DES-JAVA Encryption

/* Des Java

Complied OK with eclipse

Create a desencrypt class, copy the following code, and compile it.

*/
Import java. Security. Key;
Import java. Security. securerandom;
Import javax. crypto. cipher;
Import javax. crypto. keygenerator;

Import sun. Misc. base64decoder;
Import sun. Misc. base64encoder;

/**
*
* Use des to encrypt and decrypt byte [] and string types.
* The ciphertext can be stored using string, byte.
*
* Method:
* Void getkey (string strkey) generates a key from the strkey note
*
* String getencstring (string strming) encrypts strming and returns the string ciphertext.
* String getdesstring (string strmi) decrypts strmin and returns the string plaintext.
*
* Byte [] getenccode (byte [] bytes) byte [] Encryption
* Byte [] getdescode (byte [] byted) byte [] type decryption
*/

Public class desencrypt
{
Key key;

/**
* Generate a key based on the parameter
* @ Param strkey
*/
Public void getkey (string strkey)
{
Try {
Keygenerator _ generator = keygenerator. getinstance ("des ");
_ Generator. INIT (New securerandom (strkey. getbytes ()));
This. Key = _ generator. generatekey ();
_ Generator = NULL;
} Catch (exception e ){
E. printstacktrace ();
}
}
/**
* Encrypted string plaintext input and string ciphertext output
* @ Param strming
* @ Return
*/
Public String getencstring (string strming)
{
Byte [] bytemi = NULL;
Byte [] byteming = NULL;
String strmi = "";
Base64encoder base64en = new base64encoder ();
Try
{
Byteming = strming. getbytes ("utf8 ");
Bytemi = This. getenccode (byteming );
Strmi = base64en. encode (bytemi );
}
Catch (exception E)
{
E. printstacktrace ();
}
Finally
{
Base64en = NULL;
Byteming = NULL;
Bytemi = NULL;
}
Return strmi;
}
/**
* Decryption is input in string ciphertext and output in string plaintext.
* @ Param strmi
* @ Return
*/
Public String getdesstring (string strmi)
{
Base64decoder base64de = new base64decoder ();
Byte [] byteming = NULL;
Byte [] bytemi = NULL;
String strming = "";
Try
{
Bytemi = base64de. decodebuffer (strmi );
Byteming = This. getdescode (bytemi );
Strming = new string (byteming, "utf8 ");
}
Catch (exception E)
{
E. printstacktrace ();
}
Finally
{
Base64de = NULL;
Byteming = NULL;
Bytemi = NULL;
}
Return strming;
}
/**
* Encryption is input in byte [] plaintext, and byte [] ciphertext is output.
* @ Param bytes
* @ Return
*/
Private byte [] getenccode (byte [] bytes)
{
Byte [] bytefina = NULL;
Cipher cipher;
Try
{
Cipher = cipher. getinstance ("des ");
Cipher. INIT (Cipher. encrypt_mode, key );
Bytefina = cipher. dofinal (bytes );
}
Catch (exception E)
{
E. printstacktrace ();
}
Finally
{
Cipher = NULL;
}
Return bytefina;
}
/**
* Decryption is input in byte [] ciphertext and output in byte [] plaintext
* @ Param byted
* @ Return
*/
Private byte [] getdescode (byte [] byted)
{
Cipher cipher;
Byte [] bytefina = NULL;
Try {
Cipher = cipher. getinstance ("des ");
Cipher. INIT (Cipher. decrypt_mode, key );
Bytefina = cipher. dofinal (byted );
} Catch (exception e ){
E. printstacktrace ();
} Finally {
Cipher = NULL;
}
Return bytefina;

}

Public static void main (string [] ARGs ){

System. Out. println ("des Demo ");
Desencrypt des = new desencrypt (); // instantiate an object
Des. getkey ("mykey11"); // generate a key
System. Out. println ("Key = mykey11 ");
String strenc = des. getencstring ("China"); // encrypted string, returns the ciphertext of string
System. Out. println ("ciphertext =" + strenc );

String strdes = des. getdesstring (strenc); // decrypt the string-type ciphertext.
System. Out. println ("plaintext =" + strdes );

}

}

/*

Running result:

Des demo
Key = mykey11
Ciphertext = n2r7f/mmyiy =
Plaintext = China

*/

This article from the csdn blog, reproduced please indicate the source: http://blog.csdn.net/chinayaosir/archive/2008/10/20/3111507.aspx