Android--DES加密

Base64.java

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

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

    /**
     * data[]进行编码
     * 
     * @param data
     * @return
     */
    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 = ((((int) data[i]) & 0x0ff) << 16)
                            | ((((int) data[i + 1]) & 0x0ff) << 8)
                            | (((int) 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 = ((((int) data[i]) & 0x0ff) << 16)
                            | ((((int) 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 = (((int) 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 ((int) c) - 65;
        else if (c >= 'a' && c <= 'z')
            return ((int) c) - 97 + 26;
        else if (c >= '0' && c <= '9')
            return ((int) 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 cn.crane.game.puzzle.utils.security;
import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

public class DES {
    private static byte[] iv = { 1, 2, 3, 4, 5, 6, 7, 8 };

    /**
     * 加密
     * 
     * @param encryptString
     * @param encryptKey
     * @return
     * @throws Exception
     */
    public static String encryptDES(String encryptString, String encryptKey) {
        // IvParameterSpec zeroIv = new IvParameterSpec(new byte[8]);
        try {
            IvParameterSpec zeroIv = new IvParameterSpec(iv);
            SecretKeySpec key = new SecretKeySpec(encryptKey.getBytes(), "DES");
            Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
            cipher.init(Cipher.ENCRYPT_MODE, key, zeroIv);
            byte[] encryptedData = cipher.doFinal(encryptString.getBytes());

            return Base64.encode(encryptedData);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "";
    }

    /**
     * 解密
     * 
     * @param decryptString
     * @param decryptKey
     * @return
     * @throws Exception
     */
    public static String decryptDES(String decryptString, String decryptKey) {
        try {
            byte[] byteMi = Base64.decode(decryptString);
            IvParameterSpec zeroIv = new IvParameterSpec(iv);
            // IvParameterSpec zeroIv = new IvParameterSpec(new byte[8]);
            SecretKeySpec key = new SecretKeySpec(decryptKey.getBytes(), "DES");
            Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");

            cipher.init(Cipher.DECRYPT_MODE, key, zeroIv);
            byte decryptedData[] = cipher.doFinal(byteMi);

            return new String(decryptedData);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "";

    }
}