DES加密、解密字符串算法(java版)

 package siyue; import java.security.Key; import java.security.SecureRandom; import javax.crypto.Cipher; import javax.crypto.KeyGenerator; import sun.misc.BASE64Decoder; import sun.misc.BASE64Encoder; public class DES { Key key; public DES(String str) { setKey(str);//生成密匙 } public DES() { setKey("siyue_qi"); } /** * 根据参数生成KEY */ public void setKey(String strKey) { try { KeyGenerator _generator = KeyGenerator.getInstance("DES"); _generator.init(new SecureRandom(strKey.getBytes())); this.key = _generator.generateKey(); _generator = null; } catch (Exception e) { throw new RuntimeException( "Error initializing SqlMap class. Cause: " + e); } } /** * 加密String明文输入,String密文输出 */ 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) { throw new RuntimeException( "Error initializing SqlMap class. Cause: " + e); } finally { base64en = null; byteMing = null; byteMi = null; } return strMi; } /** * 解密 以String密文输入,String明文输出 * @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) { throw new RuntimeException( "Error initializing SqlMap class. Cause: " + e); } finally { base64De = null; byteMing = null; byteMi = null; } return strMing; } /** * 加密以byte[]明文输入,byte[]密文输出 * @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) { throw new RuntimeException( "Error initializing SqlMap class. Cause: " + e); } finally { cipher = null; } return byteFina; } /** * 解密以byte[]密文输入,以byte[]明文输出 * @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) { throw new RuntimeException( "Error initializing SqlMap class. Cause: " + e); } finally { cipher = null; } return byteFina; } public static void main(String args[]) { DES des = new DES(); // 设置密钥 //des.setKey("12345678"); String str1 = "密文"; //DES加密 String str2 = des.getEncString(str1); String deStr = des.getDesString(str2); System.out.println("密文:" + str2); //DES解密 System.out.println("明文:" + deStr); } } 本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/siyue_qi/archive/2008/05/28/2490858.aspx 

本文转自：http://blog.csdn.net/siyue_qi/archive/2008/05/28/2490858.aspx

另外给大家介绍一个学算法好的地方

去这里，无数的密码学源程序，对称的、非对称的、单向散列的···应有尽有。  
  ftp://ftp.funet.fi/pub/crypt/  
  ftp://ftp.funet.fi/pub/crypt/cryptography/