MD5加密 Base64加密和解密算法 java

最新推荐文章于 2024-07-20 18:25:34 发布

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1、测试方法（从测试方法入手解析）

package md5;

public class Test {
	public static void main(String[] args) {
		//MD5加密 0 CFCD208495D565EF66E7DFF9F98764DA
		System.out.println(UtilTools.encrypt("0"));
		 //Base64加密和解码
		System.out.println(UtilTools.decrypt("pBhpw2FUxCY="));
		System.out.println(UtilTools.revEncrypt("yza"));
	}

}

2、定义公共工具类

package md5;

public class UtilTools { 
	//base64解码
	public static String revEncrypt(String str) {
		if (str == null || str.equals(""))
			return null;

		try {
			Encrypt ent = new Encrypt();
			ent.init("passwd");
			String sString = null;
			byte[] cleartext = str.getBytes();
			byte[] ciphertext = ent.encrypt(cleartext);
			sString = new String(Base64.base64Encode(ciphertext));

			return sString;
		} catch (Exception e) {
			e.printStackTrace();
			return null;
		}
		// return str == null ? null : new Double( ( str.doubleValue() + 343.2 )
		// * 1.5 - 500 );
	}

	//base64加密
	public static String decrypt(String str) {
		if (str == null || str.trim().equals(""))
			return null;

		try {
			Encrypt ent = new Encrypt();
			ent.init("passwd");
			byte ciphertext[] = new byte[str.length()];
			ciphertext = str.getBytes("GB2312");
			byte ciphertext1[] = Base64.base64Decode(ciphertext);
			byte[] ct = ent.decrypt(ciphertext1);
			return new String(ct);
		} catch (Exception e) {
			e.printStackTrace();
			return null;
		}

		// return str == null ? null : new Double( ( ( str.doubleValue() + 500 )
		// / 1.5 ) - 343.2 );
	}

	//MD5加密
	public static String encrypt(String str) {
		// return str;
		if (str == null || str.trim().equals(""))
			return null;
		return new MD5().getMD5ofStr(str);
	}
}

3、MD5类

package md5;

public class MD5 {
/* 下面这些S11-S44实际上是一个4*4的矩阵，在原始的C实现中是用#define 实现的，
这里把它们实现成为static final是表示了只读，切能在同一个进程空间内的多个
Instance间共享*/
    static final int S11 = 7;
    static final int S12 = 12;
    static final int S13 = 17;
    static final int S14 = 22;

    static final int S21 = 5;
    static final int S22 = 9;
    static final int S23 = 14;
    static final int S24 = 20;

    static final int S31 = 4;
    static final int S32 = 11;
    static final int S33 = 16;
    static final int S34 = 23;

    static final int S41 = 6;
    static final int S42 = 10;
    static final int S43 = 15;
    static final int S44 = 21;

    static final byte[] PADDING = {-128, 0, 0, 0, 0, 0, 0, 0, 0,
                                   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                                   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                                   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
/* 下面的三个成员是MD5计算过程中用到的3个核心数据，在原始的C实现中
   被定义到MD5_CTX结构中

*/
    private long[] state = new long[4];  // state (ABCD)
    private long[] count = new long[2];  // number of bits, modulo 2^64 (lsb first)
    private byte[] buffer = new byte[64]; // input buffer

/* digestHexStr是MD5的唯一一个公共成员，是最新一次计算结果的
　 16进制ASCII表示.
*/
    public String digestHexStr;

/* digest,是最新一次计算结果的2进制内部表示，表示128bit的MD5值.
*/
    private byte[] digest = new byte[16];

/*
  getMD5ofStr是类MD5最主要的公共方法，入口参数是你想要进行MD5变换的字符串
  返回的是变换完的结果，这个结果是从公共成员digestHexStr取得的．
*/
    public String getMD5ofStr(String inbuf) {
        md5Init();
        md5Update(inbuf.getBytes(), inbuf.length());
        md5Final();
        digestHexStr = "";
        for (int i = 0; i < 16; i++) {
            digestHexStr += byteHEX(digest[i]);
        }
        return digestHexStr;

    }
// 这是MD5这个类的标准构造函数，JavaBean要求有一个public的并且没有参数的构造函数
    public MD5() {
        md5Init();

        return;
    }



/* md5Init是一个初始化函数，初始化核心变量，装入标准的幻数 */
    private void md5Init() {
        count[0] = 0L;
        count[1] = 0L;
///* Load magic initialization constants.

        state[0] = 0x67452301L;
        state[1] = 0xefcdab89L;
        state[2] = 0x98badcfeL;
        state[3] = 0x10325476L;

        return;
    }
/* F, G, H ,I 是4个基本的MD5函数，在原始的MD5的C实现中，由于它们是
简单的位运算，可能出于效率的考虑把它们实现成了宏，在java中，我们把它们
　　实现成了private方法，名字保持了原来C中的。 */

    private long F(long x, long y, long z) {
        return (x & y) | ((~x) & z);

    }

    private long G(long x, long y, long z) {
        return (x & z) | (y & (~z));

    }

    private long H(long x, long y, long z) {
        return x ^ y ^ z;
    }

    private long I(long x, long y, long z) {
        return y ^ (x | (~z));
    }

    /*
   FF,GG,HH和II将调用F,G,H,I进行近一步变换
   FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
   Rotation is separate from addition to prevent recomputation.
    */

    private long FF(long a, long b, long c, long d, long x, long s,
                    long ac) {
        a += F(b, c, d) + x + ac;
        a = ((int) a << s) | ((int) a >>> (32 - s));
        a += b;
        return a;
    }

    private long GG(long a, long b, long c, long d, long x, long s,
                    long ac) {
        a += G(b, c, d) + x + ac;
        a = ((int) a << s) | ((int) a >>> (32 - s));
        a += b;
        return a;
    }

    private long HH(long a, long b, long c, long d, long x, long s,
                    long ac) {
        a += H(b, c, d) + x + ac;
        a = ((int) a << s) | ((int) a >>> (32 - s));
        a += b;
        return a;
    }

    private long II(long a, long b, long c, long d, long x, long s,
                    long ac) {
        a += I(b, c, d) + x + ac;
        a = ((int) a << s) | ((int) a >>> (32 - s));
        a += b;
        return a;
    }
/*
md5Update是MD5的主计算过程，inbuf是要变换的字节串，inputlen是长度，这个
函数由getMD5ofStr调用，调用之前需要调用md5init，因此把它设计成private的
*/
    private void md5Update(byte[] inbuf, int inputLen) {

        int i, index, partLen;
        byte[] block = new byte[64];
        index = (int) (count[0] >>> 3) & 0x3F;
// /* Update number of bits */
        if ((count[0] += (inputLen << 3)) < (inputLen << 3)) {
            count[1]++;
        }
        count[1] += (inputLen >>> 29);

        partLen = 64 - index;

// Transform as many times as possible.
        if (inputLen >= partLen) {
            md5Memcpy(buffer, inbuf, index, 0, partLen);
            md5Transform(buffer);

            for (i = partLen; i + 63 < inputLen; i += 64) {

                md5Memcpy(block, inbuf, 0, i, 64);
                md5Transform(block);
            }
            index = 0;

        } else {
            i = 0;
        }

///* Buffer remaining input */
        md5Memcpy(buffer, inbuf, index, i, inputLen - i);

    }

/*
  md5Final整理和填写输出结果
*/
    private void md5Final() {
        byte[] bits = new byte[8];
        int index, padLen;

///* Save number of bits */
        Encode(bits, count, 8);

///* Pad out to 56 mod 64.
        index = (int) (count[0] >>> 3) & 0x3f;
        padLen = (index < 56) ? (56 - index) : (120 - index);
        md5Update(PADDING, padLen);

///* Append length (before padding) */
        md5Update(bits, 8);

///* Store state in digest */
        Encode(digest, state, 16);

    }

/* md5Memcpy是一个内部使用的byte数组的块拷贝函数，从input的inpos开始把len长度的
　　　　　 字节拷贝到output的outpos位置开始
*/

    private void md5Memcpy(byte[] output, byte[] input,
                           int outpos, int inpos, int len) {
        int i;

        for (i = 0; i < len; i++) {
            output[outpos + i] = input[inpos + i];
        }
    }

/*
   md5Transform是MD5核心变换程序，有md5Update调用，block是分块的原始字节
*/
    private void md5Transform(byte block[]) {
        long a = state[0], b = state[1], c = state[2], d = state[3];
        long[] x = new long[16];

        Decode(x, block, 64);

/* Round 1 */
        a = FF(a, b, c, d, x[0], S11, 0xd76aa478L); /* 1 */
        d = FF(d, a, b, c, x[1], S12, 0xe8c7b756L); /* 2 */
        c = FF(c, d, a, b, x[2], S13, 0x242070dbL); /* 3 */
        b = FF(b, c, d, a, x[3], S14, 0xc1bdceeeL); /* 4 */
        a = FF(a, b, c, d, x[4], S11, 0xf57c0fafL); /* 5 */
        d = FF(d, a, b, c, x[5], S12, 0x4787c62aL); /* 6 */
        c = FF(c, d, a, b, x[6], S13, 0xa8304613L); /* 7 */
        b = FF(b, c, d, a, x[7], S14, 0xfd469501L); /* 8 */
        a = FF(a, b, c, d, x[8], S11, 0x698098d8L); /* 9 */
        d = FF(d, a, b, c, x[9], S12, 0x8b44f7afL); /* 10 */
        c = FF(c, d, a, b, x[10], S13, 0xffff5bb1L); /* 11 */
        b = FF(b, c, d, a, x[11], S14, 0x895cd7beL); /* 12 */
        a = FF(a, b, c, d, x[12], S11, 0x6b901122L); /* 13 */
        d = FF(d, a, b, c, x[13], S12, 0xfd987193L); /* 14 */
        c = FF(c, d, a, b, x[14], S13, 0xa679438eL); /* 15 */
        b = FF(b, c, d, a, x[15], S14, 0x49b40821L); /* 16 */

/* Round 2 */
        a = GG(a, b, c, d, x[1], S21, 0xf61e2562L); /* 17 */
        d = GG(d, a, b, c, x[6], S22, 0xc040b340L); /* 18 */
        c = GG(c, d, a, b, x[11], S23, 0x265e5a51L); /* 19 */
        b = GG(b, c, d, a, x[0], S24, 0xe9b6c7aaL); /* 20 */
        a = GG(a, b, c, d, x[5], S21, 0xd62f105dL); /* 21 */
        d = GG(d, a, b, c, x[10], S22, 0x2441453L); /* 22 */
        c = GG(c, d, a, b, x[15], S23, 0xd8a1e681L); /* 23 */
        b = GG(b, c, d, a, x[4], S24, 0xe7d3fbc8L); /* 24 */
        a = GG(a, b, c, d, x[9], S21, 0x21e1cde6L); /* 25 */
        d = GG(d, a, b, c, x[14], S22, 0xc33707d6L); /* 26 */
        c = GG(c, d, a, b, x[3], S23, 0xf4d50d87L); /* 27 */
        b = GG(b, c, d, a, x[8], S24, 0x455a14edL); /* 28 */
        a = GG(a, b, c, d, x[13], S21, 0xa9e3e905L); /* 29 */
        d = GG(d, a, b, c, x[2], S22, 0xfcefa3f8L); /* 30 */
        c = GG(c, d, a, b, x[7], S23, 0x676f02d9L); /* 31 */
        b = GG(b, c, d, a, x[12], S24, 0x8d2a4c8aL); /* 32 */

/* Round 3 */
        a = HH(a, b, c, d, x[5], S31, 0xfffa3942L); /* 33 */
        d = HH(d, a, b, c, x[8], S32, 0x8771f681L); /* 34 */
        c = HH(c, d, a, b, x[11], S33, 0x6d9d6122L); /* 35 */
        b = HH(b, c, d, a, x[14], S34, 0xfde5380cL); /* 36 */
        a = HH(a, b, c, d, x[1], S31, 0xa4beea44L); /* 37 */
        d = HH(d, a, b, c, x[4], S32, 0x4bdecfa9L); /* 38 */
        c = HH(c, d, a, b, x[7], S33, 0xf6bb4b60L); /* 39 */
        b = HH(b, c, d, a, x[10], S34, 0xbebfbc70L); /* 40 */
        a = HH(a, b, c, d, x[13], S31, 0x289b7ec6L); /* 41 */
        d = HH(d, a, b, c, x[0], S32, 0xeaa127faL); /* 42 */
        c = HH(c, d, a, b, x[3], S33, 0xd4ef3085L); /* 43 */
        b = HH(b, c, d, a, x[6], S34, 0x4881d05L); /* 44 */
        a = HH(a, b, c, d, x[9], S31, 0xd9d4d039L); /* 45 */
        d = HH(d, a, b, c, x[12], S32, 0xe6db99e5L); /* 46 */
        c = HH(c, d, a, b, x[15], S33, 0x1fa27cf8L); /* 47 */
        b = HH(b, c, d, a, x[2], S34, 0xc4ac5665L); /* 48 */

/* Round 4 */
        a = II(a, b, c, d, x[0], S41, 0xf4292244L); /* 49 */
        d = II(d, a, b, c, x[7], S42, 0x432aff97L); /* 50 */
        c = II(c, d, a, b, x[14], S43, 0xab9423a7L); /* 51 */
        b = II(b, c, d, a, x[5], S44, 0xfc93a039L); /* 52 */
        a = II(a, b, c, d, x[12], S41, 0x655b59c3L); /* 53 */
        d = II(d, a, b, c, x[3], S42, 0x8f0ccc92L); /* 54 */
        c = II(c, d, a, b, x[10], S43, 0xffeff47dL); /* 55 */
        b = II(b, c, d, a, x[1], S44, 0x85845dd1L); /* 56 */
        a = II(a, b, c, d, x[8], S41, 0x6fa87e4fL); /* 57 */
        d = II(d, a, b, c, x[15], S42, 0xfe2ce6e0L); /* 58 */
        c = II(c, d, a, b, x[6], S43, 0xa3014314L); /* 59 */
        b = II(b, c, d, a, x[13], S44, 0x4e0811a1L); /* 60 */
        a = II(a, b, c, d, x[4], S41, 0xf7537e82L); /* 61 */
        d = II(d, a, b, c, x[11], S42, 0xbd3af235L); /* 62 */
        c = II(c, d, a, b, x[2], S43, 0x2ad7d2bbL); /* 63 */
        b = II(b, c, d, a, x[9], S44, 0xeb86d391L); /* 64 */

        state[0] += a;
        state[1] += b;
        state[2] += c;
        state[3] += d;

    }

/*Encode把long数组按顺序拆成byte数组，因为java的long类型是64bit的，
  只拆低32bit，以适应原始C实现的用途
*/
    private void Encode(byte[] output, long[] input, int len) {
        int i, j;

        for (i = 0, j = 0; j < len; i++, j += 4) {
            output[j] = (byte) (input[i] & 0xffL);
            output[j + 1] = (byte) ((input[i] >>> 8) & 0xffL);
            output[j + 2] = (byte) ((input[i] >>> 16) & 0xffL);
            output[j + 3] = (byte) ((input[i] >>> 24) & 0xffL);
        }
    }

/*Decode把byte数组按顺序合成成long数组，因为java的long类型是64bit的，
  只合成低32bit，高32bit清零，以适应原始C实现的用途
*/
    private void Decode(long[] output, byte[] input, int len) {
        int i, j;


        for (i = 0, j = 0; j < len; i++, j += 4) {
            output[i] = b2iu(input[j]) |
                    (b2iu(input[j + 1]) << 8) |
                    (b2iu(input[j + 2]) << 16) |
                    (b2iu(input[j + 3]) << 24);
        }

        return;
    }

/*
  b2iu是我写的一个把byte按照不考虑正负号的原则的＂升位＂程序，因为java没有unsigned运算
*/
    public static long b2iu(byte b) {
        return b < 0 ? b & 0x7F + 128 : b;
    }

/*byteHEX()，用来把一个byte类型的数转换成十六进制的ASCII表示，
　因为java中的byte的toString无法实现这一点，我们又没有C语言中的
  sprintf(outbuf,"%02X",ib)
*/
    public static String byteHEX(byte ib) {
        char[] Digit = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
        char[] ob = new char[2];
        ob[0] = Digit[(ib >>> 4) & 0X0F];
        ob[1] = Digit[ib & 0X0F];
        String s = new String(ob);
        return s;
    }
}

3、base64算法

package md5;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.PBEParameterSpec;
import java.security.NoSuchAlgorithmException;
import java.security.spec.InvalidKeySpecException;

public class Encrypt {
    private PBEParameterSpec pbeParamSpec = null;
    private SecretKey pbeKey = null;
    private Cipher pbeCipher = null;

    public void init(String initParameter) throws Exception {                /*
             * In order to use Password-Based Encryption (PBE) as defined in PKCS
             * #5, we have to specify a salt and an iteration count. The same salt
             * and iteration count that are used for encryption must be used for
             * decryption:
             */
        char[] passwd = {'1', '2', '3', '4', '5', '6'};
        pbeParamSpec = getParamSpec();
        pbeKey = createPBEKey(passwd);           // Create PBE Cipher
        pbeCipher = Cipher.getInstance("PBEWithMD5AndDES");
    }

    public byte[] encrypt(byte[] enSource) throws Exception {
        // Initialize PBE Cipher with key and parameters
        pbeCipher.init(Cipher.ENCRYPT_MODE, pbeKey, pbeParamSpec);
        // Encrypt the cleartext
        return pbeCipher.doFinal(enSource);
    }

    public byte[] decrypt(byte[] deSource) throws Exception {
        // Initialize PBE Cipher with key and parameters
        pbeCipher.init(Cipher.DECRYPT_MODE, pbeKey, pbeParamSpec);

        // decrypt the cleartext
        return pbeCipher.doFinal(deSource);
    }

    /**
     * @return
     * @throws NoSuchAlgorithmException
     * @throws InvalidKeySpecException
     */
    private SecretKey createPBEKey(char[] passwd) throws  NoSuchAlgorithmException, InvalidKeySpecException {
        PBEKeySpec pbeKeySpec;
        SecretKeyFactory keyFac;
        // Prompt user for encryption password.
        // Collect user password as char array (using the "readPasswd" method from above), and convert
        // it into a SecretKey object, using a PBE key
        // factory.
        pbeKeySpec = new PBEKeySpec(passwd);
        keyFac = SecretKeyFactory.getInstance("PBEWithMD5AndDES");
        SecretKey pbeKey = keyFac.generateSecret(pbeKeySpec);
        return pbeKey;
    }

    /**
     * @return
     */
    private PBEParameterSpec getParamSpec() {
        PBEParameterSpec pbeParamSpec;
        // Salt
        byte[] salt = {(byte) 0xc7, (byte) 0x73, (byte) 0x41, (byte) 0x8c, (byte) 0x7e, (byte) 0xc8, (byte) 0xea, (byte) 0x99};
        int count = 17;        // Iteration count
        // Create PBE parameter set
        pbeParamSpec = new PBEParameterSpec(salt, count);
        return pbeParamSpec;
    }
}

 
package md5;


import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;

public final class Base64 {
    private static final byte[] DECODE_TABLE = new byte[]
    {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 62, 0, 0, 0, 63,
     52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 0, 0, 0, 0, 0, 0,
     0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
     15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 0, 0, 0, 0, 0,
     0, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
     41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 0, 0, 0, 0, 0
    };

    //"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
    private static final byte[] ENCODE_TABLE = new byte[]{65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90,
                                                          97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122,
                                                          48, 49, 50, 51, 52, 53, 54, 55, 56, 57,
                                                          43, 47
    };

    static {
        //create encode table
        //ENCODE_TABLE = new byte[64];
        int index = 0;
        for (char c = 'A'; c <= 'Z'; c++)
            ENCODE_TABLE[index++] = (byte) c;
        for (char c = 'a'; c <= 'z'; c++)
            ENCODE_TABLE[index++] = (byte) c;
        for (char c = '0'; c <= '9'; c++)
            ENCODE_TABLE[index++] = (byte) c;
        ENCODE_TABLE[index++] = (byte) '+';
        ENCODE_TABLE[index++] = (byte) '/';

        //create decode table
        for (int i = 0; i < 64; i++)
            DECODE_TABLE[(int) ENCODE_TABLE[i]] = (byte) i;
    }

    public final static byte[] base64Encode(byte[] byteData) {
        if (byteData == null)
            return null;
        int iSrcIdx; // index into source (byteData)
        int iDestIdx; // index into destination (byteDest)
        byte byteDest[] = new byte[((byteData.length + 2) / 3) * 4];

        for (iSrcIdx = 0, iDestIdx = 0; iSrcIdx < byteData.length - 2; iSrcIdx += 3) {
            byteDest[iDestIdx++] = (byte) ((byteData[iSrcIdx] >>> 2) & 077);
            byteDest[iDestIdx++] = (byte) ((byteData[iSrcIdx + 1] >>> 4) & 017 | (byteData[iSrcIdx] << 4) & 077);
            byteDest[iDestIdx++] = (byte) ((byteData[iSrcIdx + 2] >>> 6) & 003 | (byteData[iSrcIdx + 1] << 2) & 077);
            byteDest[iDestIdx++] = (byte) (byteData[iSrcIdx + 2] & 077);
        }

        if (iSrcIdx < byteData.length) {
            byteDest[iDestIdx++] = (byte) ((byteData[iSrcIdx] >>> 2) & 077);
            if (iSrcIdx < byteData.length - 1) {
                byteDest[iDestIdx++] = (byte) ((byteData[iSrcIdx + 1] >>> 4) & 017 | (byteData[iSrcIdx] << 4) & 077);
                byteDest[iDestIdx++] = (byte) ((byteData[iSrcIdx + 1] << 2) & 077);
            } else
                byteDest[iDestIdx++] = (byte) ((byteData[iSrcIdx] << 4) & 077);
        }

        for (iSrcIdx = 0; iSrcIdx < iDestIdx; iSrcIdx++) {
            if (byteDest[iSrcIdx] < 26)
                byteDest[iSrcIdx] = (byte) (byteDest[iSrcIdx] + 'A');
            else if (byteDest[iSrcIdx] < 52)
                byteDest[iSrcIdx] = (byte) (byteDest[iSrcIdx] + 'a' - 26);
            else if (byteDest[iSrcIdx] < 62)
                byteDest[iSrcIdx] = (byte) (byteDest[iSrcIdx] + '0' - 52);
            else if (byteDest[iSrcIdx] < 63)
                byteDest[iSrcIdx] = (byte) '+';
            else
                byteDest[iSrcIdx] = (byte) '/';
        }

        for (; iSrcIdx < byteDest.length; iSrcIdx++)
            byteDest[iSrcIdx] = (byte) '=';

        return byteDest;
    }

    public final static String base64Encode(String strInput) {
        if (strInput == null)
            return null;
        return base64Encode(strInput, "GB2312");
    }

    public final static String base64Encode(String strInput, String charSet) {
        if (strInput == null)
            return null;
        String strOutput = null;
        byte byteData[] = new byte[strInput.length()];
        try {
            byteData = strInput.getBytes(charSet);
            strOutput = new String(base64Encode(byteData), charSet);
        } catch (UnsupportedEncodingException e) {
            return null;
        }
        return strOutput;
    }


    public final static String base64Encode(InputStream in, String charSet) {
        try {
            int c;
            byte[] buff = new byte[1024];
            ByteArrayOutputStream out = new ByteArrayOutputStream(2048);
            while ((c = in.read(buff, 0, 1024)) != -1) {
                out.write(buff, 0, c);
                //index+=1024;
                //out.write(c);
                //attachContent+=ss;
            }
            in.close();
            out.flush();
            byte[] tmp2 = Base64.base64Encode(out.toByteArray());
            out.close();
            return new String(tmp2, charSet);
        } catch (IOException e) {
            return "";
        }
    }

    public static byte[] base64Decode(byte[] base64Data) {
        if (base64Data == null)
            return null;
        if (base64Data.length == 0)
            return new byte[0];
        if (base64Data.length % 4 != 0) throw new IllegalArgumentException("数据不完整，长度为：" + base64Data.length);

        byte[] result = null;
        int groupCount = base64Data.length / 4;

        int lastData = base64Data.length;
        while (base64Data[lastData - 1] == 0x3D) {
            if (--lastData == 0)
                return new byte[0];
        }
        result = new byte[lastData - groupCount];

        int temp = 0;
        int resultIndex = 0;
        int dataIndex = 0;
        for (; dataIndex + 4 < base64Data.length;) {
            temp = DECODE_TABLE[base64Data[dataIndex++]];
            temp = (temp << 6) + DECODE_TABLE[base64Data[dataIndex++]];
            temp = (temp << 6) + DECODE_TABLE[base64Data[dataIndex++]];
            temp = (temp << 6) + DECODE_TABLE[base64Data[dataIndex++]];

            result[resultIndex++] = (byte) ((temp >> 16) & 0xff);
            result[resultIndex++] = (byte) ((temp >> 8) & 0xff);
            result[resultIndex++] = (byte) (temp & 0xff);
        }

        temp = 0;
        int j = 0;
        for (; dataIndex < base64Data.length; dataIndex++, j++)
            temp = (temp << 6) + DECODE_TABLE[base64Data[dataIndex]];
        for (; j < 4; j++)
            temp <<= 6;

        result[resultIndex++] = (byte) ((temp >> 16) & 0xff);
        if (base64Data[dataIndex - 2] != '=')
            result[resultIndex++] = (byte) ((temp >> 8) & 0xff);
        if (base64Data[dataIndex - 1] != '=')
            result[resultIndex++] = (byte) (temp & 0xff);

        return result;
    }

    public final static String base64Decode(String strInput) {
        if (strInput == null)
            return null;

        return base64Decode(strInput, "GB2312");
    }

    public final static String base64Decode(String strInput, String charSet) {
        if (strInput == null)
            return null;
        String strOutput = null;
        byte byteData[] = new byte[strInput.length()];
        try {
            byteData = strInput.getBytes(charSet);
            strOutput = new String(base64Decode(byteData), charSet);
        } catch (UnsupportedEncodingException e) {
            return null;
        }
        return strOutput;
    }


    public final static String base64Decode(InputStream in, String charSet) {
        try {
            int c;
            byte[] buff = new byte[1024];
            ByteArrayOutputStream out = new ByteArrayOutputStream(2048);
            while ((c = in.read(buff, 0, 1024)) != -1) {
                out.write(buff, 0, c);
                //index+=1024;
                //out.write(c);
                //attachContent+=ss;
            }
            in.close();
            out.flush();
            byte[] tmp2 = Base64.base64Decode(out.toByteArray());
            out.close();
            return new String(tmp2, charSet);
        } catch (IOException e) {
            return "";
        }
    }

//     public static void main(final String[] args) {
//          String DeString=null;
//          byte[] DeByte=null;
//          if (args[0].equals("E")){
//              if(args.length!=0)
//                DeString=base64Encode(args[1]);
//              else
//                DeString=base64Encode("oK");;
//          }else{
//                DeString=base64Decode(args[1]);
//          }
//     }
}