package weaver.loginsso;

import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

public class AES {
	/** 
	 * 加密 
	 *  
	 * @param content 需要加密的内容 
	 * @param password  加密密码 
	 * @return 
	 */
	public static String encrypt(String content, String password) {
		byte[] result = null;
		try {
			KeyGenerator kgen = KeyGenerator.getInstance("AES");
			SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG" );
            secureRandom.setSeed(password.getBytes());
			kgen.init(128, secureRandom);
			SecretKey secretKey = kgen.generateKey();
			byte[] enCodeFormat = secretKey.getEncoded();
			SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
			Cipher cipher = Cipher.getInstance("AES");// 创建密码器   
			//byte[] byteContent = content.getBytes("utf-8");
			byte[] byteContent = content.getBytes();
			cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化   
			result = cipher.doFinal(byteContent);
			
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		} catch (NoSuchPaddingException e) {
			e.printStackTrace();
		} catch (InvalidKeyException e) {
			e.printStackTrace();
		} catch (IllegalBlockSizeException e) {
			e.printStackTrace();
		} catch (BadPaddingException e) {
			e.printStackTrace();
		}
		
		return parseByte2HexStr(result);
	}
	
	/**解密 
	 * @param content  待解密内容 
	 * @param password 解密密钥 
	 * @return 
	 */
	public static String decrypt(String content, String password) {
		byte[] result = null;
		byte[] decryptFrom = parseHexStr2Byte(content);
		try {
			KeyGenerator kgen = KeyGenerator.getInstance("AES");
			SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG" );
            secureRandom.setSeed(password.getBytes());
			kgen.init(128, secureRandom);
		
			SecretKey secretKey = kgen.generateKey();
			byte[] enCodeFormat = secretKey.getEncoded();
			SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
			Cipher cipher = Cipher.getInstance("AES");// 创建密码器   
			cipher.init(Cipher.DECRYPT_MODE, key);// 初始化   
			result = cipher.doFinal(decryptFrom);
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		} catch (NoSuchPaddingException e) {
			e.printStackTrace();
		} catch (InvalidKeyException e) {
			e.printStackTrace();
		} catch (IllegalBlockSizeException e) {
			e.printStackTrace();
		} catch (BadPaddingException e) {
			e.printStackTrace();
		}
		
		return new String(result);
	}

	/**将二进制转换成16进制 
	 * @param buf 
	 * @return 
	 */
	private static String parseByte2HexStr(byte buf[]) {
		StringBuffer sb = new StringBuffer();
		for (int i = 0; i < buf.length; i++) {
			String hex = Integer.toHexString(buf[i] & 0xFF);
			if (hex.length() == 1) {
				hex = '0' + hex;
			}
			sb.append(hex.toUpperCase());
		}
		return sb.toString();
	}

	/**将16进制转换为二进制 
	 * @param hexStr 
	 * @return 
	 */
	private static byte[] parseHexStr2Byte(String hexStr) {
		if (hexStr.length() < 1)
			return null;
		byte[] result = new byte[hexStr.length() / 2];
		for (int i = 0; i < hexStr.length() / 2; i++) {
			int high = Integer.parseInt(hexStr.substring(i * 2, i * 2 + 1), 16);
			int low = Integer.parseInt(hexStr.substring(i * 2 + 1, i * 2 + 2),
					16);
			result[i] = (byte) (high * 16 + low);
		}
		return result;
	}

	
    
    
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		String content = "test";
		String password = "1";
		// 加密
		String encryptResultStr = encrypt(content, password);
		//解密   
		String decryptResult = decrypt(encryptResultStr, password);

	}

}