Java加密与解密
Posted Storm_L
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Base64
Base64是网络上最常见的用于传输8Bit(1Byte)字节码的编码方式之一,Base64就是一种基于64个可打印字符来表示二进制数据的方法。Base64编码变长,具有不可读性。其实Base64是一种编码方式而不是加密方式。
1 public class Base64 implements Encryption, Decryption { 2 3 private static Base64 instance; 4 5 private Base64() { 6 } 7 8 public static synchronized Base64 getInstance() { 9 return instance == null ? new Base64() : instance; 10 } 11 12 @Override 13 public byte[] encrypt(byte[] src) { 14 return java.util.Base64.getEncoder().encode(src); 15 } 16 17 @Override 18 public byte[] decrypt(byte[] src) { 19 return java.util.Base64.getDecoder().decode(src); 20 } 21 }
MD5
MD5即Message-Digest Algorithm 5(信息-摘要算法5),用于确保信息传输完整一致。是计算机广泛使用的杂凑算法之一(又译摘要算法、哈希算法),主流编程语言普遍已有MD5实现。将数据(如汉字)运算为另一固定长度值,是杂凑算法的基础原理。
public class Md5 implements Encryption { private static Md5 instance; private Md5() { } public static synchronized Md5 getInstance() { return instance == null ? new Md5() : instance; } @Override public byte[] encrypt(byte[] src) { MessageDigest md; byte[] result; try { md = MessageDigest.getInstance(Algorithm.MD5.value()); md.update(src); result = md.digest(); } catch (NoSuchAlgorithmException e) { throw new RuntimeException("No such algorithm: " + Algorithm.MD5.value()); } return result; } }
Sha1
安全哈希算法(Secure Hash Algorithm)主要适用于数字签名标准(Digital Signature Standard DSS)里面定义的数字签名算法(Digital Signature Algorithm DSA)。对于长度小于2^64位的消息,SHA1会产生一个160位的消息摘要。该算法的思想是接收一段明文,然后以一种不可逆的方式将它转换成一段(通常更小)密文,散列函数值可以说是对明文的一种“指纹”或是“摘要”所以对散列值的数字签名就可以视为对此明文的数字签名。
1 public class Sha implements Encryption { 2 3 private static Sha instance; 4 5 private Sha() { 6 } 7 8 public static synchronized Sha getInstance() { 9 return instance == null ? new Sha() : instance; 10 } 11 12 @Override 13 public byte[] encrypt(byte[] src) { 14 MessageDigest md; 15 byte[] result; 16 try { 17 md = MessageDigest.getInstance(Algorithm.SHA.value()); 18 md.update(src); 19 result = md.digest(); 20 } catch (NoSuchAlgorithmException e) { 21 throw new RuntimeException("No such algorithm: " + Algorithm.SHA.value()); 22 } 23 return result; 24 } 25 }
Pbe
PBE算法(Password Based Encryption,基于口令加密)是一种基于口令的加密算法,其特点是使用口令代替了密钥,而口令由用户自己掌管,采用随机数杂凑多重加密等方法保证数据的安全性。
public class Pbe implements Encryption, Decryption { /** * define the iteration count: 1000<br> */ private static final int ITERATION_COUNT = 1000; /** * define the PBE password<br> */ private static final String PBE_PASSWORD = "enfldsgbnlsngdlksdsgm"; /** * define the salt<br> */ private static final byte[] SALT = { (byte) 0xde, (byte) 0x33, (byte) 0x10, (byte) 0x12, (byte) 0xde, (byte) 0x33, (byte) 0x10, (byte) 0x12, }; private static Pbe instance; private Pbe() { } public static synchronized Pbe getInstance() { return instance == null ? new Pbe() : instance; } @Override public byte[] encrypt(byte[] src) { Key key = getPBEKey(); PBEParameterSpec parameterSpec = new PBEParameterSpec(SALT, ITERATION_COUNT); Cipher cipher; byte[] result; try { cipher = Cipher.getInstance(Algorithm.PBE.value()); cipher.init(Cipher.ENCRYPT_MODE, key, parameterSpec); result = cipher.doFinal(src); } catch (Exception e) { throw new RuntimeException("Encrypt failed."); } return result; } @Override public byte[] decrypt(byte[] src) { Key key = getPBEKey(); PBEParameterSpec parameterSpec = new PBEParameterSpec(SALT, ITERATION_COUNT); Cipher cipher; byte[] result; try { cipher = Cipher.getInstance(Algorithm.PBE.value()); cipher.init(Cipher.DECRYPT_MODE, key, parameterSpec); result = cipher.doFinal(src); } catch (Exception e) { throw new RuntimeException("Decrypt failed."); } return result; } /** * Generate a PBE secret key according to the PBE password.<br> * * @return */ private static Key getPBEKey() { SecretKeyFactory keyFactory; SecretKey secretKey; try { keyFactory = SecretKeyFactory.getInstance(Algorithm.PBE.value()); PBEKeySpec keySpec = new PBEKeySpec(PBE_PASSWORD.toCharArray()); secretKey = keyFactory.generateSecret(keySpec); } catch (NoSuchAlgorithmException e) { throw new RuntimeException("No such algorithm: " + Algorithm.PBE.value()); } catch (InvalidKeySpecException e) { throw new RuntimeException("The key is Invalid."); } return secretKey; } }
Hmac
HMAC是密钥相关的哈希运算消息认证码,HMAC运算利用哈希算法,以一个密钥和一个消息为输入,生成一个消息摘要作为输出。HMAC是密钥相关的哈希运算消息认证码,HMAC运算利用哈希算法,以一个密钥和一个消息为输入,生成一个消息摘要作为输出。
1 public class Hmac implements Encryption { 2 3 private static Hmac instance; 4 5 private static byte[] macKey; 6 7 private Hmac() { 8 } 9 10 public static synchronized Hmac getInstance() { 11 if (instance == null) { 12 macKey = initMacKey(); 13 instance = new Hmac(); 14 } 15 16 return instance; 17 } 18 19 @Override 20 public byte[] encrypt(byte[] src) { 21 SecretKey secretKey = new SecretKeySpec(macKey, Algorithm.HMAC.value()); 22 Mac mac; 23 byte[] result; 24 try { 25 mac = Mac.getInstance(secretKey.getAlgorithm()); 26 mac.init(secretKey); 27 result = mac.doFinal(src); 28 } catch (NoSuchAlgorithmException e) { 29 throw new RuntimeException("No such algorithm: " + secretKey.getAlgorithm()); 30 } catch (InvalidKeyException e) { 31 throw new RuntimeException("The key is Invalid."); 32 } 33 34 return result; 35 } 36 37 /** 38 * Generate a MAC secret key.<br> 39 * 40 * @return MAC key 41 */ 42 private static byte[] initMacKey() { 43 KeyGenerator keyGenerator; 44 Key result; 45 try { 46 keyGenerator = KeyGenerator.getInstance(Algorithm.HMAC.value()); 47 result = keyGenerator.generateKey(); 48 } catch (NoSuchAlgorithmException e) { 49 throw new RuntimeException("No such algorithm: " + Algorithm.HMAC.value()); 50 } 51 return result.getEncoded(); 52 } 53 }
[其他代码]
1 public enum Algorithm { 2 3 BASE64("BASE64"), MD5("MD5"), SHA("SHA"), HMAC("HmacMD5"), PBE("PBEWITHMD5ANDDES"); 4 5 private String value; 6 7 private Algorithm(String value) { 8 this.value = value; 9 } 10 11 public String value() { 12 return value; 13 } 14 }
public interface Decryption { byte[] decrypt(byte[] src); }
public interface Encryption { byte[] encrypt(byte[] src); }
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