Asp.net core 3.1 解密 CryptoStream 得到“输入数据不是一个完整的块”

Posted 2023-03-28

【中文标题】Asp.net core 3.1 解密 CryptoStream 得到“输入数据不是一个完整的块”

【英文标题】：Asp.net core 3.1 decrypting CryptoStream getting "The input data is not a complete block"

【发布时间】：2021-01-02 02:14:18

【问题描述】：

我正在使用这篇博文尝试在 asp.net core 3.1 中进行加密和解密。 https://tudip.com/blog-post/how-to-securely-transfer-web-api-data-in-asp-net-core/

它展示了如何使用中间件加密和解密每个请求和响应

我要加密的 JSON 字符串是 = ""pageViews":37,"subscriberCount":2"

private static Aes GetEncryptionAlgorithm()
    
        Aes aes = Aes.Create();
        aes.Key = Convert.FromBase64String("73kczzrPtnn5GXxQtOI6m4AewK34F4IkT/yaeYZxr+M=");
        aes.IV = Convert.FromBase64String("b8LAfmzY8WxGNrZeTye4hw==");
        return aes;
    

private static CryptoStream EncryptStream(Stream responseStream)
    
        Aes aes = GetEncryptionAlgorithm();
        CryptoStream base64EncodedStream = new CryptoStream(responseStream, new ToBase64Transform(), CryptoStreamMode.Write);
        CryptoStream cryptoStream = new CryptoStream(base64EncodedStream, aes.CreateEncryptor(aes.Key, aes.IV), CryptoStreamMode.Write);
        return cryptoStream;
    

string responseBody = new StreamReader(memStream).ReadToEnd();

responseBody = "ueArUlJZD2e+KaC6I/fvp1GdG0lXAVWIXJ0MPkG9"; //加密字符串。

//尝试解密

private static Stream DecryptStream(Stream cipherStream)
    
        Aes aes = GetEncryptionAlgorithm();
        CryptoStream base64DecodedStream = new CryptoStream(cipherStream, new FromBase64Transform(FromBase64TransformMode.IgnoreWhiteSpaces), CryptoStreamMode.Read);
        CryptoStream decryptedStream = new CryptoStream(base64DecodedStream, aes.CreateDecryptor(aes.Key, aes.IV), CryptoStreamMode.Read);
        return decryptedStream;
    

static async Task Main(string[] args)
    
        string text2 = "ueArUlJZD2e+KaC6I/fvp1GdG0lXAVWIXJ0MPkG9";
        MemoryStream ms = new MemoryStream();
        var streamWriter = new StreamWriter(ms);
        await streamWriter.WriteAsync(text2);
        streamWriter.Flush();
        ms.Position = 0;
        var decypted = DecryptStream(ms);
        StreamReader reader = new StreamReader(decypted);
        string text = await reader.ReadToEndAsync();

        Console.ReadLine();
    

//在reader.ReadToEndAsync()处出现异常“输入数据不是完整块”

还有一个问题 在客户端，我收到的加密字符串更短。

var httpResponseMessage = await httpclient.SendAsync(request, cancellationToken);
        var test = await httpResponseMessage.Content.ReadAsStreamAsync();
        StreamReader reader = new StreamReader(test);
        string text = reader.ReadToEnd(); // encrypted response "ueArUlJZD2e+KaC6I/fvp1GdG0lXAVWIXJ0M"

客户端收到的加密数据比服务器加密字符串短。

服务器端加密字符串 = "ueArUlJZD2e+KaC6I/fvp1GdG0lXAVWIXJ0MPkG9"; 加密字符串客户端 = "ueArUlJZD2e+KaC6I/fvp1GdG0lXAVWIXJ0M"'

【参考方案1】：

在对 CryptoStream 对象调用 Write 方法后，必须始终调用 DisposeAsync。