怎么設(shè)計(jì)Api才能保證安全

public class DES {

 public DES() {
 }

 // 測(cè)試
 public static void main(String args[]) throws Exception {
  // 待加密內(nèi)容
  String str = "123456";
  // 密碼，長(zhǎng)度要是8的倍數(shù) 密鑰隨意定
  String password = "12345678";
  byte[] encrypt = encrypt(str.getBytes(), password);
  System.out.println("加密前:" +str);
  System.out.println("加密后:" + new String(encrypt));
  // 解密
  byte[] decrypt = decrypt(encrypt, password);
  System.out.println("解密后:" + new String(decrypt));
 }


 /**
  * 加密
  */
 public static byte[] encrypt(byte[] datasource, String password) {
  try {
   SecureRandom random = new SecureRandom();
   DESKeySpec desKey = new DESKeySpec(password.getBytes());
   // 創(chuàng)建一個(gè)密匙工廠，然后用它把DESKeySpec轉(zhuǎn)換成
   SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
   SecretKey securekey = keyFactory.generateSecret(desKey);
   // Cipher對(duì)象實(shí)際完成加密操作
   Cipher cipher = Cipher.getInstance("DES");
   // 用密匙初始化Cipher對(duì)象,ENCRYPT_MODE用于將 Cipher 初始化為加密模式的常量
   cipher.init(Cipher.ENCRYPT_MODE, securekey, random);
   // 現(xiàn)在，獲取數(shù)據(jù)并加密
   // 正式執(zhí)行加密操作
   return cipher.doFinal(datasource); // 按單部分操作加密或解密數(shù)據(jù)，或者結(jié)束一個(gè)多部分操作
  } catch (Throwable e) {
   e.printStackTrace();
  }
  return null;
 }

 /**
  * 解密
  */
 public static byte[] decrypt(byte[] src, String password) throws Exception {
  // DES算法要求有一個(gè)可信任的隨機(jī)數(shù)源
  SecureRandom random = new SecureRandom();
  // 創(chuàng)建一個(gè)DESKeySpec對(duì)象
  DESKeySpec desKey = new DESKeySpec(password.getBytes());
  // 創(chuàng)建一個(gè)密匙工廠
  SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");// 返回實(shí)現(xiàn)指定轉(zhuǎn)換的
                   // Cipher
                   // 對(duì)象
  // 將DESKeySpec對(duì)象轉(zhuǎn)換成SecretKey對(duì)象
  SecretKey securekey = keyFactory.generateSecret(desKey);
  // Cipher對(duì)象實(shí)際完成解密操作
  Cipher cipher = Cipher.getInstance("DES");
  // 用密匙初始化Cipher對(duì)象
  cipher.init(Cipher.DECRYPT_MODE, securekey, random);
  // 真正開始解密操作
  return cipher.doFinal(src);
 }
}
 
輸出
加密前:123456
加密后:>p.72|
解密后:123456

/**
 * RSA加解密工具類
 */
public class RSAUtil {

 public static String publicKey; // 公鑰
 public static String privateKey; // 私鑰

 /**
  * 生成公鑰和私鑰
  */
 public static void generateKey() {
  // 1.初始化秘鑰
  KeyPairGenerator keyPairGenerator;
  try {
   keyPairGenerator = KeyPairGenerator.getInstance("RSA");
   SecureRandom sr = new SecureRandom(); // 隨機(jī)數(shù)生成器
   keyPairGenerator.initialize(512, sr); // 設(shè)置512位長(zhǎng)的秘鑰
   KeyPair keyPair = keyPairGenerator.generateKeyPair(); // 開始創(chuàng)建
   RSAPublicKey rsaPublicKey = (RSAPublicKey) keyPair.getPublic();
   RSAPrivateKey rsaPrivateKey = (RSAPrivateKey) keyPair.getPrivate();
   // 進(jìn)行轉(zhuǎn)碼
   publicKey = Base64.encodeBase64String(rsaPublicKey.getEncoded());
   // 進(jìn)行轉(zhuǎn)碼
   privateKey = Base64.encodeBase64String(rsaPrivateKey.getEncoded());
  } catch (NoSuchAlgorithmException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
 }

 /**
  * 私鑰匙加密或解密
  */
 public static String encryptByprivateKey(String content, String privateKeyStr, int opmode) {
  // 私鑰要用PKCS8進(jìn)行處理
  PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(Base64.decodeBase64(privateKeyStr));
  KeyFactory keyFactory;
  PrivateKey privateKey;
  Cipher cipher;
  byte[] result;
  String text = null;

  try {
   keyFactory = KeyFactory.getInstance("RSA");
   // 還原Key對(duì)象
   privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);
   cipher = Cipher.getInstance("RSA");
   cipher.init(opmode, privateKey);
   if (opmode == Cipher.ENCRYPT_MODE) { // 加密
    result = cipher.doFinal(content.getBytes());
    text = Base64.encodeBase64String(result);
   } else if (opmode == Cipher.DECRYPT_MODE) { // 解密
    result = cipher.doFinal(Base64.decodeBase64(content));
    text = new String(result, "UTF-8");
   }
  } catch (Exception e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
  return text;
 }

 /**
  * 公鑰匙加密或解密
  */
 public static String encryptByPublicKey(String content, String publicKeyStr, int opmode) {
  // 公鑰要用X509進(jìn)行處理
  X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(Base64.decodeBase64(publicKeyStr));
  KeyFactory keyFactory;
  PublicKey publicKey;
  Cipher cipher;
  byte[] result;
  String text = null;

  try {
   keyFactory = KeyFactory.getInstance("RSA");
   // 還原Key對(duì)象
   publicKey = keyFactory.generatePublic(x509EncodedKeySpec);
   cipher = Cipher.getInstance("RSA");
   cipher.init(opmode, publicKey);
   if (opmode == Cipher.ENCRYPT_MODE) { // 加密
    result = cipher.doFinal(content.getBytes());
    text = Base64.encodeBase64String(result);
   } else if (opmode == Cipher.DECRYPT_MODE) { // 解密
    result = cipher.doFinal(Base64.decodeBase64(content));
    text = new String(result, "UTF-8");
   }
  } catch (Exception e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
  return text;
 }

 // 測(cè)試方法
 public static void main(String[] args) {

  /**
   * 注意：私鑰加密必須公鑰解密 公鑰加密必須私鑰解密
   * // 正常在開發(fā)中的時(shí)候,后端開發(fā)人員生成好密鑰對(duì)，服務(wù)器端保存私鑰 客戶端保存公鑰
   */
  System.out.println("-------------生成兩對(duì)秘鑰，分別發(fā)送方和接收方保管-------------");
  RSAUtil.generateKey();
  System.out.println("公鑰:" + RSAUtil.publicKey);
  System.out.println("私鑰:" + RSAUtil.privateKey);
  System.out.println("-------------私鑰加密公鑰解密-------------");
   String textsr = "11111111";
   // 私鑰加密
   String cipherText = RSAUtil.encryptByprivateKey(textsr,
   RSAUtil.privateKey, Cipher.ENCRYPT_MODE);
   System.out.println("私鑰加密后：" + cipherText);
   // 公鑰解密
   String text = RSAUtil.encryptByPublicKey(cipherText,
   RSAUtil.publicKey, Cipher.DECRYPT_MODE);
   System.out.println("公鑰解密后：" + text);
  System.out.println("-------------公鑰加密私鑰解密-------------");
  // 公鑰加密
  String textsr2 = "222222";
  String cipherText2 = RSAUtil.encryptByPublicKey(textsr2, RSAUtil.publicKey, Cipher.ENCRYPT_MODE);
  System.out.println("公鑰加密后：" + cipherText2);
  // 私鑰解密
  String text2 = RSAUtil.encryptByprivateKey(cipherText2, RSAUtil.privateKey, Cipher.DECRYPT_MODE);
  System.out.print("私鑰解密后：" + text2 );
 }
}