本文實例講述了java基于AES對稱加密算法實現的加密與解密功能。分享給大家供大家參考,具體如下:
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package com.soufun.com; import java.io.UnsupportedEncodingException; import java.security.InvalidKeyException; import java.security.NoSuchAlgorithmException; import java.security.SecureRandom; import java.util.Date; 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; /** * @author WHD */ public class AesUtil { private static final String AES= "AES" ; private static final String UTF8= "UTF-8" ; static KeyGenerator kgen = null ; static { try { kgen= KeyGenerator.getInstance(AES); } catch (NoSuchAlgorithmException e) { // TODO Auto-generated catch block e.printStackTrace(); } } /* * @param content: * @param password: */ private static byte[] encrypt(String content, String password) { try { // 使用靜態代碼塊來生成KeyGenerator對象 //KeyGenerator kgen = KeyGenerator.getInstance(AES); // 使用128 位 kgen.init(128, new SecureRandom(password.getBytes())); SecretKey secretKey = kgen.generateKey(); byte[] encodeFormat = secretKey.getEncoded(); SecretKeySpec key = new SecretKeySpec(encodeFormat, AES); // Cipher對象實際完成加密操作 Cipher cipher = Cipher.getInstance(AES); // 加密內容進行編碼 byte[] byteContent = content.getBytes(UTF8); // 用密匙初始化Cipher對象 cipher.init(Cipher.ENCRYPT_MODE, key); // 正式執行加密操作 byte[] result = cipher.doFinal(byteContent); return result; } 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; } /* * @param content: * @param password: */ private static byte[] decrypt(byte[] content, String password) { try {// 使用靜態代碼塊來生成KeyGenerator對象 //KeyGenerator kgen = KeyGenerator.getInstance(AES); // 使用128 位 kgen.init(128, new SecureRandom(password.getBytes())); SecretKey secretKey = kgen.generateKey(); byte[] encodeFormat = secretKey.getEncoded(); SecretKeySpec key = new SecretKeySpec(encodeFormat, AES); // Cipher對象實際完成加密操作 Cipher cipher = Cipher.getInstance(AES); // 用密匙初始化Cipher對象 cipher.init(Cipher.DECRYPT_MODE, key); // 正式執行解密操作 byte[] result = cipher.doFinal(content); return result; } 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; } /** * 二進制--》十六進制轉化 * @param buf * @return */ private 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(); } /** * 十六進制--》二進制轉化 * @param hexStr * @return */ private 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; } public static void main(String[] args) throws UnsupportedEncodingException { long begin= new Date().getTime(); String content = "aaades加密測試" ; String password = "12345678dd" ; // 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); // 解密內容進行解碼 String result = new String(decryptResult, UTF8); System.out.println( "解密后:" + result); long end= new Date().getTime(); System.out.println(end-begin); } } |
注:SecureRandom是生成安全隨機數序列,password.getBytes()是種子,只要種子相同,序列就一樣,所以解密只要有password就行,可以復原這個序列。
希望本文所述對大家java程序設計有所幫助。