MD5加密、DES加密与解密

最近项目需要进行加密传输：

Base64.java

 

package com.zhiyicx.zycx.tools;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;

public class Base64
{
	private static final char[] legalChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".toCharArray();

	public static String encode(byte[] data)
	{
		int start = 0;
		int len = data.length;
		StringBuffer buf = new StringBuffer(data.length * 3 / 2);

		int end = len - 3;
		int i = start;
		int n = 0;

		while (i <= end)
		{
			int d = (((data[i]) & 0x0ff) << 16) | (((data[i + 1]) & 0x0ff) << 8) | ((data[i + 2]) & 0x0ff);

			buf.append(legalChars[(d >> 18) & 63]);
			buf.append(legalChars[(d >> 12) & 63]);
			buf.append(legalChars[(d >> 6) & 63]);
			buf.append(legalChars[d & 63]);

			i += 3;

			if (n++ >= 14)
			{
				n = 0;
				buf.append(" ");
			}
		}

		if (i == start + len - 2)
		{
			int d = (((data[i]) & 0x0ff) << 16) | (((data[i + 1]) & 255) << 8);

			buf.append(legalChars[(d >> 18) & 63]);
			buf.append(legalChars[(d >> 12) & 63]);
			buf.append(legalChars[(d >> 6) & 63]);
			buf.append("=");
		} else if (i == start + len - 1)
		{
			int d = ((data[i]) & 0x0ff) << 16;

			buf.append(legalChars[(d >> 18) & 63]);
			buf.append(legalChars[(d >> 12) & 63]);
			buf.append("==");
		}

		return buf.toString();
	}

	private static int decode(char c)
	{
		if (c >= 'A' && c <= 'Z')
			return (c) - 65;
		else if (c >= 'a' && c <= 'z')
			return (c) - 97 + 26;
		else if (c >= '0' && c <= '9')
			return (c) - 48 + 26 + 26;
		else
			switch (c)
			{
			case '+':
				return 62;
			case '/':
				return 63;
			case '=':
				return 0;
			default:
				throw new RuntimeException("unexpected code: " + c);
			}
	}

	/**
	 * Decodes the given Base64 encoded String to a new byte array. The byte
	 * array holding the decoded data is returned.
	 */

	public static byte[] decode(String s)
	{

		ByteArrayOutputStream bos = new ByteArrayOutputStream();
		try
		{
			decode(s, bos);
		} catch (IOException e)
		{
			throw new RuntimeException();
		}
		byte[] decodedBytes = bos.toByteArray();
		try
		{
			bos.close();
			bos = null;
		} catch (IOException ex)
		{
			System.err.println("Error while decoding BASE64: " + ex.toString());
		}
		return decodedBytes;
	}

	private static void decode(String s, OutputStream os) throws IOException
	{
		int i = 0;

		int len = s.length();

		while (true)
		{
			while (i < len && s.charAt(i) <= ' ')
				i++;

			if (i == len)
				break;

			int tri = (decode(s.charAt(i)) << 18) + (decode(s.charAt(i + 1)) << 12) + (decode(s.charAt(i + 2)) << 6) + (decode(s.charAt(i + 3)));

			os.write((tri >> 16) & 255);
			if (s.charAt(i + 2) == '=')
				break;
			os.write((tri >> 8) & 255);
			if (s.charAt(i + 3) == '=')
				break;
			os.write(tri & 255);

			i += 4;
		}
	}

}

 DES.java

package com.zhiyicx.zycx.tools;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

/**
 * DES加密
 * 
 * @author Mr . H
 *
 */
public class DES
{

    private static byte[] iv1 =
    { (byte) 0x12, (byte) 0x34, (byte) 0x56, (byte) 0x78, (byte) 0x90, (byte) 0xAB, (byte) 0xCD, (byte) 0xEF };

    public static String encrypt(String encryptString, String encryptKey) throws Exception
    {
        SecretKeySpec key = new SecretKeySpec(encryptKey.getBytes(), "DES");
        Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
        cipher.init(Cipher.ENCRYPT_MODE, key);
        byte[] encryptedData = cipher.doFinal(encryptString.getBytes());

        return Base64.encode(encryptedData);
    }

    // 解密
    public static String decrypt(String decryptString, String decryptKey) throws Exception
    {
        byte[] byteMi = Base64.decode(decryptString);
        SecretKeySpec key = new SecretKeySpec(decryptKey.getBytes(), "DES");
        Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
        cipher.init(Cipher.DECRYPT_MODE, key);
        byte decryptedData[] = cipher.doFinal(byteMi);

        return new String(decryptedData);
    }

    // 加密 参数含义 encrypt1(String encryptString, String encryptKey)
    // 第一个字符表示所加密字符串  第二个表示密钥
    public static String encrypt1(String encryptString, String encryptKey) throws Exception
    {
        IvParameterSpec iv = new IvParameterSpec(iv1);
        DESKeySpec dks = new DESKeySpec(encryptKey.getBytes());
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
        SecretKey key = keyFactory.generateSecret(dks);
        Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
        cipher.init(Cipher.ENCRYPT_MODE, key, iv);
        return Base64.encode(cipher.doFinal(encryptString.getBytes()));
    }
}

MD5.java

package com.zhiyicx.zycx.tools;

import java.security.MessageDigest;

/**
 * MD5加密
 * 
 * @author Mr . H
 *
 */
public class MD5
{
    public static byte[] encryptMD5(byte[] data) throws Exception
    {

        MessageDigest md5 = MessageDigest.getInstance("MD5");
        md5.update(data);
        return md5.digest();
    }

    /**
     * MD5加密32位的加密
     * 
     * @param data
     * @return
     * @throws Exception
     */
    public static String encryptMD5(String data) throws Exception
    {

        MessageDigest md5 = MessageDigest.getInstance("MD5");
        md5.update(data.getBytes());
        byte b[] = md5.digest();

        int i;
        StringBuffer buf = new StringBuffer("");
        for (int offset = 0; offset < b.length; offset++)
        {
            i = b[offset];
            if (i < 0)
                i += 256;
            if (i < 16)
                buf.append("0");
            buf.append(Integer.toHexString(i));
        }
        return buf.toString();
    }
}