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純JS加密解密

function Secret_Key(str,pwd,type) {	
	  var b = new Base64(); //Base64加密
    if(type=='encryption'){
        str = b.encode(str);//Base64加密
        var prand = "";
        for(var i=0; i<pwd.length; i++) {
          prand += pwd.charCodeAt(i).toString();
        }
        var sPos = Math.floor(prand.length / 5);
        var mult = parseInt(prand.charAt(sPos) + prand.charAt(sPos*2) + prand.charAt(sPos*3) + prand.charAt(sPos*4) + prand.charAt(sPos*5));
        var incr = Math.ceil(pwd.length / 2);
        var modu = Math.pow(2, 31) - 1;
        if(mult < 2) {
          alert("Please choose a more complex or longer password.");
          return null;
        }
        var salt = Math.round(Math.random() * 1000000000) % 100000000;
        prand += salt;
        while(prand.length > 10) {
          prand = (parseInt(prand.substring(0, 10)) + parseInt(prand.substring(10, prand.length))).toString();
        }
        prand = (mult * prand + incr) % modu;
        var enc_chr = "";
        var enc_str = "";
        for(var i=0; i<str.length; i++) {
          enc_chr = parseInt(str.charCodeAt(i) ^ Math.floor((prand / modu) * 255));
          if(enc_chr < 16) {
            enc_str += "0" + enc_chr.toString(16);
          } else enc_str += enc_chr.toString(16);
          prand = (mult * prand + incr) % modu;
        }
        salt = salt.toString(16);
        while(salt.length < 8)salt = "0" + salt;
        enc_str += salt;
        return enc_str;
  }
	if(type=='decryption'){
      var prand = "";
      for(var i=0; i<pwd.length; i++) {
        prand += pwd.charCodeAt(i).toString();
      }
      var sPos = Math.floor(prand.length / 5);
      var mult = parseInt(prand.charAt(sPos) + prand.charAt(sPos*2) + prand.charAt(sPos*3) + prand.charAt(sPos*4) + prand.charAt(sPos*5));
      var incr = Math.round(pwd.length / 2);
      var modu = Math.pow(2, 31) - 1;
      var salt = parseInt(str.substring(str.length - 8, str.length), 16);
      str = str.substring(0, str.length - 8);
      prand += salt;
      while(prand.length > 10) {
        prand = (parseInt(prand.substring(0, 10)) + parseInt(prand.substring(10, prand.length))).toString();
      }
      prand = (mult * prand + incr) % modu;
      var enc_chr = "";
      var enc_str = "";
      for(var i=0; i<str.length; i+=2) {
        enc_chr = parseInt(parseInt(str.substring(i, i+2), 16) ^ Math.floor((prand / modu) * 255));
        enc_str += String.fromCharCode(enc_chr);
        prand = (mult * prand + incr) % modu;
      }
      //return enc_str;
      return b.decode(enc_str);
  }
}

輸入字元之後,加密前和解密後資料對比

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
    <input type="text" id="inp"><br/>
    加密後:<div id="showEncry"></div>
    解密後:<div id="showDncry"></div>
</body>
<script src="Base64.js"></script>
<script src="test.js"></script>
<script>
    var psd = '123456';
    document.getElementById('inp').oninput = function(){
        var pass1 = Secret_Key(document.getElementById('inp').value,psd,'encryption'); //給字串加密
        var pass2 = Secret_Key(pass1,psd,'decryption');    // 解密
        document.getElementById('showEncry').innerHTML = pass1
        document.getElementById('showDncry').innerHTML = pass2
    }
</script>
</html>

注意:還需要載入Base64.js控制元件 如下:

/**
*
*  Base64 encode / decode
*
*  @author haitao.tu
*  @date   2010-04-26
*  @email  [email protected]
*
*/
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;
	}
}