RSA签名算法，计算调用加密报文，安全传输

RSA签名算法

1. 获取当前的时间戳参数

2. 计算参数签名

3. 获取请求对象的MD5密文

4. 通过私钥计算某个参数的RSA签名

5. 转换字符集到utf8

6. MD5加密字符串

7. base64编码

8. base64编码字符串

9. base64解码

/*** 参数签名算法工具类*/
public class RSAUtils {/*** 获取当前的时间戳参数* @return*/public static String getRtick(){long timestamp = new Date().getTime();int rnd = (int)Math.random() * 1000;String rtick = timestamp + "" + rnd;return rtick;}/*** 计算参数签名* @param developerId 开发者ID* @param privateKey 用户私钥* @param host 请求的HOST地址（http://ip:port/context）* @param methodName 请求的接口方法名* @param rtick 时间戳参数* @param urlParams url参数（param1=value1&param2=value2&param3=value3）* @param requestBody request body 参数（JSON字符串）* @return*/public static String calcRsaSign(String developerId, String privateKey, String host, String methodName, String rtick, String urlParams, String requestBody) {String url = host+methodName;Map<String, String> mySignedURLParams = new TreeMap<String, String>();mySignedURLParams.put("developerId", developerId);mySignedURLParams.put("rtick", rtick);mySignedURLParams.put("signType", "rsa");if(urlParams != null && !"".equals(urlParams)){String[] params = urlParams.split("&");for(String p1 : params){String[] p2 = p1.split("=");String key = p2[0];String value = "";if(p2.length == 2){value = p2[1];}mySignedURLParams.put(key, value);}}String requestPath;try {requestPath = new URL(url).getPath();}catch (MalformedURLException e) {throw new RuntimeException(e.getMessage(), e);}StringBuilder signStringBuilder = new StringBuilder();for (String name : mySignedURLParams.keySet()) {String value = mySignedURLParams.get(name);signStringBuilder.append(name);signStringBuilder.append("=");signStringBuilder.append(value);}signStringBuilder.append(requestPath);if (requestBody != null && !"".equals(requestBody) ) {String requestMd5 = getRequestMd5(requestBody);signStringBuilder.append(requestMd5);}String signString = signStringBuilder.toString();String rsaSign =  calcRsaSign(privateKey, signString);//rsa算出来的sign，需要urlencodetry {rsaSign = URLEncoder.encode(rsaSign,"UTF-8");} catch (UnsupportedEncodingException e) {rsaSign = null;}return rsaSign;}/*** 获取request body 的MD5* @param requestBody* @return*/private static String getRequestMd5(final String requestBody) {byte[] data;String newRequestBody = convertToUtf8(requestBody);try {data = newRequestBody.getBytes("UTF-8");}catch (UnsupportedEncodingException e) {throw new RuntimeException(e.getMessage(), e);}return md5(data);}/*** 计算参数RSA签名* @param privateKey* @param signData* @return*/private static String calcRsaSign(String privateKey, final String signData) {byte[] data;try {data = signData.getBytes("UTF-8");}catch (UnsupportedEncodingException e) {throw new RuntimeException(e.getMessage(), e);}byte[] sign = null;// 解密由base64编码的私钥byte[] privateKeyBytes = base64decode(privateKey.getBytes());// 构造PKCS8EncodedKeySpec对象PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(privateKeyBytes);// KEY_ALGORITHM 指定的加密算法KeyFactory keyFactory;try {keyFactory = KeyFactory.getInstance("RSA");}catch (NoSuchAlgorithmException e) {throw new RuntimeException(e.getMessage(), e);}// 取私钥匙对象PrivateKey priKey;try {priKey = keyFactory.generatePrivate(pkcs8KeySpec);}catch (InvalidKeySpecException e) {throw new RuntimeException(e.getMessage(), e);}// 用私钥对信息生成数字签名Signature signature;try {signature = Signature.getInstance("SHA1withRSA");}catch (NoSuchAlgorithmException e) {throw new RuntimeException(e.getMessage(), e);}try {signature.initSign(priKey);}catch (InvalidKeyException e) {throw new RuntimeException(e.getMessage(), e);}try {signature.update(data);sign = signature.sign();}catch (SignatureException e) {throw new RuntimeException(e.getMessage(), e);}return new String(base64encode(sign));}/*** 转换字符集到utf8** @param src* @return*/private static String convertToUtf8(String src) {if (src == null || src.length() == 0) {return src;}if ("UTF-8".equalsIgnoreCase(Charset.defaultCharset().name())) {return src;}byte[] srcData = src.getBytes();try {return new String(srcData, "UTF-8");}catch (UnsupportedEncodingException e) {throw new RuntimeException(e.getMessage(), e);}}/*** md5* @param data* @return*/public static String md5(byte[] data) {char hexDigits[]={'0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f'};byte[] btInput = data;// 获得MD5摘要算法的 MessageDigest 对象MessageDigest mdInst;try {mdInst = MessageDigest.getInstance("MD5");}catch (NoSuchAlgorithmException e) {throw new RuntimeException(e.getMessage(), e);}// 使用指定的字节更新摘要mdInst.update(btInput);// 获得密文byte[] md = mdInst.digest();// 把密文转换成十六进制的字符串形式int j = md.length;char str[] = new char[j * 2];int k = 0;for (int i = 0; i < j; i++) {byte byte0 = md[i];str[k++] = hexDigits[byte0 >>> 4 & 0xf];str[k++] = hexDigits[byte0 & 0xf];}return new String(str);}/*** base64编码* @param data* @return*/public static byte[] base64encode(byte[] data) {return Base64.encodeBase64(data);}/*** base64编码字符串* @param data* @return*/public static String base64encodeString(byte[] data) {return Base64.encodeBase64String(data);}/*** base64解码* @param data* @return*/public static byte[] base64decode(byte[] data) {try {return Base64.decodeBase64(data);} catch (Exception e) {ByteArrayOutputStream outputStream = new ByteArrayOutputStream();for (int i = 0; i < data.length; i++) {byte c = data[i];if (c == 13 || c == 10) {continue;}outputStream.write(c);}try {outputStream.close();} catch (IOException e2) {}data = outputStream.toByteArray();return Base64.decodeBase64(data);}}
}