[转载]c#实现文件加密、解密及文件拖拽至程序图标直接打开

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[转载]『原创』c#实现文件加密、解密及文件拖拽至程序图标直接打开 – 初学博闻 of .NET CF/.Net – 博客园.

最近,工作特别忙,一直没空子来写Blog,这不,忙里偷闲,顺手写了个文件加解密的小程序,本来公司市场部的同事出去带着合同,怕弄丢了,所以让我们开发个小程序,用于加密合同文件,到客户那里解密打开,然后签订合同,最后加密,带回公司保存。

时间不充裕,也就一上午时间吧,下午就要去签合同了,嘿嘿,于是我亲自试验了一把,下面和大家分享一下吧。

首先,这是个winform的程序,部署在市场部同事的笔记本上面,基于.Net 2.0做的,它的功能大致如下:

  • 加密合同文档(*.doc)
  • 在客户处解密此合同文档,进行编辑,再次加密
  • 回到公司可以通过密码打开它

由于时间关系,只是很粗略的做了个大概。打开vs2008,建立一个winform项目,设计程序界面如下:

很简单的,待会儿在文章最后会有下载地址。我们可以把任意文件,拖入程序界面,即可进行加密,在此暂不作说明,大家可以待会儿下载回去试试,很简单的。

下面分享一下加密代码吧:

代码

using System; using System.Collections.Generic; using System.Text; using System.Security.Cryptography; using System.IO; namespace FileLock { /// <summary> /// 异常处理类 /// </summary> public class CryptoHelpException : ApplicationException { public CryptoHelpException(string msg) : base(msg) { } } public class CryptoHelp { private const ulong FC_TAG = 0xFC010203040506CF; private const int BUFFER_SIZE = 128 * 1024; /// <summary> /// 检验两个Byte数组是否相同 /// </summary> /// <param name="b1">Byte数组</param> /// <param name="b2">Byte数组</param> /// <returns>true-相等</returns> private static bool CheckByteArrays(byte[] b1, byte[] b2) { if (b1.Length == b2.Length) { for (int i = 0; i < b1.Length; ++i) { if (b1[i] != b2[i]) return false; } return true; } return false; } /// <summary> /// 创建Rijndael SymmetricAlgorithm /// </summary> /// <param name="password">密码</param> /// <param name="salt"></param> /// <returns>加密对象</returns> private static SymmetricAlgorithm CreateRijndael(string password, byte[] salt) { PasswordDeriveBytes pdb = new PasswordDeriveBytes(password, salt, "SHA256", 1000); SymmetricAlgorithm sma = Rijndael.Create(); sma.KeySize = 256; sma.Key = pdb.GetBytes(32); sma.Padding = PaddingMode.PKCS7; return sma; } /// <summary> /// 加密文件随机数生成 /// </summary> private static RandomNumberGenerator rand = new RNGCryptoServiceProvider(); /// <summary> /// 生成指定长度的随机Byte数组 /// </summary> /// <param name="count">Byte数组长度</param> /// <returns>随机Byte数组</returns> private static byte[] GenerateRandomBytes(int count) { byte[] bytes = new byte[count]; rand.GetBytes(bytes); return bytes; } /// <summary> /// 加密文件 /// </summary> /// <param name="inFile">待加密文件</param> /// <param name="outFile">加密后输入文件</param> /// <param name="password">加密密码</param> public static void EncryptFile(string inFile, string outFile, string password) { using (FileStream fin = File.OpenRead(inFile), fout = File.OpenWrite(outFile)) { long lSize = fin.Length; // 输入文件长度 int size = (int)lSize; byte[] bytes = new byte[BUFFER_SIZE]; // 缓存 int read = -1; // 输入文件读取数量 int value = 0; // 获取IV和salt byte[] IV = GenerateRandomBytes(16); byte[] salt = GenerateRandomBytes(16); // 创建加密对象 SymmetricAlgorithm sma = CryptoHelp.CreateRijndael(password, salt); sma.IV = IV; // 在输出文件开始部分写入IV和salt fout.Write(IV, 0, IV.Length); fout.Write(salt, 0, salt.Length); // 创建散列加密 HashAlgorithm hasher = SHA256.Create(); using (CryptoStream cout = new CryptoStream(fout, sma.CreateEncryptor(), CryptoStreamMode.Write), chash = new CryptoStream(Stream.Null, hasher, CryptoStreamMode.Write)) { BinaryWriter bw = new BinaryWriter(cout); bw.Write(lSize); bw.Write(FC_TAG); // 读写字节块到加密流缓冲区 while ((read = fin.Read(bytes, 0, bytes.Length)) != 0) { cout.Write(bytes, 0, read); chash.Write(bytes, 0, read); value += read; } // 关闭加密流 chash.Flush(); chash.Close(); // 读取散列 byte[] hash = hasher.Hash; // 输入文件写入散列 cout.Write(hash, 0, hash.Length); // 关闭文件流 cout.Flush(); cout.Close(); } } } /// <summary> /// 解密文件 /// </summary> /// <param name="inFile">待解密文件</param> /// <param name="outFile">解密后输出文件</param> /// <param name="password">解密密码</param> public static void DecryptFile(string inFile, string outFile, string password) { // 创建打开文件流 using (FileStream fin = File.OpenRead(inFile), fout = File.OpenWrite(outFile)) { int size = (int)fin.Length; byte[] bytes = new byte[BUFFER_SIZE]; int read = -1; int value = 0; int outValue = 0; byte[] IV = new byte[16]; fin.Read(IV, 0, 16); byte[] salt = new byte[16]; fin.Read(salt, 0, 16); SymmetricAlgorithm sma = CryptoHelp.CreateRijndael(password, salt); sma.IV = IV; value = 32; long lSize = -1; // 创建散列对象, 校验文件 HashAlgorithm hasher = SHA256.Create(); //using (CryptoStream cin = new CryptoStream(fin, sma.CreateDecryptor(), CryptoStreamMode.Read), // chash = new CryptoStream(Stream.Null, hasher, CryptoStreamMode.Write)) //{ CryptoStream cin = new CryptoStream(fin, sma.CreateDecryptor(), CryptoStreamMode.Read), chash = new CryptoStream(Stream.Null, hasher, CryptoStreamMode.Write); // 读取文件长度 BinaryReader br = new BinaryReader(cin); lSize = br.ReadInt64(); ulong tag = br.ReadUInt64(); if (FC_TAG != tag) throw new CryptoHelpException("文件被破坏或者密码不正确"); long numReads = lSize / BUFFER_SIZE; long slack = (long)lSize % BUFFER_SIZE; for (int i = 0; i < numReads; ++i) { read = cin.Read(bytes, 0, bytes.Length); fout.Write(bytes, 0, read); chash.Write(bytes, 0, read); value += read; outValue += read; } if (slack > 0) { read = cin.Read(bytes, 0, (int)slack); fout.Write(bytes, 0, read); chash.Write(bytes, 0, read); value += read; outValue += read; } chash.Flush(); chash.Close(); fout.Flush(); fout.Close(); byte[] curHash = hasher.Hash; // 获取比较和旧的散列对象 byte[] oldHash = new byte[hasher.HashSize / 8]; read = cin.Read(oldHash, 0, oldHash.Length); if ((oldHash.Length != read) || (!CheckByteArrays(oldHash, curHash))) throw new CryptoHelpException("文件被破坏"); cin.Flush(); cin.Close(); //} if (outValue != lSize) throw new CryptoHelpException("文件大小不匹配"); } } } }

是不是很明了呢?当然了,网上一搜一大把,我这个也是不小心搜到的,感觉比较不错的代码,后来经过我少许加工,即可使用了。当然,在这里,还要提一 句,这个小程序,为了让它更方便,直接拖拽文件到其图标之上,就默认打开程序,加载该文件,并进行加密操作,听起来是不是很cool!?呵呵,下面再和大 家分享一下如何实现吧:

在窗体的DragDrop和DragEnter事件下,添加如下代码:

代码

private void MainForm_DragEnter(object sender, DragEventArgs e) { if (e.Data.GetDataPresent(DataFormats.FileDrop)) e.Effect = DragDropEffects.Move; else e.Effect = DragDropEffects.None; } private void MainForm_DragDrop(object sender, DragEventArgs e) { string path = ((System.Array)e.Data.GetData(DataFormats.FileDrop)).GetValue(0).ToString(); extension = System.IO.Path.GetExtension(path);//扩展名 if (extension == ".encrypted") { btnEncy.Enabled = false; btnDecy.Enabled = true; } else { btnEncy.Enabled = true; btnDecy.Enabled = false; } txtInFile.Text = path; }

Ok,是不是很简单,这样,在程序未启动时,拖拽一个目标文件到程序图标上,程序会自动打开,并进行相应操作。具体的操作,大家可以自己创造更有意义的代码来进行操作!

最后,献上下载地址,源代码:点击下载。

希望对大家有用哦

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