AJAX通讯加密[通俗易懂]

大家好，又见面了，我是你们的朋友全栈君。

前端HTML

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>AJAX base64加密通讯实例</title>
<script type="text/javascript" src="js/base64.js"></script>
<script src="https://cdn.bootcss.com/jquery/1.10.2/jquery.min.js"></script>
<script type="text/javascript">
	var base = new Base64();
	function passWord() {
		var val = $("#yw").val();
		var result = base.encode(val);
		$("#mw").val(result);
	}

	function send() {
		var val = $("#mw").val();
		if (val == "") {
			alert("请将数据进行加密处理");
			return;
		}
		$.ajax({
			type : "post",
			url : "Base64Servlet",
			data : "pass=" + val,
			success : function(data) {
				$("span").html("后台解密:" + data);
			}
		});
	}
</script>
</head>
<body>
	原文
	<br />
	<textarea id="yw" rows="5" cols="50">Hello Word</textarea>
	<br />
	<button onclick="passWord()">进行BASE64加密</button>
	密文
	<br />
	<textarea id="mw" rows="5" cols="50"></textarea>
	<br />
	<button onclick="send()">进行后台验证</button>
	<br />
	<hr />
	<span style="color: red; font-size: 30px;"></span>
</body>
</html>

用到的Base64.js

function Base64() {  

  // private property  
  _keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";  

  // public method for encoding  
  this.encode = function (input) {  
      var output = "";  
      var chr1, chr2, chr3, enc1, enc2, enc3, enc4;  
      var i = 0;  
      input = _utf8_encode(input);  
      while (i < input.length) {  
          chr1 = input.charCodeAt(i++);  
          chr2 = input.charCodeAt(i++);  
          chr3 = input.charCodeAt(i++);  
          enc1 = chr1 >> 2;  
          enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);  
          enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);  
          enc4 = chr3 & 63;  
          if (isNaN(chr2)) {  
              enc3 = enc4 = 64;  
          } else if (isNaN(chr3)) {  
              enc4 = 64;  
          }  
          output = output +  
          _keyStr.charAt(enc1) + _keyStr.charAt(enc2) +  
          _keyStr.charAt(enc3) + _keyStr.charAt(enc4);  
      }  
      return output;  
  }  

  // public method for decoding  
  this.decode = function (input) {  
      var output = "";  
      var chr1, chr2, chr3;  
      var enc1, enc2, enc3, enc4;  
      var i = 0;  
      input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");  
      while (i < input.length) {  
          enc1 = _keyStr.indexOf(input.charAt(i++));  
          enc2 = _keyStr.indexOf(input.charAt(i++));  
          enc3 = _keyStr.indexOf(input.charAt(i++));  
          enc4 = _keyStr.indexOf(input.charAt(i++));  
          chr1 = (enc1 << 2) | (enc2 >> 4);  
          chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);  
          chr3 = ((enc3 & 3) << 6) | enc4;  
          output = output + String.fromCharCode(chr1);  
          if (enc3 != 64) {  
              output = output + String.fromCharCode(chr2);  
          }  
          if (enc4 != 64) {  
              output = output + String.fromCharCode(chr3);  
          }  
      }  
      output = _utf8_decode(output);  
      return output;  
  }  

  // private method for UTF-8 encoding  
  _utf8_encode = function (string) {  
      string = string.replace(/\r\n/g,"\n");  
      var utftext = "";  
      for (var n = 0; n < string.length; n++) {  
          var c = string.charCodeAt(n);  
          if (c < 128) {  
              utftext += String.fromCharCode(c);  
          } else if((c > 127) && (c < 2048)) {  
              utftext += String.fromCharCode((c >> 6) | 192);  
              utftext += String.fromCharCode((c & 63) | 128);  
          } else {  
              utftext += String.fromCharCode((c >> 12) | 224);  
              utftext += String.fromCharCode(((c >> 6) & 63) | 128);  
              utftext += String.fromCharCode((c & 63) | 128);  
          }  

      }  
      return utftext;  
  }  

  // private method for UTF-8 decoding  
  _utf8_decode = function (utftext) {  
      var string = "";  
      var i = 0;  
      var c = c1 = c2 = 0;  
      while ( i < utftext.length ) {  
          c = utftext.charCodeAt(i);  
          if (c < 128) {  
              string += String.fromCharCode(c);  
              i++;  
          } else if((c > 191) && (c < 224)) {  
              c2 = utftext.charCodeAt(i+1);  
              string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));  
              i += 2;  
          } else {  
              c2 = utftext.charCodeAt(i+1);  
              c3 = utftext.charCodeAt(i+2);  
              string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));  
              i += 3;  
          }  
      }  
      return string;  
  }  
}

Servlet 后台代码

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet("/Base64Servlet")
public class Base64Servlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		response.getWriter().append("<h1>Hello </h1>");
	}

	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		String data = request.getParameter("pass");
		if(data == null || data.isEmpty()){
			response.getWriter().write("Fail");
			return;
		}
        //后台进行Base64解密操作
        byte[] decode = java.util.Base64.getDecoder().decode(data.getBytes());
		response.getWriter().write(new String(decode));
	}
}

运行流程图