Android DES加密解密

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定义DES工具类

public class DES {    //初始化向量，随意填充    private static byte[] iv = {1,2,3,4,5,6,7,8};    /**     * DES加密     * @param encryptString 为原文     * @param encryptKey 为密钥     * @return     * @throws Exception     */    public static String encryptDES(String encryptString, String encryptKey) throws Exception {        //实例化IvParameterSpec对象，使用指定的初始化向量        IvParameterSpec zeroIv = new IvParameterSpec(iv);        //实例化SecretKeySpec类，根据字节数组来构造SecretKey        SecretKeySpec key = new SecretKeySpec(encryptKey.getBytes(), "DES");        //创建密码器        Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");        //用密钥初始化Cipher对象        cipher.init(Cipher.ENCRYPT_MODE, key, zeroIv);        //执行加密操作        byte[] encryptedData = cipher.doFinal(encryptString.getBytes());        return JrBase64.encode(encryptedData);    }    /**     * DES解密     * @param decryptString 为原文     * @param decryptKey 为密钥     * @return     * @throws Exception     */    public static String decryptDES(String decryptString, String decryptKey) throws Exception {        //先使用Base64解密        byte[] byteMi = new JrBase64().decode(decryptString);        //实例化IvParameterSpec对象，使其指向初始化向量        IvParameterSpec zeroIv = new IvParameterSpec(iv);        //实例化SecretKeySpec类，根据字节数组来构造SecretKey        SecretKeySpec key = new SecretKeySpec(decryptKey.getBytes(), "DES");        //创建密码器        Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");        //用密钥初始化Cipher对象        cipher.init(Cipher.DECRYPT_MODE, key, zeroIv);        //获取解密的数据        byte decryptedData[] = cipher.doFinal(byteMi);        //解密数据转化成字符串输出        return new String(decryptedData);    }}

定义Base64工具类：

public class JrBase64 {    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;        }    }}

调用方式：

String key = "12345678";String text = "12345678678768";String result1 = null;String result2=null;try {    result1 = DES.encryptDES(text,key);    result2 = DES.decryptDES(result1, key);    System.out.println(result1);//加密文    System.out.println(result2);//解密文} catch (Exception e) {    e.printStackTrace();}

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