Cryptographic decryption helper Class (symmetric encryption)

1   //Symmetric encryption Helper class2      Public Static classCryptohelper3     {4         //For more information, refer to http://www.cnblogs.com/JimmyZhang/archive/2008/10/02/Cryptograph.html5         Private StaticICryptoTransform encryptor;//Crypto Object6         Private StaticICryptoTransform decryptor;//Decryption Object7 8         Private StaticSymmetricAlgorithm Provider = Symmetricalgorithm.create ("TripleDES");9 Ten         Private Const intBufferSize =1024x768; One  A  -         /// <summary> -         ///Encryption Algorithm the         /// </summary> -         /// <param name= "key" >is 24 or 16-bit characters</param> -         /// <param name= "Encrypttext" >strings that are encrypted</param> -         /// <returns></returns> +          Public Static stringEncrypt (stringKeystringencryptedtext) -         { +PROVIDER.IV =New byte[] {0x12,0x34,0x56,0x78,0x90,0xAB,0xCD,0xEF }; AProvider. Key =Encoding.UTF8.GetBytes (key); at  -Encryptor =provider. CreateEncryptor (); -             //create a clear flow -             byte[] Clearbuffer =Encoding.UTF8.GetBytes (encryptedtext); -MemoryStream ClearStream =NewMemoryStream (clearbuffer); -  in             //create an empty ciphertext stream -MemoryStream Encryptedstream =NewMemoryStream (); to  +CryptoStream CryptoStream = -                 NewCryptoStream (Encryptedstream, Encryptor, cryptostreammode.write); the  *             //write plaintext stream to buffer $             //writes data from buffer to CryptoStreamPanax Notoginseng             intBytesread =0; -             byte[] buffer =New byte[buffersize]; the              Do +             { ABytesread = clearstream.read (buffer,0, buffersize); theCryptostream.write (Buffer,0, bytesread); +} while(Bytesread >0); -  $ Cryptostream.flushfinalblock (); $  -             //gets the encrypted text -Buffer =Encryptedstream.toarray (); the             stringstr =convert.tobase64string (buffer); -             returnstr;Wuyi         } the  -         //Decryption Algorithm Wu         /// <summary> -         /// </summary> About         /// <param name= "key" >is 24 or 16-bit characters</param> $         /// <param name= "Decryptedtext" >the decrypted string</param> -         /// <returns></returns> -          Public Static stringDecrypt (stringKeystringdecryptedtext) -         { APROVIDER.IV =New byte[] {0x12,0x34,0x56,0x78,0x90,0xAB,0xCD,0xEF }; +Provider. Key =Encoding.UTF8.GetBytes (key); the  -Decryptor =provider. CreateDecryptor (); $             byte[] Encryptedbuffer =convert.frombase64string (decryptedtext); theStream Encryptedstream =NewMemoryStream (encryptedbuffer); the  theMemoryStream ClearStream =NewMemoryStream (); theCryptoStream CryptoStream = -                 NewCryptoStream (Encryptedstream, Decryptor, cryptostreammode.read); in  the             intBytesread =0; the             byte[] buffer =New byte[buffersize]; About  the              Do the             { theBytesread = cryptostream.read (buffer,0, buffersize); +Clearstream.write (Buffer,0, bytesread); -} while(Bytesread >0); the BayiBuffer =Clearstream.getbuffer (); the             stringstr = theEncoding.UTF8.GetString (Buffer,0, (int) clearstream.length); -  -             returnstr; the         } the  the}

Cryptographic decryption helper Class (symmetric encryption)