DES 加密

/** * DES加密 * @param plainData * @param secretKey * @return * @throws Exception */public static String encryption(String plainData) throws Exception{Cipher cipher = null;try {cipher = Cipher.getInstance(DES_ALGORITHM);cipher.init(Cipher.ENCRYPT_MODE, generateKey(KEY));} catch (NoSuchAlgorithmException e) {e.printStackTrace();} catch (NoSuchPaddingException e) {e.printStackTrace();}catch(InvalidKeyException e){}try {// 为了防止解密时报javax.crypto.IllegalBlockSizeException: Input length must be multiple of 8 when decrypting with padded cipher异常，// 不能把加密后的字节数组直接转换成字符串byte[] buf = cipher.doFinal(plainData.getBytes());return Base64Utils.encode(buf);} catch (IllegalBlockSizeException e) {e.printStackTrace();throw new Exception("IllegalBlockSizeException", e);} catch (BadPaddingException e) {e.printStackTrace();throw new Exception("BadPaddingException", e);}    }/** * DES解密 * @param secretData * @param secretKey * @return * @throws Exception */public static String decryption(String secretData) throws Exception{Cipher cipher = null;try {cipher = Cipher.getInstance(DES_ALGORITHM);cipher.init(Cipher.DECRYPT_MODE, generateKey(KEY));} catch (NoSuchAlgorithmException e) {e.printStackTrace();throw new Exception("NoSuchAlgorithmException", e);} catch (NoSuchPaddingException e) {e.printStackTrace();throw new Exception("NoSuchPaddingException", e);}catch(InvalidKeyException e){e.printStackTrace();throw new Exception("InvalidKeyException", e);}try {byte[] buf = cipher.doFinal(Base64Utils.decode(secretData.toCharArray()));return new String(buf);} catch (IllegalBlockSizeException e) {e.printStackTrace();throw new Exception("IllegalBlockSizeException", e);} catch (BadPaddingException e) {e.printStackTrace();throw new Exception("BadPaddingException", e);}}/** * 获得秘密密钥 *  * @param secretKey * @return * @throws NoSuchAlgorithmException  */private static SecretKey generateKey(String secretKey) throws NoSuchAlgorithmException{//SecureRandom secureRandom = new SecureRandom(secretKey.getBytes());  SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");    secureRandom.setSeed(secretKey.getBytes());// 为我们选择的DES算法生成一个KeyGenerator对象KeyGenerator kg = null;try {kg = KeyGenerator.getInstance(DES_ALGORITHM);} catch (NoSuchAlgorithmException e) {}kg.init(secureRandom);//kg.init(56, secureRandom);// 生成密钥return kg.generateKey();}static class Base64Utils {static private char[] alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=".toCharArray();static private byte[] codes = new byte[256];static {for (int i = 0; i < 256; i++)codes[i] = -1;for (int i = 'A'; i <= 'Z'; i++)codes[i] = (byte) (i - 'A');for (int i = 'a'; i <= 'z'; i++)codes[i] = (byte) (26 + i - 'a');for (int i = '0'; i <= '9'; i++)codes[i] = (byte) (52 + i - '0');codes['+'] = 62;codes['/'] = 63;}/** * 将原始数据编码为base64编码 */static public String encode(byte[] data) {char[] out = new char[((data.length + 2) / 3) * 4];for (int i = 0, index = 0; i < data.length; i += 3, index += 4) {boolean quad = false;boolean trip = false;int val = (0xFF & (int) data[i]);val <<= 8;if ((i + 1) < data.length) {val |= (0xFF & (int) data[i + 1]);trip = true;}val <<= 8;if ((i + 2) < data.length) {val |= (0xFF & (int) data[i + 2]);quad = true;}out[index + 3] = alphabet[(quad ? (val & 0x3F) : 64)];val >>= 6;out[index + 2] = alphabet[(trip ? (val & 0x3F) : 64)];val >>= 6;out[index + 1] = alphabet[val & 0x3F];val >>= 6;out[index + 0] = alphabet[val & 0x3F];}return new String(out);}/** * 将base64编码的数据解码成原始数据 */static public byte[] decode(char[] data) {int len = ((data.length + 3) / 4) * 3;if (data.length > 0 && data[data.length - 1] == '=')--len;if (data.length > 1 && data[data.length - 2] == '=')--len;byte[] out = new byte[len];int shift = 0;int accum = 0;int index = 0;for (int ix = 0; ix < data.length; ix++) {int value = codes[data[ix] & 0xFF];if (value >= 0) {accum <<= 6;shift += 6;accum |= value;if (shift >= 8) {shift -= 8;out[index++] = (byte) ((accum >> shift) & 0xff);}}}if (index != out.length)throw new Error("miscalculated data length!");return out;}}public static void main(String[] a) throws Exception{String input = "test";  String result = encryption(input);System.out.println(result);System.out.println( decryption(result));//H+Ac2AysRv6CWn3ncH1HIw==}}