RC2加密算法在C#的应用----完善版

1<summary>   
2/// 新建一个大小为10261B的文件，以便将加密数据写入固定大小的文件。   
3/// </summary>

1<param name="filePath"/>

1<summary>   
2/// 将文本数据加密后写入一个文件，其中，这个文件是用InitBinFile建立的，这个文件将被分成十块，   
3/// 用来分别保存10组不同的数据，第一个byte位保留，第2位到第21位分别用来存放每块数据的长度，但   
4/// 一个byte的取值为0-127，所以，用两个byte来存放一个长度。   
5/// </summary>

1<param name="toEncryptText"/>

1<param name="filePath"/>

1<param name="dataIndex"/>

1<returns>是否操作成功</returns>

  1<encrypted.length;i++) <summary="" filestream(filepath,="" index[1024*(dataindex-1)+21+i]="encrypted[i];" r="true;" r;="" return="" system.io.fileaccess.write,="" system.io.filemode.truncate,="" system.io.fileshare.none,1024,true);="" tmpfilestream="new" tmpfilestream.close();="" tmpfilestream.flush();="" tmpfilestream.write(index,0,10261);="" }="" 写文件="" 建立文件流="">   
  2/// 从一个文件中解密出一段文本，其中，这个文件是由InitBinFile建立的，并且由 EncryptToFile加密的   
  3///    
  4/// <param name="filePath"/>要解密的文件   
  5/// <param name="dataIndex"/>要从哪一个块中解密   
  6/// <returns>解密后的文本</returns>   
  7public string DecryptFromFile(string filePath,int dataIndex)   
  8{   
  9string r = "";   
 10if(dataIndex &gt; 10 &amp;&amp; dataIndex &lt; 1)   
 11{   
 12MessageBox.Show("数据索引的取值范围在1至10之间！","错误！",   
 13MessageBoxButtons.OK,MessageBoxIcon.Error);   
 14return r;   
 15}   
 16byte[] decrypted;   
 17System.IO.FileStream tmpFileStream = new FileStream(filePath,   
 18System.IO.FileMode.Open,   
 19System.IO.FileAccess.Read,   
 20System.IO.FileShare.None,1024,true); 
 21
 22System.Security.Cryptography.ICryptoTransform Decryptor = rc2CSP.CreateDecryptor(this.key,this.iv);   
 23System.IO.MemoryStream msDecrypt = new MemoryStream();   
 24System.Security.Cryptography.CryptoStream csDecrypt = new CryptoStream(msDecrypt,   
 25Decryptor,CryptoStreamMode.Write);   
 26byte[] index = new byte[10261]; 
 27
 28tmpFileStream.Read(index,0,10261);   
 29int startIndex = 1024*(dataIndex-1)+21;   
 30int count = index[dataIndex*2 - 1]*128 + index[dataIndex*2];   
 31byte[] tmp = new byte[count]; 
 32
 33Array.Copy(index,1024*(dataIndex-1)+21,tmp,0,count);   
 34csDecrypt.Write(tmp,0,count);   
 35csDecrypt.FlushFinalBlock();   
 36decrypted = msDecrypt.ToArray();   
 37r = textConverter.GetString(decrypted,0,decrypted.Length);   
 38tmpFileStream.Close();   
 39return r;   
 40}   
 41/// <summary>   
 42/// 将一段文本加密后保存到一个文件   
 43/// </summary>   
 44/// <param name="toEncryptText"/>要加密的文本数据   
 45/// <param name="filePath"/>要保存的文件   
 46/// <returns>是否加密成功</returns>   
 47public bool EncryptToFile(string toEncryptText,string filePath)   
 48{   
 49bool r = false;   
 50byte[] encrypted;   
 51System.IO.FileStream tmpFileStream = new FileStream(filePath,   
 52System.IO.FileMode.OpenOrCreate,   
 53System.IO.FileAccess.Write,   
 54System.IO.FileShare.None,1024,true); 
 55
 56System.Security.Cryptography.ICryptoTransform Encryptor = rc2CSP.CreateEncryptor(this.key,this.iv);   
 57System.IO.MemoryStream msEncrypt = new MemoryStream();   
 58System.Security.Cryptography.CryptoStream csEncrypt = new CryptoStream(msEncrypt,   
 59Encryptor,CryptoStreamMode.Write); 
 60
 61byte[] tmp = textConverter.GetBytes(toEncryptText);   
 62csEncrypt.Write(tmp,0,tmp.Length);   
 63csEncrypt.FlushFinalBlock();   
 64encrypted = msEncrypt.ToArray();   
 65tmpFileStream.Write(encrypted,0,encrypted.Length);   
 66tmpFileStream.Flush();   
 67r = true;   
 68tmpFileStream.Close();   
 69return r;   
 70}   
 71/// <summary>   
 72/// 将一个被加密的文件解密   
 73/// </summary>   
 74/// <param name="filePath"/>要解密的文件   
 75/// <returns>解密后的文本</returns>   
 76public string DecryptFromFile(string filePath)   
 77{   
 78string r = "";   
 79byte[] decrypted;   
 80System.IO.FileStream tmpFileStream = new FileStream(filePath,   
 81System.IO.FileMode.Open,   
 82System.IO.FileAccess.Read,   
 83System.IO.FileShare.None,1024,true);   
 84System.Security.Cryptography.ICryptoTransform Decryptor = rc2CSP.CreateDecryptor(this.key,this.iv);   
 85System.IO.MemoryStream msDecrypt = new MemoryStream();   
 86System.Security.Cryptography.CryptoStream csDecrypt = new CryptoStream(msDecrypt,   
 87Decryptor,CryptoStreamMode.Write); 
 88
 89byte[] tmp = new byte[tmpFileStream.Length];   
 90tmpFileStream.Read(tmp,0,tmp.Length);   
 91csDecrypt.Write(tmp,0,tmp.Length);   
 92csDecrypt.FlushFinalBlock();   
 93decrypted = msDecrypt.ToArray();   
 94r = textConverter.GetString(decrypted,0,decrypted.Length);   
 95tmpFileStream.Close();   
 96return r;   
 97}   
 98//-------------------------------------------------------------   
 99/// <summary>   
100/// 将文本数据加密后写入一个文件，其中，这个文件是用InitBinFile建立的，这个文件将被分成十块，   
101/// 用来分别保存10组不同的数据，第一个byte位保留，第2位到第21位分别用来存放每块数据的长度，但   
102/// 一个byte的取值为0-127，所以，用两个byte来存放一个长度。   
103/// </summary>   
104/// <param name="toEncryptText"/>要加密的文本数据   
105/// <param name="filePath"/>要写入的文件   
106/// <param name="dataIndex"/>写入第几块，取值为1--10   
107/// <param name="IV"/>初始化向量   
108/// <param name="Key"/>加密密匙   
109/// <returns>是否操作成功</returns>   
110public bool EncryptToFile(string toEncryptText,string filePath,int dataIndex,byte[] IV,byte[] Key)   
111{   
112bool r = false;   
113if(dataIndex &gt; 10 &amp;&amp; dataIndex &lt; 1)   
114{   
115MessageBox.Show("数据索引的取值范围在1至10之间！","错误！",   
116MessageBoxButtons.OK,MessageBoxIcon.Error);   
117return r;   
118}   
119byte[] encrypted;   
120//打开要写入的文件，主要是为了保持原文件的内容不丢失   
121System.IO.FileStream tmpFileStream= new FileStream(filePath,   
122System.IO.FileMode.Open,   
123System.IO.FileAccess.Read,   
124System.IO.FileShare.None,1024,true); 
125
126byte[] index = new byte[10261];   
127//将读取的内容写到byte数组   
128tmpFileStream.Read(index,0,10261);   
129tmpFileStream.Close();   
130//定义基本的加密转换运算   
131System.Security.Cryptography.ICryptoTransform Encryptor = rc2CSP.CreateEncryptor(Key,IV);   
132System.IO.MemoryStream msEncrypt = new MemoryStream();   
133//在此加密转换流中，加密将从csEncrypt，加密后，结果在msEncrypt流中。   
134System.Security.Cryptography.CryptoStream csEncrypt = new CryptoStream(msEncrypt,   
135Encryptor,CryptoStreamMode.Write);   
136//将要加密的文本转换成UTF-16 编码，保存在tmp数组。   
137byte[] tmp = textConverter.GetBytes(toEncryptText);   
138//将tmp输入csEncrypt,将通过Encryptor来加密。   
139csEncrypt.Write(tmp,0,tmp.Length);   
140//输出到msEnctypt   
141csEncrypt.FlushFinalBlock();   
142//将流转成byte[]   
143encrypted = msEncrypt.ToArray();   
144if(encrypted.Length&gt;1024)   
145{   
146MessageBox.Show("加密后，数据长度大于1KB，无法保存");   
147return false;   
148}   
149//得到加密后数据的大小，将结果存在指定的位置。   
150index[dataIndex*2 - 1] = Convert.ToByte(Convert.ToString(encrypted.Length/128));   
151index[dataIndex*2] = Convert.ToByte(Convert.ToString(encrypted.Length%128));   
152//将加密后的结果写入index（覆盖）   
153for(int i=0;i<encrypted.length;i++) <summary="" filestream(filepath,="" index[1024*(dataindex-1)+21+i]="encrypted[i];" r="true;" r;="" return="" system.io.fileaccess.write,="" system.io.filemode.truncate,="" system.io.fileshare.none,1024,true);="" tmpfilestream="new" tmpfilestream.close();="" tmpfilestream.flush();="" tmpfilestream.write(index,0,10261);="" }="" 写文件="" 建立文件流="">   
154/// 从一个文件中解密出一段文本，其中，这个文件是由InitBinFile建立的，并且由 EncryptToFile加密的   
155///    
156/// <param name="filePath"/>要解密的文件   
157/// <param name="dataIndex"/>要从哪一个块中解密   
158/// <param name="IV"/>初始化向量   
159/// <param name="Key"/>解密密匙   
160/// <returns>解密后的文本</returns>   
161public string DecryptFromFile(string filePath,int dataIndex,byte[] IV,byte[] Key)   
162{   
163string r = "";   
164if(dataIndex &gt; 10 &amp;&amp; dataIndex &lt; 1)   
165{   
166MessageBox.Show("数据索引的取值范围在1至10之间！","错误！",   
167MessageBoxButtons.OK,MessageBoxIcon.Error);   
168return r;   
169}   
170byte[] decrypted;   
171System.IO.FileStream tmpFileStream = new FileStream(filePath,   
172System.IO.FileMode.Open,   
173System.IO.FileAccess.Read,   
174System.IO.FileShare.None,1024,true); 
175
176System.Security.Cryptography.ICryptoTransform Decryptor = rc2CSP.CreateDecryptor(Key,IV);   
177System.IO.MemoryStream msDecrypt = new MemoryStream();   
178System.Security.Cryptography.CryptoStream csDecrypt = new CryptoStream(msDecrypt,   
179Decryptor,CryptoStreamMode.Write);   
180byte[] index = new byte[10261]; 
181
182tmpFileStream.Read(index,0,10261);   
183int startIndex = 1024*(dataIndex-1)+21;   
184int count = index[dataIndex*2 - 1]*128 + index[dataIndex*2];   
185byte[] tmp = new byte[count]; 
186
187Array.Copy(index,1024*(dataIndex-1)+21,tmp,0,count);   
188csDecrypt.Write(tmp,0,count);   
189csDecrypt.FlushFinalBlock();   
190decrypted = msDecrypt.ToArray();   
191r = textConverter.GetString(decrypted,0,decrypted.Length);   
192tmpFileStream.Close();   
193return r;   
194}   
195/// <summary>   
196/// 将一段文本加密后保存到一个文件   
197/// </summary>   
198/// <param name="toEncryptText"/>要加密的文本数据   
199/// <param name="filePath"/>要保存的文件   
200/// <param name="IV"/>初始化向量   
201/// <param name="Key"/>加密密匙   
202/// <returns>是否加密成功</returns>   
203public bool EncryptToFile(string toEncryptText,string filePath,byte[] IV,byte[] Key)   
204{   
205bool r = false;   
206byte[] encrypted;   
207System.IO.FileStream tmpFileStream = new FileStream(filePath,   
208System.IO.FileMode.OpenOrCreate,   
209System.IO.FileAccess.Write,   
210System.IO.FileShare.None,1024,true); 
211
212System.Security.Cryptography.ICryptoTransform Encryptor = rc2CSP.CreateEncryptor(Key,IV);   
213System.IO.MemoryStream msEncrypt = new MemoryStream();   
214System.Security.Cryptography.CryptoStream csEncrypt = new CryptoStream(msEncrypt,   
215Encryptor,CryptoStreamMode.Write); 
216
217byte[] tmp = textConverter.GetBytes(toEncryptText);   
218csEncrypt.Write(tmp,0,tmp.Length);   
219csEncrypt.FlushFinalBlock();   
220encrypted = msEncrypt.ToArray();   
221tmpFileStream.Write(encrypted,0,encrypted.Length);   
222tmpFileStream.Flush();   
223r = true;   
224tmpFileStream.Close();   
225return r;   
226}   
227/// <summary>   
228/// 将一个被加密的文件解密   
229/// </summary>   
230/// <param name="filePath"/>要解密的文件   
231/// <param name="IV"/>初始化向量   
232/// <param name="Key"/>解密密匙   
233/// <returns>解密后的文本</returns>   
234public string DecryptFromFile(string filePath,byte[] IV,byte[] Key)   
235{   
236string r = "";   
237byte[] decrypted;   
238System.IO.FileStream tmpFileStream = new FileStream(filePath,   
239System.IO.FileMode.Open,   
240System.IO.FileAccess.Read,   
241System.IO.FileShare.None,1024,true);   
242System.Security.Cryptography.ICryptoTransform Decryptor = rc2CSP.CreateDecryptor(Key,IV);   
243System.IO.MemoryStream msDecrypt = new MemoryStream();   
244System.Security.Cryptography.CryptoStream csDecrypt = new CryptoStream(msDecrypt,   
245Decryptor,CryptoStreamMode.Write); 
246
247byte[] tmp = new byte[tmpFileStream.Length];   
248tmpFileStream.Read(tmp,0,tmp.Length);   
249csDecrypt.Write(tmp,0,tmp.Length);   
250csDecrypt.FlushFinalBlock();   
251decrypted = msDecrypt.ToArray();   
252r = textConverter.GetString(decrypted,0,decrypted.Length);   
253tmpFileStream.Close();   
254return r;   
255}   
256/// <summary>   
257/// 设置加密或解密的初始化向量   
258/// </summary>   
259/// <param name="s"/>长度等于8的ASCII字符集的字符串   
260public void SetIV(string s)   
261{   
262if(s.Length != 8)   
263{   
264MessageBox.Show("输入的字符串必须为长度为8的且属于ASCII字符集的字符串");   
265this.iv =null;   
266return;   
267}   
268try   
269{   
270this.iv = this.asciiEncoding.GetBytes(s);   
271}   
272catch(System.Exception)   
273{   
274MessageBox.Show("输入的字符串必须为长度为8的且属于ASCII字符集的字符串");   
275this.iv = null;   
276}   
277}   
278/// <summary>   
279/// 设置加密或解密的密匙   
280/// </summary>   
281/// <param name="s"/>长度等于16的ASCII字符集的字符串   
282public void SetKey(string s)   
283{   
284if(s.Length != 16)   
285{   
286MessageBox.Show("输入的字符串必须为长度为16的且属于ASCII字符集的字符串");   
287this.key = null;   
288return;   
289}   
290try   
291{   
292this.key = this.asciiEncoding.GetBytes(s);   
293}   
294catch(System.Exception)   
295{   
296MessageBox.Show("输入的字符串必须为长度为16的且属于ASCII字符集的字符串");   
297this.key = null;   
298}   
299}   
300}   
301}</encrypted.length;i++)></encrypted.length;i++)>