Files

247 lines
7.0 KiB
JavaScript
Raw Permalink Normal View History

2026-05-23 22:10:14 +08:00
/*
* base64.js
*
* Licensed under the BSD 3-Clause License.
* http://opensource.org/licenses/BSD-3-Clause
*
* References:
* http://en.wikipedia.org/wiki/Base64
*/
; ( function( global, factory ) {
typeof exports === "object" && typeof module !== "undefined"
? module.exports = factory( global )
: typeof define === "function" && define.amd
? define( factory ) : factory( global );
}( (
typeof self !== "undefined" ? self
: typeof window !== "undefined" ? window
: typeof global !== "undefined" ? global
: this
), function( global ) {
"use strict";
// existing version for noConflict()
global = global || {};
var _Base64 = global.Base64;
var version = "2.5.1";
// if node.js and NOT React Native, we use Buffer
var buffer;
if( typeof module !== "undefined" && module.exports ) {
try {
buffer = eval( "require('buffer').Buffer" );
} catch( err ) {
buffer = undefined;
}
}
// constants
var b64chars
= "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
var b64tab = function( bin ) {
var t = {};
for( var i = 0, l = bin.length; i < l; i++ ) t[ bin.charAt( i ) ] = i;
return t;
}( b64chars );
var fromCharCode = String.fromCharCode;
// encoder stuff
var cb_utob = function( c ) {
if( c.length < 2 ) {
var cc = c.charCodeAt( 0 );
return cc < 0x80 ? c
: cc < 0x800 ? ( fromCharCode( 0xc0 | ( cc >>> 6 ) )
+ fromCharCode( 0x80 | ( cc & 0x3f ) ) )
: ( fromCharCode( 0xe0 | ( ( cc >>> 12 ) & 0x0f ) )
+ fromCharCode( 0x80 | ( ( cc >>> 6 ) & 0x3f ) )
+ fromCharCode( 0x80 | ( cc & 0x3f ) ) );
}
else {
var cc = 0x10000
+ ( c.charCodeAt( 0 ) - 0xD800 ) * 0x400
+ ( c.charCodeAt( 1 ) - 0xDC00 );
return ( fromCharCode( 0xf0 | ( ( cc >>> 18 ) & 0x07 ) )
+ fromCharCode( 0x80 | ( ( cc >>> 12 ) & 0x3f ) )
+ fromCharCode( 0x80 | ( ( cc >>> 6 ) & 0x3f ) )
+ fromCharCode( 0x80 | ( cc & 0x3f ) ) );
}
};
var re_utob = /[\uD800-\uDBFF][\uDC00-\uDFFFF]|[^\x00-\x7F]/g;
var utob = function( u ) {
return u.replace( re_utob, cb_utob );
};
var cb_encode = function( ccc ) {
var padlen = [ 0, 2, 1 ][ ccc.length % 3 ],
ord = ccc.charCodeAt( 0 ) << 16
| ( ( ccc.length > 1 ? ccc.charCodeAt( 1 ) : 0 ) << 8 )
| ( ( ccc.length > 2 ? ccc.charCodeAt( 2 ) : 0 ) ),
chars = [
b64chars.charAt( ord >>> 18 ),
b64chars.charAt( ( ord >>> 12 ) & 63 ),
padlen >= 2 ? "=" : b64chars.charAt( ( ord >>> 6 ) & 63 ),
padlen >= 1 ? "=" : b64chars.charAt( ord & 63 )
];
return chars.join( "" );
};
var btoa = global.btoa ? function( b ) {
return global.btoa( b );
} : function( b ) {
return b.replace( /[\s\S]{1,3}/g, cb_encode );
};
var _encode = buffer ?
buffer.from && Uint8Array && buffer.from !== Uint8Array.from
? function( u ) {
return ( u.constructor === buffer.constructor ? u : buffer.from( u ) )
.toString( "base64" );
}
: function( u ) {
return ( u.constructor === buffer.constructor ? u : new buffer( u ) )
.toString( "base64" );
}
: function( u ) {
return btoa( utob( u ) );
}
;
var encode = function( u, urisafe ) {
return !urisafe
? _encode( String( u ) )
: _encode( String( u ) ).replace( /[+\/]/g, function( m0 ) {
return m0 == "+" ? "-" : "_";
} ).replace( /=/g, "" );
};
var encodeURI = function( u ) {
return encode( u, true );
};
// decoder stuff
var re_btou = new RegExp( [
"[\xC0-\xDF][\x80-\xBF]",
"[\xE0-\xEF][\x80-\xBF]{2}",
"[\xF0-\xF7][\x80-\xBF]{3}"
].join( "|" ), "g" );
var cb_btou = function( cccc ) {
switch( cccc.length ) {
case 4:
var cp = ( ( 0x07 & cccc.charCodeAt( 0 ) ) << 18 )
| ( ( 0x3f & cccc.charCodeAt( 1 ) ) << 12 )
| ( ( 0x3f & cccc.charCodeAt( 2 ) ) << 6 )
| ( 0x3f & cccc.charCodeAt( 3 ) ),
offset = cp - 0x10000;
return ( fromCharCode( ( offset >>> 10 ) + 0xD800 )
+ fromCharCode( ( offset & 0x3FF ) + 0xDC00 ) );
case 3:
return fromCharCode(
( ( 0x0f & cccc.charCodeAt( 0 ) ) << 12 )
| ( ( 0x3f & cccc.charCodeAt( 1 ) ) << 6 )
| ( 0x3f & cccc.charCodeAt( 2 ) )
);
default:
return fromCharCode(
( ( 0x1f & cccc.charCodeAt( 0 ) ) << 6 )
| ( 0x3f & cccc.charCodeAt( 1 ) )
);
}
};
var btou = function( b ) {
return b.replace( re_btou, cb_btou );
};
var cb_decode = function( cccc ) {
var len = cccc.length,
padlen = len % 4,
n = ( len > 0 ? b64tab[ cccc.charAt( 0 ) ] << 18 : 0 )
| ( len > 1 ? b64tab[ cccc.charAt( 1 ) ] << 12 : 0 )
| ( len > 2 ? b64tab[ cccc.charAt( 2 ) ] << 6 : 0 )
| ( len > 3 ? b64tab[ cccc.charAt( 3 ) ] : 0 ),
chars = [
fromCharCode( n >>> 16 ),
fromCharCode( ( n >>> 8 ) & 0xff ),
fromCharCode( n & 0xff )
];
chars.length -= [ 0, 0, 2, 1 ][ padlen ];
return chars.join( "" );
};
var _atob = global.atob ? function( a ) {
return global.atob( a );
} : function( a ) {
return a.replace( /\S{1,4}/g, cb_decode );
};
var atob = function( a ) {
return _atob( String( a ).replace( /[^A-Za-z0-9\+\/]/g, "" ) );
};
var _decode = buffer ?
buffer.from && Uint8Array && buffer.from !== Uint8Array.from
? function( a ) {
return ( a.constructor === buffer.constructor
? a : buffer.from( a, "base64" ) ).toString();
}
: function( a ) {
return ( a.constructor === buffer.constructor
? a : new buffer( a, "base64" ) ).toString();
}
: function( a ) {
return btou( _atob( a ) );
};
var decode = function( a ) {
return _decode(
String( a ).replace( /[-_]/g, function( m0 ) {
return m0 == "-" ? "+" : "/";
} )
.replace( /[^A-Za-z0-9\+\/]/g, "" )
);
};
var noConflict = function() {
var Base64 = global.Base64;
global.Base64 = _Base64;
return Base64;
};
// export Base64
global.Base64 = {
VERSION: version,
atob: atob,
btoa: btoa,
fromBase64: decode,
toBase64: encode,
utob: utob,
encode: encode,
encodeURI: encodeURI,
btou: btou,
decode: decode,
noConflict: noConflict,
__buffer__: buffer
};
// if ES5 is available, make Base64.extendString() available
if( typeof Object.defineProperty === "function" ) {
var noEnum = function( v ) {
return { value: v, enumerable: false, writable: true, configurable: true };
};
global.Base64.extendString = function() {
Object.defineProperty(
String.prototype, "fromBase64", noEnum( function() {
return decode( this );
} ) );
Object.defineProperty(
String.prototype, "toBase64", noEnum( function( urisafe ) {
return encode( this, urisafe );
} ) );
Object.defineProperty(
String.prototype, "toBase64URI", noEnum( function() {
return encode( this, true );
} ) );
};
}
//
// export Base64 to the namespace
//
if( global[ "Meteor" ] ) { // Meteor.js
Base64 = global.Base64;
}
// module.exports and AMD are mutually exclusive.
// module.exports has precedence.
if( typeof module !== "undefined" && module.exports ) {
module.exports.Base64 = global.Base64;
}
else if( typeof define === "function" && define.amd ) {
// AMD. Register as an anonymous module.
define( [], function() {
return global.Base64;
} );
}
// that's it!
return { Base64: global.Base64 };
} ) );