte[] desKey, byte[] desIV)
    {
        // 创建 OSS 客户端
        var client = new OssClient(endpoint, accessKeyId, accessKeySecret);

        // 上传文件
        using (var fs = new FileStream(filePath, FileMode.Open))
        {
            client.PutObject(bucketName, objectKey, fs);
        }

        // 返回加密后的文件路径
        return EncryptString($"http://{bucketName}.{endpoint}/{objectKey}", desKey, desIV);
    }

    /// <summary>
    /// 从 OSS 上下载指定的文件，并使用 DES 算法解密文件 URL
    /// </summary>
    /// <param name="accessKeyId">阿里云授权 Access Key Id</param>
    /// <param name="accessKeySecret">阿里云授权 Access Key Secret</param>
    /// <param name="endpoint">OSS 服务域名</param>
    /// <param name="bucketName">Bucket 名称</param>
    /// <param name="objectKey">Object Key，即在 OSS 上的文件名称</param>
    /// <param name="downloadPath">下载文件保存的本地路径</param>
    /// <param name="desKey">DES 密钥</param>
    /// <param name="desIV">DES 向量</param>
    public static void DownloadFileFromOSS(string accessKeyId, string accessKeySecret, string endpoint, string bucketName, string objectKey, string downloadPath, byte[] desKey, byte[] desIV)
    {
        // 创建 OSS 客户端
        var client = new OssClient(endpoint, accessKeyId, accessKeySecret);

        // 下载文件
        var obj = client.GetObject(bucketName, objectKey);
        using (var fs = new FileStream(downloadPath, FileMode.Create))
        {
            int length = 4 * 1024;
            var buffer = new byte[length];
            var bytesRead = obj.Content.Read(buffer, 0, length);
            while (bytesRead > 0)
            {
                fs.Write(buffer, 0, bytesRead);
                bytesRead = obj.Content.Read(buffer, 0, length);
            }
        }

        // 解密文件路径并输出
        var decryptedUrl = DecryptString($"http://{bucketName}.{endpoint}/{objectKey}", desKey, desIV);
        Console.WriteLine(decryptedUrl);
    }

    /// <summary>
    /// 使用 DES 算法加密字符串
    /// </summary>
    /// <param name="plainText">待加密的字符串</param>
    /// <param name="key">DES 密钥（长度为 8）</param>
    /// <param name="iv">DES 向量（长度为 8）</param>
    /// <returns>加密后的字符串</returns>
    public static string EncryptString(string plainText, byte[] key, byte[] iv)
    {
        byte[] encrypted;
        using (var des = DES.Create())
        {
            des.Key = key;
            des.IV = iv;
            var inputBuffer = Encoding.UTF8.GetBytes(plainText);
            encrypted = des.CreateEncryptor().TransformFinalBlock(inputBuffer, 0, inputBuffer.Length);
        }
        return Convert.ToBase64String(encrypted);
    }

    /// <summary>
    /// 使用 DES 算法解密字符串
    /// </summary>
    /// <param name="cipherText">待解密的字符串</param>
    /// <param name="key">DES 密钥（长度为 8）</param>
    /// <param name="iv">DES 向量（长度为 8）</param>
    /// <returns>解密后的字符串</returns>
    public static string DecryptString(string cipherText, byte[] key, byte[] iv)
    {
        byte[] decrypted;
        using (var des = DES.Create())
        {
            des.Key = key;
            des.IV = iv;
            var inputBuffer = Convert.FromBase64String(cipherText);
            decrypted = des.CreateDecryptor().TransformFinalBlock(inputBuffer, 0, inputBuffer.Length);
        }
        return Encoding.UTF8.GetString(decrypted);
    }
}

//    在完成了上述代码之后，我们可以按照以下方式调用这些方法：
//// 定义加密所使用的 DES 密钥和向量
//byte[] desKey = Encoding.ASCII.GetBytes("01234567");
//    byte[] desIV = Encoding.ASCII.GetBytes("abcdefgh");

//    // 调用上传文件至 OSS 并加密返回 URL 的方法
//    string encryptedUrl = OSSHelper.UploadFileToOSS("your-access-key-id", "your-access-key-secret", "your-endpoint", "your-bucket-name", "test.txt", "C:\\test.txt", desKey, desIV);
//    Console.WriteLine(encryptedUrl);

//// 调用从 OSS 下载文件并解密 URL 的方法
//OSSHelper.DownloadFileFromOSS("your-access-key-id", "your-access-key-secret", "your-endpoint", "your-bucket-name", "test.txt", "C:\\download.txt", desKey, desIV);