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Lina Cortés
Asked: 2020-07-04 12:41:07 +0800 CST 2020-07-04 12:41:07 +0800 CST

Failed to execute 'atob' on 'Window'

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I am sending the following string "Search not found" when sending it without the ú it takes it perfectly, but when it goes with ú I get the following error:

Uncaught DOMException: Failed to execute 'atob' on 'Window': The string to be decoded is not correctly encoded.

The js code is the following:

 w._getParameterByName = function (name) {
    name = name.replace(/[\[]/, "\\[").replace(/[\]]/, "\\]");
    var regex = new RegExp("[\\?&]" + name + "=([^&#]*)"),
        results = regex.exec(location.search);
    return results === null ? "" : atob(decodeURIComponent(results[1].replace(/\+/g, " ")));
};

I appreciate your help

javascript

1 Answers

  1. Best Answer

    The problem is that as long atobas they btoaonly accept characters that occupy 1 byte and úit is a 16-bit utf8 character, that is, it occupies 2 bytes and generates the error.

    If you can encode correctly, but the problem is decoding, it's probably due to the way you're doing it, maybe just putting atobinside:

    return results === null ? "" : decodeURIComponent(atob(results[1]).replace(/\+/g, " "));

    The solution proposed by Mozilla Developer is to encode the string, in such a way that it can be ensured that all characters occupy only 1 byte:

    // Convertir cadena Unicode a cadena donde cada
// elemento 16-bit ocupe solo un byte
function toBinary(string) {
  const codeUnits = new Uint16Array(string.length);
  for (let i = 0; i < codeUnits.length; i++) {
    codeUnits[i] = string.charCodeAt(i);
  }
  return String.fromCharCode(...new Uint8Array(codeUnits.buffer));
}

// Recodificar cadena original
function fromBinary(binary) {
  const bytes = new Uint8Array(binary.length);
  for (let i = 0; i < bytes.length; i++) {
    bytes[i] = binary.charCodeAt(i);
  }
  return String.fromCharCode(...new Uint16Array(bytes.buffer));
}

// Cadena que contiene caracteres que ocupan más de 1 byte
const myString = "Búsqueda no encontrada";

// Primero se "escapan" los caracteres especiales
const converted = toBinary(myString);
// Después ya se puede codificar a base64
const encoded = btoa(converted);
console.log(encoded); // QgD6AHMAcQB1AGUAZABhACAAbgBvACAAZQBuAGMAbwBuAHQAcgBhAGQAYQA=

// Primero de codificas de base64
const decoded = atob(encoded);
// "Recuperar" caracteres especiales
const original = fromBinary(decoded);
console.log(original);  // Búsqueda no encontrada

    Update:

    If you are encoding in base64 from PHP the option can be quite simple:

    <?php
// Convierte primero a ISO-6859-1 y codifica en base 64
echo base64_encode(utf8_decode('Búsqueda no encontrada'));
// Salida: QvpzcXVlZGEgbm8gZW5jb250cmFkYQ==

    Then with javascript you just use atob()to retrieve the original string:

    console.log(atob('QvpzcXVlZGEgbm8gZW5jb250cmFkYQ=='));

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