写在前面
写前端的时候,很多的时候是避免不了注册这一关的,但是一般的注册是没有任何的难度的,无非就是一些简单的获取用户输入的数据,然后进行简单的校验以后调用接口,将数据发送到后端,完成一个简单的注册的流程,那么一般来说,密码是不做加密的。但是也有一些数据库里面存放的是加密后的密码,这样有一个比较安全的地方在于,即使黑客将用户输入的文本密码得到了,也不知道具体是什么,因为密码是经过加密的。
今天就简单的将加密这块写一下,有可以用到的看一下。
js的加密没特别多的办法,常见的就三种, MD5加密、Base64加密和shal加密,那么今天就将这三种的用法写一下。
MD5加密
H5源码
<!DOCTYPE html> <html> <head> <meta charset="utf-8" /> <title>md5加密</title> <script src="js/jquery.min.js" type="text/javascript" charset="utf-8"></script> <script src="js/md5.js" type="text/javascript" charset="utf-8"></script> </head> <body> <input type="password" name="" id="md5" value="" /> <input type="button" name="" id="" value="MD5加密" onclick="testmd5()" /> </body> <script type="text/javascript"> function testmd5(){ var password = $("#md5").val(); var md5password = $.md5(password); console.log("没有加密之前的是:"+password); console.log("加密以后是:"+md5password); } </script> </html>
js源码
(function($){ var rotateLeft = function(lValue, iShiftBits) { return (lValue << iShiftBits) | (lValue >>> (32 - iShiftBits)); } var addUnsigned = function(lX, lY) { var lX4, lY4, lX8, lY8, lResult; lX8 = (lX & 0x80000000); lY8 = (lY & 0x80000000); lX4 = (lX & 0x40000000); lY4 = (lY & 0x40000000); lResult = (lX & 0x3FFFFFFF) + (lY & 0x3FFFFFFF); if (lX4 & lY4) return (lResult ^ 0x80000000 ^ lX8 ^ lY8); if (lX4 | lY4) { if (lResult & 0x40000000) return (lResult ^ 0xC0000000 ^ lX8 ^ lY8); else return (lResult ^ 0x40000000 ^ lX8 ^ lY8); } else { return (lResult ^ lX8 ^ lY8); } } var F = function(x, y, z) { return (x & y) | ((~ x) & z); } var G = function(x, y, z) { return (x & z) | (y & (~ z)); } var H = function(x, y, z) { return (x ^ y ^ z); } var I = function(x, y, z) { return (y ^ (x | (~ z))); } var FF = function(a, b, c, d, x, s, ac) { a = addUnsigned(a, addUnsigned(addUnsigned(F(b, c, d), x), ac)); return addUnsigned(rotateLeft(a, s), b); }; var GG = function(a, b, c, d, x, s, ac) { a = addUnsigned(a, addUnsigned(addUnsigned(G(b, c, d), x), ac)); return addUnsigned(rotateLeft(a, s), b); }; var HH = function(a, b, c, d, x, s, ac) { a = addUnsigned(a, addUnsigned(addUnsigned(H(b, c, d), x), ac)); return addUnsigned(rotateLeft(a, s), b); }; var II = function(a, b, c, d, x, s, ac) { a = addUnsigned(a, addUnsigned(addUnsigned(I(b, c, d), x), ac)); return addUnsigned(rotateLeft(a, s), b); }; var convertToWordArray = function(string) { var lWordCount; var lMessageLength = string.length; var lNumberOfWordsTempOne = lMessageLength + 8; var lNumberOfWordsTempTwo = (lNumberOfWordsTempOne - (lNumberOfWordsTempOne % 64)) / 64; var lNumberOfWords = (lNumberOfWordsTempTwo + 1) * 16; var lWordArray = Array(lNumberOfWords - 1); var lBytePosition = 0; var lByteCount = 0; while (lByteCount < lMessageLength) { lWordCount = (lByteCount - (lByteCount % 4)) / 4; lBytePosition = (lByteCount % 4) * 8; lWordArray[lWordCount] = (lWordArray[lWordCount] | (string.charCodeAt(lByteCount) << lBytePosition)); lByteCount++; } lWordCount = (lByteCount - (lByteCount % 4)) / 4; lBytePosition = (lByteCount % 4) * 8; lWordArray[lWordCount] = lWordArray[lWordCount] | (0x80 << lBytePosition); lWordArray[lNumberOfWords - 2] = lMessageLength << 3; lWordArray[lNumberOfWords - 1] = lMessageLength >>> 29; return lWordArray; }; var wordToHex = function(lValue) { var WordToHexValue = "", WordToHexValueTemp = "", lByte, lCount; for (lCount = 0; lCount <= 3; lCount++) { lByte = (lValue >>> (lCount * 8)) & 255; WordToHexValueTemp = "0" + lByte.toString(16); WordToHexValue = WordToHexValue + WordToHexValueTemp.substr(WordToHexValueTemp.length - 2, 2); } return WordToHexValue; }; var uTF8Encode = function(string) { string = string.replace(/\x0d\x0a/g, "\x0a"); var output = ""; for (var n = 0; n < string.length; n++) { var c = string.charCodeAt(n); if (c < 128) { output += String.fromCharCode(c); } else if ((c > 127) && (c < 2048)) { output += String.fromCharCode((c >> 6) | 192); output += String.fromCharCode((c & 63) | 128); } else { output += String.fromCharCode((c >> 12) | 224); output += String.fromCharCode(((c >> 6) & 63) | 128); output += String.fromCharCode((c & 63) | 128); } } return output; }; $.extend({ md5: function(string) { var x = Array(); var k, AA, BB, CC, DD, a, b, c, d; var S11=7, S12=12, S13=17, S14=22; var S21=5, S22=9 , S23=14, S24=20; var S31=4, S32=11, S33=16, S34=23; var S41=6, S42=10, S43=15, S44=21; string = uTF8Encode(string); x = convertToWordArray(string); a = 0x67452301; b = 0xEFCDAB89; c = 0x98BADCFE; d = 0x10325476; for (k = 0; k < x.length; k += 16) { AA = a; BB = b; CC = c; DD = d; a = FF(a, b, c, d, x[k+0], S11, 0xD76AA478); d = FF(d, a, b, c, x[k+1], S12, 0xE8C7B756); c = FF(c, d, a, b, x[k+2], S13, 0x242070DB); b = FF(b, c, d, a, x[k+3], S14, 0xC1BDCEEE); a = FF(a, b, c, d, x[k+4], S11, 0xF57C0FAF); d = FF(d, a, b, c, x[k+5], S12, 0x4787C62A); c = FF(c, d, a, b, x[k+6], S13, 0xA8304613); b = FF(b, c, d, a, x[k+7], S14, 0xFD469501); a = FF(a, b, c, d, x[k+8], S11, 0x698098D8); d = FF(d, a, b, c, x[k+9], S12, 0x8B44F7AF); c = FF(c, d, a, b, x[k+10], S13, 0xFFFF5BB1); b = FF(b, c, d, a, x[k+11], S14, 0x895CD7BE); a = FF(a, b, c, d, x[k+12], S11, 0x6B901122); d = FF(d, a, b, c, x[k+13], S12, 0xFD987193); c = FF(c, d, a, b, x[k+14], S13, 0xA679438E); b = FF(b, c, d, a, x[k+15], S14, 0x49B40821); a = GG(a, b, c, d, x[k+1], S21, 0xF61E2562); d = GG(d, a, b, c, x[k+6], S22, 0xC040B340); c = GG(c, d, a, b, x[k+11], S23, 0x265E5A51); b = GG(b, c, d, a, x[k+0], S24, 0xE9B6C7AA); a = GG(a, b, c, d, x[k+5], S21, 0xD62F105D); d = GG(d, a, b, c, x[k+10], S22, 0x2441453); c = GG(c, d, a, b, x[k+15], S23, 0xD8A1E681); b = GG(b, c, d, a, x[k+4], S24, 0xE7D3FBC8); a = GG(a, b, c, d, x[k+9], S21, 0x21E1CDE6); d = GG(d, a, b, c, x[k+14], S22, 0xC33707D6); c = GG(c, d, a, b, x[k+3], S23, 0xF4D50D87); b = GG(b, c, d, a, x[k+8], S24, 0x455A14ED); a = GG(a, b, c, d, x[k+13], S21, 0xA9E3E905); d = GG(d, a, b, c, x[k+2], S22, 0xFCEFA3F8); c = GG(c, d, a, b, x[k+7], S23, 0x676F02D9); b = GG(b, c, d, a, x[k+12], S24, 0x8D2A4C8A); a = HH(a, b, c, d, x[k+5], S31, 0xFFFA3942); d = HH(d, a, b, c, x[k+8], S32, 0x8771F681); c = HH(c, d, a, b, x[k+11], S33, 0x6D9D6122); b = HH(b, c, d, a, x[k+14], S34, 0xFDE5380C); a = HH(a, b, c, d, x[k+1], S31, 0xA4BEEA44); d = HH(d, a, b, c, x[k+4], S32, 0x4BDECFA9); c = HH(c, d, a, b, x[k+7], S33, 0xF6BB4B60); b = HH(b, c, d, a, x[k+10], S34, 0xBEBFBC70); a = HH(a, b, c, d, x[k+13], S31, 0x289B7EC6); d = HH(d, a, b, c, x[k+0], S32, 0xEAA127FA); c = HH(c, d, a, b, x[k+3], S33, 0xD4EF3085); b = HH(b, c, d, a, x[k+6], S34, 0x4881D05); a = HH(a, b, c, d, x[k+9], S31, 0xD9D4D039); d = HH(d, a, b, c, x[k+12], S32, 0xE6DB99E5); c = HH(c, d, a, b, x[k+15], S33, 0x1FA27CF8); b = HH(b, c, d, a, x[k+2], S34, 0xC4AC5665); a = II(a, b, c, d, x[k+0], S41, 0xF4292244); d = II(d, a, b, c, x[k+7], S42, 0x432AFF97); c = II(c, d, a, b, x[k+14], S43, 0xAB9423A7); b = II(b, c, d, a, x[k+5], S44, 0xFC93A039); a = II(a, b, c, d, x[k+12], S41, 0x655B59C3); d = II(d, a, b, c, x[k+3], S42, 0x8F0CCC92); c = II(c, d, a, b, x[k+10], S43, 0xFFEFF47D); b = II(b, c, d, a, x[k+1], S44, 0x85845DD1); a = II(a, b, c, d, x[k+8], S41, 0x6FA87E4F); d = II(d, a, b, c, x[k+15], S42, 0xFE2CE6E0); c = II(c, d, a, b, x[k+6], S43, 0xA3014314); b = II(b, c, d, a, x[k+13], S44, 0x4E0811A1); a = II(a, b, c, d, x[k+4], S41, 0xF7537E82); d = II(d, a, b, c, x[k+11], S42, 0xBD3AF235); c = II(c, d, a, b, x[k+2], S43, 0x2AD7D2BB); b = II(b, c, d, a, x[k+9], S44, 0xEB86D391); a = addUnsigned(a, AA); b = addUnsigned(b, BB); c = addUnsigned(c, CC); d = addUnsigned(d, DD); } var tempValue = wordToHex(a) + wordToHex(b) + wordToHex(c) + wordToHex(d); return tempValue.toLowerCase(); } }); })(jQuery);
效果
Base64加密
H5源码
ps:理论上这个不可以称为加密,这个只是将您的文本按照一定的编码格式重新写一遍罢了,但是可以起到一定的加密作用。
第一种写法
<!DOCTYPE html> <html> <head> <meta charset="utf-8" /> <title>base64加密</title> <meta name="viewport" content="width=device-width, initial-scale=1"> <script src="js/jquery.min.js" type="text/javascript" charset="utf-8"></script> </head> <body> <input type="password" name="" id="basepass" value="" /> <input type="button" name="" id="" value="base加密" onclick="basefunc(1)"/> <input type="button" name="" id="" value="base解密" onclick="basefunc(2)"/> </body> <script src="js/funcbase64.js" type="text/javascript" charset="utf-8"></script> <script type="text/javascript"> function basefunc(e){ var password = $("#basepass").val(); var base = new Base64(); var encypass = base.encode(password); var decryptpass = base.decode(encypass); if(e == 1){ console.log("加密之前的密码是:"+password); console.log("加密之后的结果是:"+encypass); } else if(e == 2){ console.log("解密之前的结果是:"+encypass); console.log("解密之后的结果是:"+decryptpass); } } </script> </html>
js源码
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; } }
第二种写法
H5源码
<!DOCTYPE html> <html> <head> <meta charset="utf-8" /> <title>base64加密</title> <meta name="viewport" content="width=device-width, initial-scale=1"> <script src="js/jquery.min.js" type="text/javascript" charset="utf-8"></script> </head> <body> <input type="password" name="" id="basepass" value="" /> <input type="button" name="" id="" value="base加密" onclick="basefunc(1)"/> <input type="button" name="" id="" value="base解密" onclick="basefunc(2)"/> </body> <script src="js/base64.js" type="text/javascript" charset="utf-8"></script> <script type="text/javascript"> function basefunc(e){ var password = $("#basepass").val(); var encypass = Base64.encode(password); var decryptpass = Base64.decode(encypass); if(e == 1){ console.log("加密之前的密码是:"+password); console.log("加密之后的结果是:"+encypass); } else if(e == 2){ console.log("解密之前的结果是:"+encypass); console.log("解密之后的结果是:"+decryptpass); } } </script> </html>
js源码
var Base64= { _keyStr:"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=", encode:function(e){ var t=""; var n,r,i,s,o,u,a; var f=0; e=Base64._utf8_encode(e); while(f<e.length){ n=e.charCodeAt(f++); r=e.charCodeAt(f++); i=e.charCodeAt(f++); s=n>>2; o=(n&3)<<4|r>>4; u=(r&15)<<2|i>>6; a=i&63; if(isNaN(r)){ u=a=64 }else if(isNaN(i)){ a=64 } t=t+this._keyStr.charAt(s)+this._keyStr.charAt(o)+this._keyStr.charAt(u)+this._keyStr.charAt(a) } return t }, decode:function(e){ var t=""; var n,r,i; var s,o,u,a; var f=0; e=e.replace(/[^A-Za-z0-9+/=]/g,""); while(f<e.length){ s=this._keyStr.indexOf(e.charAt(f++)); o=this._keyStr.indexOf(e.charAt(f++)); u=this._keyStr.indexOf(e.charAt(f++)); a=this._keyStr.indexOf(e.charAt(f++)); n=s<<2|o>>4; r=(o&15)<<4|u>>2; i=(u&3)<<6|a; t=t+String.fromCharCode(n); if(u!=64){ t=t+String.fromCharCode(r) } if(a!=64){ t=t+String.fromCharCode(i) } } t=Base64._utf8_decode(t); return t }, _utf8_encode:function(e){ e=e.replace(/rn/g,"n"); var t=""; for(var n=0;n<e.length;n++){ var r=e.charCodeAt(n); if(r<128){ t+=String.fromCharCode(r) }else if(r>127&&r<2048){ t+=String.fromCharCode(r>>6|192); t+=String.fromCharCode(r&63|128) }else{ t+=String.fromCharCode(r>>12|224); t+=String.fromCharCode(r>>6&63|128); t+=String.fromCharCode(r&63|128) } } return t }, _utf8_decode:function(e){ var t=""; var n=0; var r=c1=c2=0; while(n<e.length){ r=e.charCodeAt(n); if(r<128){ t+=String.fromCharCode(r); n++ }else if(r>191&&r<224){ c2=e.charCodeAt(n+1); t+=String.fromCharCode((r&31)<<6|c2&63); n+=2 }else{ c2=e.charCodeAt(n+1); c3=e.charCodeAt(n+2); t+=String.fromCharCode((r&15)<<12|(c2&63)<<6|c3&63); n+=3 } } return t } };
效果
sha1加密
H5源码
<!DOCTYPE html> <html> <head> <meta charset="utf-8" /> <title>shal加密</title> <meta name="viewport" content="width=device-width, initial-scale=1"> <script src="js/jquery.min.js" type="text/javascript" charset="utf-8"></script> <script src="js/shal.js" type="text/javascript" charset="utf-8"></script> </head> <body> <input type="password" name="" id="md5" value="" /> <input type="button" name="" id="" value="hex_sha1加密" onclick="testshal(1)" /> <input type="button" name="" id="" value="b64_sha1加密" onclick="testshal(2)" /> <input type="button" name="" id="" value="str_sha1加密" onclick="testshal(3)" /> </body> <script type="text/javascript"> function testshal(e){ var password = $("#md5").val(); console.log("没有加密之前的是:"+password); if(e == 1){ var shalpassword = hex_sha1(password); console.log("hex_sha1方式加密后是:"+shalpassword); } else if(e == 2){ var shalpassword = b64_sha1(password); console.log("b64_sha1方式加密后是:"+shalpassword); } else if(e == 3){ var shalpassword = str_sha1(password); console.log("str_sha1方式加密后是:"+shalpassword); } } </script> </html>
js源码
var hexcase = 0; /* 十六进制输出格式。0 -小写;1 -大写 */ var b64pad = ""; /* base- 64填充字符。“=”表示严格的RFC合规性 */ var chrsz = 8; /* 每个输入字符的位数。8 - ASCII;16 -统一码 */ function hex_sha1(s) { return binb2hex(core_sha1(str2binb(s), s.length * chrsz)); } function b64_sha1(s) { return binb2b64(core_sha1(str2binb(s), s.length * chrsz)); } function str_sha1(s) { return binb2str(core_sha1(str2binb(s), s.length * chrsz)); } function hex_hmac_sha1(key, data) { return binb2hex(core_hmac_sha1(key, data)); } function b64_hmac_sha1(key, data) { return binb2b64(core_hmac_sha1(key, data)); } function str_hmac_sha1(key, data) { return binb2str(core_hmac_sha1(key, data)); } function sha1_vm_test() { return hex_sha1("abc") == "a9993e364706816aba3e25717850c26c9cd0d89d"; } function core_sha1(x, len) { x[len >> 5] |= 0x80 << (24 - len % 32); x[((len + 64 >> 9) << 4) + 15] = len; var w = Array(80); var a = 1732584193; var b = -271733879; var c = -1732584194; var d = 271733878; var e = -1009589776; for (var i = 0; i < x.length; i += 16) { var olda = a; var oldb = b; var oldc = c; var oldd = d; var olde = e; for (var j = 0; j < 80; j++) { if (j < 16) w[j] = x[i + j]; else w[j] = rol(w[j - 3] ^ w[j - 8] ^ w[j - 14] ^ w[j - 16], 1); var t = safe_add(safe_add(rol(a, 5), sha1_ft(j, b, c, d)), safe_add(safe_add(e, w[j]), sha1_kt(j))); e = d; d = c; c = rol(b, 30); b = a; a = t; } a = safe_add(a, olda); b = safe_add(b, oldb); c = safe_add(c, oldc); d = safe_add(d, oldd); e = safe_add(e, olde); } return Array(a, b, c, d, e); } function sha1_ft(t, b, c, d) { if (t < 20) return (b & c) | ((~b) & d); if (t < 40) return b ^ c ^ d; if (t < 60) return (b & c) | (b & d) | (c & d); return b ^ c ^ d; } function sha1_kt(t) { return (t < 20) ? 1518500249 : (t < 40) ? 1859775393 : (t < 60) ? -1894007588 : -899497514; } function core_hmac_sha1(key, data) { var bkey = str2binb(key); if (bkey.length > 16) bkey = core_sha1(bkey, key.length * chrsz); var ipad = Array(16), opad = Array(16); for (var i = 0; i < 16; i++) { ipad[i] = bkey[i] ^ 0x36363636; opad[i] = bkey[i] ^ 0x5C5C5C5C; } var hash = core_sha1(ipad.concat(str2binb(data)), 512 + data.length * chrsz); return core_sha1(opad.concat(hash), 512 + 160); } function safe_add(x, y) { var lsw = (x & 0xFFFF) + (y & 0xFFFF); var msw = (x >> 16) + (y >> 16) + (lsw >> 16); return (msw << 16) | (lsw & 0xFFFF); } function rol(num, cnt) { return (num << cnt) | (num >>> (32 - cnt)); } function str2binb(str) { var bin = Array(); var mask = (1 << chrsz) - 1; for (var i = 0; i < str.length * chrsz; i += chrsz) bin[i >> 5] |= (str.charCodeAt(i / chrsz) & mask) << (24 - i % 32); return bin; } function binb2str(bin) { var str = ""; var mask = (1 << chrsz) - 1; for (var i = 0; i < bin.length * 32; i += chrsz) str += String.fromCharCode((bin[i >> 5] >>> (24 - i % 32)) & mask); return str; } function binb2hex(binarray) { var hex_tab = hexcase ? "0123456789ABCDEF" : "0123456789abcdef"; var str = ""; for (var i = 0; i < binarray.length * 4; i++) { str += hex_tab.charAt((binarray[i >> 2] >> ((3 - i % 4) * 8 + 4)) & 0xF) + hex_tab.charAt((binarray[i >> 2] >> ((3 - i % 4) * 8)) & 0xF); } return str; } function binb2b64(binarray) { var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; var str = ""; for (var i = 0; i < binarray.length * 4; i += 3) { var triplet = (((binarray[i >> 2] >> 8 * (3 - i % 4)) & 0xFF) << 16) | (((binarray[i + 1 >> 2] >> 8 * (3 - (i + 1) % 4)) & 0xFF) << 8) | ((binarray[i + 2 >> 2] >> 8 * (3 - (i + 2) % 4)) & 0xFF); for (var j = 0; j < 4; j++) { if (i * 8 + j * 6 > binarray.length * 32) str += b64pad; else str += tab.charAt((triplet >> 6 * (3 - j)) & 0x3F); } } return str; }
效果