加密代码
/**解密 * @param content 待解密内容 * @param password 解密密钥 * @return */ public static byte[] decrypt(byte[] content, String password) { try { KeyGenerator kgen = KeyGenerator.getInstance("AES"); kgen.init(128, new SecureRandom(password.getBytes())); SecretKey secretKey = kgen.generateKey(); byte[] enCodeFormat = secretKey.getEncoded(); SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES"); Cipher cipher = Cipher.getInstance("AES");// 创建密码器 cipher.init(Cipher.DECRYPT_MODE, key);// 初始化 byte[] result = cipher.doFinal(content); return result; // 加密 } catch (NoSuchAlgorithmException e) { e.printStackTrace(); } catch (NoSuchPaddingException e) { e.printStackTrace(); } catch (InvalidKeyException e) { e.printStackTrace(); } catch (IllegalBlockSizeException e) { e.printStackTrace(); } catch (BadPaddingException e) { e.printStackTrace(); } return null; }
解密代码
/**解密 * @param content 待解密内容 * @param password 解密密钥 * @return */ public static byte[] decrypt(byte[] content, String password) { try { KeyGenerator kgen = KeyGenerator.getInstance("AES"); kgen.init(128, new SecureRandom(password.getBytes())); SecretKey secretKey = kgen.generateKey(); byte[] enCodeFormat = secretKey.getEncoded(); SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES"); Cipher cipher = Cipher.getInstance("AES");// 创建密码器 cipher.init(Cipher.DECRYPT_MODE, key);// 初始化 byte[] result = cipher.doFinal(content); return result; // 加密 } catch (NoSuchAlgorithmException e) { e.printStackTrace(); } catch (NoSuchPaddingException e) { e.printStackTrace(); } catch (InvalidKeyException e) { e.printStackTrace(); } catch (IllegalBlockSizeException e) { e.printStackTrace(); } catch (BadPaddingException e) { e.printStackTrace(); } return null; }
解密代码
String content = "test"; String password = "12345678"; //加密 System.out.println("加密前：" + content); byte[] encryptResult = encrypt(content, password); try { String encryptResultStr = new String(encryptResult,"utf-8"); //解密 byte[] decryptResult = decrypt(encryptResultStr.getBytes("utf-8"),password); System.out.println("解密后：" + new String(decryptResult)); } catch (UnsupportedEncodingException e) { e.printStackTrace(); }
偶尔会报错 抛出异常，
javax.crypto.IllegalBlockSizeException: Input length must be multiple of 16 when decrypting with padded cipher
原因 加密后的byte数组是不能强制转换成字符串的，换言之：字符串和byte数组在这种情况下不是互逆的；要避免这种情况，我们需要做一些修订，可以考虑将二进制数据转换成十六进制表示
解决方案
二进制转换成16进制
/**将16进制转换为二进制 * @param hexStr * @return */ public static byte[] parseHexStr2Byte(String hexStr) { if (hexStr.length() < 1) return null; byte[] result = new byte[hexStr.length()/2]; for (int i = 0;i< hexStr.length()/2; i++) { int high = Integer.parseInt(hexStr.substring(i*2, i*2+1), 16); int low = Integer.parseInt(hexStr.substring(i*2+1, i*2+2), 16); result[i] = (byte) (high * 16 + low); } return result; }
16进制转换为二进制
测试结果，问题解决
String content = "test"; String password = "12345678"; //加密 System.out.println("加密前：" + content); byte[] encryptResult = encrypt(content, password); String encryptResultStr = parseByte2HexStr(encryptResult); System.out.println("加密后：" + encryptResultStr); //解密 byte[] decryptFrom = parseHexStr2Byte(encryptResultStr); byte[] decryptResult = decrypt(decryptFrom,password); System.out.println("解密后：" + new String(decryptResult));
测试结果如下：
加密前：test 加密后：73C58BAFE578C59366D8C995CD0B9D6D 解密后：test
文档参考