首页 » js » javascript 常用小工具函数之-JS实现base64加密解密

javascript 常用小工具函数之-JS实现base64加密解密

 

方法1

<HTML>
<HEAD>
<TITLE>Base64</TITLE>
<script language=JavaScript>
var base64EncodeChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
var base64DecodeChars = new Array(
  -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);
function base64encode(str) {
  var out, i, len;
  var c1, c2, c3;
  len = str.length;
  i = 0;
  out = "";
  while(i < len) {
 c1 = str.charCodeAt(i++) & 0xff;
 if(i == len)
 {
   out += base64EncodeChars.charAt(c1 >> 2);
   out += base64EncodeChars.charAt((c1 & 0x3) << 4);
   out += "==";
   break;
 }
 c2 = str.charCodeAt(i++);
 if(i == len)
 {
   out += base64EncodeChars.charAt(c1 >> 2);
   out += base64EncodeChars.charAt(((c1 & 0x3)<< 4) | ((c2 & 0xF0) >> 4));
   out += base64EncodeChars.charAt((c2 & 0xF) << 2);
   out += "=";
   break;
 }
 c3 = str.charCodeAt(i++);
 out += base64EncodeChars.charAt(c1 >> 2);
 out += base64EncodeChars.charAt(((c1 & 0x3)<< 4) | ((c2 & 0xF0) >> 4));
 out += base64EncodeChars.charAt(((c2 & 0xF) << 2) | ((c3 & 0xC0) >>6));
 out += base64EncodeChars.charAt(c3 & 0x3F);
  }
  return out;
}
function base64decode(str) {
  var c1, c2, c3, c4;
  var i, len, out;
  len = str.length;
  i = 0;
  out = "";
  while(i < len) {
 /* c1 */
 do {
   c1 = base64DecodeChars[str.charCodeAt(i++) & 0xff];
 } while(i < len && c1 == -1);
 if(c1 == -1)
   break;
 /* c2 */
 do {
   c2 = base64DecodeChars[str.charCodeAt(i++) & 0xff];
 } while(i < len && c2 == -1);
 if(c2 == -1)
   break;
 out += String.fromCharCode((c1 << 2) | ((c2 & 0x30) >> 4));
 /* c3 */
 do {
   c3 = str.charCodeAt(i++) & 0xff;
   if(c3 == 61)
 return out;
   c3 = base64DecodeChars[c3];
 } while(i < len && c3 == -1);
 if(c3 == -1)
   break;
 out += String.fromCharCode(((c2 & 0XF) << 4) | ((c3 & 0x3C) >> 2));
 /* c4 */
 do {
   c4 = str.charCodeAt(i++) & 0xff;
   if(c4 == 61)
 return out;
   c4 = base64DecodeChars[c4];
 } while(i < len && c4 == -1);
 if(c4 == -1)
   break;
 out += String.fromCharCode(((c3 & 0x03) << 6) | c4);
  }
  return out;
}
function utf16to8(str) {
  var out, i, len, c;
  out = "";
  len = str.length;
  for(i = 0; i < len; i++) {
 c = str.charCodeAt(i);
 if ((c >= 0x0001) && (c <= 0x007F)) {
   out += str.charAt(i);
 } else if (c > 0x07FF) {
   out += String.fromCharCode(0xE0 | ((c >> 12) & 0x0F));
   out += String.fromCharCode(0x80 | ((c >> 6) & 0x3F));
   out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F));
 } else {
   out += String.fromCharCode(0xC0 | ((c >> 6) & 0x1F));
   out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F));
 }
  }
  return out;
}
function utf8to16(str) {
  var out, i, len, c;
  var char2, char3;
  out = "";
  len = str.length;
  i = 0;
  while(i < len) {
 c = str.charCodeAt(i++);
 switch(c >> 4)
 {
  case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7:
   // 0xxxxxxx
   out += str.charAt(i-1);
   break;
  case 12: case 13:
   // 110x xxxx  10xx xxxx
   char2 = str.charCodeAt(i++);
   out += String.fromCharCode(((c & 0x1F) << 6) | (char2 & 0x3F));
   break;
  case 14:
   // 1110 xxxx 10xx xxxx 10xx xxxx
   char2 = str.charCodeAt(i++);
   char3 = str.charCodeAt(i++);
   out += String.fromCharCode(((c & 0x0F) << 12) |
    ((char2 & 0x3F) << 6) |
    ((char3 & 0x3F) << 0));
   break;
 }
  }
  return out;
}

function doit() {
  var f = document.f
  f.output.value = base64encode(utf16to8(f.source.value))
  f.decode.value = utf8to16(base64decode(f.output.value))
}
</script>
</HEAD>
<BODY>
<H1>Base64</H1>
<FORM NAME="f">
原码<BR>
<TEXTAREA NAME="source" ROWS=4 COLS=60 WRAP="soft"></TEXTAREA><BR><BR>
Base64 encode<BR>
<TEXTAREA NAME="output" ROWS=4 COLS=60 WRAP="soft"></TEXTAREA><BR><BR>
Base64 decode<BR>
<TEXTAREA NAME="decode" ROWS=4 COLS=60 WRAP="soft"></TEXTAREA><BR><BR>
<INPUT TYPE=BUTTON VALUE="转换" ONCLICK="doit()">
</FORM>
</BODY>

 

 

方法2

/**
*
*  Base64 encode / decode
*
*  @author haitao.tu
*  @date   2010-04-26
*  @email  tuhaitao@foxmail.com
*
*/
 
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;
  }
}

 

<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<title>base64加密解密</title>
<script type="text/javascript">  
        var b = new Base64();  
        var str = b.encode("admin:admin");  
        alert("base64 encode:" + str);  
     //解密
        str = b.decode(str);  
        alert("base64 decode:" + str);  
</script>  
</head>

<body>
</body>
</html>

 

方法3,我在使用的

/**
 * 
 * btoa():字符串或二进制值转为Base64编码
 * atob():Base64编码转为原来的编码
  */
  var string = 'Hello World!';
  console.log(btoa(string)) // "SGVsbG8gV29ybGQh"
  console.log(atob('SGVsbG8gV29ybGQh')) // "Hello World!"

  function base64_encode(str) {
      return btoa(encodeURIComponent(str));
  }

  function base64_decode(str) {
      return decodeURIComponent(atob(str));
  }
  console.log(base64_encode('Hello World! 你好!'))
  console.log(base64_decode('SGVsbG8lMjBXb3JsZCElMjAlRTQlQkQlQTAlRTUlQTUlQkQlRUYlQkMlODE='))

 

原文链接:javascript 常用小工具函数之-JS实现base64加密解密,转载请注明来源!

0