AS2协议详解（二）

　　上一篇中主要讲解了加密的理论知识，这篇来上代码。
　　签名和验签
　　通过信息摘要算法和非对称加密，可以实现信息的防伪造，防篡改，通过我们的私钥来签名消息，接收方就能通过我们的公钥来校验该消息是否是我们发送的。
　　/**  * 获取证书库  */ public static KeyStore getKeyStore(InputStream keyStoreInputStream, String keyStorePassword, String keyStoreType) throws Exception {     return getKeyStore(keyStoreInputStream, keyStorePassword, keyStoreType); }  public static KeyStore getKeyStore(InputStream keyStoreInputStream, String keyStorePassword, String keyStoreType, String provider) throws Exception {     KeyStore keyStore;     if (StringUtils.isNotBlank(provider)) {         keyStore = KeyStore.getInstance(keyStoreType, provider);     } else {         keyStore = KeyStore.getInstance(keyStoreType);     }     keyStore.load(keyStoreInputStream, keyStorePassword.toCharArray());     IoUtil.close(keyStoreInputStream);     return keyStore; }  /**  * 从证书库中获取公钥  */ public static PublicKey getPublicKeyFromKeyStore(KeyStore keyStore, String alias) throws Exception {     Certificate certificate = keyStore.getCertificate(alias);     return certificate.getPublicKey(); }  /**  * 从证书库获取私钥  */ public static PrivateKey getPrivateKeyFromKeyStore(KeyStore keyStore, String alias, String password) throws Exception {     return (PrivateKey) keyStore.getKey(alias, password.toCharArray()); }  /**  * 签名  */ public static byte[] sign(byte[] message, PrivateKey privateKey, String algorithm) throws Exception {     Signature signature;     signature = Signature.getInstance(algorithm);     signature.initSign(privateKey);     signature.update(message);     return signature.sign(); }  /**  * 验签  */ public static boolean verify(byte[] message, byte[] signMessage, PublicKey publicKey, String algorithm) throws Exception {     Signature signature;     boolean verifyResult;     signature = Signature.getInstance(algorithm);     signature.initVerify(publicKey);     signature.update(message);     verifyResult = signature.verify(signMessage);     return verifyResult; }
　　然后写个单元测试来验证下
　　@Test public void testVerify() throws Exception {     FileInputStream fis = new FileInputStream(new File(＂d:/keys/testkeystore.keystore＂));     //获取证书库     KeyStore keyStore = getKeyStore(fis, ＂mypassword＂, ＂JKS＂);     //获取私钥     PrivateKey privateKey = getPrivateKeyFromKeyStore(keyStore, ＂mykeystore＂, ＂mypassword＂);     //摘要算法用SHA1,非对称加密算法用RSA进行签名     byte[] signMessage = sign(CONTENT.getBytes(), privateKey, ＂SHA1withRSA＂);     //获取公钥     PublicKey publicKey = getPublicKeyFromKeyStore(keyStore, ＂mykeystore＂);     //进行验签     boolean verify = verify(CONTENT.getBytes(), signMessage, publicKey, ＂SHA1withRSA＂);     System.out.println(verify); }
　　加密和解密
　　/**  * 使用私钥加密  */ public static byte[] encodeByPrivateKey(byte[] data, PrivateKey privateKey) throws Exception {     // 对数据加密,加密算法由创建秘钥时指定，也可以自己指定,一般用RSA     Cipher cipher = Cipher.getInstance(privateKey.getAlgorithm());     cipher.init(Cipher.ENCRYPT_MODE, privateKey);     return cipher.doFinal(data); }  /**  * 使用公钥解密  */ public static byte[] decodeByPublicKey(byte[] data, PublicKey publicKey)         throws Exception {     // 对数据加密     Cipher cipher = Cipher.getInstance(publicKey.getAlgorithm());     cipher.init(Cipher.DECRYPT_MODE, publicKey);     return cipher.doFinal(data); }  /**  * 公钥加密  */ public static byte[] encodeByPublicKey(byte[] data, PublicKey publicKey)         throws Exception {     // 对数据加密     Cipher cipher = Cipher.getInstance(publicKey.getAlgorithm());     cipher.init(Cipher.ENCRYPT_MODE, publicKey);     return cipher.doFinal(data); }  /**  * 私钥解密  */ public static byte[] decodeByPrivateKey(byte[] data, PrivateKey privateKey) throws Exception {     // 对数据加密     Cipher cipher = Cipher.getInstance(privateKey.getAlgorithm());     cipher.init(Cipher.DECRYPT_MODE, privateKey);     return cipher.doFinal(data); }
　　单元测试
　　public static String CONTENT = ＂寥落古行宫，宫花寂寞红。白头宫女在，闲坐说玄宗＂; @Test public void testDecode() throws Exception {     FileInputStream fis = new FileInputStream(new File(＂d:/keys/testkeystore.keystore＂));     KeyStore keyStore = getKeyStore(fis, ＂mypassword＂, ＂JKS＂);     PrivateKey privateKey = getPrivateKeyFromKeyStore(keyStore, ＂mykeystore＂, ＂mypassword＂);     PublicKey publicKey = getPublicKeyFromKeyStore(keyStore, ＂mykeystore＂);     //加密     byte[] encode = encodeByPrivateKey(CONTENT.getBytes(), privateKey);     //解密     byte[] message = decodeByPublicKey(encode, publicKey);     System.out.println(new String(message)); }