JS实现的3des+base64加密解密算法完整示例

程序员文章站 2022-05-15 10:57:00

本文实例讲述了js实现的3des+base64加密解密算法。分享给大家供大家参考，具体如下： 1. index.html：

本文实例讲述了js实现的3des+base64加密解密算法。分享给大家供大家参考，具体如下：

1. index.html：

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
  <title>www.jb51.net base64编码</title>
  <meta http-equiv="content-type" content="text/html; charset=utf-8" />
  <script type="text/javascript" src="base64.js"></script>
  <script type="text/javascript" src="des3.js"></script>
</head>
<body>
<script type="text/javascript">
var str = "网址：//www.jb51.net";
document.write("原始字符串:</br>"+str);
var base64 = base64.encoder(str);//返回编码后的字符
document.write("</br>base64后:</br>"+base64);
//alert(base64);
var unicode= base64.decoder(base64);//返回会解码后的字符串。
//alert(unicode);
document.write("</br>还原:</br>"+unicode);
//var str= "你好123hello";
var key = "qxsdhwfbszaalehbrhlgxbig";
//alert(decrypt_3des);
var des3en = des3.encrypt(key,str);
document.write("</br>des3加密:</br>"+des3en);
document.write("</br>des3解密:</br>"+des3.decrypt(key,des3en));
</script>
</body>

2. des3.js文件：

/** 
 * des 加密算法 
 * 
 * 该函数接受一个 8 字节字符串作为普通 des 算法的密钥（也就是 64 位，但是算法只使用 56 位），或者接受一个 24 字节字符串作为 3des 
 * 算法的密钥；第二个参数是要加密或解密的信息字符串；第三个布尔值参数用来说明信息是加密还是解密；接下来的可选参数 mode 如果是 0 表示 ecb 
 * 模式，1 表示 cbc 模式，默认是 ecb 模式；最后一个可选项是一个 8 字节的输入向量字符串（在 ecb 模式下不使用）。返回的密文是字符串。 
 * 
 * 参数： <br> 
 * key: 8字节字符串作为普通 des 算法的密钥,或 24 字节字符串作为 3des <br> 
 * message： 加密或解密的信息字符串<br> 
 * encrypt: 布尔值参数用来说明信息是加密还是解密<br> 
 * mode: 1:cbc模式，0:ecb模式(默认)<br> 
 * iv:<br> 
 * padding: 可选项, 8字节的输入向量字符串（在 ecb 模式下不使用） 
 */
//this takes the key, the message, and whether to encrypt or decrypt
function des (key, message, encrypt, mode, iv, padding) {
  if(encrypt) //如果是加密的话，首先转换编码
    message = unescape(encodeuricomponent(message));
  //declaring this locally speeds things up a bit
  var spfunction1 = new array (0x1010400,0,0x10000,0x1010404,0x1010004,0x10404,0x4,0x10000,0x400,0x1010400,0x1010404,0x400,0x1000404,0x1010004,0x1000000,0x4,0x404,0x1000400,0x1000400,0x10400,0x10400,0x1010000,0x1010000,0x1000404,0x10004,0x1000004,0x1000004,0x10004,0,0x404,0x10404,0x1000000,0x10000,0x1010404,0x4,0x1010000,0x1010400,0x1000000,0x1000000,0x400,0x1010004,0x10000,0x10400,0x1000004,0x400,0x4,0x1000404,0x10404,0x1010404,0x10004,0x1010000,0x1000404,0x1000004,0x404,0x10404,0x1010400,0x404,0x1000400,0x1000400,0,0x10004,0x10400,0,0x1010004);
  var spfunction2 = new array (-0x7fef7fe0,-0x7fff8000,0x8000,0x108020,0x100000,0x20,-0x7fefffe0,-0x7fff7fe0,-0x7fffffe0,-0x7fef7fe0,-0x7fef8000,-0x80000000,-0x7fff8000,0x100000,0x20,-0x7fefffe0,0x108000,0x100020,-0x7fff7fe0,0,-0x80000000,0x8000,0x108020,-0x7ff00000,0x100020,-0x7fffffe0,0,0x108000,0x8020,-0x7fef8000,-0x7ff00000,0x8020,0,0x108020,-0x7fefffe0,0x100000,-0x7fff7fe0,-0x7ff00000,-0x7fef8000,0x8000,-0x7ff00000,-0x7fff8000,0x20,-0x7fef7fe0,0x108020,0x20,0x8000,-0x80000000,0x8020,-0x7fef8000,0x100000,-0x7fffffe0,0x100020,-0x7fff7fe0,-0x7fffffe0,0x100020,0x108000,0,-0x7fff8000,0x8020,-0x80000000,-0x7fefffe0,-0x7fef7fe0,0x108000);
  var spfunction3 = new array (0x208,0x8020200,0,0x8020008,0x8000200,0,0x20208,0x8000200,0x20008,0x8000008,0x8000008,0x20000,0x8020208,0x20008,0x8020000,0x208,0x8000000,0x8,0x8020200,0x200,0x20200,0x8020000,0x8020008,0x20208,0x8000208,0x20200,0x20000,0x8000208,0x8,0x8020208,0x200,0x8000000,0x8020200,0x8000000,0x20008,0x208,0x20000,0x8020200,0x8000200,0,0x200,0x20008,0x8020208,0x8000200,0x8000008,0x200,0,0x8020008,0x8000208,0x20000,0x8000000,0x8020208,0x8,0x20208,0x20200,0x8000008,0x8020000,0x8000208,0x208,0x8020000,0x20208,0x8,0x8020008,0x20200);
  var spfunction4 = new array (0x802001,0x2081,0x2081,0x80,0x802080,0x800081,0x800001,0x2001,0,0x802000,0x802000,0x802081,0x81,0,0x800080,0x800001,0x1,0x2000,0x800000,0x802001,0x80,0x800000,0x2001,0x2080,0x800081,0x1,0x2080,0x800080,0x2000,0x802080,0x802081,0x81,0x800080,0x800001,0x802000,0x802081,0x81,0,0,0x802000,0x2080,0x800080,0x800081,0x1,0x802001,0x2081,0x2081,0x80,0x802081,0x81,0x1,0x2000,0x800001,0x2001,0x802080,0x800081,0x2001,0x2080,0x800000,0x802001,0x80,0x800000,0x2000,0x802080);
  var spfunction5 = new array (0x100,0x2080100,0x2080000,0x42000100,0x80000,0x100,0x40000000,0x2080000,0x40080100,0x80000,0x2000100,0x40080100,0x42000100,0x42080000,0x80100,0x40000000,0x2000000,0x40080000,0x40080000,0,0x40000100,0x42080100,0x42080100,0x2000100,0x42080000,0x40000100,0,0x42000000,0x2080100,0x2000000,0x42000000,0x80100,0x80000,0x42000100,0x100,0x2000000,0x40000000,0x2080000,0x42000100,0x40080100,0x2000100,0x40000000,0x42080000,0x2080100,0x40080100,0x100,0x2000000,0x42080000,0x42080100,0x80100,0x42000000,0x42080100,0x2080000,0,0x40080000,0x42000000,0x80100,0x2000100,0x40000100,0x80000,0,0x40080000,0x2080100,0x40000100);
  var spfunction6 = new array (0x20000010,0x20400000,0x4000,0x20404010,0x20400000,0x10,0x20404010,0x400000,0x20004000,0x404010,0x400000,0x20000010,0x400010,0x20004000,0x20000000,0x4010,0,0x400010,0x20004010,0x4000,0x404000,0x20004010,0x10,0x20400010,0x20400010,0,0x404010,0x20404000,0x4010,0x404000,0x20404000,0x20000000,0x20004000,0x10,0x20400010,0x404000,0x20404010,0x400000,0x4010,0x20000010,0x400000,0x20004000,0x20000000,0x4010,0x20000010,0x20404010,0x404000,0x20400000,0x404010,0x20404000,0,0x20400010,0x10,0x4000,0x20400000,0x404010,0x4000,0x400010,0x20004010,0,0x20404000,0x20000000,0x400010,0x20004010);
  var spfunction7 = new array (0x200000,0x4200002,0x4000802,0,0x800,0x4000802,0x200802,0x4200800,0x4200802,0x200000,0,0x4000002,0x2,0x4000000,0x4200002,0x802,0x4000800,0x200802,0x200002,0x4000800,0x4000002,0x4200000,0x4200800,0x200002,0x4200000,0x800,0x802,0x4200802,0x200800,0x2,0x4000000,0x200800,0x4000000,0x200800,0x200000,0x4000802,0x4000802,0x4200002,0x4200002,0x2,0x200002,0x4000000,0x4000800,0x200000,0x4200800,0x802,0x200802,0x4200800,0x802,0x4000002,0x4200802,0x4200000,0x200800,0,0x2,0x4200802,0,0x200802,0x4200000,0x800,0x4000002,0x4000800,0x800,0x200002);
  var spfunction8 = new array (0x10001040,0x1000,0x40000,0x10041040,0x10000000,0x10001040,0x40,0x10000000,0x40040,0x10040000,0x10041040,0x41000,0x10041000,0x41040,0x1000,0x40,0x10040000,0x10000040,0x10001000,0x1040,0x41000,0x40040,0x10040040,0x10041000,0x1040,0,0,0x10040040,0x10000040,0x10001000,0x41040,0x40000,0x41040,0x40000,0x10041000,0x1000,0x40,0x10040040,0x1000,0x41040,0x10001000,0x40,0x10000040,0x10040000,0x10040040,0x10000000,0x40000,0x10001040,0,0x10041040,0x40040,0x10000040,0x10040000,0x10001000,0x10001040,0,0x10041040,0x41000,0x41000,0x1040,0x1040,0x40040,0x10000000,0x10041000);
  //create the 16 or 48 subkeys we will need
  var keys = des_createkeys (key);
  var m=0, i, j, temp, temp2, right1, right2, left, right, looping;
  var cbcleft, cbcleft2, cbcright, cbcright2
  var endloop, loopinc;
  var len = message.length;
  var chunk = 0;
  //set up the loops for single and triple des
  var iterations = keys.length == 32 ? 3 : 9; //single or triple des
  if (iterations == 3) {looping = encrypt ? new array (0, 32, 2) : new array (30, -2, -2);}
  else {looping = encrypt ? new array (0, 32, 2, 62, 30, -2, 64, 96, 2) : new array (94, 62, -2, 32, 64, 2, 30, -2, -2);}
  //pad the message depending on the padding parameter
  if (padding == 2) message += "    "; //pad the message with spaces
  else if (padding == 1) {
    if(encrypt) {
      temp = 8-(len%8);
      message += string.fromcharcode(temp,temp,temp,temp,temp,temp,temp,temp);
      if (temp===8) len+=8;
    }
  } //pkcs7 padding
  else if (!padding) message += "\0\0\0\0\0\0\0\0"; //pad the message out with null bytes
  //store the result here
  var result = "";
  var tempresult = "";
  if (mode == 1) { //cbc mode
    cbcleft = (iv.charcodeat(m++) << 24) | (iv.charcodeat(m++) << 16) | (iv.charcodeat(m++) << 8) | iv.charcodeat(m++);
    cbcright = (iv.charcodeat(m++) << 24) | (iv.charcodeat(m++) << 16) | (iv.charcodeat(m++) << 8) | iv.charcodeat(m++);
    m=0;
  }
  //loop through each 64 bit chunk of the message
  while (m < len) {
    left = (message.charcodeat(m++) << 24) | (message.charcodeat(m++) << 16) | (message.charcodeat(m++) << 8) | message.charcodeat(m++);
    right = (message.charcodeat(m++) << 24) | (message.charcodeat(m++) << 16) | (message.charcodeat(m++) << 8) | message.charcodeat(m++);
    //for cipher block chaining mode, xor the message with the previous result
    if (mode == 1) {if (encrypt) {left ^= cbcleft; right ^= cbcright;} else {cbcleft2 = cbcleft; cbcright2 = cbcright; cbcleft = left; cbcright = right;}}
    //first each 64 but chunk of the message must be permuted according to ip
    temp = ((left >>> 4) ^ right) & 0x0f0f0f0f; right ^= temp; left ^= (temp << 4);
    temp = ((left >>> 16) ^ right) & 0x0000ffff; right ^= temp; left ^= (temp << 16);
    temp = ((right >>> 2) ^ left) & 0x33333333; left ^= temp; right ^= (temp << 2);
    temp = ((right >>> 8) ^ left) & 0x00ff00ff; left ^= temp; right ^= (temp << 8);
    temp = ((left >>> 1) ^ right) & 0x55555555; right ^= temp; left ^= (temp << 1);
    left = ((left << 1) | (left >>> 31));
    right = ((right << 1) | (right >>> 31));
    //do this either 1 or 3 times for each chunk of the message
    for (j=0; j<iterations; j+=3) {
      endloop = looping[j+1];
      loopinc = looping[j+2];
      //now go through and perform the encryption or decryption
      for (i=looping[j]; i!=endloop; i+=loopinc) { //for efficiency
        right1 = right ^ keys[i];
        right2 = ((right >>> 4) | (right << 28)) ^ keys[i+1];
        //the result is attained by passing these bytes through the s selection functions
        temp = left;
        left = right;
        right = temp ^ (spfunction2[(right1 >>> 24) & 0x3f] | spfunction4[(right1 >>> 16) & 0x3f]
          | spfunction6[(right1 >>> 8) & 0x3f] | spfunction8[right1 & 0x3f]
          | spfunction1[(right2 >>> 24) & 0x3f] | spfunction3[(right2 >>> 16) & 0x3f]
          | spfunction5[(right2 >>> 8) & 0x3f] | spfunction7[right2 & 0x3f]);
      }
      temp = left; left = right; right = temp; //unreverse left and right
    } //for either 1 or 3 iterations
    //move then each one bit to the right
    left = ((left >>> 1) | (left << 31));
    right = ((right >>> 1) | (right << 31));
    //now perform ip-1, which is ip in the opposite direction
    temp = ((left >>> 1) ^ right) & 0x55555555; right ^= temp; left ^= (temp << 1);
    temp = ((right >>> 8) ^ left) & 0x00ff00ff; left ^= temp; right ^= (temp << 8);
    temp = ((right >>> 2) ^ left) & 0x33333333; left ^= temp; right ^= (temp << 2);
    temp = ((left >>> 16) ^ right) & 0x0000ffff; right ^= temp; left ^= (temp << 16);
    temp = ((left >>> 4) ^ right) & 0x0f0f0f0f; right ^= temp; left ^= (temp << 4);
    //for cipher block chaining mode, xor the message with the previous result
    if (mode == 1) {if (encrypt) {cbcleft = left; cbcright = right;} else {left ^= cbcleft2; right ^= cbcright2;}}
    tempresult += string.fromcharcode ((left>>>24), ((left>>>16) & 0xff), ((left>>>8) & 0xff), (left & 0xff), (right>>>24), ((right>>>16) & 0xff), ((right>>>8) & 0xff), (right & 0xff));
    chunk += 8;
    if (chunk == 512) {result += tempresult; tempresult = ""; chunk = 0;}
  } //for every 8 characters, or 64 bits in the message
  //return the result as an array
  result += tempresult;
  result = result.replace(/\0*$/g, "");
  if(!encrypt ) { //如果是解密的话，解密结束后对pkcs7 padding进行解码，并转换成utf-8编码
    if(padding === 1) { //pkcs7 padding解码
      var len = result.length, paddingchars = 0;
      len && (paddingchars = result.charcodeat(len-1));
      (paddingchars <= 8) && (result = result.substring(0, len - paddingchars));
    }
    //转换成utf-8编码
    result = decodeuricomponent(escape(result));
  }
  return result;
} //end of des
//des_createkeys
//this takes as input a 64 bit key (even though only 56 bits are used)
//as an array of 2 integers, and returns 16 48 bit keys
function des_createkeys (key) {
  //declaring this locally speeds things up a bit
  var pc2bytes0 = new array (0,0x4,0x20000000,0x20000004,0x10000,0x10004,0x20010000,0x20010004,0x200,0x204,0x20000200,0x20000204,0x10200,0x10204,0x20010200,0x20010204);
  var pc2bytes1 = new array (0,0x1,0x100000,0x100001,0x4000000,0x4000001,0x4100000,0x4100001,0x100,0x101,0x100100,0x100101,0x4000100,0x4000101,0x4100100,0x4100101);
  var pc2bytes2 = new array (0,0x8,0x800,0x808,0x1000000,0x1000008,0x1000800,0x1000808,0,0x8,0x800,0x808,0x1000000,0x1000008,0x1000800,0x1000808);
  var pc2bytes3 = new array (0,0x200000,0x8000000,0x8200000,0x2000,0x202000,0x8002000,0x8202000,0x20000,0x220000,0x8020000,0x8220000,0x22000,0x222000,0x8022000,0x8222000);
  var pc2bytes4 = new array (0,0x40000,0x10,0x40010,0,0x40000,0x10,0x40010,0x1000,0x41000,0x1010,0x41010,0x1000,0x41000,0x1010,0x41010);
  var pc2bytes5 = new array (0,0x400,0x20,0x420,0,0x400,0x20,0x420,0x2000000,0x2000400,0x2000020,0x2000420,0x2000000,0x2000400,0x2000020,0x2000420);
  var pc2bytes6 = new array (0,0x10000000,0x80000,0x10080000,0x2,0x10000002,0x80002,0x10080002,0,0x10000000,0x80000,0x10080000,0x2,0x10000002,0x80002,0x10080002);
  var pc2bytes7 = new array (0,0x10000,0x800,0x10800,0x20000000,0x20010000,0x20000800,0x20010800,0x20000,0x30000,0x20800,0x30800,0x20020000,0x20030000,0x20020800,0x20030800);
  var pc2bytes8 = new array (0,0x40000,0,0x40000,0x2,0x40002,0x2,0x40002,0x2000000,0x2040000,0x2000000,0x2040000,0x2000002,0x2040002,0x2000002,0x2040002);
  var pc2bytes9 = new array (0,0x10000000,0x8,0x10000008,0,0x10000000,0x8,0x10000008,0x400,0x10000400,0x408,0x10000408,0x400,0x10000400,0x408,0x10000408);
  var pc2bytes10 = new array (0,0x20,0,0x20,0x100000,0x100020,0x100000,0x100020,0x2000,0x2020,0x2000,0x2020,0x102000,0x102020,0x102000,0x102020);
  var pc2bytes11 = new array (0,0x1000000,0x200,0x1000200,0x200000,0x1200000,0x200200,0x1200200,0x4000000,0x5000000,0x4000200,0x5000200,0x4200000,0x5200000,0x4200200,0x5200200);
  var pc2bytes12 = new array (0,0x1000,0x8000000,0x8001000,0x80000,0x81000,0x8080000,0x8081000,0x10,0x1010,0x8000010,0x8001010,0x80010,0x81010,0x8080010,0x8081010);
  var pc2bytes13 = new array (0,0x4,0x100,0x104,0,0x4,0x100,0x104,0x1,0x5,0x101,0x105,0x1,0x5,0x101,0x105);
  //how many iterations (1 for des, 3 for triple des)
  var iterations = key.length > 8 ? 3 : 1; //changed by paul 16/6/2007 to use triple des for 9+ byte keys
  //stores the return keys
  var keys = new array (32 * iterations);
  //now define the left shifts which need to be done
  var shifts = new array (0, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0);
  //other variables
  var lefttemp, righttemp, m=0, n=0, temp;
  for (var j=0; j<iterations; j++) { //either 1 or 3 iterations
    var left = (key.charcodeat(m++) << 24) | (key.charcodeat(m++) << 16) | (key.charcodeat(m++) << 8) | key.charcodeat(m++);
    var right = (key.charcodeat(m++) << 24) | (key.charcodeat(m++) << 16) | (key.charcodeat(m++) << 8) | key.charcodeat(m++);
    temp = ((left >>> 4) ^ right) & 0x0f0f0f0f; right ^= temp; left ^= (temp << 4);
    temp = ((right >>> -16) ^ left) & 0x0000ffff; left ^= temp; right ^= (temp << -16);
    temp = ((left >>> 2) ^ right) & 0x33333333; right ^= temp; left ^= (temp << 2);
    temp = ((right >>> -16) ^ left) & 0x0000ffff; left ^= temp; right ^= (temp << -16);
    temp = ((left >>> 1) ^ right) & 0x55555555; right ^= temp; left ^= (temp << 1);
    temp = ((right >>> 8) ^ left) & 0x00ff00ff; left ^= temp; right ^= (temp << 8);
    temp = ((left >>> 1) ^ right) & 0x55555555; right ^= temp; left ^= (temp << 1);
    //the right side needs to be shifted and to get the last four bits of the left side
    temp = (left << 8) | ((right >>> 20) & 0x000000f0);
    //left needs to be put upside down
    left = (right << 24) | ((right << 8) & 0xff0000) | ((right >>> 8) & 0xff00) | ((right >>> 24) & 0xf0);
    right = temp;
    //now go through and perform these shifts on the left and right keys
    for (var i=0; i < shifts.length; i++) {
      //shift the keys either one or two bits to the left
      if (shifts[i]) {left = (left << 2) | (left >>> 26); right = (right << 2) | (right >>> 26);}
      else {left = (left << 1) | (left >>> 27); right = (right << 1) | (right >>> 27);}
      left &= -0xf; right &= -0xf;
      //now apply pc-2, in such a way that e is easier when encrypting or decrypting
      //this conversion will look like pc-2 except only the last 6 bits of each byte are used
      //rather than 48 consecutive bits and the order of lines will be according to
      //how the s selection functions will be applied: s2, s4, s6, s8, s1, s3, s5, s7
      lefttemp = pc2bytes0[left >>> 28] | pc2bytes1[(left >>> 24) & 0xf]
        | pc2bytes2[(left >>> 20) & 0xf] | pc2bytes3[(left >>> 16) & 0xf]
        | pc2bytes4[(left >>> 12) & 0xf] | pc2bytes5[(left >>> 8) & 0xf]
        | pc2bytes6[(left >>> 4) & 0xf];
      righttemp = pc2bytes7[right >>> 28] | pc2bytes8[(right >>> 24) & 0xf]
        | pc2bytes9[(right >>> 20) & 0xf] | pc2bytes10[(right >>> 16) & 0xf]
        | pc2bytes11[(right >>> 12) & 0xf] | pc2bytes12[(right >>> 8) & 0xf]
        | pc2bytes13[(right >>> 4) & 0xf];
      temp = ((righttemp >>> 16) ^ lefttemp) & 0x0000ffff;
      keys[n++] = lefttemp ^ temp; keys[n++] = righttemp ^ (temp << 16);
    }
  } //for each iterations
  //return the keys we've created
  return keys;
} //end of des_createkeys
function genkey(key, start, end) {
  //8 byte / 64 bit key (des) or 192 bit key
  return {key:pad(key.slice(start, end)),vector: 1};
}
function pad(key) {
  for (var i = key.length; i<24; i++) {
    key+="0";
  }
  return key;
}
var des3iv = '12345678';
var des3 = {
  //3des加密，cbc/pkcs5padding
  encrypt:function(key,input){
    var genkey = genkey(key, 0, 24);
    return btoa(des(genkey.key, input, 1, 1, des3iv, 1));
  },
  ////3des解密，cbc/pkcs5padding
  decrypt:function(key,input){
    var genkey = genkey(key, 0, 24); 
    return des(genkey.key, atob(input), 0, 1, des3iv, 1); 
  }
};

3. base64.js文件：

/**
 *create by 2014年7月9日 http://javascript.css-js.com/
 *base64 encode and decode by utf-8 unicode
 *可以和java的base64编码和解码互相转化
 */
  var base64_mapping = [
    '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','+','/'
  ];
  /**
   *ascii convert to binary
   */
  var _tobinary = function(ascii){
    var binary = new array();
    while(ascii > 0){
      var b = ascii%2;
      ascii = math.floor(ascii/2);
      binary.push(b);
    }
    /*
    var len = binary.length;
    if(6-len > 0){
      for(var i = 6-len ; i > 0 ; --i){
        binary.push(0);
      }
    }*/
    binary.reverse();
    return binary;
  };
  /**
   *binary convert to decimal
   */
  var _todecimal = function(binary){
    var dec = 0;
    var p = 0;
    for(var i = binary.length-1 ; i >= 0 ; --i){
      var b = binary[i];
      if(b == 1){
        dec += math.pow(2 , p);
      }
      ++p;
    }
    return dec;
  };
  /**
   *unicode convert to utf-8
   */
  var _toutf8binary = function(c , binaryarray){
    var mustlen = (8-(c+1)) + ((c-1)*6);
    var fatlen = binaryarray.length;
    var diff = mustlen - fatlen;
    while(--diff >= 0){
      binaryarray.unshift(0);
    }
    var binary = [];
    var _c = c;
    while(--_c >= 0){
      binary.push(1);
    }
    binary.push(0);
    var i = 0 , len = 8 - (c+1);
    for(; i < len ; ++i){
      binary.push(binaryarray[i]);
    }
    for(var j = 0 ; j < c-1 ; ++j){
      binary.push(1);
      binary.push(0);
      var sum = 6;
      while(--sum >= 0){
        binary.push(binaryarray[i++]);
      }
    }
    return binary;
  };
  var base64 = {
      /**
       *base64 encode
       */
      encoder:function(str){
        var base64_index = [];
        var binaryarray = [];
        for(var i = 0 , len = str.length ; i < len ; ++i){
          var unicode = str.charcodeat(i);
          var _tmpbinary = _tobinary(unicode);
          if(unicode < 0x80){
            var _tmpdiff = 8 - _tmpbinary.length;
            while(--_tmpdiff >= 0){
              _tmpbinary.unshift(0);
            }
            binaryarray = binaryarray.concat(_tmpbinary);
          }else if(unicode >= 0x80 && unicode <= 0x7ff){
            binaryarray = binaryarray.concat(_toutf8binary(2 , _tmpbinary));
          }else if(unicode >= 0x800 && unicode <= 0xffff){//utf-8 3byte
            binaryarray = binaryarray.concat(_toutf8binary(3 , _tmpbinary));
          }else if(unicode >= 0x10000 && unicode <= 0x1fffff){//utf-8 4byte
            binaryarray = binaryarray.concat(_toutf8binary(4 , _tmpbinary));  
          }else if(unicode >= 0x200000 && unicode <= 0x3ffffff){//utf-8 5byte
            binaryarray = binaryarray.concat(_toutf8binary(5 , _tmpbinary));
          }else if(unicode >= 4000000 && unicode <= 0x7fffffff){//utf-8 6byte
            binaryarray = binaryarray.concat(_toutf8binary(6 , _tmpbinary));
          }
        }
        var extra_zero_count = 0;
        for(var i = 0 , len = binaryarray.length ; i < len ; i+=6){
          var diff = (i+6)-len;
          if(diff == 2){
            extra_zero_count = 2;
          }else if(diff == 4){
            extra_zero_count = 4;
          }
          //if(extra_zero_count > 0){
          // len += extra_zero_count+1;
          //}
          var _tmpextra_zero_count = extra_zero_count;
          while(--_tmpextra_zero_count >= 0){
            binaryarray.push(0);
          }
          base64_index.push(_todecimal(binaryarray.slice(i , i+6)));
        }
        var base64 = '';
        for(var i = 0 , len = base64_index.length ; i < len ; ++i){
          base64 += base64_mapping[base64_index[i]];
        }
        for(var i = 0 , len = extra_zero_count/2 ; i < len ; ++i){
          base64 += '=';
        }
        return base64;
      },
      /**
       *base64 decode for utf-8 
       */
      decoder : function(_base64str){
        var _len = _base64str.length;
        var extra_zero_count = 0;
        /**
         *计算在进行base64编码的时候，补了几个0
         */
        if(_base64str.charat(_len-1) == '='){
          //alert(_base64str.charat(_len-1));
          //alert(_base64str.charat(_len-2));
          if(_base64str.charat(_len-2) == '='){//两个等号说明补了4个0
            extra_zero_count = 4;
            _base64str = _base64str.substring(0 , _len-2);
          }else{//一个等号说明补了2个0
            extra_zero_count = 2;
            _base64str = _base64str.substring(0 , _len - 1);
          }
        }
        var binaryarray = [];
        for(var i = 0 , len = _base64str.length; i < len ; ++i){
          var c = _base64str.charat(i);
          for(var j = 0 , size = base64_mapping.length ; j < size ; ++j){
            if(c == base64_mapping[j]){
              var _tmp = _tobinary(j);
              /*不足6位的补0*/
              var _tmplen = _tmp.length;
              if(6-_tmplen > 0){
                for(var k = 6-_tmplen ; k > 0 ; --k){
                  _tmp.unshift(0);
                }
              }
              binaryarray = binaryarray.concat(_tmp);
              break;
            }
          }
        }
        if(extra_zero_count > 0){
          binaryarray = binaryarray.slice(0 , binaryarray.length - extra_zero_count);
        }
        var unicode = [];
        var unicodebinary = [];
        for(var i = 0 , len = binaryarray.length ; i < len ; ){
          if(binaryarray[i] == 0){
            unicode=unicode.concat(_todecimal(binaryarray.slice(i,i+8)));
            i += 8;
          }else{
            var sum = 0;
            while(i < len){
              if(binaryarray[i] == 1){
                ++sum;
              }else{
                break;
              }
              ++i;
            }
            unicodebinary = unicodebinary.concat(binaryarray.slice(i+1 , i+8-sum));
            i += 8 - sum;
            while(sum > 1){
              unicodebinary = unicodebinary.concat(binaryarray.slice(i+2 , i+8));
              i += 8;
              --sum;
            }
            unicode = unicode.concat(_todecimal(unicodebinary));
            unicodebinary = [];
          }
        }
        //---------直接转换为结果
        var strresult = ''; 
        for(var i = 0 , len = unicode.length ; i < len ;++i){ 
           strresult += string.fromcharcode(unicode[i]); 
        }
        return strresult;
      }
  };

运行结果：

JS实现的3des+base64加密解密算法完整示例