Question

在我的程序中会发生以下情况。

生成并加密随机字符串 这是加密例程：

private static readonly byte[] SALT = new byte[] { 0x26, 0xdc, 0xff, 0x00, 0xad, 0xed, 0x7a, 0xee, 0xc5, 0xfe, 0x07, 0xaf, 0x4d, 0x08, 0x22, 0x3c };
    //TODO: The SALT needs to be derived and unique for each user!

    internal  byte[] Encrypt(byte[] plain)
    {
        string password = Properties.Settings.Default.PasswordOne;
        MemoryStream memoryStream;
        CryptoStream cryptoStream;
        Rijndael rijndael = Rijndael.Create();
        rijndael.Padding = PaddingMode.Zeros;
        Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(password, SALT);
        rijndael.Key = pdb.GetBytes(32);
        rijndael.IV = pdb.GetBytes(16);
        memoryStream = new MemoryStream();
        cryptoStream = new CryptoStream(memoryStream, rijndael.CreateEncryptor(), CryptoStreamMode.Write);
        cryptoStream.Write(plain, 0, plain.Length);
        cryptoStream.Close();
        return memoryStream.ToArray();
    }

此加密字符串将保存到名为DEFT的文件中 这是保存例程：

 private void CreateDeft2(FileSystemEncryption fse, string Deft2FileName, string drive)
{
    if (DrivesLog != null) DrivesLog("Creating DEFT2");
    FileStream fs = null;
    StreamWriter sw = null;
    string location = Path.Combine(drive, Deft2FileName);
    try
    {
        fs = new FileStream(location, FileMode.CreateNew, FileAccess.Write, FileShare.None);
        sw = new StreamWriter(fs, Encoding.Unicode);

        if (DrivesLog != null) DrivesLog("Creating Random Contents");
        string fakeContents = CreateRandomString(1024000);      // Create the fake contents
        if (DrivesLog != null) DrivesLog("Converting Random Contents to Bytes");
        byte[] bFakeContents = GetBytes(fakeContents);          // Convert to bytes
        if (DrivesLog != null) DrivesLog("Encrypting Random Content Bytes");
        byte[] ebFakeContents = fse.Encrypt(bFakeContents);     // Encrypt
        if (DrivesLog != null) DrivesLog("Converting Encrypted Bytes to String");
        string sedFakeContents = GetString(ebFakeContents);     // Convert to string

        if (DrivesLog != null) DrivesLog("Writing DEFT2");
        sw.Write(sedFakeContents);                              // Write it out
        fs.Flush();                                             // Flush the buffer

        sw.Close();
        fs.Close();
        if (DrivesLog != null) DrivesLog("Successfully Created DEFT2");
    }
    catch (Exception ex)
    {
        if (DrivesLog != null) DrivesLog("Failed to Create DEFT2 " + ex.Message);
        sw.Close();
        fs.Close();
    }
}

在DEFT文件中的特定位置创建并保存另一个包含32个字符的字符串 这是代码：

private void InsertDEFT2NameLength(FileSystemEncryption fse, FileStream fs, StreamWriter sw)
    {
        if (DrivesLog != null) DrivesLog("Inserting DEFT2 Name");
        string deft2NameLength = "0";                                       // init the length
        if (DrivesLog != null) DrivesLog("Converting DEFT2 Name to Bytes");
        if (fDEFT2Name.Length < 32)
        {
            for (int idx = fDEFT2Name.Length; idx < 32; idx++)
            {
                fDEFT2Name = fDEFT2Name + "!";
            }
        }
        byte[] bdeft2Name = GetBytes(fDEFT2Name);                        // convert filename to bytes
        if (DrivesLog != null) DrivesLog("Encrypting DEFT2 Name");
        byte[] ebdeft2Name = fse.Encrypt(bdeft2Name);                       // Encrypt
        if (DrivesLog != null) DrivesLog("Getting Length of Encrypted DEFT2 Name");
        long ebdeft2NameLength = ebdeft2Name.LongLength;                    // Get Length of the Encrypted Bytes as a long
        if (DrivesLog != null) DrivesLog("Converting DEFT2 Name Length to String");
        string sebdeft2NameLength = ebdeft2NameLength.ToString();     // Convert Length to string Add Shebang so we know when we have read the full length
        if (DrivesLog != null) DrivesLog("Converting DEFT2 Name Length to Bytes");
        byte[] bsebdeft2NameLength = GetBytes(sebdeft2NameLength);          // Convert length string to bytes
        if (DrivesLog != null) DrivesLog("Encrypting DEFT2 Name Length");
        byte[] ebsebdeft2NameLength = fse.Encrypt(bsebdeft2NameLength);     // Encrypt
        if (DrivesLog != null) DrivesLog("Converting Encrypted DEFT2 Name Length to String");
        deft2NameLength = GetString(ebsebdeft2NameLength);                  // Convert to string

        if (DrivesLog != null) DrivesLog("Seeking to Correct Location");
        long startPos = GenerateDEFT2LengthStartPosition();
        fs.Seek(startPos, SeekOrigin.Current);    // Seek to correct location
        if (DrivesLog != null) DrivesLog("New Position " + startPos.ToString("N0"));
        if (DrivesLog != null) DrivesLog("Writing Encrypted Name Length to New Position");
        sw.Write(deft2NameLength);                                          // Write the Encrypted length
        fs.Flush();                                                         // Flush the buffer immediately
    }

然后我尝试解密那个新字符串。 解密字符串（或者至少应该！）

private long ReadDEFT2Len（string DEFT，long lenPos，FileSystemEncryption fse） { if（DrivesLog！= null）DrivesLog（＆＃34;读取DEFT2名称长度＆＃34;）; StringBuilder sb = new StringBuilder（）;

    FileStream fs = null;
    StreamReader sr = null;

    try
    {
        fs = new FileStream(DEFT, FileMode.Open, FileAccess.Read, FileShare.Read);
        sr = new StreamReader(fs, Encoding.Unicode);

        char[] C = new char[32];
        fs.Seek(lenPos, SeekOrigin.Begin);
        sr.Read(C, 0, 32);

        string sC = new string(C);
        byte[] bsC = GetBytes(sC);

        byte[] dRes = fse.Decrypt(bsC);
        string sbdRes = GetString(dRes);
        foreach (char ic in sbdRes)
        {
            if (ic == '!') break;
            sb.Append(ic.ToString());
        }

        sr.Close();
        fs.Close();

        if (DrivesLog != null) DrivesLog("DEFT2 Name Length = " + sb.ToString());
        return long.Parse(sb.ToString());
    }
    catch (Exception ex)
    {
        if (DrivesLog != null) DrivesLog("ERROR Reading DEFT2 Name Length " + ex.Message);
        if (sr != null) sr.Close();
        if (fs != null) fs.Close();
        return -1;
    }

}

原谅格式化 - 它只是赢得了不错！

解密例程不解密原始字符串 - 它只返回难以理解的文本。 解密路由在此处：

internal  byte[] Decrypt(byte[] cipher)
    {
        string password = Properties.Settings.Default.PasswordOne;
        MemoryStream memoryStream;
        CryptoStream cryptoStream;
        Rijndael rijndael = Rijndael.Create();
        rijndael.Padding = PaddingMode.Zeros;
        Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(password, SALT);
        rijndael.Key = pdb.GetBytes(32);
        rijndael.IV = pdb.GetBytes(16);
        memoryStream = new MemoryStream();
        cryptoStream = new CryptoStream(memoryStream, rijndael.CreateDecryptor(), CryptoStreamMode.Write);
        cryptoStream.Write(cipher, 0, cipher.Length);
        cryptoStream.FlushFinalBlock();
        cryptoStream.Close();
        return memoryStream.ToArray();
    }

它使用与加密器相同的盐。密码相同，读取的字节数相同，并且从文件中的正确位置开始。那么，任何想法为什么会这样呢？

更新1：

此代码为我提供了我将在先前创建的加密DEFT文件中插入新信息的位置。

private long GenerateDEFT2LengthStartPosition()
        {
            if (DrivesLog != null) DrivesLog("Generating DEFT2 Length Start Position");
            return long.Parse((Properties.Settings.Default.PasswordOne.Length * Properties.Settings.Default.PasswordOne.Length).ToString());
        }

只要我使用与保存时相同的密码（出于测试目的），它将返回相同的位置以插入新加密的文本。在这种情况下，它总是100返回。

但是，在Hex编辑器中使用Decimals作为偏移量时，它显示新加密的文本存储在偏移量418处。

为什么要保存这样的文字：

long startPos = GenerateDEFT2LengthStartPosition();
            fs.Seek(startPos, SeekOrigin.Current);    // Seek to correct location                
            sw.Write(deft2NameLength);

并加载它：

long lenPos = GenerateDEFT2LengthStartPosition();
 char[] C = new char[32];
                fs.Seek(lenPos, SeekOrigin.Begin);
                sr.Read(C, 0, 32);

将我置于文件中完全不同的位置？

所以问题：为什么使用相同的值100来编写和读取文件中的加密文本，将文本放在不同的位置从哪里读取？

c＃decryption产生错误结果[更新1]

0 个答案: