- package com.example.bcloud;
- import java.security.MessageDigest;
- import javax.crypto.Cipher;
- import javax.crypto.spec.IvParameterSpec;
- import javax.crypto.spec.SecretKeySpec;
- public class Security {
- private static String key = null;
- private static String ivKey = null;
- public static void hashToKey(String hash) {
- String md5Code = MD5Util.MD5(hash);
- key = md5Code.substring(0, 16);
- ivKey = md5Code.substring(16);
- }
- public static String encrypt(String data) {
- try {
- Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
- int blockSize = cipher.getBlockSize();
- byte[] dataBytes = data.getBytes();
- int plaintextLength = dataBytes.length;
- if (plaintextLength % blockSize != 0) {
- plaintextLength = plaintextLength + (blockSize - (plaintextLength % blockSize));
- }
- byte[] plaintext = new byte[plaintextLength];
- System.arraycopy(dataBytes, 0, plaintext, 0, dataBytes.length);
- SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), "AES");
- IvParameterSpec ivspec = new IvParameterSpec(ivKey.getBytes());
- cipher.init(Cipher.ENCRYPT_MODE, keyspec, ivspec);
- byte[] encrypted = cipher.doFinal(plaintext);
- return Base64.encode(encrypted);
- } catch (Exception e) {
- System.out.println(e.toString());
- }
- return null;
- }
- public static String decrypt(String data) {
- try {
- String text = Base64.decode(data.getBytes());
- byte[] by = ConvertTobyte(text);
- Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
- SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), "AES");
- IvParameterSpec ivspec = new IvParameterSpec(ivKey.getBytes());
- cipher.init(Cipher.DECRYPT_MODE, keyspec, ivspec);
- byte[] original = cipher.doFinal(by);
- String originalString = new String(original);
- return originalString.trim();
- }catch (Exception e) {
- System.out.println(e.toString());
- }
- return null;
- }
- private static byte[] ConvertTobyte(String data) {
- int maxLength = data.length();
- byte[] by = new byte[maxLength];
- char[] chars = data.toCharArray();
- for(int i = 0; i < chars.length; i++) {
- by[i] = (byte) chars[i];
- }
- return by;
- }
- }
- 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};
- 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();
- }
- public static String decode(byte[] data) {
- StringBuffer sb = new StringBuffer();
- int len = data.length;
- int i = 0;
- int b1, b2, b3, b4;
- while (i < len) {
- do {
- b1 = base64DecodeChars[data[i++]];
- } while (i < len && b1 == -1);
- if (b1 == -1) break;
- do {
- b2 = base64DecodeChars
- [data[i++]];
- } while (i < len && b2 == -1);
- if (b2 == -1) break;
- sb.append((char) ((b1 << 2) | ((b2 & 0x30) >>> 4)));
- do {
- b3 = data[i++];
- if (b3 == 61) return sb.toString();
- b3 = base64DecodeChars[b3];
- } while (i < len && b3 == -1);
- if (b3 == -1) break;
- sb.append((char) (((b2 & 0x0f) << 4) | ((b3 & 0x3c) >>> 2)));
- do {
- b4 = data[i++];
- if (b4 == 61) return sb.toString();
- b4 = base64DecodeChars[b4];
- } while (i < len && b4 == -1);
- if (b4 == -1) break;
- sb.append((char) (((b3 & 0x03) << 6) | b4));
- }
- return sb.toString();
- }
- }
- class MD5Util {
- public final static String MD5(String s) {
- char hexDigits[]={'0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f'};
- try {
- byte[] btInput = s.getBytes();
- MessageDigest mdInst = MessageDigest.getInstance("MD5");
- mdInst.update(btInput);
- byte[] md = mdInst.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];
- }
- return new String(str);
- } catch (Exception e) {
- System.out.println(e.toString());
- }
- return null;
- }
- }
- //该片段来自于http://www.codesnippet.cn/detail/2610201513904.html
来源: http://www.codesnippet.cn/detail/2610201513904.html