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using system;
using system.io;
using system.text;
using system.security.cryptography;
namespace common
{
/// <summary>
/// securityservice 的摘要說明。
/// </summary>
public class securityservice
{
static protected byte[] bytekey = {125, 14, 45, 67, 112, 79, 77, 99, 37, 104, 13, 9, 118, 51, 87, 108};
static protected byte[] byteiv = {86, 19, 79, 15, 72, 58, 117, 45};
static public string symmetricencrypt(string splaintext)
{
byte[] byteplaintext;
memorystream encryptedstream;
icryptotransform encryptor;
cryptostream thecryptostream;
if(splaintext=="") return "";
byteplaintext = encoding.ascii.getbytes(splaintext);
encryptedstream = new memorystream(splaintext.length);
encryptor = getencryptor();
thecryptostream = new cryptostream(encryptedstream, encryptor, cryptostreammode.write);
thecryptostream.write(byteplaintext, 0, byteplaintext.length);
thecryptostream.flushfinalblock();
thecryptostream.close();
return convert.tobase64string(encryptedstream.toarray());
}//end function
static public string symmetricdecrypt(string sencryptedtext)
{
byte[] byteencrypted;
memorystream plaintextstream;
icryptotransform decryptor;
cryptostream thecryptostream;
if (sencryptedtext == "") return "";
byteencrypted = convert.frombase64string(sencryptedtext.trim());
plaintextstream = new memorystream(sencryptedtext.length);
decryptor = getdecryptor();
thecryptostream = new cryptostream(plaintextstream, decryptor, cryptostreammode.write);
thecryptostream.write(byteencrypted, 0, byteencrypted.length);
thecryptostream.flushfinalblock();
thecryptostream.close();
return encoding.ascii.getstring(plaintextstream.toarray());
}//end function
static private icryptotransform getencryptor()
{
rc2cryptoserviceprovider cryptoprovider = new rc2cryptoserviceprovider();
cryptoprovider.mode = ciphermode.cbc;
return cryptoprovider.createencryptor(bytekey, byteiv);
}//end function
static private icryptotransform getdecryptor()
{
rc2cryptoserviceprovider cryptoprovider = new rc2cryptoserviceprovider();
cryptoprovider.mode = ciphermode.cbc;
return cryptoprovider.createdecryptor(bytekey, byteiv);
}//end function
}
}
