Question

假设我的程序有一个名为“customer”的类，并且客户类是可序列化的，因此我可以读取并将其写入磁盘。客户类持有我想要加密的敏感信息，我知道可以保证文件安全的唯一方法是：

1 - 将文件序列化为磁盘

2 - 重新打开并加载文件

3 - 加密文件

4 - 将文件重写到磁盘

这样可行，但是文件可能会在未加密的状态下被拦截，而且这样做效率非常低。

相反，我想：

1 - 在内存中创建文件

2加密内存中的文件

3 - 将加密文件写入磁盘

这可能吗？如果是这样的话？提前谢谢。

Answer 1

您可以在将类序列化为文件的同时使用CryptoStream进行加密：

byte[] key = { 1, 2, 3, 4, 5, 6, 7, 8 }; // Where to store these keys is the tricky part, 
    // you may need to obfuscate them or get the user to input a password each time
byte[] iv = { 1, 2, 3, 4, 5, 6, 7, 8 };
string path = @"C:\path\to.file";

DESCryptoServiceProvider des = new DESCryptoServiceProvider();

// Encryption
using (var fs = new FileStream(path, FileMode.Create, FileAccess.Write))
using (var cryptoStream = new CryptoStream(fs, des.CreateEncryptor(key, iv), CryptoStreamMode.Write))
{
    BinaryFormatter formatter = new BinaryFormatter();

    // This is where you serialize the class
    formatter.Serialize(cryptoStream, customClass);
}

// Decryption
using (var fs = new FileStream(path, FileMode.Open, FileAccess.Read))
using (var cryptoStream = new CryptoStream(fs, des.CreateDecryptor(key, iv), CryptoStreamMode.Read))
{
    BinaryFormatter formatter = new BinaryFormatter();

    // This is where you deserialize the class
    CustomClass deserialized = (CustomClass)formatter.Deserialize(cryptoStream);
}

Answer 2

除了评论中表达的担忧之外，如果您要问的是如何处理内存中的字节并且只将它们写入文件一次，那么首先将对象序列化为内存流。加密这些字节并将它们写入文件。

using (var fileStream = File.OpenWrite(theFileName))
using (var memoryStream = new MemoryStream())
{
    // Serialize to memory instead of to file
    var formatter = new BinaryFormatter();
    formatter.Serialize(memoryStream, customer);

    // This resets the memory stream position for the following read operation
    memoryStream.Seek(0, SeekOrigin.Begin);

    // Get the bytes
    var bytes = new byte[memoryStream.Length];
    memoryStream.Read(bytes, 0, (int)memoryStream.Length);

    // Encrypt your bytes with your chosen encryption method, and write the result instead of the source bytes
    var encryptedBytes = yourCrypto.Encrypt(bytes);
    fileStream.Write(encryptedBytes, 0, encryptedBytes.Length);
}

Answer 3

很有可能，

让我们说你的课看起来像

public class Customer
{
public string Name{get;set;}
public int salary {get;set;}
}

您可以加密对象属性中保存的数据所以customer.Name ='ABC'可以成为customer.Name ='WQW'之类的东西

而不是序列化。

在反序列化时，在向用户显示数据之前必须显示数据时必须解密数据

希望这个帮助

Answer 4

我会为序列化创建一个提供属性的类。读取它（给出一个文件名）返回反序列化的对象，写入它（也给出一个文件名）序列化对象。我添加了第二个带有字符串密码的属性。使用它时，您可以加密序列化的对象字符串和nwrite到磁盘或从中读取1.加密，然后反序列化。

要加密，我建议使用密码而不是直接使用密码。不幸的是我在vb.net中只有一个代码示例：

Function Encrypt(ByVal data As String, ByVal password As String) As String
  Dim pdb As New Rfc2898DeriveBytes(password, Salt)
  Dim alg As Rijndael = Rijndael.Create()
  alg.Key = pdb.GetBytes(32)
  alg.IV = pdb.GetBytes(16)
  Dim ms As New IO.MemoryStream
  Dim cs As New CryptoStream(ms, alg.CreateEncryptor, CryptoStreamMode.Write)
  cs.Write(System.Text.Encoding.Default.GetBytes(data), 0, data.Length)
  cs.Close()
  ms.Close()
  Return Convert.ToBase64String(ms.ToArray)
End Function

Private Salt As Byte() = {100, 86, 34, 53, 11, 224, 145, 123, _
                                 237, 213, 12, 124, 45, 65, 71, 127, _
                                 135, 165, 234, 164, 127, 234, 231, 211, _
                                 10, 9, 114, 234, 44, 63, 75, 12}


Function Decrypt(ByVal data As String, ByVal password As String) As String
  Dim pdb As New Rfc2898DeriveBytes(password, Salt)
  Dim alg As Rijndael = Rijndael.Create()
  alg.Key = pdb.GetBytes(32)
  alg.IV = pdb.GetBytes(16)

  Dim ms As New IO.MemoryStream
  Dim cs As New CryptoStream(ms, alg.CreateDecryptor, CryptoStreamMode.Write)
  cs.Write(Convert.FromBase64String(data), 0, Convert.FromBase64String(data).Length)
  cs.Close()
  ms.Close()
  Return System.Text.Encoding.Default.GetString(ms.ToArray)
End Function

和

Function EncryptWithHash(ByVal data As String, ByVal passToHash As String) As String
  Dim _hash As String = getMd5Hash(passToHash)
  Dim _result As String = Encrypt(data, _hash)
  Return _result
End Function

Function DecryptWithHash(ByVal data As String, ByVal passToHash As String) As String
  Dim _hash As String = getMd5Hash(passToHash)
  Dim _result As String = Encrypt(data, _hash)
  Return _result
End Function

Function getMd5Hash(ByVal input As String) As String
  ' Create a new instance of the MD5CryptoServiceProvider object.
  Dim md5Hasher As New MD5CryptoServiceProvider()

  ' Convert the input string to a byte array and compute the hash.
  Dim data As Byte() = md5Hasher.ComputeHash(Encoding.Default.GetBytes(input))

  ' Create a new Stringbuilder to collect the bytes
  ' and create a string.
  Dim sBuilder As New StringBuilder()

  ' Loop through each byte of the hashed data 
  ' and format each one as a hexadecimal string.
  Dim i As Integer
  For i = 0 To data.Length - 1
    sBuilder.Append(data(i).ToString("x2"))
  Next i

  ' Return the hexadecimal string.
  Return sBuilder.ToString()
End Function

我的代码中的属性有Get：

    Dim _dataC As String = ReadFile(filename)

    Dim _dataR As String = Crypt.Decrypt(_dataC, password)

    Dim _result = tmpS.ReadString(_dataR)

和设置：

    Dim _tmpS As New Custom.Serialization(Of Object)
    Dim _tmpRaw As String = _tmpS.WriteString(value)

    Dim _tmpCrypt As String = Crypt.Encrypt(_tmpRaw, password)

WriteFile(tmpPath, _tmpCrypt)

您必须定义自己的序列化，并读取/写入文件：

My.Computer.FileSystem.WriteAllText(filename, data, False)

_result = My.Computer.FileSystem.ReadAllText(FileName)

C＃在写入磁盘之前加密序列化文件

4 个答案: