BASE64, MD5, SHA, and HMAC encryption algorithms

The code is as follows:

Copy code

Package com. ice. webos. util. security;   Import java. io. UnsupportedEncodingException; Import java. math. BigInteger; Import java. security. Key; Import java. security. MessageDigest; Import java. security. SecureRandom;   Import javax. crypto. Cipher; Import javax. crypto. KeyGenerator; Import javax. crypto. Mac; Import javax. crypto. SecretKey; Import javax. crypto. SecretKeyFactory; Import javax. crypto. spec. DESKeySpec; Import javax. crypto. spec. SecretKeySpec;   Import sun. misc. BASE64Decoder; Import sun. misc. BASE64Encoder;   /** * <Ul> * <Li> BASE64 encryption and decryption are bidirectional and can be reversed. </Li> * <Li> MD5, SHA, and HMAC are unidirectional encryption. After any data is encrypted, only one unique encryption string is generated, which is usually used to verify whether the data is modified during transmission. </Li> * <Li> The HMAC algorithm has a key that enhances the security during data transmission and the uncontrollable factors outside the algorithm. </Li> * <Li> DES-Data Encryption Standard, which is the Data Encryption algorithm. * The DES algorithm has three Entry parameters: Key, Data, and Mode. * <Ul> * <Li> Key: The 8-byte 64-bit Key used by the DES algorithm. </li> * <Li> Data: 8-byte 64-bit. It is the Data to be encrypted or decrypted. </li> * <Li> Mode: DES can be encrypted or decrypted. </Li> * </Ul> * </Li> * <Ul>   * * @ Author Ice_Liu   * */ Public class CryptUtil { Private static final String KEY_MD5 = "MD5 "; Private static final String KEY_SHA = "SHA "; /** * The MAC algorithm can be any of the following algorithms:       * * <Pre>       *  * HmacMD5 * HmacSHA1 * HmacSHA256 * HmacSHA384 * HmacSHA512 * </Pre> */ Public static final String KEY_MAC = "HmacMD5 ";   /** * BASE64 decryption       * * @ Param key * @ Return * @ Throws Exception */ Public static byte [] decryptBASE64 (String key) throws Exception { Return (new BASE64Decoder (). decodeBuffer (key );      }   /** * BASE64 encryption       * * @ Param key * @ Return * @ Throws Exception */ Public static String encryptBASE64 (byte [] key) throws Exception { Return (new BASE64Encoder (). encodeBuffer (key );      }   /** * MD5 encryption       * * @ Param data * @ Return * @ Throws Exception */ Public static byte [] encryptMD5 (byte [] data) throws Exception {   MessageDigest md5 = MessageDigest. getInstance (KEY_MD5 ); Md5.update (data );   Return md5.digest ();        }   /** * SHA encryption       * * @ Param data * @ Return * @ Throws Exception */ Public static byte [] encryptSHA (byte [] data) throws Exception {   MessageDigest sha = MessageDigest. getInstance (KEY_SHA ); Sha. update (data );   Return sha. digest ();        }   /** * Initialize the HMAC key.       * * @ Return * @ Throws Exception */ Public static String initMacKey () throws Exception { KeyGenerator keyGenerator = KeyGenerator. getInstance (KEY_MAC ); SecretKey secretKey = keyGenerator. generateKey (); Return encryptBASE64 (secretKey. getEncoded ());      }   /** * HMAC encryption       * * @ Param data * @ Param key * @ Return * @ Throws Exception */ Public static byte [] encryptHMAC (byte [] data, String key) throws Exception { SecretKey secretKey = new SecretKeySpec (decryptBASE64 (key), KEY_MAC ); Mac mac = Mac. getInstance (secretKey. getAlgorithm ()); Mac. init (secretKey ); Return mac. doFinal (data );      }   /** * DES algorithm <br> * It can be replaced by any of the following algorithms, and the size of the key value changes accordingly.       * * <Pre> * DES key size must be equal to 56 * DESede (TripleDES) key size must be equal to 112 or 168 * AES key size must be equal to 128,192 or 256, but 192 and 256 bits may not be available * Blowfish key size must be multiple of 8, and can only range from 32 to 448 (random) * RC2 key size must be between 40 and 1024 bits * RC4 (ARCFOUR) key size must be between 40 and 1024 bits * </Pre> */ Public static final String ALGORITHM = "DES ";   /** * DES algorithm conversion key <br>       * * @ Param key * @ Return * @ Throws Exception */ Private static Key toKey (byte [] key) throws Exception { SecretKey secretKey = null; If (ALGORITHM. equals ("DES") | ALGORITHM. equals ("DESede ")){ DESKeySpec dks = new DESKeySpec (key ); SecretKeyFactory keyFactory = SecretKeyFactory. getInstance (ALGORITHM ); SecretKey = keyFactory. generateSecret (dks ); } Else { // When using other symmetric encryption algorithms, such as AES and Blowfish, replace the preceding three lines of code with the following code: SecretKey = new SecretKeySpec (key, ALGORITHM );          } Return secretKey;      }   /** * DES algorithm decryption       * * @ Param data * @ Param key * @ Return * @ Throws Exception */ Public static byte [] decrypt (byte [] data, String key) throws Exception { Key k = toKey (decryptBASE64 (key )); Cipher cipher = Cipher. getInstance (ALGORITHM ); Cipher. init (Cipher. DECRYPT_MODE, k ); Return cipher. doFinal (data );      }   /** * DES algorithm encryption       * * @ Param data * @ Param key * @ Return * @ Throws Exception */ Public static byte [] encrypt (byte [] data, String key) throws Exception { Key k = toKey (decryptBASE64 (key )); Cipher cipher = Cipher. getInstance (ALGORITHM ); Cipher. init (Cipher. ENCRYPT_MODE, k ); Return cipher. doFinal (data );      }   /** * DES algorithm generation key       * * @ Return * @ Throws Exception */ Public static String initKey () throws Exception { Return initKey (null );      }   /** * DES algorithm generation key       * * @ Param seed * @ Return * @ Throws Exception */ Public static String initKey (String seed) throws Exception { SecureRandom secureRandom = null; If (seed! = Null ){ SecureRandom = new SecureRandom (decryptBASE64 (seed )); } Else { SecureRandom = new SecureRandom ();          } KeyGenerator kg = KeyGenerator. getInstance (ALGORITHM ); Kg. init (secureRandom ); SecretKey secretKey = kg. generateKey (); Return encryptBASE64 (secretKey. getEncoded ());      }   Public static void main (String [] args ){ Try { String s = "ampersand overwrite "; String B = CryptUtil. encryptBASE64 (s. getBytes ("UTF-8 ")); System. out. println ("after BASE64 encryption:" + B ); Byte [] c = CryptUtil. decryptBASE64 (B ); System. out. println ("BASE64 decrypted:" + new String (c, "UTF-8 "));   C = encryptMD5 (s. getBytes ()); System. out. println ("after MD5 encryption:" + new BigInteger (c). toString (16 ));   C = encryptSHA (s. getBytes ()); System. out. println ("SHA encrypted:" + new BigInteger (c). toString (16 ));   String key = initMacKey (); System. out. println ("HMAC key:" + key ); C = encryptHMAC (s. getBytes (), key ); System. out. println ("HMAC encrypted:" + new BigInteger (c). toString (16 ));   Key = initKey (); System. out. println (ALGORITHM + "key: t" + key ); C = encrypt (s. getBytes ("UTF-8"), key ); System. out. println (ALGORITHM + "encrypted:" + new BigInteger (c). toString (16 )); C = decrypt (c, key ); System. out. println (ALGORITHM + "decrypted:" + new String (c, "UTF-8 ")); } Catch (UnsupportedEncodingException e ){ // TODO Auto-generated catch block E. printStackTrace (); } Catch (Exception e ){ // TODO Auto-generated catch block E. printStackTrace ();          }      }  }