在不使用任何外部库的情况下使用简单的 Javascript 加密和解密字符串

Question

我想创建一个函数来加密一个字符串，它将把字符串缩短为字母数字字符，并创建一个函数 decrypt 来取回加密的字符串。

下面是我参考网上编码的。

function compress(string) {
  string = unescape(encodeURIComponent(string));
  var newString = '',
    char, nextChar, combinedCharCode;
  for (var i = 0; i < string.length; i += 2) {
    char = string.charCodeAt(i);

    if ((i + 1) < string.length) {

      
      nextChar = string.charCodeAt(i + 1) - 31;

      
      combinedCharCode = char + "" + nextChar.toLocaleString('en', {
        minimumIntegerDigits: 2
      });

      newString += String.fromCharCode(parseInt(combinedCharCode, 10));

    } else {

     
      newString += string.charAt(i);
    }
  }
  return newString;
}

function decompress(string) {

  var newString = '',
    char, codeStr, firstCharCode, lastCharCode;

  for (var i = 0; i < string.length; i++) {
    char = string.charCodeAt(i);
    if (char > 132) {
      codeStr = char.toString(10);

      firstCharCode = parseInt(codeStr.substring(0, codeStr.length - 2), 10);

      lastCharCode = parseInt(codeStr.substring(codeStr.length - 2, codeStr.length), 10) + 31;

      newString += String.fromCharCode(firstCharCode) + String.fromCharCode(lastCharCode);
    } else {
      newString += string.charAt(i);
    }
  }
  return newString;
}

var stringToCompress = 'awesome';
var compressedString = compress(stringToCompress);
var decompressedString = decompress(compressedString);


console.log("encrypted :",compressedString);
console.log("decrypted :",decompressedString);

目前 sting="awesome" 的输出是

encrypted: ☼⟈⮪e
decrypted: awesome

我想要类似的加密，但必须只使用字母数字值而不是符号。

Answer 1

我不知道你的目标是什么（它是使字符串更短，但二进制或加密并在 ascii 范围内），所以如果是后者，那么你可以使用 base64 编码：

function compress(string) {
  string = unescape(encodeURIComponent(string));
  var newString = '',
    char, nextChar, combinedCharCode;
  for (var i = 0; i < string.length; i += 2) {
    char = string.charCodeAt(i);

    if ((i + 1) < string.length) {

      
      nextChar = string.charCodeAt(i + 1) - 31;

      
      combinedCharCode = char + "" + nextChar.toLocaleString('en', {
        minimumIntegerDigits: 2
      });

      newString += String.fromCharCode(parseInt(combinedCharCode, 10));

    } else {

     
      newString += string.charAt(i);
    }
  }
  return btoa(unescape(encodeURIComponent(newString)));
}

function decompress(string) {

  var newString = '',
    char, codeStr, firstCharCode, lastCharCode;
  string = decodeURIComponent(escape(atob(string)));
  for (var i = 0; i < string.length; i++) {
    char = string.charCodeAt(i);
    if (char > 132) {
      codeStr = char.toString(10);

      firstCharCode = parseInt(codeStr.substring(0, codeStr.length - 2), 10);

      lastCharCode = parseInt(codeStr.substring(codeStr.length - 2, codeStr.length), 10) + 31;

      newString += String.fromCharCode(firstCharCode) + String.fromCharCode(lastCharCode);
    } else {
      newString += string.charAt(i);
    }
  }
  return newString;
}

var stringToCompress = 'awesome';
var compressedString = compress(stringToCompress);
var decompressedString = decompress(compressedString);


console.log("encrypted :",compressedString);
console.log("decrypted :",decompressedString);

或者如果你真的想要字母数字，那么你可以简单地将它转换成十六进制：

function compress(string) {
  string = unescape(encodeURIComponent(string));
  var newString = '',
    char, nextChar, combinedCharCode;
  for (var i = 0; i < string.length; i += 2) {
    char = string.charCodeAt(i);

    if ((i + 1) < string.length) {

      
      nextChar = string.charCodeAt(i + 1) - 31;

      
      combinedCharCode = char + "" + nextChar.toLocaleString('en', {
        minimumIntegerDigits: 2
      });

      newString += String.fromCharCode(parseInt(combinedCharCode, 10));

    } else {

     
      newString += string.charAt(i);
    }
  }
  return newString.split("").reduce((hex,c)=>hex+=c.charCodeAt(0).toString(16).padStart(4,"0"),"");
}

function decompress(string) {

  var newString = '',
    char, codeStr, firstCharCode, lastCharCode;
  string = string.match(/.{1,4}/g).reduce((acc,char)=>acc+String.fromCharCode(parseInt(char, 16)),"");
  for (var i = 0; i < string.length; i++) {
    char = string.charCodeAt(i);
    if (char > 132) {
      codeStr = char.toString(10);

      firstCharCode = parseInt(codeStr.substring(0, codeStr.length - 2), 10);

      lastCharCode = parseInt(codeStr.substring(codeStr.length - 2, codeStr.length), 10) + 31;

      newString += String.fromCharCode(firstCharCode) + String.fromCharCode(lastCharCode);
    } else {
      newString += string.charAt(i);
    }
  }
  return newString;
}

var stringToCompress = 'awesome';
var compressedString = compress(stringToCompress);
var decompressedString = decompress(compressedString);


console.log("encrypted :",compressedString);
console.log("decrypted :",decompressedString);

在不使用任何外部库的情况下使用简单的 Javascript 加密和解密字符串

Encrypt and decrypt a string using simple Javascript without using any external library

javascript

encryption

algorithm

hash