Android加密算法:AES、Base64加密算法
摘自: http://blog.csdn.net/yuxlong2010/article/details/7892146
android常用加密算法之Base64加密算法:
- package com.long;
- /**
- * Copyright (C) 2010 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
- import java.io.ByteArrayOutputStream;
- import java.io.IOException;
- import java.io.OutputStream;
- /*
- * @author long
- *
- */
- 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 = ((((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);
- }
- }
- 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;
- }
- }
- }
android常用加密算法之AES加密算法:
- package com.long;
- import java.security.SecureRandom;
- import javax.crypto.Cipher;
- import javax.crypto.KeyGenerator;
- import javax.crypto.SecretKey;
- import javax.crypto.spec.SecretKeySpec;
- /**
- * AES加密解密算法
- *
- * @author long
- *
- */
- public class Encryption {
- private final static String HEX = "0123456789ABCDEF";
- public static String encrypt(String seed, String cleartext)
- throws Exception {
- byte[] rawKey = getRawKey(seed.getBytes());
- byte[] result = encrypt(rawKey, cleartext.getBytes());
- return toHex(result);
- }
- public static String decrypt(String seed, String encrypted)
- throws Exception {
- byte[] rawKey = getRawKey(seed.getBytes());
- byte[] enc = toByte(encrypted);
- byte[] result = decrypt(rawKey, enc);
- return new String(result);
- }
- private static byte[] getRawKey(byte[] seed) throws Exception {
- KeyGenerator kgen = KeyGenerator.getInstance("AES");
- SecureRandom sr = SecureRandom.getInstance("SHA1PRNG");
- sr.setSeed(seed);
- kgen.init(128, sr); // 192 and 256 bits may not be available
- SecretKey skey = kgen.generateKey();
- byte[] raw = skey.getEncoded();
- return raw;
- }
- private static byte[] encrypt(byte[] raw, byte[] clear) throws Exception {
- SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
- Cipher cipher = Cipher.getInstance("AES");
- cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
- byte[] encrypted = cipher.doFinal(clear);
- return encrypted;
- }
- private static byte[] decrypt(byte[] raw, byte[] encrypted)
- throws Exception {
- SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
- Cipher cipher = Cipher.getInstance("AES");
- cipher.init(Cipher.DECRYPT_MODE, skeySpec);
- byte[] decrypted = cipher.doFinal(encrypted);
- return decrypted;
- }
- public static String toHex(String txt) {
- return toHex(txt.getBytes());
- }
- public static String fromHex(String hex) {
- return new String(toByte(hex));
- }
- public static byte[] toByte(String hexString) {
- int len = hexString.length() / 2;
- byte[] result = new byte[len];
- for (int i = 0; i < len; i++)
- result[i] = Integer.valueOf(hexString.substring(2 * i, 2 * i + 2),
- 16).byteValue();
- return result;
- }
- public static String toHex(byte[] buf) {
- if (buf == null)
- return "";
- StringBuffer result = new StringBuffer(2 * buf.length);
- for (int i = 0; i < buf.length; i++) {
- appendHex(result, buf[i]);
- }
- return result.toString();
- }
- private static void appendHex(StringBuffer sb, byte b) {
- sb.append(HEX.charAt((b >> 4) & 0x0f)).append(HEX.charAt(b & 0x0f));
- }
- }