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仍然是一个“多重处置”问题,即使已处理

ca2202 .net c#

blcamp · 技术社区 · 7 年前

在我的一些项目中,我使用了一对经过验证的数据加密/解密方法(下面粘贴了加密方法)。但是我一直被这个关于memoryStream对象的唠叨的CA2202警告(“不要多次处理对象”)困扰着。我相信我以适当的方式处理了这个问题,但是每当我在visualstudio中运行分析时仍然会收到警告。它从未在生产代码中抛出异常,但我仍然希望彻底消除警告。有可能吗?或者我应该忽略它?提前谢谢。

public static string Encrypt(string clearText, string passPhrase, string saltValue)
{
    byte[] clearTextBytes = Encoding.UTF8.GetBytes(clearText);
    byte[] saltValueBytes = Encoding.UTF8.GetBytes(saltValue);

    Rfc2898DeriveBytes passPhraseDerviedBytes = new Rfc2898DeriveBytes(passPhrase, saltValueBytes);
    byte[] keyBytes = passPhraseDerviedBytes.GetBytes(32);
    byte[] initVectorBytes = passPhraseDerviedBytes.GetBytes(16);

    RijndaelManaged symmetricKey = new RijndaelManaged() { Mode = CipherMode.CBC };
    ICryptoTransform encryptor = symmetricKey.CreateEncryptor(keyBytes, initVectorBytes);

    byte[] cipherTextBytes = null;
    MemoryStream memoryStream = null;
    try
    {
        memoryStream = new MemoryStream();
        using (CryptoStream cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write))
        {
            cryptoStream.Write(clearTextBytes, 0, clearTextBytes.Length);
            cryptoStream.FlushFinalBlock();
            cipherTextBytes = memoryStream.ToArray();
        }
    }
    finally
    {
        if (memoryStream != null)
        {
            memoryStream.Dispose();
        }
    }

    return Convert.ToBase64String(cipherTextBytes);
}

2 回复 | 直到 7 年前

Guy 7 年前

是因为 CryptoStream memoryStream

您正在使用构造函数

public CryptoStream(Stream stream, ICryptoTransform transform, CryptoStreamMode mode)
    : this(stream, transform, mode, false) {
}

哪个电话

public CryptoStream(Stream stream, ICryptoTransform transform, CryptoStreamMode mode, bool leaveOpen) {
    _stream = stream;
    _leaveOpen = leaveOpen;
    //...
}

_leaveOpen _stream 以后用于 Dispose

protected override void Dispose(bool disposing) {
    try {
        if (!_leaveOpen) {
            _stream.Close();
        }
        //...
    }
}

您可以删除 memoryStream.Dispose(); ,或通过 true 作为参数 标准接口 建造师

using (CryptoStream cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write, true)) { }

github source code reference

Camilo Terevinto Chase R Lewis 7 年前

CryptoStream.Dispose 可以对给定流调用dispose:

protected override void Dispose(bool disposing) 
{
    try 
    {
        if (disposing) 
        {
            if (!_finalBlockTransformed) 
            {
                FlushFinalBlock();
            }
            if (!_leaveOpen) 
            {
                _stream.Close();
            }
        }
    }
    ...
}

如果使用接受4个参数的构造函数:

CryptoStream(Stream stream, ICryptoTransform transform, CryptoStreamMode mode, bool leaveOpen)

最后一个参数决定流是否关闭。使命感 Close() Dispose :

public virtual void Close()
{
    /* These are correct, but we'd have to fix PipeStream & NetworkStream very carefully.
    Contract.Ensures(CanRead == false);
    Contract.Ensures(CanWrite == false);
    Contract.Ensures(CanSeek == false);
    */

    Dispose(true);
    GC.SuppressFinalize(this);
}

MemoryStream 在大多数情况下并不重要。