我们在做技术接口时，尤其对外提供时，为了提高服务接口的安全（防爆破，防重放，防篡改等）一般会采用接口验证的方式，但是在验证的时候为了提升参数请求前后的安全，我们会采用加密。普通加密基本都是对称的，不能逆向。
下面，我介绍一种RSA的算法，通过这个加密算法实现接口请求前后的数字签名验证。具体实现流程为：
接口数字签名验证的而基本流程
下面我将RSA的签名算法代码分享下，下载即用：
public class RSAEncrypt { private static Map<Integer, String> keyMap = new HashMap<Integer, String>(); //用于封装随机产生的公钥与私钥 private static String pirvateKey="MIIBUwIBADANBgkqhkiG9w0BAQEFAASCAT0wggE5AgEAAkEAgS8Vf8eKVf9YoqoyhFy4hHgYpNkSkrrmkJrfrKeZHfZWFx2cCoon74QZ3qw15VV9jMD5DWaPdMVAVx5HckNURwIDAQABAkBpS6Fwd4pwMiNi4usuLA1SHDmqFC0pYCISd8odBratTjRv6w9OH+A/CIKDir4DZ0PsS9qh0mxb0bthRQ9vS0wBAiEAx+y2VcrbnOZNQSWUONZcVKIHazkrAWXOBR8mQfJnOUcCIQClavCvg0SesKWv65vs2ZR0quQnaFdcCMh7B4GM2DCNAQIgAsXgvY3jv+hd1/J6fNNUUoQw0Cbp1sofsmh9Mlr3XY8CIFEyGex9Cay/VsTwaLws3PMbgxxY2jDB2u6Q86VX5RUBAiBhoiUOYrxrS77ifDFm1KYFHRPyZNStYJhcVu4U5kwwIA=="; private static String publicKey="MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBAIEvFX/HilX/WKKqMoRcuIR4GKTZEpK65pCa36ynmR32VhcdnAqKJ++EGd6sNeVVfYzA+Q1mj3TFQFceR3JDVEcCAwEAAQ=="; private static String ssb="fSAUUCYm3FI3EYJWZRPXnI1dbwcLT3bFUqL5Wsdv24QtLmYmrN2i5WRKQgGxMTewRJ78Obf1Zke9rTpE+23zzw=="; public static void main(String[] args) throws Exception { //生成公钥和私钥 //genKeyPair(); //String randomStr= RandomStrUtil.getRandom(24, RandomStrUtil.TYPE.LETTER_CAPITAL_NUMBER); String uuid=UUIDUtil.getUUID(); String hashCode=String.valueOf(uuid.hashCode()); System.out.println("hashcode="+hashCode); long time=System.currentTimeMillis(); //System.out.println("随机hash"+hashCode); //加密字符串 String message = time+"@=@"+uuid; //System.out.println("随机生成的公钥为:" + publicKey); //System.out.println("随机生成的私钥为:" + pirvateKey); String messageEn = encrypt(message,publicKey); System.out.println("加密后的字符串为:" + messageEn); String messageDe = decrypt(messageEn,pirvateKey); System.out.println("源文数据="+message); System.out.println("解密数据=" + messageDe); String bs=messageDe.split("@=@")[1]; System.out.println(bs); } /** * 随机生成密钥对 * @throws NoSuchAlgorithmException */ public static void genKeyPair() throws NoSuchAlgorithmException { // KeyPairGenerator类用于生成公钥和私钥对，基于RSA算法生成对象 KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA"); // 初始化密钥对生成器，密钥大小为96-1024位 keyPairGen.initialize(1024,new SecureRandom()); // 生成一个密钥对，保存在keyPair中 KeyPair keyPair = keyPairGen.generateKeyPair(); // 得到私钥 RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate(); // 得到公钥 RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic(); String publicKeyString = new String(Base64.encodeBase64(publicKey.getEncoded())); System.out.println("公钥="+publicKeyString); // 得到私钥字符串 String privateKeyString = new String(Base64.encodeBase64((privateKey.getEncoded()))); System.out.println("私钥="+privateKeyString); // 将公钥和私钥保存到Map //0表示公钥 keyMap.put(0,publicKeyString); //1表示私钥 keyMap.put(1,privateKeyString); } /** * RSA公钥加密 * * @param str * 加密字符串 * @param publicKey * 公钥 * @return 密文 * @throws Exception * 加密过程中的异常信息 */ public static String encrypt( String str, String publicKey ) throws Exception{ //base64编码的公钥 byte[] decoded = Base64.decodeBase64(publicKey); RSAPublicKey pubKey = (RSAPublicKey) KeyFactory.getInstance("RSA").generatePublic(new X509EncodedKeySpec(decoded)); //RSA加密 Cipher cipher = Cipher.getInstance("RSA"); cipher.init(Cipher.ENCRYPT_MODE, pubKey); String outStr = Base64.encodeBase64String(cipher.doFinal(str.getBytes("UTF-8"))); return outStr; } /** * RSA私钥解密 * * @param str * 加密字符串 * @param privateKey * 私钥 * @return 铭文 * @throws Exception * 解密过程中的异常信息 */ public static String decrypt(String str, String privateKey) throws Exception{ //64位解码加密后的字符串 byte[] inputByte = Base64.decodeBase64(str.getBytes("UTF-8")); //base64编码的私钥 byte[] decoded = Base64.decodeBase64(privateKey); RSAPrivateKey priKey = (RSAPrivateKey) KeyFactory.getInstance("RSA").generatePrivate(new PKCS8EncodedKeySpec(decoded)); //RSA解密 Cipher cipher = Cipher.getInstance("RSA"); cipher.init(Cipher.DECRYPT_MODE, priKey); String outStr = new String(cipher.doFinal(inputByte)); return outStr; }} 
