常用加解密工具类（MD5、SHA、DES、AES、RSA）详解编程语言

下面展示部分关键代码    

MD5 单向加密： 
	/** 
	 * 返回MD5单向加密后的十六进制字符串 
	 * @param data 
	 * @return 
	 * @throws Exception 
	 */ 
	public String getEncryptForHex(byte[] data) throws Exception 
	{ 
		byte[] digestData = encrypt(data); 
		StringBuffer hex = new StringBuffer(); 
		for(int i = 0; i < digestData.length; i++) 
		{ 
			int h = ((int)digestData[i]) & 0XFF; 
			if(h < 16) 
			{ 
				hex.append("0"); 
			} 
			hex.append(Integer.toHexString(h)); 
		} 
		 
		return hex.toString(); 
	} 
 
 
DES 对称加密类： 
	@Override 
	public byte[] encrypt(byte[] data) throws Exception  
	{ 
		if(secretKey == null || "".equals(secretKey)) 
		{ 
			throw new Exception("scretKey need to exists"); 
		} 
		 
		SecretKey md5Key = getKey(secretKey); 
		Cipher cipher = Cipher.getInstance(ALGORITHM); 
		cipher.init(Cipher.ENCRYPT_MODE, md5Key); 
		return cipher.doFinal(data); 
	} 
 
	@Override 
	public byte[] decrypt(byte[] data) throws Exception  
	{ 
		if(secretKey == null || "".equals(secretKey)) 
		{ 
			throw new Exception("scretKey need to exists"); 
		} 
		 
		SecretKey md5Key = getKey(secretKey); 
		Cipher cipher = Cipher.getInstance(ALGORITHM); 
		cipher.init(Cipher.DECRYPT_MODE, md5Key); 
		return cipher.doFinal(data); 
	} 
 
 
 
RSA 非对称加密。私钥加密 & 私钥解密 & 私钥签名 
	@Override 
	public byte[] encrypt(byte[] data) throws Exception  
	{ 
		PrivateKey rsaPrivateKey = getRSAPrivateKey(); 
		Cipher cipher = Cipher.getInstance(ALGORITHM); 
		cipher.init(Cipher.ENCRYPT_MODE, rsaPrivateKey); 
		return cipher.doFinal(data); 
	} 
 
	@Override 
	public byte[] decrypt(byte[] data) throws Exception  
	{ 
		PrivateKey rsaPrivateKey = getRSAPrivateKey(); 
		Cipher cipher = Cipher.getInstance(ALGORITHM); 
		cipher.init(Cipher.DECRYPT_MODE, rsaPrivateKey); 
		return cipher.update(data); 
	} 
 
        /** 
	 * 使用私钥 对数据进行签名 
	 * @param data 
	 * @return 
	 * @throws Exception 
	 */ 
	public String sign(byte[] data) throws Exception 
	{ 
		PrivateKey rsaPrivateKey = getRSAPrivateKey(); 
		Signature signature = Signature.getInstance(SIGN_ALGORITHM); 
		signature.initSign(rsaPrivateKey); 
		signature.update(data); 
		return encoder(signature.sign()); 
	} 
 
RSA 非对称加密。公钥加密 & 公钥解密 & 公钥校验签名 
	@Override 
	public byte[] encrypt(byte[] data) throws Exception 
	{ 
		if(publicKey == null || "".equals(publicKey)) 
		{ 
			throw new Exception("publicKey is need exists"); 
		} 
		 
		PublicKey rsaPublicKey = getRSAPublicKey(publicKey); 
		Cipher cipher = Cipher.getInstance(ALGORITHM); 
		cipher.init(Cipher.ENCRYPT_MODE, rsaPublicKey); 
		return cipher.doFinal(data); 
	} 
 
	@Override 
	public byte[] decrypt(byte[] data) throws Exception 
	{ 
		if(publicKey == null || "".equals(publicKey)) 
		{ 
			throw new Exception("publicKey is need exists"); 
		} 
		 
		PublicKey rsaPublicKey = getRSAPublicKey(publicKey); 
		Cipher cipher = Cipher.getInstance(ALGORITHM); 
		cipher.init(Cipher.DECRYPT_MODE, rsaPublicKey); 
		return cipher.doFinal(data); 
	} 
 
	/** 
	 * 使用公钥校验签名 
	 * @param data 
	 * @param sign 
	 * @return 
	 * @throws Exception 
	 */ 
	public boolean verifySign(byte[] data, String sign) throws Exception 
	{ 
		if(publicKey == null || "".equals(publicKey)) 
		{ 
			throw new Exception("publicKey is need exists"); 
		} 
		 
		PublicKey rsaPublicKey = getRSAPublicKey(publicKey); 
		Signature signature = Signature.getInstance(SIGN_ALGORITHM); 
		signature.initVerify(rsaPublicKey); 
		signature.update(data); 
		return signature.verify(decoder(sign)); 
	}