转自：http://www.16aspx.com/Article/3904
using System;
using System.Security.Cryptography;
using System.Text;
using System.IO; namespace SEDO
{
/// <summary>
/// SEDO 的摘要说明。
/// SEDO 实现的是用一个封装了4种对称加密方法(Des,Rc2,Rijndael,TripleDes)的组件
///
/// 注意事项：
/// 1:TripleDes和Rijndael加密/解密对象使用16或者24位byte的Key
/// 2:Rijndael只能使用16位的初始化向量IV
/// 3:Des和Rc2均使用8位Byte的Key和IV
/// 4:对需要加密/解密的数据流采用何种方法进行编码/解码，由调用组件的用户自己决定
/// 5:密钥和初始化向量IV由使用者自己定义
/// 程序员： 罗旭成2010-10-30 lxc880615@163.com
/// </summary> //定义加密类型的枚举
public enum EncryptionAlgorithm { Des = 1, Rc2, Rijndael, TripleDes }; //定义加密类
internal class EncryptTransformer
{
private EncryptionAlgorithm algorithmID;
private byte[] initVec;
private byte[] encKey; internal EncryptTransformer(EncryptionAlgorithm algId)
{
//Save the algorithm being used.
algorithmID = algId;
} internal ICryptoTransform GetCryptoServiceProvider(byte[] bytesKey)
{
//当数据密钥Key或者初始化向量IV为空的时候，
//将使用加密对象自动产生的密钥Key或者初始化向量IV
switch (algorithmID)
{
case EncryptionAlgorithm.Des:
{
DES des = new DESCryptoServiceProvider();
des.Mode = CipherMode.CBC; // See if a key was provided
if (null == bytesKey)
{
encKey = des.Key;
}
else
{
des.Key = bytesKey;
encKey = des.Key;
}
// See if the client provided an initialization vector
if (null == initVec)
{ // Have the algorithm create one
initVec = des.IV;
}
else
{ //No, give it to the algorithm
des.IV = initVec;
}
return des.CreateEncryptor();
}
case EncryptionAlgorithm.TripleDes:
{
TripleDES des3 = new TripleDESCryptoServiceProvider();
des3.Mode = CipherMode.CBC;
// See if a key was provided
if (null == bytesKey)
{
encKey = des3.Key;
}
else
{
des3.Key = bytesKey;
encKey = des3.Key;
}
// See if the client provided an IV
if (null == initVec)
{ //Yes, have the alg create one
initVec = des3.IV;
}
else
{ //No, give it to the alg.
des3.IV = initVec;
}
return des3.CreateEncryptor();
}
case EncryptionAlgorithm.Rc2:
{
RC2 rc2 = new RC2CryptoServiceProvider();
rc2.Mode = CipherMode.CBC;
// Test to see if a key was provided
if (null == bytesKey)
{
encKey = rc2.Key;
}
else
{
rc2.Key = bytesKey;
encKey = rc2.Key;
}
// See if the client provided an IV
if (null == initVec)
{ //Yes, have the alg create one
initVec = rc2.IV;
}
else
{ //No, give it to the alg.
rc2.IV = initVec;
}
return rc2.CreateEncryptor();
}
case EncryptionAlgorithm.Rijndael:
{
Rijndael rijndael = new RijndaelManaged();
rijndael.Mode = CipherMode.CBC;
// Test to see if a key was provided
if (null == bytesKey)
{
encKey = rijndael.Key;
}
else
{
rijndael.Key = bytesKey;
encKey = rijndael.Key;
}
// See if the client provided an IV
if (null == initVec)
{ //Yes, have the alg create one
initVec = rijndael.IV;
}
else
{ //No, give it to the alg.
rijndael.IV = initVec;
}
return rijndael.CreateEncryptor();
}
default:
{
throw new CryptographicException("Algorithm ID ''" +
algorithmID +
"'' not supported.");
}
}
} //加密的偏移向量
internal byte[] IV
{
get { return initVec; }
set { initVec = value; }
}
//加密的密钥
internal byte[] Key
{
get { return encKey; }
set { encKey = value; }
} } //定义解密类
internal class DecryptTransformer
{
private EncryptionAlgorithm algorithmID;
private byte[] initVec;
private byte[] encKey; internal DecryptTransformer(EncryptionAlgorithm deCryptId)
{
algorithmID = deCryptId;
} //加密的偏移向量
internal byte[] IV
{
get { return initVec; }
set { initVec = value; }
} //加密的密钥
internal byte[] Key
{
get { return encKey; }
set { encKey = value; }
} internal ICryptoTransform GetCryptoServiceProvider(byte[] bytesKey)
{
//当数据密钥Key或者初始化向量IV为空的时候，
//将使用加密对象自动产生的密钥Key或者初始化向量IV
switch (algorithmID)
{
case EncryptionAlgorithm.Des:
{
DES des = new DESCryptoServiceProvider();
des.Mode = CipherMode.CBC;
des.Key = bytesKey;
des.IV = initVec;
return des.CreateDecryptor();
}
case EncryptionAlgorithm.TripleDes:
{
TripleDES des3 = new TripleDESCryptoServiceProvider();
des3.Mode = CipherMode.CBC;
return des3.CreateDecryptor(bytesKey, initVec);
}
case EncryptionAlgorithm.Rc2:
{
RC2 rc2 = new RC2CryptoServiceProvider();
rc2.Mode = CipherMode.CBC;
return rc2.CreateDecryptor(bytesKey, initVec);
}
case EncryptionAlgorithm.Rijndael:
{
Rijndael rijndael = new RijndaelManaged();
rijndael.Mode = CipherMode.CBC;
return rijndael.CreateDecryptor(bytesKey, initVec);
}
default:
{
throw new CryptographicException("Algorithm ID ''" +
algorithmID +
"'' not supported.");
}
}
} //end GetCryptoServiceProvider } //定义加密者类
public class Encryptor
{
private EncryptTransformer transformer;
private byte[] initVec;
private byte[] encKey; public Encryptor(EncryptionAlgorithm algId)
{
transformer = new EncryptTransformer(algId);
} public byte[] Encrypt(byte[] bytesData, byte[] bytesKey, byte[] bytesIV)
{
//设置流对象用来保存加密数据字节流.
MemoryStream memStreamEncryptedData = new MemoryStream(); transformer.IV = bytesIV;
transformer.Key = bytesKey; ICryptoTransform transform =
transformer.GetCryptoServiceProvider(bytesKey);
CryptoStream encStream =
new CryptoStream(memStreamEncryptedData,
transform, CryptoStreamMode.Write); try
{
//将加密数据写进流对象
encStream.Write(bytesData, 0, bytesData.Length);
}
catch (Exception ex)
{
throw new Exception("在数据加密的时候出现错误！"+
"错误提示： \n" + ex.Message);
} //设置加密的Key和初始向量IV属性
encKey = transformer.Key;
initVec = transformer.IV; encStream.FlushFinalBlock();
encStream.Close(); //Send the data back.
return memStreamEncryptedData.ToArray();
} public byte[] IV
{
get { return initVec; }
set { initVec = value; }
} public byte[] Key
{
get { return encKey; }
set { encKey = value; }
} } //定义解密者类
public class Decryptor
{
private DecryptTransformer transformer;
private byte[] initVec;
private byte[] encKey; public Decryptor(EncryptionAlgorithm algId)
{
transformer = new DecryptTransformer(algId);
} public byte[] Decrypt(byte[] bytesData,
byte[] bytesKey, byte[] bytesIV)
{
//设置流对象用来保存解密数据字节流.
MemoryStream memStreamDecryptedData =
new MemoryStream(); //Pass in the initialization vector.
transformer.IV = bytesIV;
transformer.Key = bytesKey; ICryptoTransform transform =
transformer.GetCryptoServiceProvider(bytesKey);
CryptoStream decStream =
new CryptoStream(memStreamDecryptedData,
transform, CryptoStreamMode.Write); try
{
decStream.Write(bytesData, 0, bytesData.Length);
}
catch (Exception ex)
{
throw new Exception("在数据解密的时候出现错误！"+
"错误提示： \n" + ex.Message);
}
decStream.FlushFinalBlock();
decStream.Close();
// 返回解密数据.
return memStreamDecryptedData.ToArray();
} public byte[] IV
{
get { return initVec; }
set { initVec = value; }
} public byte[] Key
{
get { return encKey; }
set { encKey = value; }
} } //类描述：文件加密/解密类
public class SecurityFile
{
private DecryptTransformer Dec_Transformer; //解密转换器
private EncryptTransformer Enc_Transformer; //加密转换器
private byte[] initVec;
private byte[] encKey; public SecurityFile(EncryptionAlgorithm algId)
{
Dec_Transformer = new DecryptTransformer(algId);
Enc_Transformer = new EncryptTransformer(algId);
} //加密的偏移向量
internal byte[] IV
{
get { return initVec; }
set { initVec = value; }
}
//加密的密钥
internal byte[] Key
{
get { return encKey; }
set { encKey = value; }
} //功能描述：加密文件
public void EncryptFile(string inFileName,
string outFileName, byte[] bytesKey, byte[] bytesIV)
{
try
{
FileStream fin =
new FileStream(inFileName, FileMode.Open,
FileAccess.Read);
FileStream fout = new FileStream(outFileName,
FileMode.OpenOrCreate, FileAccess.Write);
fout.SetLength(0); //Create variables to help with read and write.
//This is intermediate storage for the encryption.
byte[] bin = new byte[100];
//This is the total number of bytes written.
long rdlen = 0;
//This is the total length of the input file.
long totlen = fin.Length;
//This is the number of bytes to be written at a time.
int len; Enc_Transformer.IV = bytesIV;
Enc_Transformer.Key = bytesKey; ICryptoTransform transform =
Enc_Transformer.GetCryptoServiceProvider(bytesKey);
CryptoStream encStream =
new CryptoStream(fout, transform, CryptoStreamMode.Write); //Read from the input file, then encrypt and write to the output file.
while (rdlen < totlen)
{
len = fin.Read(bin, 0, 100);
encStream.Write(bin, 0, len);
rdlen = rdlen + len;
} encStream.Close();
fout.Close();
fin.Close();
}
catch (Exception ex)
{
throw new Exception("在文件加密的时候出现错误！"+
"错误提示： \n" + ex.Message);
}
} //功能描述：解密文件
public void DecryptFile(string inFileName,
string outFileName, byte[] bytesKey, byte[] bytesIV)
{
try
{
FileStream fin =
new FileStream(inFileName, FileMode.Open,
FileAccess.Read);
FileStream fout =
new FileStream(outFileName,
FileMode.OpenOrCreate, FileAccess.Write);
fout.SetLength(0); //Create variables to help with read and write.
//This is intermediate storage for the encryption.
byte[] bin = new byte[100];
//This is the total number of bytes written.
long rdlen = 0;
//This is the total length of the input file.
long totlen = fin.Length;
//This is the number of bytes to be written at a time.
int len; Dec_Transformer.IV = bytesIV;
Dec_Transformer.Key = bytesKey; ICryptoTransform transform =
Dec_Transformer.GetCryptoServiceProvider(bytesKey);
CryptoStream encStream =
new CryptoStream(fout, transform, CryptoStreamMode.Write); //Read from the input file, then encrypt and
//write to the output file.
while (rdlen < totlen)
{
len = fin.Read(bin, 0, 100);
encStream.Write(bin, 0, len);
rdlen = rdlen + len;
}
encStream.Close();
fout.Close();
fin.Close();
}
catch (Exception ex)
{
throw new Exception("在文件加密的时候出现"+
"错误！错误提示： \n" + ex.Message);
}
}
}
}