JS前台加密,java后台解密实现，js前台,因项目需求，需要对用户信

JS前台加密,java后台解密实现，js前台,因项目需求，需要对用户信

因项目需求，需要对用户信息进行加密(以登录为例),前台js中对用户名密码进行加密传输。1.前台JS```javascript <script type="text/javascript">
$(function() {
$("#btn").click(function() {
var username = encode64($("#username").val()); //对数据加密
var password = encode64($("#password").val());
$("#username").val(username);
$("#password").val(password);
document.fm.submit(); //fm为form表单name
})
})

    // base64加密开始      var keyStr = "ABCDEFGHIJKLMNOP" + "QRSTUVWXYZabcdef" + "ghijklmnopqrstuv"              + "wxyz0123456789+/" + "=";    function encode64(input) {        var output = "";          var chr1, chr2, chr3 = "";          var enc1, enc2, enc3, enc4 = "";          var i = 0;          do {              chr1 = input.charCodeAt(i++);              chr2 = input.charCodeAt(i++);              chr3 = input.charCodeAt(i++);              enc1 = chr1 >> 2;              enc2 = ((chr1 &amp; 3) << 4) | (chr2 >> 4);              enc3 = ((chr2 &amp; 15) << 2) | (chr3 >> 6);              enc4 = chr3 &amp; 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);              chr1 = chr2 = chr3 = "";              enc1 = enc2 = enc3 = enc4 = "";          } while (i < input.length);        return output;      }      // base64加密结束  </script>

2、后台java代码```java    private static char[] base64EncodeChars = new char[] { 'A', 'B', 'C', 'D',              'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q',              'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd',              'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q',              'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3',              '4', '5', '6', '7', '8', '9', '+', '/', };      private static byte[] base64DecodeChars = new byte[] { -1, -1, -1, -1, -1,              -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,              -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,              -1, -1, -1, -1, 62, -1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59,              60, 61, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,              10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1,              -1, -1, -1, -1, -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37,              38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1,              -1, -1 };      /**      * 解密      * @param str      * @return      */      public static byte[] decode(String str) {          byte[] data = str.getBytes();          int len = data.length;          ByteArrayOutputStream buf = new ByteArrayOutputStream(len);          int i = 0;          int b1, b2, b3, b4;          while (i < len) {              do {                  b1 = base64DecodeChars[data[i++]];              } while (i < len &amp;&amp; b1 == -1);              if (b1 == -1) {                  break;              }              do {                  b2 = base64DecodeChars[data[i++]];              } while (i < len &amp;&amp; b2 == -1);              if (b2 == -1) {                  break;              }              buf.write((int) ((b1 << 2) | ((b2 &amp; 0x30) >>> 4)));              do {                  b3 = data[i++];                  if (b3 == 61) {                      return buf.toByteArray();                  }                  b3 = base64DecodeChars[b3];              } while (i < len &amp;&amp; b3 == -1);              if (b3 == -1) {                  break;              }              buf.write((int) (((b2 &amp; 0x0f) << 4) | ((b3 &amp; 0x3c) >>> 2)));              do {                  b4 = data[i++];                  if (b4 == 61) {                      return buf.toByteArray();                  }                  b4 = base64DecodeChars[b4];              } while (i < len &amp;&amp; b4 == -1);              if (b4 == -1) {                  break;              }              buf.write((int) (((b3 &amp; 0x03) << 6) | b4));          }          return buf.toByteArray();      }  

System.out.println(new String(decode(username))); // 使用decode()方法进行解密

Java加密算法还包括如下：

MD5(Message Digest algorithm 5，信息摘要算法)

SHA(Secure Hash Algorithm，安全散列算法)

HMAC(Hash Message Authentication Code，散列消息鉴别码)