243 lines
8.0 KiB
JavaScript
243 lines
8.0 KiB
JavaScript
|
/**
|
||
|
|
* Created by SLICE_30_K on 2017/5/22.
|
||
|
|
*
|
||
|
|
* 支持一般Base64的编码和解码
|
||
|
|
* 支持符合RFC_4648标准中"URL and Filename Safe Alphabet"的URL安全Base64编解码
|
||
|
|
* 支持中文字符的编解码(Unicode编码)
|
||
|
|
*/
|
||
|
|
;(function (root, factory) {
|
||
|
|
if (typeof exports === "object") {
|
||
|
|
// CommonJS
|
||
|
|
module.exports = exports = factory();
|
||
|
|
}
|
||
|
|
else if (typeof define === "function" && define.amd) {
|
||
|
|
// AMD
|
||
|
|
define(factory);
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
// Global (browser)
|
||
|
|
window.BASE64 = factory();
|
||
|
|
}
|
||
|
|
}(this, function () {
|
||
|
|
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', '+', '/'
|
||
|
|
];
|
||
|
|
var URLSAFE_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', '-', '_'
|
||
|
|
];
|
||
|
|
|
||
|
|
var _toBinary = function (ascii) {
|
||
|
|
var binary = [];
|
||
|
|
while (ascii > 0) {
|
||
|
|
var b = ascii % 2;
|
||
|
|
ascii = Math.floor(ascii / 2);
|
||
|
|
binary.push(b);
|
||
|
|
}
|
||
|
|
binary.reverse();
|
||
|
|
return binary;
|
||
|
|
};
|
||
|
|
|
||
|
|
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;
|
||
|
|
};
|
||
|
|
|
||
|
|
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 _toBinaryArray = function (str) {
|
||
|
|
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));
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return binaryArray;
|
||
|
|
};
|
||
|
|
|
||
|
|
var _toUnicodeStr = function (binaryArray) {
|
||
|
|
var unicode;
|
||
|
|
var unicodeBinary = [];
|
||
|
|
var str = "";
|
||
|
|
for (var i = 0, len = binaryArray.length; i < len;) {
|
||
|
|
if (binaryArray[i] == 0) {
|
||
|
|
unicode = _toDecimal(binaryArray.slice(i, i + 8));
|
||
|
|
str += String.fromCharCode(unicode);
|
||
|
|
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 = _toDecimal(unicodeBinary);
|
||
|
|
str += String.fromCharCode(unicode);
|
||
|
|
unicodeBinary = [];
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return str;
|
||
|
|
};
|
||
|
|
|
||
|
|
var _encode = function (str, url_safe) {
|
||
|
|
var base64_Index = [];
|
||
|
|
var binaryArray = _toBinaryArray(str);
|
||
|
|
var dictionary = url_safe ? URLSAFE_BASE64_MAPPING : BASE64_MAPPING;
|
||
|
|
|
||
|
|
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;
|
||
|
|
}
|
||
|
|
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 += dictionary[base64_Index[i]];
|
||
|
|
}
|
||
|
|
|
||
|
|
for (var i = 0, len = extra_Zero_Count / 2; i < len; ++i) {
|
||
|
|
base64 += '=';
|
||
|
|
}
|
||
|
|
return base64;
|
||
|
|
};
|
||
|
|
|
||
|
|
var _decode = function (_base64Str, url_safe) {
|
||
|
|
var _len = _base64Str.length;
|
||
|
|
var extra_Zero_Count = 0;
|
||
|
|
var dictionary = url_safe ? URLSAFE_BASE64_MAPPING : BASE64_MAPPING;
|
||
|
|
|
||
|
|
if (_base64Str.charAt(_len - 1) == '=') {
|
||
|
|
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 = dictionary.length; j < size; ++j) {
|
||
|
|
if (c == dictionary[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 str = _toUnicodeStr(binaryArray);
|
||
|
|
return str;
|
||
|
|
};
|
||
|
|
|
||
|
|
var __BASE64 = {
|
||
|
|
encode: function (str) {
|
||
|
|
return _encode(str, false);
|
||
|
|
},
|
||
|
|
decode: function (base64Str) {
|
||
|
|
return _decode(base64Str, false);
|
||
|
|
},
|
||
|
|
urlsafe_encode: function (str) {
|
||
|
|
return _encode(str, true);
|
||
|
|
},
|
||
|
|
urlsafe_decode: function (base64Str) {
|
||
|
|
return _decode(base64Str, true);
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
return __BASE64;
|
||
|
|
}));
|