Java实现的Base64、MD5、3DES工具

package com.lavasoft.common.security;

/**
 * MD5工具
 *
 * @author leizhimin 2010-6-3 11:10:29
 */

import java.security.MessageDigest;

public class MD5 {
    /**
     * MD5值计算<p>
     * MD5的算法在RFC1321 中定义:
     * 在RFC 1321中,给出了Test suite用来检验你的实现是否正确:
     * MD5 ("") = d41d8cd98f00b204e9800998ecf8427e
     * MD5 ("a") = 0cc175b9c0f1b6a831c399e269772661
     * MD5 ("abc") = 900150983cd24fb0d6963f7d28e17f72
     * MD5 ("message digest") = f96b697d7cb7938d525a2f31aaf161d0
     * MD5 ("abcdefghijklmnopqrstuvwxyz") = c3fcd3d76192e4007dfb496cca67e13b
     *
     * @param res 源字符串
     * @return md5值
     */
    public final static String MD5(String res) {
        char hexDigits[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
                'a', 'b', 'c', 'd', 'e', 'f'};
        try {
            byte[] strTemp = res.getBytes();
            MessageDigest mdTemp = MessageDigest.getInstance("MD5");
            mdTemp.update(strTemp);
            byte[] md = mdTemp.digest();
            int j = md.length;
            char str[] = new char[j * 2];
            int k = 0;
            for (int i = 0; i < j; i++) {
                byte byte0 = md[i];
                str[k++] = hexDigits[byte0 >>> 4 & 0xf];
                str[k++] = hexDigits[byte0 & 0xf];
            }
            String dd = new String(str);
            return dd;
        } catch (Exception e) {
            return null;
        }
    }

    public static void main(String[] args) {
        System.out.println(MD5.MD5(""));
        System.out.println(MD5.MD5("a"));
        System.out.println(MD5.MD5("abc"));
    }
}

package com.lavasoft.common.security;

import java.io.UnsupportedEncodingException;

/**
 * Base64双向加密工具
 *
 * @author leizhimin 2010-6-3 14:10:11
 */
public class Base64 {
    private static char[] base64EncodeChars = new char[]{
            'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
            'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
            'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
            'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
            'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
            'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
            'w', 'x', 'y', 'z', '0', '1', '2', '3',
            '4', '5', '6', '7', '8', '9', '+', '/'};

    private static byte[] base64DecodeChars = new byte[]{
            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
            52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1,
            -1, 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, -1, -1, -1, -1, -1,
            -1, 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, -1, -1, -1, -1, -1};

    /**
     * 加密
     *
     * @param data 明文的字节数组
     * @return 密文字符串
     */
    public static String encode(byte[] data) {
        StringBuffer sb = new StringBuffer();
        int len = data.length;
        int i = 0;
        int b1, b2, b3;
        while (i < len) {
            b1 = data[i++] & 0xff;
            if (i == len) {
                sb.append(base64EncodeChars[b1 >>> 2]);
                sb.append(base64EncodeChars[(b1 & 0x3) << 4]);
                sb.append("==");
                break;
            }
            b2 = data[i++] & 0xff;
            if (i == len) {
                sb.append(base64EncodeChars[b1 >>> 2]);
                sb.append(base64EncodeChars[((b1 & 0x03) << 4) | ((b2 & 0xf0) >>> 4)]);
                sb.append(base64EncodeChars[(b2 & 0x0f) << 2]);
                sb.append("=");
                break;
            }
            b3 = data[i++] & 0xff;
            sb.append(base64EncodeChars[b1 >>> 2]);
            sb.append(base64EncodeChars[((b1 & 0x03) << 4) | ((b2 & 0xf0) >>> 4)]);
            sb.append(base64EncodeChars[((b2 & 0x0f) << 2) | ((b3 & 0xc0) >>> 6)]);
            sb.append(base64EncodeChars[b3 & 0x3f]);
        }
        return sb.toString();
    }

    /**
     * 解密
     *
     * @param str 密文
     * @return 明文的字节数组
     * @throws UnsupportedEncodingException
     */
    public static byte[] decode(String str) throws UnsupportedEncodingException {
        StringBuffer sb = new StringBuffer();
        byte[] data = str.getBytes("US-ASCII");
        int len = data.length;
        int i = 0;
        int b1, b2, b3, b4;
        while (i < len) {
            /* b1 */
            do {
                b1 = base64DecodeChars[data[i++]];
            } while (i < len && b1 == -1);
            if (b1 == -1) break;
            /* b2 */
            do {
                b2 = base64DecodeChars
                        [data[i++]];
            } while (i < len && b2 == -1);
            if (b2 == -1) break;
            sb.append((char) ((b1 << 2) | ((b2 & 0x30) >>> 4)));
            /* b3 */
            do {
                b3 = data[i++];
                if (b3 == 61) return sb.toString().getBytes("iso8859-1");
                b3 = base64DecodeChars[b3];
            } while (i < len && b3 == -1);
            if (b3 == -1) break;
            sb.append((char) (((b2 & 0x0f) << 4) | ((b3 & 0x3c) >>> 2)));
            /* b4 */
            do {
                b4 = data[i++];
                if (b4 == 61) return sb.toString().getBytes("iso8859-1");
                b4 = base64DecodeChars[b4];
            } while (i < len && b4 == -1);
            if (b4 == -1) break;
            sb.append((char) (((b3 & 0x03) << 6) | b4));
        }
        return sb.toString().getBytes("iso8859-1");
    }

    public static void main(String[] args) throws UnsupportedEncodingException {
        String s = "abcd";
        System.out.println("加密前:" + s);
        String x = encode(s.getBytes());
        System.out.println("加密后:" + x);
        String x1 = new String(decode(x));
        System.out.println("解密后:" + x1);
    }
}

package com.lavasoft.common.security;

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

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import java.security.Key;
import java.security.SecureRandom;

/**
 * 使用3DES加密与解密,可对byte[],String类型进行加密与解密 密文可使用String,byte[]存储.
 *
 * @author leizhimin 2010-6-3 11:10:54
 */
public class ThreeDES {
    private Key key;        //密钥

    /**
     * 根据参数生成KEY
     *
     * @param strKey 密钥字符串
     */
    public void getKey(String strKey) {
        try {
            KeyGenerator _generator = KeyGenerator.getInstance("DES");
            _generator.init(new SecureRandom(strKey.getBytes()));
            this.key = _generator.generateKey();
            _generator = null;
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 加密String明文输入,String密文输出
     *
     * @param strMing String明文
     * @return String密文
     */
    public String getEncString(String strMing) {
        byte[] byteMi = null;
        byte[] byteMing = null;
        String strMi = "";
        BASE64Encoder base64en = new BASE64Encoder();
        try {
            byteMing = strMing.getBytes("UTF8");
            byteMi = this.getEncCode(byteMing);
            strMi = base64en.encode(byteMi);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            base64en = null;
            byteMing = null;
            byteMi = null;
        }
        return strMi;
    }

    /**
     * 解密 以String密文输入,String明文输出
     *
     * @param strMi String密文
     * @return String明文
     */
    public String getDesString(String strMi) {
        BASE64Decoder base64De = new BASE64Decoder();
        byte[] byteMing = null;
        byte[] byteMi = null;
        String strMing = "";
        try {
            byteMi = base64De.decodeBuffer(strMi);
            byteMing = this.getDesCode(byteMi);
            strMing = new String(byteMing, "UTF8");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            base64De = null;
            byteMing = null;
            byteMi = null;
        }
        return strMing;
    }

    /**
     * 加密以byte[]明文输入,byte[]密文输出
     *
     * @param byteS byte[]明文
     * @return byte[]密文
     */
    private byte[] getEncCode(byte[] byteS) {
        byte[] byteFina = null;
        Cipher cipher;
        try {
            cipher = Cipher.getInstance("DES");
            cipher.init(Cipher.ENCRYPT_MODE, key);
            byteFina = cipher.doFinal(byteS);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            cipher = null;
        }
        return byteFina;
    }

    /**
     * 解密以byte[]密文输入,以byte[]明文输出
     *
     * @param byteD byte[]密文
     * @return byte[]明文
     */
    private byte[] getDesCode(byte[] byteD) {
        Cipher cipher;
        byte[] byteFina = null;
        try {
            cipher = Cipher.getInstance("DES");
            cipher.init(Cipher.DECRYPT_MODE, key);
            byteFina = cipher.doFinal(byteD);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            cipher = null;
        }
        return byteFina;
    }

    public static void main(String[] args) {
        ThreeDES des = new ThreeDES();  // 实例化一个对像
        des.getKey("abcdefgasiainfo");  // 生成密匙

        String strEnc = des.getEncString("abc");// 加密字符串,返回String的密文
        System.out.println(strEnc);

        String strDes = des.getDesString(strEnc);// 把String 类型的密文解密
        System.out.println(strDes);
    }
}

原文地址:https://www.cnblogs.com/cuker919/p/4878615.html