java实现AES加密(解决中文解密后乱码问题,解决传输字符串后解密报错的问题)
在对安全性要求比较高的报文做加密的时候,算法有很多种,我这里主要用到的就是AES加密算法。由于在国内使用,所以不可避免的要对中文进行加密和解密,而在这个过程中,发现,如果不做处理,很容易会出现中文乱码。
下面是常见的情况:
一、中文乱码
不对密码进行编码处理
byte[] decryptResult = decrypt(encryptResult, password); System.out.println("解密后:" + new String(decryptResult));
运行后
加密前:我是shoneworn
解密后:鎴戞槸shoneworn
二、对文字进行编码处理,但是在传输过程中草率的将byte[]转成String, String code = new String(bytes); 由于AES加密算法要求密文是16位的倍数。所以,这么处理,在解密的时候,就会报各种错。比如下面的。
String code = new String(encryptResult); byte[] decryptResult = decrypt(code.getBytes(), password);
结果就.........
加密前:我是shoneworn javax.crypto.BadPaddingException: Given final block not properly padded at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:966) at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:824) at com.sun.crypto.provider.AESCipher.engineDoFinal(AESCipher.java:436) at javax.crypto.Cipher.doFinal(Cipher.java:2165) at com.ailin.test.AES.decrypt(AES.java:72) at com.ailin.test.AES.main(AES.java:173) Exception in thread "main" java.lang.NullPointerException at java.lang.String.<init>(Unknown Source) at com.ailin.test.AES.main(AES.java:174)
三、给功能正常的,能传中文的,不报错的AES加密加密算法源码
package com.ailin.test; import java.io.UnsupportedEncodingException; import java.security.InvalidKeyException; import java.security.NoSuchAlgorithmException; import java.security.SecureRandom; import javax.crypto.BadPaddingException; import javax.crypto.Cipher; import javax.crypto.IllegalBlockSizeException; import javax.crypto.KeyGenerator; import javax.crypto.NoSuchPaddingException; import javax.crypto.SecretKey; import javax.crypto.spec.SecretKeySpec; public class AES { /** * 加密 * * @param content * 需要加密的内容 * @param password * 加密密码 * @return */ public static byte[] encrypt(String 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 byte[] byteContent = content.getBytes("utf-8"); cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化 byte[] result = cipher.doFinal(byteContent); return result; // 加密 } catch (NoSuchAlgorithmException e) { e.printStackTrace(); } catch (NoSuchPaddingException e) { e.printStackTrace(); } catch (InvalidKeyException e) { e.printStackTrace(); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } catch (IllegalBlockSizeException e) { e.printStackTrace(); } catch (BadPaddingException e) { e.printStackTrace(); } return null; } /** * 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; } /** * 将二进制转换成16进制 * * @param buf * @return */ public static String parseByte2HexStr(byte buf[]) { StringBuffer sb = new StringBuffer(); for (int i = 0; i < buf.length; i++) { String hex = Integer.toHexString(buf[i] & 0xFF); if (hex.length() == 1) { hex = '0' + hex; } sb.append(hex.toUpperCase()); } return sb.toString(); } /** * 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; } /** * 加密 * * @param content * 需要加密的内容 * @param password * 加密密码 * @return */ public static byte[] encrypt2(String content, String password) { try { SecretKeySpec key = new SecretKeySpec(password.getBytes(), "AES"); Cipher cipher = Cipher.getInstance("AES/ECB/NoPadding"); byte[] byteContent = content.getBytes("utf-8"); cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化 byte[] result = cipher.doFinal(byteContent); return result; // 加密 } catch (NoSuchAlgorithmException e) { e.printStackTrace(); } catch (NoSuchPaddingException e) { e.printStackTrace(); } catch (InvalidKeyException e) { e.printStackTrace(); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } catch (IllegalBlockSizeException e) { e.printStackTrace(); } catch (BadPaddingException e) { e.printStackTrace(); } return null; } public static void main(String[] args) throws UnsupportedEncodingException { String content = "我是shoneworn"; String password = "12345678"; // 加密 System.out.println("加密前:" + content); byte[] encode = encrypt(content, password); //传输过程,不转成16进制的字符串,就等着程序崩溃掉吧 String code = parseByte2HexStr(encode); System.out.println("密文字符串:" + code); byte[] decode = parseHexStr2Byte(code); // 解密 byte[] decryptResult = decrypt(decode, password); System.out.println("解密后:" + new String(decryptResult, "UTF-8")); //不转码会乱码 } }
不积跬步,无以至千里。