Javascript编码打破&组合多字节字符？ [英] Javascript encoding breaking & combining multibyte characters?

问题描述

我打算为我的网络应用程序使用客户端AES加密。

现在，我一直在寻找破解多字节字符的方法加密（以具有相同的加密文本长度），

将它们解密，将它们转换为一个字节的'非字符'

我已经看过维基的UTF-8（据称是默认编码的JS？）和UTF-16，但我可以

感谢：）

解决方案

JavaScript字符串是UTF -16存储在16位字符。对于需要超过16位（一些代码点在UTF-16中需要32位）的Unicode字符（代码点），每个JavaScript字符实际上只是代码点的一半。

因此，为了将JavaScript字符断开为字节，只需取出字符代码并拆分高字节和低字节：

  var code = str.charCodeAt（0）; //第一个字符，显然你将有一个循环
 var lowbyte = code& 0xFF; 
 var highbyte =（code& 0xFF00）> 8; 
  

（即使JavaScript的数字是浮点数，位运算符以32位整数，当然在我们的例子中只有16位是相关的。）

你永远不会有奇数个字节，因为这是UTF-16。 / p>

I'm planning to use a client-side AES encryption for my web-app.

Right now, I've been looking for ways to break multibyte characters into one byte-'non-characters' ,encrypt (to have the same encrypted text length),

de-crypt them back, convert those one-byte 'non-characters' back to multibyte characters.

I've seen the wiki for UTF-8 (the supposedly-default encoding for JS?) and UTF-16, but I can't figure out how to detect "fragmented" multibyte characters and how I can combine them back.

Thanks : )

解决方案

JavaScript strings are UTF-16 stored in 16-bit "characters". For Unicode characters ("code points") that require more than 16 bits (some code points require 32 bits in UTF-16), each JavaScript "character" is actually only half of the code point.

So to "break" a JavaScript character into bytes, you just take the character code and split off the high byte and the low byte:

var code = str.charCodeAt(0); // The first character, obviously you'll have a loop
var lowbyte = code & 0xFF;
var highbyte = (code & 0xFF00) >> 8;

(Even though JavaScript's numbers are floating point, the bitwise operators work in terms of 32-bit integers, and of course in our case only 16 of those bits are relevant.)

You'll never have an odd number of bytes, because again this is UTF-16.

这篇关于Javascript编码打破&组合多字节字符？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！