lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame^] | 1 | var Base64 = { |
| 2 | |
| 3 | // private property |
| 4 | _basekey : "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=", |
| 5 | |
| 6 | // public method for decoding |
| 7 | decode : function (input, isBinaryData) { |
| 8 | if(!input) return ""; |
| 9 | var output = ""; |
| 10 | var chr1, chr2, chr3; |
| 11 | var enc1, enc2, enc3, enc4; |
| 12 | var i = 0; |
| 13 | |
| 14 | input = input.replace(/[^A-Za-z0-9\+\/\=]/g, ""); |
| 15 | |
| 16 | while (i < input.length) { |
| 17 | |
| 18 | enc1 = this._basekey.indexOf(input.charAt(i++)); |
| 19 | enc2 = this._basekey.indexOf(input.charAt(i++)); |
| 20 | enc3 = this._basekey.indexOf(input.charAt(i++)); |
| 21 | enc4 = this._basekey.indexOf(input.charAt(i++)); |
| 22 | |
| 23 | chr1 = (enc1 << 2) | (enc2 >> 4); |
| 24 | chr2 = ((enc2 & 15) << 4) | (enc3 >> 2); |
| 25 | chr3 = ((enc3 & 3) << 6) | enc4; |
| 26 | |
| 27 | output = output + String.fromCharCode(chr1); |
| 28 | |
| 29 | if (enc3 != 64) { |
| 30 | output = output + String.fromCharCode(chr2); |
| 31 | } |
| 32 | if (enc4 != 64) { |
| 33 | output = output + String.fromCharCode(chr3); |
| 34 | } |
| 35 | |
| 36 | } |
| 37 | |
| 38 | if (!isBinaryData) { |
| 39 | output = Base64._utf8_decode(output); |
| 40 | } |
| 41 | |
| 42 | return output; |
| 43 | |
| 44 | }, |
| 45 | |
| 46 | // public method for encoding |
| 47 | encode : function (input, isBinaryData) { |
| 48 | if(!input) return ""; |
| 49 | var output = ""; |
| 50 | var chr1, chr2, chr3, enc1, enc2, enc3, enc4; |
| 51 | var i = 0; |
| 52 | |
| 53 | if (!isBinaryData) { |
| 54 | input = Base64._utf8_encode(input); |
| 55 | } |
| 56 | |
| 57 | while (i < input.length) { |
| 58 | |
| 59 | chr1 = input.charCodeAt(i++); |
| 60 | chr2 = input.charCodeAt(i++); |
| 61 | chr3 = input.charCodeAt(i++); |
| 62 | |
| 63 | enc1 = chr1 >> 2; |
| 64 | enc2 = ((chr1 & 3) << 4) | (chr2 >> 4); |
| 65 | enc3 = ((chr2 & 15) << 2) | (chr3 >> 6); |
| 66 | enc4 = chr3 & 63; |
| 67 | |
| 68 | if (isNaN(chr2)) { |
| 69 | enc3 = enc4 = 64; |
| 70 | } else if (isNaN(chr3)) { |
| 71 | enc4 = 64; |
| 72 | } |
| 73 | |
| 74 | output = output + |
| 75 | this._basekey.charAt(enc1) + this._basekey.charAt(enc2) + |
| 76 | this._basekey.charAt(enc3) + this._basekey.charAt(enc4); |
| 77 | |
| 78 | } |
| 79 | |
| 80 | return output; |
| 81 | }, |
| 82 | |
| 83 | // private method for UTF-8 decoding |
| 84 | _utf8_decode : function (utftext) { |
| 85 | var string = ""; |
| 86 | var i = 0; |
| 87 | //var c = c1 = c2 = 0; cov_2 |
| 88 | var c = 0; |
| 89 | var c1 = 0; |
| 90 | var c2 = 0; |
| 91 | |
| 92 | while ( i < utftext.length ) { |
| 93 | |
| 94 | c = utftext.charCodeAt(i); |
| 95 | |
| 96 | if (c < 128) { |
| 97 | string += String.fromCharCode(c); |
| 98 | i++; |
| 99 | } |
| 100 | else if((c > 191) && (c < 224)) { |
| 101 | c2 = utftext.charCodeAt(i+1); |
| 102 | string += String.fromCharCode(((c & 31) << 6) | (c2 & 63)); |
| 103 | i += 2; |
| 104 | } |
| 105 | else { |
| 106 | c2 = utftext.charCodeAt(i+1); |
| 107 | c3 = utftext.charCodeAt(i+2); |
| 108 | string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63)); |
| 109 | i += 3; |
| 110 | } |
| 111 | |
| 112 | } |
| 113 | |
| 114 | return string; |
| 115 | }, |
| 116 | |
| 117 | // private method for UTF-8 encoding |
| 118 | _utf8_encode : function (string) { |
| 119 | string = string.replace(/\r\n/g,"\n"); |
| 120 | var utftext = ""; |
| 121 | |
| 122 | for (var n = 0; n < string.length; n++) { |
| 123 | |
| 124 | var c = string.charCodeAt(n); |
| 125 | |
| 126 | if (c < 128) { |
| 127 | utftext += String.fromCharCode(c); |
| 128 | } |
| 129 | else if((c > 127) && (c < 2048)) { |
| 130 | utftext += String.fromCharCode((c >> 6) | 192); |
| 131 | utftext += String.fromCharCode((c & 63) | 128); |
| 132 | } |
| 133 | else { |
| 134 | utftext += String.fromCharCode((c >> 12) | 224); |
| 135 | utftext += String.fromCharCode(((c >> 6) & 63) | 128); |
| 136 | utftext += String.fromCharCode((c & 63) | 128); |
| 137 | } |
| 138 | |
| 139 | } |
| 140 | |
| 141 | return utftext; |
| 142 | } |
| 143 | |
| 144 | |
| 145 | } |