加密工具

import java.math.BigInteger;
import java.security.MessageDigest;

import javax.crypto.KeyGenerator;
import javax.crypto.Mac;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

import com.fnic.cdnmgr.sdk.comm.CDNException;
import com.fnic.cdnmgr.sdk.comm.CommUtils;

/**
 * @Description:
 * @author: weijingbo
 * @CreateDate: 2012-10-9
 * @version: V1.0
 */

public final class EncryptUtils
{
    /**
     * SHA算法
     */
    private static final String KEY_SHA = "SHA";

    /**
     * MD5算法
     */
    private static final String KEY_MD5 = "MD5";

    /**
     * MAC算法可选以下多种算法
     * 
     * HmacMD5 HmacSHA1 HmacSHA256 HmacSHA384 HmacSHA512
     */
    private static final String KEY_MAC = "HmacMD5";

    /**
     * 编码格式
     */
    private static final String ENCODING = "UTF-8";

    /**
     * 加密次数
     */
    private static final int ENCODETIMES = 100;

    /**
     * 加密
     * 
     * @param key 名文
     * @return 密文
     * @throws CDNException 异常信息
     */
    public static String encode(final String key) throws CDNException
    {
        if (CommUtils.isInValid(key))
        {
            throw new CDNException("key is null");
        }

        String strBase64 = "";
        try
        {
            strBase64 = encryptBASE64(key.getBytes(ENCODING));
        }
        catch (Exception e)
        {
            throw new CDNException("encode error", e);
        }

        return CaesarAlgorithm.encrypt(strBase64);
    }

    /**
     * 解密
     * 
     * @param key 密文
     * @return 名文
     * @throws CDNException 异常信息
     */
    public static String decode(final String key) throws CDNException
    {
        if (CommUtils.isInValid(key))
        {
            throw new CDNException("key is null");
        }

        String strBase64 = CaesarAlgorithm.decrypt(key);

        String strResult = "";

        try
        {
            byte[] decodeKey = decryptBASE64(strBase64);

            strResult = new String(decodeKey, ENCODING);
        }
        catch (Exception e)
        {
            throw new CDNException("decode error", e);
        }

        return strResult;
    }

    /**
     * 不可逆加密
     * 
     * @param key 明文
     * @return 密文
     * @throws CDNException 异常信息
     */
    public static String encodeIrreversible(final String key) throws CDNException
    {
        String strResult = "";

        try
        {
            byte[] bResult = encode(key).getBytes(ENCODING);

            for (int i = 0; i <= ENCODETIMES; ++i)
            {
                bResult = encryptMD5(bResult);
            }

            strResult = new BigInteger(bResult).toString(32);

        }
        catch (Exception e)
        {
            throw new CDNException("encode error", e);
        }

        return strResult;

    }

    /**
     * BASE64解密
     * 
     * @param key
     * @return
     * @throws Exception
     */
    private static byte[] decryptBASE64(final String key) throws Exception
    {
        return (new BASE64Decoder()).decodeBuffer(key);
    }

    /**
     * BASE64加密
     * 
     * @param key
     * @return
     * @throws Exception
     */
    private static String encryptBASE64(final byte[] key) throws Exception
    {
        return (new BASE64Encoder()).encodeBuffer(key);
    }

    /**
     * MD5加密
     * 
     * @param data
     * @return
     * @throws Exception
     */
    private static byte[] encryptMD5(final byte[] data) throws Exception
    {

        MessageDigest md5 = MessageDigest.getInstance(KEY_MD5);
        md5.update(data);

        return md5.digest();

    }

    /**
     * SHA加密
     * 
     * @param data
     * @return
     * @throws Exception
     */
    private static byte[] encryptSHA(final byte[] data) throws Exception
    {

        MessageDigest sha = MessageDigest.getInstance(KEY_SHA);
        sha.update(data);

        return sha.digest();

    }

    /**
     * 初始化HMAC密钥
     * 
     * @return
     * @throws Exception
     */
    private static String initMacKey() throws Exception
    {
        KeyGenerator keyGenerator = KeyGenerator.getInstance(KEY_MAC);

        SecretKey secretKey = keyGenerator.generateKey();
        return encryptBASE64(secretKey.getEncoded());
    }

    /**
     * HMAC加密
     * 
     * @param data
     * @param key
     * @return
     * @throws Exception
     */
    private static byte[] encryptHMAC(final byte[] data, final 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);

    }

    private static class CaesarAlgorithm
    {
        private static final char[] UC_ENCRYPT_CHARS = { 'D', 'X', 'U', 'P', 'I', 'B', 'M', 'J', 'C', 'E', 'T', 'N',
                'K', 'O', 'G', 'W', 'R', 'S', 'F', 'Y', 'V', 'L', 'Z', 'Q', 'A', 'H' };

        private static final char[] LC_ENCRYPT_CHARS = { 'd', 'x', 'u', 'p', 'i', 'b', 'm', 'j', 'c', 'e', 't', 'n',
                'k', 'o', 'g', 'w', 'r', 's', 'f', 'y', 'v', 'l', 'z', 'q', 'a', 'h' };

        private static char[] UC_DECRYPT_CHARS = new char[26];

        private static char[] LC_DECRYPT_CHARS = new char[26];

        static
        {
            for (int i = 0; i < 26; i++)
            {
                char b = UC_ENCRYPT_CHARS[i];
                UC_DECRYPT_CHARS[b - 'A'] = (char) ('A' + i);
                b = LC_ENCRYPT_CHARS[i];
                LC_DECRYPT_CHARS[b - 'a'] = (char) ('a' + i);
            }
        }

        public static char encrypt(final char b)
        {
            if ((b >= 'A') && (b <= 'Z'))
            {
                return UC_ENCRYPT_CHARS[b - 'A'];
            }
            else if ((b >= 'a') && (b <= 'z'))
            {
                return LC_ENCRYPT_CHARS[b - 'a'];
            }
            else
            {
                return b;
            }
        }

        public static char decrypt(final char b)
        {
            if ((b >= 'A') && (b <= 'Z'))
            {
                return UC_DECRYPT_CHARS[b - 'A'];
            }
            else if ((b >= 'a') && (b <= 'z'))
            {
                return LC_DECRYPT_CHARS[b - 'a'];
            }
            else
            {
                return b;
            }
        }

        public static String encrypt(final String input)
        {
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < input.length(); i++)
            {
                sb.append(encrypt(input.charAt(i)));
            }

            return sb.toString().trim();
        }

        public static String decrypt(final String input)
        {
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < input.length(); i++)
            {
                sb.append(decrypt(input.charAt(i)));
            }
            return sb.toString();
        }
    }

    public static void main(final String[] args)
    {
        String inputStr = "Admin123";
        System.out.println("原文: " + inputStr);
        byte[] inputData = inputStr.getBytes();

        try
        {

            String code = EncryptUtils.encode(inputStr);
            System.out.println("BASE64+凯撒加密后: " + code);
            System.out.println("BASE64+凯撒解密后: " + EncryptUtils.decode(code));
            System.out.println("不可逆加密后" + "(" + ENCODETIMES + " times): " + EncryptUtils.encodeIrreversible(code));

            String key = EncryptUtils.initMacKey();
            System.out.println("Mac密钥: " + key);

            BigInteger md5 = new BigInteger(EncryptUtils.encryptMD5(inputData));
            System.out.println("MD5: " + md5.toString(16));

            BigInteger sha = new BigInteger(EncryptUtils.encryptSHA(inputData));
            System.out.println("SHA: " + sha.toString(32));

            BigInteger mac = new BigInteger(EncryptUtils.encryptHMAC(inputData, inputStr));
            System.out.println("HMAC: " + mac.toString(16));

        }
        catch (Exception ex)
        {
            ex.printStackTrace();
        }
    }

}