Base64解碼不適用於二進制數據

Question

well 我需要Base64解碼功能。但是當我使用二進制數據時，它不會返回所需的輸出。我知道atob和atob函數，但我的問題是我在工作人員和用戶代理chrome中實現它。 chrome沒有在atob中實現，btoa在worker中的功能，所以建議我使用base64函數來處理二進制數據。現在我正在使用下面的函數，它不適用於二進制數據。

var Base64 = { 

// private property 
_keyStr : "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz/=", 

// public method for encoding 
encode : function (input) { 
    var output = ""; 
    var chr1, chr2, chr3, enc1, enc2, enc3, enc4; 
    var i = 0; 

    input = Base64._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 + 
     this._keyStr.charAt(enc1) + this._keyStr.charAt(enc2) + 
     this._keyStr.charAt(enc3) + this._keyStr.charAt(enc4); 

    } 

    return output; 
}, 

// public method for decoding 
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 = this._keyStr.indexOf(input.charAt(i++)); 
     enc2 = this._keyStr.indexOf(input.charAt(i++)); 
     enc3 = this._keyStr.indexOf(input.charAt(i++)); 
     enc4 = this._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 = Base64._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; 
} 

} 

在此先感謝！

Answer 1

我做了快速搜索，發現聲稱解碼的二進制數據，雖然我還沒有嘗試過一個解碼器：

https://github.com/danguer/blog-examples/blob/master/js/base64-binary.js