c# - c#.net中的简单加密算法

Question

我正在尝试从文件中读取文本并对其进行加密并将其传递给字符串格式的函数。后来我也想解密。

我尝试了以下方法，但没有进行任何加密。有人可以建议任何简单的加密算法吗？

fileStream = store.OpenFile(strFilePath, FileMode.Open, FileAccess.Read);
strEncryptedFileStream = Encoding.Unicode.GetBytes(fileStream.ToString()).ToString();

Answer 1

使用AES。这是它的助手类。使用“简单”，或者换句话说，容易破解的加密是没有意义的。要么你希望人们能够打破它，要么你不想。选择一个众所周知且经过测试的加密标准。

如果下面的示例不能满足您的需要，您可以修改它。

using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;
using System.Diagnostics;

namespace Common.Cryptography
{
    /// <summary>
    /// AES is a symmetric 256-bit encryption algorthm.
    /// Read more: http://en.wikipedia.org/wiki/Advanced_Encryption_Standard
    /// </summary>
    public static class AES
    {
        private const string _SALT = "g46dzQ80";
        private const string _INITVECTOR = "OFRna74m*aze01xY";

        private static byte[] _saltBytes;
        private static byte[] _initVectorBytes;

        static AES()
        {
            _saltBytes = Encoding.UTF8.GetBytes(_SALT);
            _initVectorBytes = Encoding.UTF8.GetBytes(_INITVECTOR);
        }


        /// <summary>
        /// Encrypts a string with AES
        /// </summary>
        /// <param name="plainText">Text to be encrypted</param>
        /// <param name="password">Password to encrypt with</param>   
        /// <param name="salt">Salt to encrypt with</param>    
        /// <param name="initialVector">Needs to be 16 ASCII characters long</param>    
        /// <returns>An encrypted string</returns>        
        public static string Encrypt(string plainText, string password, string salt = null, string initialVector = null)
        {
            return Convert.ToBase64String(EncryptToBytes(plainText, password, salt, initialVector));
        }

        /// <summary>
        /// Encrypts a string with AES
        /// </summary>
        /// <param name="plainText">Text to be encrypted</param>
        /// <param name="password">Password to encrypt with</param>   
        /// <param name="salt">Salt to encrypt with</param>    
        /// <param name="initialVector">Needs to be 16 ASCII characters long</param>    
        /// <returns>An encrypted string</returns>        
        public static byte[] EncryptToBytes(string plainText, string password, string salt = null, string initialVector = null)
        {
            byte[] plainTextBytes = Encoding.UTF8.GetBytes(plainText);
            return EncryptToBytes(plainTextBytes, password, salt, initialVector);
        }

        /// <summary>
        /// Encrypts a string with AES
        /// </summary>
        /// <param name="plainTextBytes">Bytes to be encrypted</param>
        /// <param name="password">Password to encrypt with</param>   
        /// <param name="salt">Salt to encrypt with</param>    
        /// <param name="initialVector">Needs to be 16 ASCII characters long</param>    
        /// <returns>An encrypted string</returns>        
        public static byte[] EncryptToBytes(byte[] plainTextBytes, string password, string salt = null, string initialVector = null)
        {
            int keySize = 256;

            byte[] initialVectorBytes = string.IsNullOrEmpty(initialVector) ? _initVectorBytes : Encoding.UTF8.GetBytes(initialVector);
            byte[] saltValueBytes = string.IsNullOrEmpty(salt) ? _saltBytes : Encoding.UTF8.GetBytes(salt);
            byte[] keyBytes = new Rfc2898DeriveBytes(password, saltValueBytes).GetBytes(keySize / 8);

            using (RijndaelManaged symmetricKey = new RijndaelManaged())
            {
                symmetricKey.Mode = CipherMode.CBC;

                using (ICryptoTransform encryptor = symmetricKey.CreateEncryptor(keyBytes, initialVectorBytes))
                {
                    using (MemoryStream memStream = new MemoryStream())
                    {
                        using (CryptoStream cryptoStream = new CryptoStream(memStream, encryptor, CryptoStreamMode.Write))
                        {
                            cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);
                            cryptoStream.FlushFinalBlock();

                            return memStream.ToArray();
                        }
                    }
                }
            }
        }

        /// <summary>  
        /// Decrypts an AES-encrypted string. 
        /// </summary>  
        /// <param name="cipherText">Text to be decrypted</param> 
        /// <param name="password">Password to decrypt with</param> 
        /// <param name="salt">Salt to decrypt with</param> 
        /// <param name="initialVector">Needs to be 16 ASCII characters long</param> 
        /// <returns>A decrypted string</returns>
        public static string Decrypt(string cipherText, string password, string salt = null, string initialVector = null)
        {
            byte[] cipherTextBytes = Convert.FromBase64String(cipherText.Replace(' ','+'));
            return Decrypt(cipherTextBytes, password, salt, initialVector).TrimEnd('\0');
        }

        /// <summary>  
        /// Decrypts an AES-encrypted string. 
        /// </summary>  
        /// <param name="cipherText">Text to be decrypted</param> 
        /// <param name="password">Password to decrypt with</param> 
        /// <param name="salt">Salt to decrypt with</param> 
        /// <param name="initialVector">Needs to be 16 ASCII characters long</param> 
        /// <returns>A decrypted string</returns>
        public static string Decrypt(byte[] cipherTextBytes, string password, string salt = null, string initialVector = null)
        {
            int keySize = 256;

            byte[] initialVectorBytes = string.IsNullOrEmpty(initialVector) ? _initVectorBytes : Encoding.UTF8.GetBytes(initialVector);
            byte[] saltValueBytes = string.IsNullOrEmpty(salt) ? _saltBytes : Encoding.UTF8.GetBytes(salt);
            byte[] keyBytes = new Rfc2898DeriveBytes(password, saltValueBytes).GetBytes(keySize / 8);
            byte[] plainTextBytes = new byte[cipherTextBytes.Length];

            using (RijndaelManaged symmetricKey = new RijndaelManaged())
            {
                symmetricKey.Mode = CipherMode.CBC;

                using (ICryptoTransform decryptor = symmetricKey.CreateDecryptor(keyBytes, initialVectorBytes))
                {
                    using (MemoryStream memStream = new MemoryStream(cipherTextBytes))
                    {
                        using (CryptoStream cryptoStream = new CryptoStream(memStream, decryptor, CryptoStreamMode.Read))
                        {
                            int byteCount = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length);

                            return Encoding.UTF8.GetString(plainTextBytes, 0, byteCount);
                        }
                    }
                }
            }
        }
    }
}

Answer 2

您的代码中没有任何内容进行加密。您只是将其转换为 Unicode。

您可以看一下这个问题，它提供了一个很好的 C# 加密示例。

Answer 3

Enconding 方法涉及文本编码（UTF-8、ANSI 等），您应该使用加密算法，有几种方法可以做到这一点，一个简单的例子是使用 XOR 加密。

看到这个：

string XorEncryptDecryptText(string stringText, string stringKey){
// Variable that receives the result of processode encryption.
string stringNewText = "";
// First we take the difference in size of the two strings.
int diff = (stringText.Length - stringKey.Length);
// If the size difference that we put stringKey with the same size as the XOR stringText that no errors occur.
if (diff > 0){
    // We calculate the rest and the amount of times we repeat the stringKey to equal sizes.
    int cont = (int)diff / stringKey.Length;
    int resto = diff % stringKey.Length;
    string stringKeyAux = stringKey;
    // At this point the stringText concatenate the stringKey to be equal sizes.
    for (int i = 0; i < cont; i++){
        stringKeyAux += stringKey;
    }

    for (int i = 0; (i < resto); i++){
        stringKeyAux += stringKey[i];
    }
    stringKey = stringKeyAux;
}
// At this point piece of code is done the process of XOR.
for (int i = 0; i < stringText.Length; i++){
    int charValue = Convert.ToInt32(stringText[i]);
    int charKey = Convert.ToInt32(stringKey[i]);
    charValue ^= charKey;
    stringNewText += char.ConvertFromUtf32(charValue);
}
return stringNewText;}

string XOREncriptDecriptFile(string FileName, string stringKey){
string stringAux = System.IO.File.ReadAllLines(FileName);
return XorEncryptDecryptText(stringAux, stringKey);}

此代码基于http://julioborges.p.ht/?p=769。

为了更安全，请使用smdrager的答案